Dictation - 전남대학교 치과대학 교정과 대학원 세미나

Surface Modification of Orthodontic Wires with Photocatalytic Titanium Oxide for its Antiadherent and Antibacterial Properties. Chun M-J, Shim E, et al Angle Orthod 2007;77:483-8 March 7, 2008 Dr. Sang-Su Han
[초벌원고] Have you ever removed the patient's orthodontic archwire, and noticed how much plaque is present on the archwire itself if the patient doesn't clean adequately? Most patients can clean the labiopart of the archwire, but the part of the archwire closest to the teeth often is not clean well by the patient. Therefore bacteria are present near the area of the teeth that could potentially cause problems with decalcification or gingival inflammation.	[수정원고] Have you ever removed a patient's orthodontic archwire, and noticed how much plaque is present on the archwire itself if the patient doesn't clean adequately? Most patients can clean the labial part of the archwire, but the part of the archwire closest to the teeth often is not cleaned well by the patient. Therefore bacteria are present near the area of the teeth that could potentially cause problems with decalcification or gingival inflammation.
Is there any way to reduce the adherence of bacteria to an archwire? Apparently, that may be possible in the near future. I would like to review an article for you that I found in the May 2007 Angle Orthodontist, which discussed the application of a coating on a stainless steel archwire that resists adherence of bacteria and this coating is bactericidal.	Is there any way to reduce the adherence of bacteria to an archwire? Apparently, that may be possible in the near future. I would like to review an article for you that I found in the May 2007 Angle Orthodontist, which discusses the application of a coating on a stainless steel archwire that resists adherence of bacteria and this coating is bactericidal.
The title of the article is"Surface Modification of Orthodontic Wires with Photocatalytic Titanium Oxide for its Antiadherent and Antibacterial Properties." This paper comes out of South Korea and the research was performed at Chonnam National University in Gwangju, South Korea. The purpose of this study was to determine if titanium oxide coating on stainless steel archwires could reduce the amount of the bacteria adhering to the metal archwire.	The title of the article is"Surface Modification of Orthodontic Wires with Photocatalytic Titanium Oxide for its Antiadherent and Antibacterial Properties." This paper comes out of South Korea and the research was performed at Chonnam National University in Gwangju, South Korea. The purpose of this study was to determine if titanium oxide coating on stainless steel archwires could reduce the amount of bacteria adhering to the metal archwire.
Initially, in this laboratory study, researchers modified a typical stainless steel wire by dipping the wire into a solution of titanium oxide. This produced the coating on the wire which does not interfere with the mechanical properties of the wire. Then each of these wires along with stainless steel control archwires were placed in test tubes containing Streptococcus mutans and Porphyromonas gingivalis. The wires were capped in these test tubes for twenty four hours, then the archwires were removed and the surface was assayed to determine the antiadherent and antibacterial properties of the titanium oxide coated wires compared to the control stainless steel wires.	Initially, in this laboratory study, researchers modified a typical stainless steel wire by dipping the wire into a solution of titanium oxide. This produced a coating on the wire which does not interfere with the mechanical properties of the wire. Then each of these wires along with stainless steel control archwires were placed in test tubes containing Streptococcus mutans and Porphyromonas gingivalis. The wires were capped in these test tubes for twenty four hours, then the archwires were removed and the surface was assayed to determine the antiadherent and antibacterial properties of the titanium oxide coated wires compared to the control stainless steel wires.
Okay, I think you get the idea of the experiment. What did these researchers find? Remember the question. Does the titanium oxide render the archwire less susceptible to adherence by bacteria. And the answer to the question is definitely "Yes". The titanium oxide creates and anti-adherent quality to the surface of the wire so that the bacteria do not adhere to it. In addition one of the authors evaluated and compared the numbers of the bacteria in the control and experimental test tubes, they found that the titanium oxide also had an antibacterial effect reducing the numbers of bacteria in the test tubes. So there, we have it. This experiment did work. Titanium oxide coating of stainless steel archwires is an excellent method of enhancing the antiadherence and antibacterial properties of an archwire.	Okay, I think you get the idea of the experiment. What did these researchers find? Remember the question. Does the titanium oxide render the archwire less susceptible to adherence by bacteria? And the answer to that question is definitely "Yes". The titanium oxide creates an anti-adherent quality to the surface of the wire so that the bacteria do not adhere to it. In addition when the authors evaluated and compared the numbers of bacteria in the control and experimental test tubes, they found that the titanium oxide also had an antibacterial effect, reducing the numbers of bacteria in the test tubes. So there, you have it. This experiment did work. Titanium oxide coating of stainless steel archwires is an excellent method of enhancing the antiadherent and antibacterial properties of an archwire.
This could be very helpful in the treatment of the some of our lactescent orthodontic patients who simply don't take good care of their teeth. If you would like to review the informations on this interesting new coating for orthodontic archwires, you can find it in the May 2007 issue of the Angle Orthodontists.	This could be very helpful in the treatment of some of our lactescent orthodontic patients who simply don't take good care of their teeth. If you would like to review this information on this interesting new coating for orthodontic archwires, you can find it in the May 2007 issue of the Angle Orthodontists.

Changes in Gingival Recession Related to Orthodontic Treatment of Traumatic Deep Bite in Adults Zimmer B, Seifi-Shirvandeh N. Orofacial Orthop 2007;68:232-44 March 14, 2008 Dr. Sang-Rok Kim
[초벌원고] Let me describe a patient who might well show up in your practice tomorrow. The patient is an adult female who has been referred by her general dentist for treatment of a Class Ⅱ division 1 malocclusion with a severe deep bite. A concern of both the patient and her general dentist is that the anterior overbite is so deep that it has caused elongation and gingival recession along the lingual of the maxillary incisors and has actually left an impression of the mandibular incisors on the palatal soft tissue lingual to the maxillary incisors.	[수정원고] Let me describe a patient who might well show up in your practice tomorrow. The patient is an adult female who has been referred by her general dentist for treatment of a Class Ⅱ division 1 malocclusion with a severe deep bite. A concern of both the patient and her general dentist is that the anterior overbite is so deep that it has caused elongation and gingival recession along the lingual of the maxillary incisors and has actually left an impression of the mandibular incisors on the palatal soft tissue lingual to the maxillary incisors.
I'm sure you have seen a number of patients with a condition similar to that which I have just described. One of the questions that your patient has is if she pursues orthodontic treatment with you, will the recession on the lingual of her maxillary incisors and the inflammation of her gingival tissue improve as a result of the orthodontic treatment? How would you answer this question? Will the gingival recession and inflammation improve as a result of your treatment?	I'm sure you have seen a number of patients with a condition similar to that which I have just described. One of the questions that your patient has is if she pursues orthodontic treatment with you, will the recession on the lingual of her maxillary incisors and the inflammation of her gingival tissue improve as a result of the orthodontic treatment? How would you answer this question? Will the gingival recession and inflammation improve as a result of your treatment?
An article titled "Changes in Gingival Recession Related to Orthodontic Treatment of Traumatic Deep Bite in Adults" by Bern Zimmer et al, which appears in the May 2007 issue of The Journal of Orofacial Orthopedics, addresses this question. In this study the authors evaluated twelve patients who had a traumatic deep bite. These patients had an overbite of greater than six millimeters, which had led to recession on at least one incisor due to direct traumatization resulting from contact with the antagonistic dentition. No gingival surgery for pre-existing recessions took place before or during orthodontic treatment. All patients received comprehensive orthodontic treatment, the main aim of which was to correct the traumatic deep bite.	An article titled "Changes in Gingival Recession Related to Orthodontic Treatment of Traumatic Deep Bite in Adults" by Bern Zimmer et al, which appears in the May 2007 issue of The Journal of Orofacial Orthopedics, addresses this question. In this study the authors evaluated twelve patients who had a traumatic deep bite. These patients had an overbite of greater than six millimeters, which had led to recession on at least one incisor due to direct traumatization resulting from contact with the antagonistic dentition. No gingival surgery for pre-existing recessions took place before or during orthodontic treatment. All patients received comprehensive orthodontic treatment, the main aim of which was to correct the traumatic deep bite.
This treatment was essentially carried out by means of intrusion mechanics as proposed by Burstone. The authors who study models and intraoral images to determine the changes in crown lengths and recession depths that had occurred as a result of orthodontic treatment. When they evaluated these records, what do they find? The answer is that both clinical crown lengths and recession depths decrease significantly as a result of the comprehensive orthodontic treatment alone. I was impressed by these results and also some of the photographs presented in the article, which demonstrated significant improvement before and after treatment.	This treatment was essentially carried out by means of intrusion mechanics as proposed by Burstone. The authors used study models and intraoral images to determine the changes in crown lengths and recession depths that had occurred as a result of orthodontic treatment. When they evaluated these records, what did they find? The answer is that both clinical crown lengths and recession depths decrease significantly as a result of the comprehensive orthodontic treatment alone. I was impressed by these results and also some of the photographs presented in the article, which demonstrated significant improvement before and after treatment.
So, you can tell your patient that orthodontic treatment alone can significantly improve her gingival condition. You can find this study in the May 2007 issue of the Journal of Orofacial Orthopedics.	So, you can tell your patient that orthodontic treatment alone can significantly improve her gingival condition. You can find this study in the May 2007 issue of the Journal of Orofacial Orthopedics.

Shear Bond Strength Differences of Types of Maxillary Deciduous and Permanent Teeth Used as Anchor Teeth Endo T, Yoshino S, et al. Angle Orthod 2007;77:537-41 March 21, 2008 Dr. Hak-Hee Choi
[초벌원고] Do you provide orthodontic treatment for patients during the mixed dentition? What I really mean is 'Do you bond brackets to primary teeth?'. Occasionally, in order to achieve better anchorage if you were placing brackets during mixed dentition, it could be advantages to bracket a primary second molar or primary canine in order to move adjacent permanent teeth. If you placed brackets on primary teeth, what has been your success rate? Do you use any special techniques to bracket the primary teeth? Is there any difference in bond strength between permanent and primary teeth? Those questions were addressed in the study that was published in May 2007 issue of the Angle orthodontist. The title of the article is "Shear Bond Strength Differences of Maxillary Deciduous and Permanent Teeth Used as Anchor Teeth". Since we as orthodontist occasionally do provide treatment during the mixed dentition and may want to bracket a primary tooth, I thought this information about relative success rates would be good for us to review on this issue of practical reviews in orthodontics.	[수정원고] Do you provide orthodontic treatment for patients during the mixed dentition? What I really mean is 'Do you bond brackets to primary teeth?'. Occasionally, in order to achieve better anchorage if you were placing brackets during the mixed dentition, it could be advantages to bracket a primary second molar or primary canine in order to move adjacent permanent teeth. If you’ve placed brackets on primary teeth, what has been your success rate? Do you use any special techniques to bracket the primary teeth? Is there any difference in bond strength between permanent and primary teeth? Those questions were addressed in the study that was published in the May 2007 issue of the Angle orthodontist. The title of the article is "Shear Bond Strength Differences of Maxillary Deciduous and Permanent Teeth Used as Anchor Teeth". Since we as orthodontist occasionally do provide treatment during the mixed dentition and may want to bracket a primary tooth, I thought this information about relative success rates would be good for us to review on this issue of practical reviews in orthodontics.
This article came out of Japan. It was co-authored by Toshiya Endo and several other research colleagues from the department of orthodontics at Nippon University in Japan. The purpose of this study was to determine the effects of different permanent and primary tooth types on the bond strengths of individual orthodontic brackets. Now, this was centrally a laboratory study. The authors gathered extracted first and second premolars and maxillary primary canines and primary second molars. These were divided into four groups. A standard metal premolar bracket was bonded to each of the teeth. The bonding was preformed using a typical light-cured composite. Then the universal testing machine was used to debracket the teeth and to determine the shear bond strength. This was a typical protocol for determining shear bond strength.	This article came out of Japan and was co-authored by Toshiya Endo and several other research colleagues from the department of orthodontics at Nippon University in Japan. The purpose of this study was to determine the effects of different permanent and primary tooth types on the bond strengths of individual orthodontic brackets. Now, this was centrally a laboratory study. The authors gathered extracted first and second premolars and maxillary primary canines and primary second molars. These were divided into four groups. A standard metal premolar bracket was bonded to each of the teeth. The bonding was performed using a typical light-cured composite. Then the universal testing machine was used to debracket the teeth and to determine the shear bond strength. This is a typical protocol for determining shear bond strength.
Okay, what happened? Is there a difference between the shear bond strength of primary enamel compared to permanent enamel? And the answer to that question is yes. In fact, the shear bond strength of the permanent maxillary first and second premolars was nearly twice that of the primary canine and primary second molar. Question number two. Was there a difference between the shear bond strength of primary canines and primary second molars? The answer to that question is no. The shear bond strength between these primary teeth was similar. Last question! Was the shear bond strength of the primary canine and primary second molar within the acceptable range of 6-8 MPa? And the answer to that question is yes, but barely. There realizes the good news if you occasionally place the brackets on primary teeth although shear bond strength is low compared to permanent enamel. When you bond brackets with light-cured composite to primary teeth, the shear bond strength is just above the acceptable clinical range for shear bond strength.	Okay, what happened? Is there a difference between the shear bond strength of primary enamel compared to permanent enamel? And the answer to that question is yes. In fact, the shear bond strength of the permanent maxillary first and second premolars was nearly twice that of the primary canine and primary second molar. Question number two. Was there a difference between the shear bond strength of primary canines and primary second molars? The answer to that question is no. The shear bond strength between these primary teeth was similar. Last question! Was the shear bond strength of the primary canine and primary second molar within the acceptable range of 6-8 MPa? And the answer to that question is yes, but barely. Therein lies the good news if you occasionally place brackets on primary teeth. Although the shear bond strength is low compared to permanent enamel, when you bond brackets with light-cured composite to primary teeth, the shear bond strength is just above the acceptable clinical range for shear bond strength.
So, there you have it. If you occasionally place brackets on primary teeth, you will achieve sufficient bond strength to use those teeth as anchors to facilitate the movement of permanent teeth. If you'd like to review the study for yourself, you can find it in the March 2007 issue of the Angle Orthodontist.	So, there you have it. If you occasionally place brackets on primary teeth, you will achieve sufficient bond strength to use those teeth as anchors to facilitate the movement of permanent teeth. If you'd like to review the study for yourself, you can find it in the March 2007 issue of the Angle Orthodontist.

Nonsurgical correction of skeletal Class III malocclusion with lateral shift in an adult Hisano M, Chung CR, Soma K. Am J Orthod Dentofacial Orthop 2007;131:797-804 March 28, 2008 Dr. Hyun-Kyu Lee
[초벌원고] Adult patients with class III malocclusions usually present a difficult diagnostic in treatment challenge for the orthodontist. I often tell our residents that if they go to an orthodontic meeting or read an article that show dramatic results for an adult patient with a class III malocclusion that almost invariably that patient will have presented with a deep bite class III malocclusion and in overclosed facial profile.	[수정원고] Adult patients with class III malocclusions usually present a difficult diagnostic and treatment challenge for the orthodontist. I often tell our residents that if they go to an orthodontic meeting or read an article that shows dramatic results for an adult patient with a class III malocclusion that almost invariably that patient will have presented with a deep bite class III malocclusion and an overclosed facial profile.
A Class III adult patient with these characteristics can be an excellent candidate for orthodontic only treatment because by rotating the mandible downward and backward the overclosed facial profile, the dental deep bite, and the protrusiveness of the chin are all improved. This is why it is very rare to see an adult patient with a class III open bite malocclusion treated successfully with orthodontics alone. In this case, if you rotate the mandible downward and backward, the protrusiveness of the chin would improve, but the severity of the open bite would increase. That is why this type of patient often requires combine surgical-orthodontic treatment. For these reasons, I was attracted to an article titled non-surgical correction of skeletal III malocclusion with lateral shift in an adult by Masataka Hisano, et al. which appeared in the June 2007 issue of The American Journal of Orthodontics and Dentofacial Orthopedics.	A Class III adult patient with these characteristics can be an excellent candidate for orthodontic only treatment because by rotating the mandible downward and backward the overclosed facial profile, the dental deep bite, and the protrusiveness of the chin are all improved. This is why it is very rare to see an adult patient with a class III open bite malocclusion treated successfully with orthodontics alone. In this case, if you rotate the mandible downward and backward, the protrusiveness of the chin would improve, but the severity of the open bite would increase. That is why this type of patient often requires combined surgical-orthodontic treatment. For these reasons, I was attracted to an article titled non-surgical correction of skeletal class III malocclusion with lateral shift in an adult by Masataka Hisano, et al. which appeared in the June 2007 issue of The American Journal of Orthodontics and Dentofacial Orthopedics.
The patient, whose case records were displayed in this article was 27-year old female who presented with a class III malocclusion with significant midline deviation to the left and the mandibular molars were tipped mesially. I assume the midline deviation was due to lateral shift because although was not mentioned in the case write up it was included in the title of the article. I was impressed with the excellent occlusal and facial results that were achieved by treating this class III open bite malocclusion, non extraction. As you might imagine by uprighting the mandibular molars to gain additional space to retract the mandibular anterior teeth and correct negative overjet. The authors rotated the mandible down and backward and increase the open bite which was corrected by significant extrusion of the mandibular incisiors.	The patient, whose case records were displayed in this article, was a 27-year old female who presented with a class III malocclusion with a significant midline deviation to the left and the mandibular molars were tipped mesially. I assume the midline deviation was due to a lateral shift because although was not mentioned in the case write up, it was included in the title of the article. I was impressed with the excellent occlusal and facial results that were achieved by treating this class III open bite malocclusion, non extraction. As you might have imagined, by uprighting the mandibular molars to gain additional space to retract the mandibular anterior teeth and correct the negative overjet, the authors rotated the mandible down and backward and increased the open bite which was corrected by significant extrusion of the mandibular incisiors.
The authors made a number of interesting comments in their case write up, and I would like to address some of them. First, they indicated that they considered extracting only mandibular premolars. But this would not have allowed them to correct the class III molar relationship and retraction of mandibular incisors would have negatively affected the concave profile. In response to this comment, I would like to emphasize that the first rule in treating adult patients who have full class III malocclusions with orthodontics alone is not to retract the maxillary canines. The reason for this is that if you do, you will have created more than a full step class III malocclusion in the canine area making it necessary to retract the mandibular canines more than a full step first premolar spaces which is usually extremely difficult if not impossible. This is why class III adult patients are often treated with only mandibular first premolar extraction.	The authors made a number of interesting comments in their case write up, and I would like to address some of them. First, they indicated that they considered extracting only mandibular premolars. But this would not have allowed them to correct the class III molar relationship and retraction of the mandibular incisors would have negatively affected the concave profile. In response to these comments, I would like to emphasize that the first rule in treating adult patients who have full class III malocclusions with orthodontics alone is not to retract the maxillary canines. The reason for this is that if you do, you will have created more than a full step class III malocclusion in the canine area, making it necessary to retract the mandibular canines more than a full step first premolar space which is usually extremely difficult if not impossible. This is why class III adult patients are often treated with only mandibular first premolar extractions.
I would also like to emphasize, that a class III malocclusion can be a very acceptable occlusion, particularly if you alternative would be to extract the maxillary arch which would necessitate retraction of the maxillary canines. The other thing that I would like to mention, is that in a class III patient it is the final position of the maxillary incisors that would determine the final profile because it is the position of the maxillary incisors that determine how much the mandibular incisors will be retracted. I again congratulate the authors by achieving the excellent results in this case. However, with the amount of mandibular incisors extrusion that was required to correct the increased open bite, I would very much like to obtain long term records to see of the overbite correction was stable. you can find this excellent case report in the June 2007 issue of the American Journal of Orthodontics and Dentofacial Orthopedics.	I would also like to emphasize, that a class III molar occlusion can be a very acceptable occlusion, particularly if the alternative would be to extract a maxillary arch which would necessitate retraction of the maxillary canines. The other thing that I would like to mention is that in a class III patient it is the final position of the maxillary incisors that will determine the final profile because it is the position of the maxillary incisors that determine how much the mandibular incisors will be retracted. I again congratulate the authors on achieving an excellent results in this case. However, with the amount of mandibular incisor extrusion that was required to correct the increased open bite, I would very much like to have seen long term records to see if the overbite correction was stable. You can find this excellent case report in the June 2007 issue of the American Journal of Orthodontics and Dentofacial Orthopedics.

A Simple Three-Dimensional Guide for Safe Miniscrew Placement Suzuki EY, Suxuki B. J Clin Orthod 2007;41:342-6 April 4, 2008 Dr. Eun-Ji Kim
[초벌원고] How many of you are placing miniscrews in your office for anchorage? It amazes me how fast it in easiest to do. And yet I'm still a bit uneasy in some incidencies placing between two throughts because I don't reliable guide systems that help with the location and angulation for screw insertion. That is why with drawn to article in the June 2007 issue of the Journal of the Clinical Orthodontics. The article was written by two authors from Tailand and describes to new simple guide designed to aid in interdental miniscrew placement. Your article is called "A Simple Three-Dimensional guide for Safe Miniscrew Placement."This report is only the discription of a guide and of it's a clinical use. it does not scientifically investigated how well it works.	[수정원고] How many of you are placing miniscrews in your office for anchorage? It amazes me how fast and easy it is to do. And yet I'm still a bit uneasy in some incidencies placing them between tooth roots because I don't have a reliable guide system to help with the location and angulation for screw insertion. That is why I was drawn to an article in the June 2007 issue of the Journal of Clinical Orthodontics. The article was written by two authors from Tailand and it describes a new simple guide designed to aid in interdental miniscrew placement. The article is called "A Simple Three-Dimensional guide for Safe Miniscrew Placement."This report is only a description of the guide and of its clinical use. It does not scientifically investigate how well it works.
Let me tell you little more about this placement guide and how it is designed to assist orthodontists. The device has a Gurin lock that clamps on to the arch wire. Attached to the Gurin lock is a vertical wire of either 5, 7, or 9 mm. At the other end of the wire is a 5 mm length of stainless still tube that sticks out perpendicular to the tissue surface. It is a this stainless steel tube that is the actual guide for placement. The guide is selected with the proper vertical wire length as estimated for the patient. The Gurin lock is used to attach the guide to the arch wire in the area the screw is to be placed. The position of the guide tube is adjusted to other pierces to be the best position clinically and locked it in the position.	Let me tell you a little more about this placement guide and how it is designed to assist the orthodontists. The device has a Gurin lock that clamps on to the arch wire. Attached to the Gurin lock is a vertical wire of either 5, 7, or 9 mm. At the other end of the wire is a 5 mm length of stainless still tube that sticks out perpendicular to the tissue surface. It is a this stainless steel tube that is the actual guide for placement. The guide is selected with the proper vertical wire length as estimated for that patient. The Gurin lock is used to attach the guide to the arch wire in the area the screw is to be placed. The position of the guide tube is adjusted to other pierces to be the best position clinically and then locked it to position.
At this point a standardized by wing radiograph is taken and the radiograph reviewed for proper guided positioning. If the guide is not positioned properly it is adjusted and the radiograph retaken. Once the radiograph confirms good positioning then the guide tube is used for screw placement. The authors use a miniscrew that has a head small enough that fit through the guide tube. This allows proceeding of the screw before removing the guide. After screw placement and the removal of the guide a new radiograph is taken to confirm good screw positioning. It appears to me that this placement guide could be available to the interdental screws locations. It can be simply clamped to the orthodontic arch wire and it is easily adjustable. What really appeals to me is the use of guide tube rather than just a guide ring. This allows more three-dimensional control and guidance. And this can even be visualized on the bite-wing radiograph.	At this point a standardized bite wing radiograph is taken and the radiograph reviewed for proper guide positioning. If the guide is not positioned properly, it is adjusted and the radiograph retaken. Once the radiograph confirms good positioning, then the guide tube is used for screw placement. The authors use a miniscrew that has a head small enough to fit through the guide tube. This allows full seating of the screw before removing the guide. After screw placement and removal of the guide, a new radiograph is taken to confirm good screw positioning. It appears to me that this placement guide could be available for interdental screw locations. It can be simply clamped to the orthodontic arch wire and is easily adjustable. What really appeals to me is the use of a guide tube rather than just a guide ring. This allows more three-dimensional control and guidance. And this can even be visualized on the bite-wing radiograph.
There are many photographs and diagrams in this article that make the guide and its use easy to understand. I want you to know however that the authors do have a financial interest in this product and therefore the comment should be interpreted accordingly. Although that I mentioned this is not a scientific study the authors do refer to a retrospective study that is currently reviewed that demonstrates better screw placement when using this guide compare to the other methods. I will look for that to be published. If you are would like more information about this miniscrew placement guide look in the June 2007 issue of the Journal of Clinical Orthodontics.	There are many photographs and diagrams in the article that make the guide and its use easier to understand. I want you to know, however, that the authors do have a financial interest in this product and therefore their comment should be interpreted accordingly. Although I mentioned initially this is not a scientific study, the authors do refer to a retrospective study that is currently in review that demonstrates better screw placement when using this guide compared to the other methods. I will look for that to be published. If you are would like more information about this miniscrew placement guide, look in the June 2007 issue of the Journal of Clinical Orthodontics.

Orthodontic and Surgical Treatment of a Patient with an Ankylosed Temporomandibular Joint Motta A, Louro RS, et al. Am J Orthod Dentofacial Orthop 2007;131:785-96 April 11, 2008 Dr. Hoon Noh
[초벌원고] What would you do if a 10 year old female patient presented to your office who had an ankylosed left TMJ that resulted in a severe facial deformity expressed by a very retrusive chin which also deviated to the left which was the side of the ankylosis? Essentially the patient had a birdbeak facial appearance. I strongly suspect that of this patient presented to your office that you will refer her to an orthodontic or oromaxillofacial surgery department associated with your local or regional medical center.	[수정원고]
A case report titled orthodontic and surgical treatment of a patient with an ankylosed temporomandibular joint by Alexandra Motta et al which appeared in the June 2007 issue of the American Journal of Orthodontics and Dentofacial Orthopedics discussed and presented the treatment records for the patient that I just described. While the surgical treatment for a patient with unilateral condylar ankylosis that has resulted in a severe facial deformity is quite complicated and would also certainly be done at a major medical center, the orthodontic treatment is essentially similar to the orthodontic treatment required for a patient who is undergoing combined treatment for a more typical orthognathic surgery problem such as mandibular advancement or reduction. For this reason I believe it is helpful to understand the options and treatment possibilities that are available for a patient similar to the one that I described.
First of all, it is important to understand that unilateral or bilateral joint fusion is most commonly a result of trauma and can also be caused by infection. In the case of ten year old, whose treatment was described in this case report, her medical history indicated that the condylar fracture was due to a forceps delivery during birth. It is also important to understand that TMJ ankylosis can occur during or after growth, and it each instance it can occur with or without dentofacial deformities. If it occurs, either during growth or after growth, and is not associated with a dentofacial deformity, arthroplasty may successfully treat the bony ankylosis. However, if dentofacial deformities are associated with ankylosis, surgical treatment is mandatory, in particularly in the growing patient, is extremely complex and demanding. The treatment for the patient described in this article was documented over a twelve year period which included five separate surgical procedures. When the patient was eleven years old, a costochondral graft was performed between the mandibular body gap and the ankylosed joint. A gap arthroplasty was also performed along with the sagittal split osteotomy. A four year post-operative evaluation showed relapse of the ankylosis and the resorption of the costochondral graft and another arthroplasty was performed when the patient was 15 years 6 months old. A new costochondral graft was performed at the 16 years 5 months at which point surgical orthodontic treatment was initiated. When the patient was 20 years old, orthognatic surgery was performed which involve a 4 mm maxillary impaction with 2 mm of rotation combined with mandibular advancement and advancement and lateralization genioplasty.
What would motivate a patient to cooperate and willing to undergo five separate surgical procedures such as I just described? I think the answer to this question would become obvious to you if you read this case report article and compare the initial and the final facial and intraoral records that are presented. To say that the changes are dramatic would be understatement. Costochondral grafts are used in growing patients with ankylous temporomandibular joints because they have the potential for growth. However this potential can be very unpredictable ranging from excessive, insufficient or adequate to correct a specific facial deformity. Unfortunately for this patient, the costochondral grafts were not effective. However in spite of this, an excellent treatment result was achieved.
As Dr. David Turfin stated in his editor’s choice column, a patient such as this should become the poster child for our next public relations effort making the point that our services are more than cosmetic. If you are interested in gaining a better understanding of the treatment required and the results that can be achieved for the patients with severe facial deformity as a result of temporomandibular joint ankylosis, I would strongly recommend that you read this article. It appears in the June 2007 issue of the American Journal of Orthodontics and Dentofacial Orthopedics.

Systematic Review of the Experimental Use of Temporary Skeletal Anchorage Devices Cornelis MA, Scheffler NR, et al. Am J Orthod Dentofacial Orthop 2007;131:S52-8 April 18, 2008 Dr. Hyun-Jung Lee
[초벌원고] Temporary anchorage devices in orthodontics do work. This factor is clear. There have been many clinical reports in the literature that document the effectiveness of these mini screws or mini plates. But you are about to begin using these devices I am certain that you will have many questions in your mind regarding various aspects of the process. First of all, it would be valuable to have information that is based on animal studies so that histology around these implants can be utilized to help give us information. Second, it would also be valuable to use the collective knowledge of various studies that had been performed on temporary anchorage devices. To that end what we really need is systematic review of the literature focusing on animal studies that pertain to this topic. That is the subject of this review. The title of this article is systematic review of the experimental use of temporary skeletal anchorage devices in orthodontic. This study was published in the April 2007 supplement of the American Journal of Orthodontics and Dentofacial Orthopedics. This systematic review was co-authored by Mary Cornelis and several other research associates from Catholique University in Brussels, Belgium. and the University of North Carolina in Chapel Hill.	[수정원고]
I liked the systematic review because it did focus on animal experiments that were well constructed and well analyzed. The purpose of this article was to examine the available evidence in the literature to characterize functional and morphologic tissue reactions around temporary anchorage devices to determine guidelines that could be useful for clinicians. Initially this researchers used Pubmed, the electronic data base, to search for original articles. Their inclusion criteria require that articles would only be accepted at they were animal studies on orthodontically loaded skeletal anchorage that consisted of either metallic bone plates, or mini screws that were 2 mm in diameter or less. So in other words, they excluded all types of palatal, retromolar, or prosthetic implants. Out of their search they identified over 30 abstracts that met their criteria. But on further examination they narrow this list down to 8 articles that actually fulfill their requirements. 6 of these articles were on orthodontic screw implants and the other 2 were on mini plates. All 8 articles supplied information on experimental animal research. Now 3 different animal models were used that included dogs, mini-pigs, and monkeys. The number of loaded implants per study range from a low of 10 to high of over 150 implants. Now I don't want to bore you with lots of numbers because I think that would be unproductive. It is critical for us clinicians to use these types of studies to answer clinical questions. The authors did accomplish that. Let me brake this down into categories.
First of all, healing time, in other word, how long do you need to wait before you load implant. From their review the authors found that the studies involving immediate loading, and 1 week healing period had some failures. But they found 100 percent stability, if the loading was delayed for up to 3 weeks. In fact, one study tested the difference between 3 week, 6 week, and 12 week healing periods, and showed that the 3 week period before loading were sufficient to resist orthodontic forces in the dog. Question number 2. How much force should be applied to an implant initially? There was a great variability in these studies ranging from a low of 25g to high of 500g. In a study involving mini-pigs 5 out of over 150 immediately loaded mini-screws were lost. But these failures occurred with 300g of loading. In the same study, No failure was reported with 100g force applied immediately. What is the bottom line? Begin with a lighter load if you load the implant immediately. Question number 3. are there any side effects on adjacent tissues when an implant is placed? The authors found that there was some inflammations noted in 6 of the studies, but no severe inflammatory reactions were reported. Question number 4. Do these implants undergo osseointegration? You see that is the benefit of having animal studies. Histologic analysis can be evaluated after loading of implants to determine if bone is contacting the implant. These authors found that in 5 articles the amount of bone contacting the implant surface varied from a low of 10% to a high of 60%. The authors believed that possible influences on the amount of bone contacting the implant included the healing time before loading, the amount of force applied, as well as location of the implant in the alveolus. A positive aspect, related to bone to implant contact found in 2 of the study showed significant increases in the bone turn over around loaded implants compare to unloaded implants. This suggests that loading of the implant enhances its stability to withstand the stress of orthodontic force.
I really like this article. It gave valuable information that can not be gained from clinical studies. The ability to evaluate implants placed in animals at the histologic level gives us as clinicians the opportunity to assess various aspects of implant responses that can not be done with a pure clinical study. If you like to review this article you will find it in the April 2007 supplement of American Journal of Orthodontics and Dentofacial Orthopedics.

Three-Dimensional Evaluation of Surgically Assisted Implant Bone-Borne Rapid Maxillary Expansion: A Pilot Study. Tausche E, Hansen L, et al. Am J Orthod Dentofacial Orthop 2007;131:S92-9 April 25, 2008 Dr. Kyung-Min Lee
[초벌원고] How do you expand maxilla in an adult? In most adults, palatal expansion requires some sort of surgical procedure of the maxilla to assist in the palatal expansion. This process is known as surgically assisted maxillary expansion. But we still attach the expander to the teeth and because of that the teeth tend to tip. Would it be possible to expand maxilla in an adult using miniscrews as the anchors rather than the teeth? Would this result in natural expansion in avoid tooth tipping? Those questions were addressed in the study that was published in the April 2007 supplement of the American Journal of Orthodontics and Dentofacial Orthopedics. The title of this article is"Three-Dimensional Evaluation of Surgically Assisted Implant Bone-Borne Rapid Maxillary Expansion". The study was co-authored by Eve Tausche and several other researchers from the departments of orthodontics at Technical University in Dresden Germany and the University of Alberta in Edmonton Canada.	[수정원고]
The purpose of this study was to perform a three dimensional analysis of the movement of teeth, alveolar processes and skeletal structures caused by a bone borne rapid maxillary expansion device. In order to accomplish this project the authors used the sample of 10 subjects. Their average age was 25 years. All subjects needed rapid maxillary expansion as a part of their orthodontic therapy. But instead of using a typical palatal expander for these adults, the authors placed 2 palatal screws between the maxillary first and second premolars on the palatal side. Then a typical Hyrax expander was placed on top of these implants. Therefore the implant provided anchorage so that the maxilla could be expanded. After the surgical osteotomy, the expansion screw was activated 4 times a day (twice in the morning and twice in the evening) for 8 days. Immediately after expansion, the maxillary teeth were aligned. Computed Tomography scans were made of each subject parallel to the occlusal plane before the actual procedure begin and then after the procedure was completed. You see the authors wanted to evaluate where the expansion occurred and also how much the teeth tipped relative to the orientation of the two halves of the maxilla before and after expansion. OK. I think you get the idea of this experiment. What happened?
First of all, the authors showed that using their expansion device which was anchored to the bone using miniscrews, the typically V shaped opening of the suture, the dental arch and the alveolar processes was greatest in the anterior and converged toward posterior aspect of the palate. Now this is typical with most surgical expansions. But the striking difference in this sample compare to most surgical expansion occurred with the dentition. Remember direct force application to the bone was produced with the screws. Therefore the author showed in the results that the teeth tip between 6 to 9 degrees or less than the alveolar processes. In addition the authors found no root resorption, no bony dehiscence and no buccal tipping of the teeth. So in conclusion these authors found that by anchoring the expansion device into the palate they could actually expand the bones and not tip the teeth. And additional side effect occurred after the expansion was removed. You see the authors could use the implants for stabilization by attaching a transpalatal arch as the bone was filling in the sutural site.
If you are interested in viewing the photographs of the expander and the specific description of how and where the implants were placed, you can find all of these information in the April 2007 supplement of the American Journal of Orthodontics and Dentofacial Orthopedics.

Root Proximity is a Major Factor for Screw Failure in Orthodontic Anchorage Kuroda S, Yamada K, et al. Am J Orthod Dentofacial Orthop 2007;131:S68-73 May 2, 2008 Dr. Gi-Soo Uhm
[초벌원고] Imagine that you have just placed your first two miniscrews in the maxilla. You placed them using topical anesthetic only, and the patient tolerate the procedure well, no significant discomfort. So you are relatively confident that you did not contact the tooth root. When you evaluate the screws with periapical radiographs, the screw on the left looks perfectly placed between the two adjacent tooth roots with bone clearly evident between miniscrew and roots. The picture on the right is different. The body of the screw is partially superimposed on the lamina dura of the first molar. Even though you are confident you didn’t hit the root with the screw, shouldn’t you be concerned? Dr. Kuroda and colleagues in Japan examined the relationship between root proximity and miniscrew success and the research project reported in the April 2007 supplement of AJODO.	[수정원고]
The report is called root proximity is a major factor for screw failure in orthodontic anchorage. This study was a retrospective look at 110 patients that had total of 216 miniscrews placed for orthodontic anchorage. A successful outcome with judge to be a screw that last the least the one year or until the end of orthodontic treatment. The proximity of the miniscrew to the tooth root was judged from the periapical radiographs. The proximity was classified as category 1, if the screw was clearly separate from the tooth root, category 2, if the screw apex approximate the lamina dura of an adjacent tooth, and category 3, if the body of the screw overlapped the lamina dura. The success of the miniscrews placed in the maxilla with compared to those in the mandible and the relative success of the three categories of root proximity was investigated. So what are the authors find? The overall miniscrew success was greater than 80%. This is quite good, but still means that one and five screws likely to fail and need replacement. The screws in the maxilla were more successful than those in the mandible. This confirms other reports of greater miniscrew success in the maxilla.
What about root proximity? According to this study, the category 1 screws, those clearly separate from the tooth roots on the radiograph are significantly more successful. And the category 3 screws, those where the radiographs show superimposition of the miniscrew under the lamina dura were the least successful. In fact, the category 3 screws in the mandible had a success rate of only 35%. So getting back to those first two screws that you placed in the maxilla, the one on the left that is clearly separate from the tooth roots would have a very high chance of success about 95%. The screw on the right though, what would be a category 3 in the study has a chance of success of 50-75%. Although you may not choose to replace this right side screw immediately, you would be wise to watch it carefully for signs of failure. As you plan miniscrew placement in the future, you should keep this association between root proximity and screw failure in mind. For more detail about the type of miniscrews used in this project and the technique they use for placement, look in the April 2007 supplement of AJODO.

Masticatory Exercise as an Adjunctive Treatment for Hyperdivergent Patients Angle Orthod 2007;77:457-62 Parks LR, Buschang PH, et al. May 9, 2008 Dr. Mi-Young Kim
[초벌원고] Is it possible to reduce vertical dimension in a growing patients? In order to accomplish a reduction in facial heights, one would have to intrude or at least prevent eruption of either maxillary or mandibular posterior teeth. Now past tempts to accomplish this have ranged from using posterior bite-blocks, high -pull headgear or vertical pull chin-cups. Although these may have temporary effects, overall the effect is typically limited.	[수정원고]
What if a patient, however, clenches their teeth together a significant amount of time? Could the masticatory muscles be used to help limit the development of the facial skeleton? That thought process was the subject of the research project that was published in the May 2007 issue of the Angle Orthodontist. The title of this article is"Masticatory Exercise as an Adjunctive Treatment for Hyperdivergent Patients".
This study was performed at Baylor college of dentistry. It was co-authored by Laurie R. Parks and several research colleagues from the department of orthodontics at that school. The purpose of their study was to evaluate the morphologic effects of masticatory muscle exercise in treating hyperdivergent patients with fixed orthodontic appliances. This was a very interesting study. It was extremely well done although it was a retrospective and not a prospective research design. Three samples of 50 subjects were selected including one sample treated with orthodontics combined with exercise, one sample treated with orthodontics only and no exercise, and the untreated control sample.
First question, what do we mean by exercise? Well, patients in the exercise sample were instructed to clench their teeth together as hard as possible for 15 seconds. They were asked to repeat this process at least 4 times for a total of the minute. This one minute exercise was to be performed as often as possible throughout the day. Now, the amount of this exercise was not monitored but these patients were asked to accomplish this over the time of their orthodontic treatment. The compliance of these patients was based on written instructions documented in the progress notes of these treated individuals.
In order to determine if any effect occurred in the sample the authors compared the exercise group with another group of 50 subjects who had similar mandibular plane angles and facial heights but were treated with orthodontics alone and no exercise. Then both of these groups were compared to an untreated sample of controls with similar cephalometric variables.
I think you get the idea of the experiment. The big question was whether or not exercise along with orthodontics created change in the mandibular plane angle and vertical dimension of these orthodontic patients. And the answer of that questions is no. There was no skeletal effect when the three samples were compared. In other words, routine regular masticatory forces on the posterior teeth during the day do not have an effect on altering vertical dimension in growing patients. Now the authors did show some effects. In those subjects in the exercise group, there was a slight deepening of the anterior overbite. Now whether or not this was due to orthodontic extrusion or limitation of molar eruption was not really determined in this study. Only the observation of the overbite increase was mentioned. So in conclusion, the authors found that masticatory muscle exercise performed during the treatment of hyperdivergent patients does produce greater overbite but had no significant effect on vertical morphologic measurements of these patients.
If you would like to review this study in its findings, you can find it in the May 2007 issue of Angle Orthodontist.

Orthodontists'and Surgeons'Opinions on the Role of Third Molars as a Cause of Dental Crowding Lindauer SJ, Laskin DM, et al. Am J Orthod Dentofacial Orthop 2007;132:43-8 June 13, 2008 Dr. Suk-Cheol Lee
[초벌원고] If unerupted third molars are present at the end of orthodontic treatment, what do you advise your patients to do about them? Do you believe that erupting third molars can produce an anterior component of force that results in crowding of either the maxillary or mandibular dentition? If I ask the same questions to an oral and maxillofacial surgeon with whom you work. Do you think his or her answers would be the same as yours? A study titled "Orthodontists' and Surgeons' Opinions on the Role of Third Molars as a Cause of Dental Crowding" by Steven Lindauer et al., which appeared in the July 2007 issue of the American Journal of Orthodontics and Dentofacial orthopedics address these questions.	[수정원고]
In this study, the authors evaluated questionnaires that were sent to 393 orthodontists and 458 oral and maxillofacial surgeons. The respondents were asked to answer 6 questions which related to whether or not they felt that erupting their molars produce that anterior component of force on adjacent dentition. Their philosophy, and frequency of either routinely or never recommending extraction of erupting third molars and whether or not, they recommended prophylactic removal of maxillary or mandibular third molars. The answers to these questions are very interesting. I suspect that it might not surprise you that surgeons were significantly more likely than orthodontists to believe that erupting third molars produce an anterior component of force and cause crowding of the anterior dentition and were therefore more likely to recommend prophylactic removal of third molars to prevent crowding. The authors also noted that surgeons graduating before 1970, however were less likely to recommend prophylactic removal of erupting third molars possibly reflecting a difference in their original education or a better ability to keep up with current literature. I also found that interesting that opinions about the roll of third molars in causing crowding of anterior dentition were significantly related to the year of graduation for both orthodontist and oral and maxillofacial surgeons. Orthodontists became less likely to believe that third molars cause crowding and were less likely to recommend their prophylactic removal when they graduated more recently from orthodontic programs.
The authors noted that disagrees with most recent literature on the topic, that suggest little association between the eruption of third molars and crowding of anterior teeth. Based on the cause for extracting impacted third molars and known risks of postoperative problems, it is hard to accept that whether a patients is told that they should have third molars extracted or that there is no need for extraction would depend not only on whether they talked an orthodontist or oral and maxillofacial surgeon, but also on the year of graduation of the orthodontist and surgeon. It is reports of surveys like the one described in this study, that emphasized the need for evidence based treatment. I should note that in spite of the great differences whether erupting third molars should be extracted to prevent eventual crowding, there seems to be no question that third molars should be extracted when they present with symptoms or pathology. You can find this article in the July 2007 issue of the American Journal of Orthodontics and Dentofacial Orthopedics.

Decision Making and the Dental Practice Levin RP. J Am Dent Assoc 2007;138:1016-7 June 20, 2008 Dr. Eun-Ji Kim
[초벌원고] If you have been subscribing to Practical Reviews of Orthodontics for sometime, I'm sure that you are aware that I have reviewed a number of article by Dr, Roger Levin on the topic 'A Practice Management'. Dr. Levin is the co-founder and chief executive officer of the Levin group which is a very successful practice management group. In a number of his articles, Dr. Levin has suggested that we as orthodontist or dentist are actually running a business as well as practicing our profession. A major difference between business CEOs and members of the dental professions is that we as a orthodontist not only have the ultimate responsibility for running our businesses, but also a major responsibility for providing patient care which is essentially production. Most business CEOs do not have steward responsibility to and can concentrate one hundred percent of their time on making management decisions. I have reviewed the number of Dr. Laven's articles because I have found his advice and his suggestions to be very practical and straight forward. In a recent article title 'Decision Making and the Dental Practice' which appeared in the July 2007 issue of the Journal of American Dental Association.	[수정원고]
Dr. Levin discusses the importance of making effective and timely decisions which is a requirement for any well run business or practice. He also notes that dental practices differ from most business in other significant way. That is that underperforming business usually go bankrupt or as most underperforming dental practices continue to exist but at a much lower level of success. Dr. Levin suggests that in making decisions in your practice, it is helpful to place each decision that you make into one of two categories. Namely, decisions that require immediate attention and decisions that require more facts. Doing this will help improve your time management and avoid putting off decisions that are critical to the success of your practice. He also notes that there are some decisions that regimentally require more facts before making them. If you have a decision like this, it is critical that you establish a timeline that allows its information to be gathered and analyzed so that the proper decision can be made by a specified date. It is easy to fall into the trap of using the collection of information to put off the decision indefinitely. The buttom line of this articles is that dentist who make decision at the right time with your appropriate information often achieve more in their practices and their personal lives.
How are you making the decisions in your practice? If you feel that you would like to improve your performances in this area, I would suggest that you read the article which appears in the July 2007 issue of the Journal of American Dental Association.

Integrating Space Closure and Esthetic Dentistry in patients with missing maxillary lateral incisors : Further improvements. Rosa M, Zachrisson BU. J Clin Orthod 2007;41:563-73 June 27,2008 Dr. Hoon Noh
[초벌원고] I have always been a fan of canine substitution for the treatement of missing maxillary lateral incisors but I present this option to the family as an esthetic compromise compare to implant replacement. I may be changing the way I approach these cases after reading the article by Rosa and Zachrisson in the september 2007 JCO. This is a follow-up to 2001 article and it is called "Integrating Space Closure and Esthetic Dentistry in patients with missing maxillary lateral incisors further improvements". This is a very practical straight forward discription of specific steps can be taken to maximized the esthetic results of canine substitution treatment. I am going to highlight a few of the important point, but you need to see the photographs to understand the quality of the results.	[수정원고]
When planning treatment for the canine substitution, the following orthodontic movements must be part of the plan. First, the canine must be extruded to bring the gingival margin to the proper level. In addition, the root must have lingual root torque added to mimic the position of the lateral incisor root. The opposite must be done to the premolar that were serves the canine. The tooth must be intruded to raise the gingival margin to the proper level and the root move to labially to create an eminence. As these movements are being made the canine can be shortened and narrowed by grinding.
At the end of the orthodontic treatment, the first premolar will not be in occlusion. Following orthodontic positioning esthetic dentistry is required. The premolar must be lengthened and widened to provide esthetics and functions as a canine. The canine in the lateral position must be restored to provide proper crown shape. Although this restoration can be done with composite resin build-up, after observing many cases over an extended time, the authors recommend the use of ultrathin porcelain veneer. This is because they are found more maintenance expected keep things looking good with the resin build-ups.
The other significant new recommendation is to consider widening and lengthening the central incisors with veneers. This is because the canines, now laterals, are wider and the esthetic proportion of tooth widths is often better if the central incisors are widened and lengthened as well. The two case reports that are shown, demonstrated an excellent esthetic results and a certainly the equal of any implant restore case. The authors emphasize that substitution treatment is preferred since it can be completed before the completion of growth and since of promote long-term esthetics by having a natural dentition that ages together.
You really must see the photographs to appreciate of the results that have been obtained. One of the cases, as a Class Ⅲ tendency patient with generalized maxillary spacing, I know brainer? open the space for the lateral replacement case. Yet the authors close all the space using canine substitution, and it looks great. As I said, this makes me rethink how I will handle missing incisor cases. You can find more information, and most importantly those photographs of cases reports in the september 2007 issue Journal of Clinical Orthodontics.

The influence of lead thyroid collars on cephalometric landmark identification Wiechmann D, Decker A, et al. Oral Surg Oral Med Oral Pathol oral Radiol Endod 2007;104:560-8 July 4, 2008 Dr. Hyun-Jung Lee
[초벌원고] You probably remember the reports, couple of years ago describing a study that linked dental x-rays during pregnancy to low birth weight infants. Although this finding is still controversial, it has been theorized that this fact could be due to irradiation of the thyroid gland. This has fueled to some renewed suggestion that lead thyroid collar be used for taking lateral cephalograms. This suggestion would only be valid if the use of thyroid collar does not affect that diagnostic information gathered from the film. The October 2007 issue of Oral surgery, Oral medicine, Oral Pathology, Oral radiology and Endodontology includes a paper from Germany that gives us more information about this subject. The report is titled "The influence of lead thyroid collars on cephalometric landmark identification."	[수정원고]
To answer the question of whether the presence of lead thyroid collar affects landmark identification, the authors gathers 100 lateral cephalograms taken without thyroid collar and then collected 100 more after the protocol at the university change to include routine use of thyroid collar. All identifying information was removed from the films, and 2 observers were asked to identify 15 landmarks on each film. The observers were told the study was looking at landmark identification errors, but were blinded to the fact the study was comparing errors in films with collars and those without. The interobserver landmark errors were used to determine whether the collar had an affect on landmark location. When the authors looked at the results of the study, there was an average increase in the interobserver landmark error when the thyroid collar was used from 1.3 to 1.5 mm. The source of this error was isolated to 3 landmarks. one in the hyoid bone, and two in the cervical spine. These are areas that are likely to be obscured by the collar. If these 3 landmarks were eliminated from the analysis then there were no difference when the collar was used.
The author suggests that use of lead thyroid collars during cephalometry is simple and easy way to ensure the lowest possible radiation exposure to your patients. If landmarks on hyoid bone and cervical vertebrae are not used, there should be no diagnostic impact. However, there is also been increased interest lately and the use of the cervical vertebrae maturation index or CBM to assess the skeletal maturation of our patients. Certainly if a thyroid collar is used using the CBM is not possible. So the real question is whether the CBM index gives enough information to warn the additional thyroid exposure. I don't know the answer to that question. But it is something at least you should think about. More information about the use of thyroid collars for cephalometry can be found in the October 2007 3O. By the way the thyroid collar should not be used when taking PA ceph, since the collar obscures much of mandible in that projection.

Quantitative Evaluation of Lip Symmetry in Skeletal Asymmetry Gazit-Rappaport T, Gazit E, Weinreb M. Eur J Orthod 2007;29:345-9 July 11, 2008 Dr. Kyung-Min Lee
[초벌원고] As you complete your clinical examination on an adult patient named Julie, it is apparent that she has a mild to moderate mandibular asymmetry. This is resulted in a dental occlusion with a crossbite of the right canine through the second premolar. Although you can see her chin is deviated to the right for about 4 or 5 mm, Julie says the biggest concern for her is that she notices a significant asymmetry of her lips when putting on lipstick. She asks you whether her lip asymmetry will improve significantly if she chooses to have orthodontic treatment alone to correct her crossbite without surgery to address her skeletal asymmetry. A recent study from Israel called "Quantitative Evaluation of Lip Symmetry in Skeletal Asymmetry" addresses this question. It appears in the August 2007 issue of the European Journal of Orthodontics. And I will review it with you quickly, so you have more information to give your patient Julie.	[수정원고]
This research was done using facial photographs of adult female orthodontic patients. Thirteen patients that were much like Julie made up the study group. These patients all have mild to moderate skeletal asymmetry and unilateral crossbite of at least canine. Another 13 adult females without asymmetry served as a control group and were age-matched to the study subjects. All subjects in both the study and control groups had full fixed orthodontic treatment. The measurement of lip symmetry was made from the frontal photographs. The photographs were all taken by the same photographer using a standardized technique. On the photographs a vertical reference line was drawn from the middle of the nose through the middle of upper lip philtrum. This divided the lips into halves. The lip area of each half of the upper and lower lips was measured and compared with the opposite side. The percent asymmetry was calculated and compared before and after treatment. As you would expect the control group had very little measurable asymmetry before treatment and there was no significant change after treatment. The study group those with skeletal asymmetry and crossbite had lower lip asymmetry measured at about 14% before treatment. This improved significantly reduced to about 4% after treatment.
I have to admit I was surprised how much the lip asymmetry improved as a result of the orthodontic-only treatment. The upper lip did not have measurable asymmetry in either group before or after treatment. There are some significant limitations with this study. The sample size is small and it is unclear whether the investigators were blinded when the lip measurements were done, which could potentially bias the result. But you can tell Julie that there is now some information suggest the lip asymmetry could improve significantly as a result of the orthodontic treatment alone. This study suggests that visible lip area is heavily influenced by the supporting dental relationships.
For more information about the effect of orthodontic treatment on lip symmetry, refer to this article by Gazit-Rappaport in the August 2007 issue of the European Journal of Orthodontics.

The Impact of Buccal Corridors on Smile Attractiveness. Martin AJ, Buschang PH, et al Eur J Orthod 2007;29:530-7 September 5, 2008 Dr. Sang-Su Han
[초벌원고] The impact of buccal corridors on smile attractiveness is still somewhat unclear. There have been studies indicating that narrow buccal corridors make smiles more attractive and others have indicated little or no impact on smile attractiveness. The assumption that narrow buccal corridors improve smile esthetics is used as justification to transversely expand the arches, even in the absence of posterior cross bite. In order to make better clinical decisions, we need more information about how buccal corridors impact smile attractiveness. In the October 2007 issue of the European Journal of Orthodontics, a study from Baylor College of Dentistry is published that investigated this question. The article is called "The impact of buccal corridors on smile attractiveness."	[수정원고]
When conducting research on smile esthetics, normal groups of people are asked to give their subjective grading of the several smiling photographs. The challenge is to limit the variables as much as possible to the ones that you are interested in the study. In this case, the size of the buccal corridors. The authors of this study made to choice to use only one smile and then altered it digitally to create many other images reflecting of varied buccal corridors. In this case, 18 photos were created with the mixture of the buccal corridors sizes and some asymmetries. These images were rated by 82 orthodontists, mostly male and 94 lay people who were found seating in dental waiting areas or airport lounges. Each subject was asked to rate the attractiveness of the 18 smiles using a visual analogue scale. The ratings were analyzed to look for the differences between orthodontists and lay people and to attempt to define the impact the buccal corridors have on smile esthetics. The results showed that not surprisingly, both orthodontists and lay people prefer smiles with narrow or no buccal corridors. Orthodontists were little more sensitive to buccal corridor size, in other words, they noticed smaller changes than the lay people.
Orthodontists prefer the smiles that displayed the teeth molar to molar whether lay people slightly prefer the premolar to premolar smile, but with small buccal corridors. Surprisingly, mild asymmetry did not have a large impact on the attractiveness ratings. The size of the buccal corridors was more important than the asymmetry. In addition, there was no affect of rater age or gender, so people of all ages and gender were similar in the smile preferences.
This study increases our understanding of how buccal corridors impact on attractiveness. But it has some significant limitations as well. The use of digitally altered images result in photos don't really represent the real smile. The author suggest they validate the images prior to the study to make sure they appear natural, but I can tell you that several looked unnatural to me. So, we still have some work to do to determine which factors are most important to smile esthetics. The authors were careful to emphasize that although this study indicate the preference for narrow buccal corridors, it should not be used as justification for indiscriminate expansion of all patients. The buccal corridors should be only one of many factors considered in the treatment planning. For more informations about this study, look in the October 2007 issue of the European Journal of Orthodontics.

Long-Term Follow-Up of Tooth Mobility in Maxillary Incisors with Orthodontically induced Apical Root Resorption Jönsson A, Malmgren O, Levander E. Eur J Orthod 2007;29:482-7 September 12, 2008 Dr. Hak-Hee Choi
[초벌원고] In spite of our best efforts, some of patients exhibit apical root resorption during orthodontic treatment. Most of these patients have a mild shortening of root which seems to be of little consequence in terms of long-term dental health. But what about those patients who demonstrate more severe root resorption? What would we expect the periodontal health and mobility status of these teeth to be like many years later? An article from Sweden which appears in the October 2007 issue of the European Journal of Orthodontics gives us a glimpse what we might expect these teeth at long term follow-up. The article is called “Long-Term Follow-Up of Tooth Mobility in Maxillary Incisors with Orthodontically induced Apical Root Resorption."	[수정원고]
The authors began by identifying 60 patients that had moderate to severe root resorption during orthodontic treatment and that had completed treatment 10 to 25 years ago. Of the 60 patients 36 agreed to return for follow-up evaluation. These 36 patients had total of 139 maxillary incisors that were studied. A complete clinical examination was done which included periodontal assessment, occlusal assessment and objective measurement of tooth mobility. In addition, standardized intraoral radiographs were taken to assess root length and bone height.
So, what can we expect to see 10 to 25 years later when incisors have significant root resorption? These results demonstrated that maxillary incisors with significant root resorption were generally quite stable when examined 10 to 25 years later. The periodontal status was good and the crestal bone levels of the teeth with severe resorption were not different from those without significant resorption. The mobility was only slightly greater on average for the teeth with resorption than for normal maxillary incisors. A subset of 16 patients have been examined 5 years earlier and there was a trend for slight increase in mobility over the 5 years in those teeth with extreme apical resorption that found in those teeth with root length of less than 10 mm. There were also 16 teeth that had twisted wire boned lingual retainers still in place and the mobility of those teeth was not found to be any different than the incisors without a lingual boned retainer.
So, what this study tells me? Is it the long term prognosis for maxillary incisors with moderate to severe root resorption is still very good? The majority of these teeth have little or no measurable tooth mobility at long term follow-up and there is no apparent loss of crestal bone height. Teeth with more severe root resorption, root length of less than 10 mm did have a tendency for mild increase in mobility with time. It also appears that a bonded lingual retainer dose not help to reduce mobility in these teeth in the long term. The information in this paper may be useful to share with referring dentists so that they too may have a better understanding of the long-term prognosis of incisors that experienced root resorption.
If you want to obtain a copy of this article for your use in this way, look in the October 2007 issue of European journal of orthodontics.

Changes in Supporting Tissue Following Loss of a Permanent Maxillary Incisor in Children Rodd HD, Malhotra R, et al. Dent Traumatol 2007;23:328-32 September 19, 2008 Dr. Sang-Rok Kim
[초벌원고] Imagine seeing a new patient in your practice named Emily. Emily is an eleven year old young lady with relatively routine irregularity that can be easily treated with non extraction orthodontic therapy. The complication is that Emily suffered trauma to her upper left central incisor about four months ago and mother says they have tried everything possible to save the tooth but it was recently discovered that the tooth has a vertical root fracture and will need to be removed. How does this impact your thinking? What do we know about the resorption of alveolar bone in children and adolescence who lose a maxillary incisor at an young age? Most of our information about alveolar bone loss comes from studies in adults and usually older adults. But, in the December 2007 issue of Dental Traumatology, researchers from the UK published a report that examined alveolar bone loss in children. The study is called "Change in Supporting Tissue Following Loss of a Permanent Maxillary Incisor in Children."	[수정원고]
This is a difficult thing to study since a loss of incisor in children is relatively rare, but these authors were able to follow sixteen children, eleven boys and five girls who required removal of an upper incisor due to complications of trauma much like Emily that I asked you to imagine. These children were on average about eleven years old when the incisor was removed. As impressions were made for diagnosis and appliance construction following tooth removal, a second pour was made for use in this study. The resulting casts were vertically sectioned through the edentulous space and also vertically sectioned through the middle of the contra lateral incisor. The cross sectional area of the alveolar in these two locations was measured using digital imaging techniques and bone loss was defined as the percentage reduction in the cross sectional area in the edentulous site. The result showed rather rapid bone loss. There was a reduction in the alveolar bone area of about fifteen percent in the first three months. The loss continued and at six months twenty five percent bone loss was measured. There did not seem to be much further loss during the rest of the follow up period which was just over two years.
When gender differences were studied, it was found that girls exhibited greater alveolar bone loss than boys. This study makes it quite clear that relatively rapid bone loss occurs in children like Emily that lose a maxillary incisor. The fact that they are growing does not protect them from this negative consequence. Most of the bone loss occurs within the first six months, so any attempt to maintain bone would need to be done immediately. The authors suggest that it is sometimes possible to maintain the tooth root when the tooth is loss and that this may be one possible solution. They also found that children with crowding may show less bone loss since adjacent teeth move or erupt into the incisor space and bring bone along. More information about alveolar bone loss in children following loss of a maxillary incisor can be found it the December 2007 issue of the journal Dental Traumatology.

Long-term Experience with Direct-Bonded Retainers : Update and Clinical Advice Zachrisson BU. J Clin Orthod 2007;41:728-37 September 26, 2008 Dr. Hyun-Kyu Lee
[초벌원고] When I was thumbing through the December 2007 issue of the Journal of Clinical Orthodontics, I was excited to see an article by Björn Zachrisson outlining huge experience with bonded retainers. I have used lower lingual bonded retainers in my practice routinely for years, but I have had some frustration using bonded retainers in the upper arch. I wanted to see if I can pick up the few tips help to me out. Dr. Zachirisson has recommendations for bonded retainer use in adolescents and adults but emphasizes at the retention for each patient should be individualized based on their pretreatment presentation and your expectations for relapse. I wonder emphasize that this information is largely based on these 30 plus use of clinical experience with the additional some retrospective data collected in this office.	[수정원고]
Here are his suggestions. For the routine adolescent, the lower retainer is a bonded canine-to-canine wire. This wire is a .030 gold plated solid wire and this bonded only on the ends. The ends are sandblasted for retention and bonded to the canines with the light-cured or chemically cured composite. The upper arch in the adolescents, has a lateral to lateral bonded retainer with an overlay removable retainer. The upper bonded retainer is made from .0215 spiral wire, and it is bonded to all four incisors. The use of .0215 spiral wire rather than the smaller size is commonly used is recommended to eliminate the problem of wire distortion resulting in unwanted active tooth movement. Based on retrospective review of several hundred patients these bonded retainers have success rate of about 95% in the author's practice. The routine recommendation for the adult patient to somewhat different based on increase potential for relapse and the typical adult wanting to maintain precise alignment. And these cases, a lower canine to canine bonded retainer is placed, but with .0215 spiral wire bonded to all six teeth. In the upper arch, the .0215 wire is again used but extended to canines rather than ending at the laterals. Again and overlay removable retainer is used in the upper arch.
This combination of bonded retainer used in adults, has higher failure rate than adolescent combination, but according to Dr. Zachirisson "not alarmingly so." He also demonstrates the additional bonded retainer types used in specific situations. One such type is the short labial bonded retainer used to maintain space closure. Gold coated wires are used to be more statically acceptable. Another specific bonded retention application is a heavier labial wire used for space maintenance in the area of planted implant. This fixed retention application helps to eliminate the problems opening counter while waiting for the final restoration to be placed. Although there is nothing really new a ground breaking in this article, it does give a nice summary of how to use bonded retainers predictably in practice. I'm going to try some of the gold torn wires recommend, and I'm also gonna change to using .0215 spiral wire retainers for bonded each tooth. If you only see many excellent clinical photographs in these techniques, or just to get more detail for your clinical use, you can find this article in the December 2007 JCO.

Localization of Impacted Maxillary Canines and Observation of Adjacent Incisor Resorption With Cone-Beam Computed Tomography Liu D-G, Zhang W-L, et al. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2008;105:91-8 October 10, 2008 Dr. Eun-JI Kim
[초벌원고] There’s a certainly a feeling among orthodontists that cone beam CT imaging may be useful in the localization of impacted maxillary canines because of its ability to show the impaction in three dimensions. This three dimensional view also allows better visualization of root damage on adjacent incisors due to the ectopic tooth. To better understand impacted maxillary canines and to provide more information to orthodontists that treat them, researchers in China conducted study to look at the position and associated root resorption of impacted canines. The results of their study were published in the January 2008 issue of Oral Surgery. Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology in a paper called “Localization of Impacted Maxillary Canines and Observation of Adjacent Incisor Resorption With Cone-Beam Computed Tomography.”	[수정원고]
This was a retrospective study where the authors collected all cone beam imaging that had been done for impacted canines at Peking University from 2002 to 2005. After excluding patients who also had impacted incisors, they had group of 175 patients with 210 impacted maxillary canines. The images were all taken on a New TOM, cone beam CT machine. The authors divided methods of classifying the canines in terms of position and inclination and then divided all the impacted teeth into the six classes, mesial-labial, mesial-palatal, in situ, distal, horizontal and inverted. The authors also looked for evidence of root resorption on adjacent lateral and central incisors and if it’s seen the resorption were classified as mild, moderate or severe. The results for impaction classification were bit unexpected. One third of impaction were mesial-palatal and equal number were mesial-labial and a Cocasion group we would expected many more palatal than labial impaction. About 15% were classified as in situ, meaning they are not displaced mesial-distally and the remaining were divided among distal, horizontal and inverted impactions. The results for incidence of incisor resorption show that 40% of the impacted canines had associated resorption of adjacent lateral and/or central incisors. So in this population, almost half impacted canines were causing some incisor resorption. The severity of the associated resoption was mild half of the time, moderate 30% of the time and severe 20% of the time. I would say that theses results can confirm that more root resorption occurred with impacted canines than we would have been aware of with conventional imaging. This study was done on a Chinese population and we need to be careful extrapolating results to Cocasional African American groups. We know the incidence of labial impactions differ and that may well affect to observe root resorption.
What we can definitely confirm is that cone beam imaging gives us more information about canine impactions and conventional imaging this is another indication that the incidence of significant incisor root resorption is likely to higher than we previously thought. As cone beam imaging become more readily available and cost comes down it is likely that we were routinely imaging impacted canines in this way to get a better diagnostic information to treat our patients. For more details about the study along with sample cone beam images of some of the impacted canines. Take a look in Jan 2008 issue of the below.

Malocclusion as a risk factor in the etiology of headaches in children and adolescents Lambourne C, Lampasso J, et al Am J Orthod Dentofacial Orthop 2007;132:754-61 October 17, 2008 Dr. Hoon Noh
[초벌원고] Tension type headache is the most common form of headache and has very damaging socioeconomic effect on general population. Tension type headache also has profound impact on a quality of life of children and adolescents. It's malocclusion, a possible risk factor for tension type headaches. Much research has been done evaluating the relationship from malocclusion to temporomandibular disorders but very little has been done related to headaches. What are your feelings on the subject? Do you think there is relationship between malocclusion and headaches? And if so, are there specific individual characteristics of malocclusion that are related to tension headaches? A study title "Malocclusion as a risk factor in the etiology of headaches in children and adolescents" by Chad Lambourne et al., which appeared in December 2007 issue of the American Journal of Orthodontics & Dentofacial Orthopedics addressed this questions.	[수정원고]
This study evaluated two groups each consisting of 50 children and adolescents, ages 8 to 16 years. One group consisted of patients with documented frequent headache in the medical history, second group which was the control group had no history of headaches. Plaster models taken during orthodontic initial records for each patient were used to calculate 11 dental characteristics for each patient. Statistical analysis were then used to determine if there was relationship between the individual malocclusion characteristics and the headache or control groups.
Let me ask you again. Do you think there is relationship between malocclusion and headaches? And if so, what specific malocclusion characteristics are related to tension headaches? The bottom line of this study is that the authors found that posterior crossbite and an overbite of 5mm or greater were associated with the significantly increased risk of headache in children and adolescents. I was somewhat surprised by the result of this study because most previous studies which evaluated the relationship between occlusion and temporomandibular disorder have found that there is little or no relationship between occlusion and TMD. For this reason, I was somewhat surprised to find a relationship between excessive overbite, posterior crossbite with tension headaches. Because of the number of characteristics that we evaluated, I questioned whether the sample size for this study was adequate. And I would like to see a similar study done on a larger sample. The bottom line, however, is that base on this study, It appears that there is a possibility that tension headache in children and adolescents could be related to excessive overbite and posterior crossbite. If you have patient with the history of tension headaches, it may be helpful to make them aware of this. You can find this article in the December 2007 issue of the American Orthodontics & Dentofacial Orthopedics.

Noncompliance Open-Bite Treatment with Zygomatic Anchorage Erverdi N, Usumez S, et al. Angle Orthod 2007;77:986-90 October 24, 2008 Dr. Hyun-Jung Lee
[초벌원고] How do you correct anterior open-bites in your young adult patients? Over the years, I think most of us have relied upon orthognathic surgery either of the maxilla, the mandible or combination of maxilla and mandible to correct skeletal open-bite deformities. But now the advent of temporary anchorage devices, researchers are now applying this technology to correct open-bites. As an orthodontist, we must keep abreast of these studies, to see if we can apply this information to our clinical patients. So I was interested in an article that appeared in November 2007 issue of the Angle Orthodontist that described the effect of using miniplates all zygomatic anchorage to provide tooth intrusion of the maxillary posterior teeth to correct open-bites. I decided that this would be a good article for us to review.	[수정원고]
The title of the article is "Noncompliance Open-Bite Treatment with Zygomatic Anchorage." The study is co-authored by Nejat Erverdi and three other research colleagues from the department of orthodontics at Marmara University, in Istanbul, Turkey. The purpose of this study is to determine the effects of zygomatic anchorage on posterior dentoalveolar intrusion of the dentition using cephalometric documentation to document the changes. The sample for the study consisted of 11 patient who are the mean age of around the 19 years. All of the subjects had zygomatic miniplate placed. After 7 to 10 days of wound healing, an intrusion appliance was placed. The appliance consisted of two shallow acrylic bite blocks that were connected by a wire across the palate. An addition of buccal wire was extended toward the gingiva, to allow connection from the miniplate to this appliance. The appliance were bonded to the teeth using Glass ionomer cement. Then two Nickel-Titanium coil-springs were used to connect the miniplate to the hook on the appliance, and it deliver a 400 gm intrusive force. The patients were seen at 4 week intervals and their progress was observed. Cephalometic radiographs were taken at the outset of treatment and then after an average of 9 months to determine the cephalometric change that had occured.
OK, what do you think happen? The authors analyzed several cephalometric points in place?. First of all, the mean intrusion of the maxillary posterior teeth was about 3.5mm. This produce an average of 3 degrees of closure of the mandibular plane. In addition the patients had an increase in overbite 5mm at an average reduction of the overjet of 1.5 mm. In other words, all 11 patients showed success at closing the open-bite using this means of anchorage. So the intrusion of teeth was successful using the miniplates. But you know I have a problem with this study. There is no report of relapse. We know from previous research that mini-screws or mini-implants can be used to intrude teeth. The question is what's the relapse potential. In this study the authors did not correct the ideology of the open-bite. They simply move the teeth or compensated for the effect of the open-bite. I'd be interested in knowing the stability of this technic over the long-term. We know, that surgical correction of open-bites is not stable to a certain degree. Why would intruding the teeth be any more stable if were done orthodontically? I'm looking forward to future studies from this group of reserchers to answer this questions regarding stability of this type of treatment. If you are interested in reviewing this current article, you'll find it in the November 2007 issue, of the Angle Orthodontist.

Who has time for effective communication? Levin PR. J Am Dent Assoc 2008;139:195-6 November 21, 2008 Dr. Gi-Soo Uhm
[초벌원고] An article title, who has time for effective communication? Roger P. Levin which appears in the February 2008 issue of the Journal of the American Dental Association starts with the following comments and I quote “Owing to the hectic pace of most dental practices, effective communication can be extremely challenging even for dentist which strong verbal skills.”	[수정원고]
In this article, Dr. Levin suggest 5 step to improve communication in your office. First, select right time to communicate. Giving instruction to your staff member who is busy trying to deal with 2 or 3 other things, such as patients, phone calls, etc. It's not a good time to communicate. It is better to communicate during morning, noon, or end of day meeting and if you have number of instructions, that your trying to convey always write them down. Two, it's ask the listener to repeat back what was heard. Last instruction is very routine. It is helpful to summarize at the end of your conversation with your staff and ask them to repeat it. The third suggestion is to hold regular meetings. Dr. Levin believes that organized morning meeting are critical for productive office. It is during these meetings that you can discuss any challenges that you and your staff expect to face during the day and also review any problem that may have occurred during previous day. Fourth, it's to improve listening skills. In this article Dr. Levin quotes Peter Drucker the famous business management guru as followed. The most important thing in communication is hearing what isn't said when listening it is the important to be aware of both the verbal and the nonverbal messages that you are receiving. Dr. Levin's fifth suggestion is to show appreciation. It is always good communication and management to thank your staff members when they have completed tasks successfully. If you do this, they are much more likely to be acceptive to future communication and instructions. Finally Dr. Levin suggest that if you are trying to improve communications in your office, it is best just to try changing a few things at a time adding additional areas after previous items as a result.
I found suggestion in this article to be very practical and easy to implement. You can find it in the January 2008 issue of the Journal of the American Dental Association.

Botulinum Toxin Type A (Botox) for the Neuromuscular Correction of Excessive Gingival Display on Smiling (gummy smile) Polo M. Am J Orthod Dentofacial Orthop 2008;133:195-203 November 28, 2008 Dr. Kyung-Min Lee
[초벌원고] It is not unusual for orthodontic patients to present with a primary concern of having an unattractive gummy smile. Sometimes this can be due to excessive eruption of maxillary incisors below the posterior occlusal plane and can be corrected orthodontically by intruding the incisors. Vertical maxillary excess is also a common cause of a gummy smile. In this situation the patient usually presents with an excessive interlabial gap at rest, excessive maxillary incisor to resting lip display, and a flat maxillary occlusal plane. This condition is usually best treated by surgical maxillary impaction.	[수정원고]
While full smile photographs are, it should be, a standard part of orthodontic records at courses that I have presented I have stressed that the decision to do maxillary impaction surgery is always based on the resting lip to incisor relationship and not the amount of gingival display during full smile. The reason for this is that there are patients who have relaxed lip contact at rest and a normal maxillary incisor to resting lip relationship but have a gummy smile simply because they have very large active smile. Doing a surgical maxillary impaction for these patients is contraindicated because while it would improve their gummy smile it would also make them look much older because they would have no resting lip to incisor display. The bottom line here is that if you have a patient that has relaxed contact, maxillary impaction is not indicated.
However what can be done to help these patients who have a very gummy smile due to a broad hyperactive smile but do not have vertical excess? A study titled “Botulinum toxin type A (Botox) for the neuromuscular correction of excessive gingival display on smiling (gummy smile)” by Mario Polo which appeared in the February 2008 issue of the American Journal of Orthodontics & Dentofacial Orthopedics addressed this issue.
In this study the author used Botox on 30 patients who had excessive gummy smile due to hyperfunctional upper lip elevator muscles. I should note that when injected intramuscularly Botox produces partial chemical denervation or paralysis of the muscle resulting in reduced muscle activity. Prior to injection the subjects in this study had an average gingival display on full smile of 5.2 mm which was reduced to almost zero at 2 weeks postinjection. For mean reduction, a 5.1 mm. Gingival display gradually increased from 2 weeks postinjection to 24 weeks but still had not returned to baseline values. The authors projected that there would be a continued gradual increase in gingival display until 30 to 32 weeks postinjection, at which time the amount of gingival display would return to the initial values. Photographs contained in this article of pre and post treatment smiles are very impressive.
I think it is important to stress that of over 8,000 patients evaluated for selection into the study only 76 met the inclusion criteria which was that the gummy smile had to be result of muscle hyperactivity. I believe that Botox has some potential to help patients with excessive gummy smiles if it is limited to the very small number of patients whose gummy smiles are due to muscle hyperactivity. However because it’s effects are time limited, it would require that patients have repeated injections which may not be acceptable to many patients.
You can find this article in the February 2008 issue of the American Journal of Orthodontics & Dentofacial Orthopedics.
Autotransplantation of 28 Premolar Donor Teeth in 24 Orthodontic Patients Tanaka T, Deguchi T, et al. Angle Orthod 2008;78:12-9 December 5, 2008 Dr. Suk-Cheol Lee
[초벌원고] How do you handle the problem of congenitally missing teeth in your orthodontic patients? In the past, I think that most orthodontists consider extraction of additional teeth in order to close all spaces and avoid significant restoration of adjacent teeth but today with the advent of dental implants the pendulum has swung and many clinicians are leaving edentulous spaces in theses patients so that implants can be used to replace congenital missing teeth. But there is another alternative. If certain strategic teeth are congenitally missing and that patient requires permanent tooth extraction autotransplantation of a tooth from one part of the mouth to the other is possible. But do you ever consider this alternative? Because this combination of crowding in one arch and congenitally missing teeth in the other arch is rare. I believe that many clinicians at least in the United States just don't think of this possibility. But in other parts of the world, this situation could be more common. I found an article in the January, 2008 issue of the Angle Orthodontist, the documents state the outcome of autotransplation of 28 premolar donor teeth in 24 orthodontic patients in Japan.	[수정원고]
We know that the Japanese often have significant crowding of the dentition waranting extraction. But if there were a congenitally missing tooth in the opposite arch, this could be a wonderful situation for autotransplantation. Basically, that's what was done in this sample of patients, then the authors followed the patients to determine the success or outcome. The title of the article is autotransplation of 28 premolar donor teeth in 24 orthodontic patients. This article was coauthored by Tadasu Tanaka and other several research colleague from Matzumoto University in Nagano, Janpan. Basically the purpose of their research project was to monitor the success rates of 28 consecutively placed premolar teeth in these 24 orthodontic patients. Let me describe what they did. All 24 orthodontic patients had complete orthodontic therapy. In these patients, 28 of their premolars were harvested and transplanted to another site in the mouth of each of these patients. In some of the sites, a primary tooth was extrated but in other areas a recipient site was created for the premolar to be transplanted. The average age of the patients was about 12 years and the sample was divided nearly equally between females and males. These premolar transplants were placed in the primary canine position, primary second molar position, maxillary central or lateral incisor area, or in two sites where other premolars were missing. In order to observe and document changes, the author took periapical radiographs prior to treatment at the time of the operation 2 years post operatively and the 4 years after the surgery. In addition, the authors evaluated the gingival condition and tooth mobility as well as the need for any root canal therapy.
OK, I think you get the idea of the experiment. It was a retrospective analysis to determine the outcome of autotransplation in these patients. What happened? First of all, 2 patients were eliminated from the sample during treatment because of systemic problem. One patient has history of histocytosis and another patient developed osteomylitis of the maxilla. What happened to the remainder of the sample? The success rate for the premolar transplants in these orthodontic patients was 100 %. In other words, no failures.
What happen to the growth of the length of the roots of these transplanted teeth? Some roots continued to grow well others showed no rooth growth? What about pulp survival? In this study, the pulp survival rate was 60 %, so 40 % of the premolars required root canal therapy. So, what's the bottom line? If you measure success, by a tooth remaining in that site without ankylosis and a functioning root the success rate of autotransplantation in this study was 100 %. However, if you think about there are other issues involved, when these autotransplants are placed in the maxilla, especially in the front of the mouth, then success must also be evaluated in terms of esthetics. This was not done in this study. I commend the authors for this excellent follow-up of autotransplantation but perhaps they should, in a future study, create some sorts of analysis of the esthetics around the implant placed in the maxillary anterior region to determine if this is a truly a good choice of treatment for this patient. In the meantime if you would like to review this clinical evaluation of the success rate of autotransplation of premolars, you can find it in the January 2008 issue of Angle Orthodontist.

A Comparison of Miniplates and Teeth for Orthodontic Anchorage Kim S, Herring S, et al. Am J Orthod Dentofacial Orthop 2008;113:189.e19 December 12, 2008 Dr. Eun-JI Kim
[초벌원고] The effectiveness of headgears to provide anchorage for space closure had been well demonstrated. However the problem of headgears is not the ability to provide anchorage but the willingness of many patients to wear them. For this reason, there's gonna proliferation of what a best termed as non-compliance appliances. Although these appliances are designed to support anchor units during retraction, because of there reciprocal forces involved most of them still allow some degree of anchorage loss. More recently, the use of temporary anchorage devices or TADs, such as miniscrews & miniplates have gained popularity. Because they appeared to have the potential for providing almost 100 % anchorage without patient cooperation. And a reasonable easy to use. If you're using miniplates to close the space between two individual teeth, how much anchorage do you think they would provide? Also, how would this compare with just retracting the two teeth against each other. In the study title “A Comparison of Miniplates and Teeth for Orthodontic Anchorage” by Soo-Jin Kim et al which appeared in the online section of the February 2008 issue of the American Journal of Orthodontics and Dentofacial Orthopedics.	[수정원고]
The authors used eight beagle dogs to compare the difference in anchorage loss in the two situations that I described. In the study, one premolar was extracted in each quadrant, and the split mouth design was used to designate contralateral quadrant in the maxillary and mandibular arches as experimental were controlled quadrants. I should know that dogs had four premolars so that even the one premolar was extracted in each quadrant there were two premolars remaining to allow for orthodontic retraction to close the extraction space. In the controlled quadrants brackets will replace on the two premolars and the premolars will retract to the against each other using only NiTi coil springs. In the experimental quadrants the premolars were retracted against miniplates. Bone markers were placed to allow accurate superimposition a lateral cephalometric degree grass would taken at the start of treatment and at 6 and 12 weeks after the initiation of treatment. In addition to cephalometric degree grass, direct measurements would taken into orally to mesure space closure. When the space closure in the experimental and controlled group were compared, what do you think the researchers found. The bottom line is that there was no difference in the amount of space closure. However in the controlled group approximately one third of the space closure was due to the loss of anchorage. Whereas in the experimental groups the miniplates provided almost 100 % anchorage.
I should also know that the successful rate of the miniplates, over the 20 weeks period was 94 % or 15 out of 16 miniplates. Although this study was performed on dogs and the teeth were retracted against each other with no arch wires being placed, results are nevertheless impressive. The only question in my mind is whether miniscrews which are much easier to place than miniplates can provide similar anchorage. You can find this article in the online section of the February 2008 issue of the American Journal of Orthodontics and Dentofacial Orthopedics.

Duration of elastomeric separation and effect on interproximal contact point characteristics Davidovitch M, Papanicolaou S, et al. Am J Orthod Dentofacial Orthop 2008;133:414-22 December 19, 2008 Dr. Hoon Noh
[초벌원고] Well bonding brackets is obviously the state of the art today, there are still many orthodontists who prefer to place the bands on first or second molars. If you are one of those orthodontists, I suspect that you use elastomeric separators prior to banding. If you do use elastomeric separators, how far ahead of the banding appointment do you place them? I would guess that the answer that most orthodontists would give to this question, it's that they place them one week prior to banding. Is there any basis for choosing this time frame? The longer elastomeric separators are in place, the longer the patient is likley to experience some pain from them and also the greater likelihood that they would fall out. With this thought in mind, the logical next question is “Would be possible to place elastomeric separators for much shorter period of time prior to banding?” Because a number of companies manufacture elastomeric separators, another logical question is “does it make any difference which type elastomeric separator that you use?” These questions were addressed in a article title, “Duration of elastomeric separation and effect on interproximal contact point characteristics” by Moshe Davidovitch et al, which appeared in the March 2008 issue of the American Journal of Orthodontics & Dentofacial Orthopedics.	[수정원고]
The sample for the study consisted of 30 adult patients who had an elastomeric separator placed between the mandibular second premolar and first molar for 1, 4, 12 and 24 hour periods. The authors wanted to determine the minimum time required for an elastomeric separator to accomplish an interproximal separation greater than 0.16 mm which is the average thickness of an orthodontic band. Basically each patient had four separate trials that differed in how long separator was left in place, namely 1, 4, 12 or 24 hours. In each time interval, the separator was removed and the interproximal space that was created was measured using special instrumentation. The results of this study are interesting.
After 12 and 24 hours of separation, all patients demonstrate space that was greater than 0.16 mm or the acceptable amount for banding. Based on these results, the authors suggest that separator should be placed a day before bands are fitted and if the separator is lost, the patient should come to the orthodontic office 3 to 4 hours before the appointment for separator replacement. The authors also found that it didn't make any difference which manufacturer's elastomeric manuals that you used. Additionally one they look at the time of took for the contact point tightness return to normal after removal of the separators, 95% of tightness of the initial dental contact point was regained within 24 hours.
I found this information will very helpful in that placing the separators when they are ahead of banding rather than one week has an advantage of reducing the amount of time that patients will experience pain and also the likelihood that the separator will be lost prior to the banding appointment. My only concern is whether or not the first molars would be more sensitive and therefore more painful one day after placing separation versus one week later. You can find this article in the 2008 issue of the American Journal of Orthodontics & Dentofacial Orthopedics.

Age and Third Molar Extraction as Risk Factors for Temporomandibular Disorder Huang GJ, Drangsholt MT, et al. J Dent Res 2008;87:283-7 December 26, 2008 Dr. Hyun-Jung Lee
[초벌원고] Has the parent ever asked you this question? Suppose you just completed orthodontic treatment on a 16 year old female. The treatment result turned out beautifully. You treated her non-extraction in order to preserve facial esthetics. And she and her parents are delighted with the result. At your post treatment consultation, when you are reviewing panoramic radiograph with the parents, you note that the mandibular third molars are impacted and their roots are about two-third forms. So you recommend to the parents that they consider having the third molar extracted as soon as possible. But then the mother comments that she had her third molar out at young age and after the surgery she began to develop popping of the temporomandibular joints which has lasted for her entire lifetime. So the mother asks you what's the risk of her daughter developing TMD during third molar extraction surgery. In fact, she wants to know if there would be any greater risk doing the extractions now or perhaps waiting a few years. How would you answer that question? Well, let me give you some assistance. There was a study published in the Journal of Dental Research in March 2008 which shed some light on this topic. The title of the article is “Age and third molar extraction as risk factors for TMD.” This study comes out of the University of Washington and both coauthored by Grake Huang and Mark Drangsholt. I know both of these coauthors personally and I think this was an excellent study that has great information for orthodontists. The purpose of their study was to determine if third molar removal is a risk factor for TMD especially in younger individuals.	[수정원고]
Now, this was an extensive study. It involved an assessment of over 4,000 individuals of various ages. Half of the sample or about 2,000 subjects had had third molar extraction. The other half of the sample had their third molar still present. Both groups were stratified and age and gender matched so that the question about third molar removal could apply to ages from 15 up to over 40 years of age. Then the authors determined the incidence of temporomandibular disorders based upon insurance data that confirmed if patients have received treatment for TMD after the third molar extractions. The authors calculated the risk of developing TMD based upon the results of their assessment. Okay, without making this anymore complicated, let me just give you their findings. First of all, for the entire sample, the relative risk of developing TMD in individuals who have their third molars removed compared with individuals who did not was about 1.4. In other words, there was a slightly elevated risk but this increase was not statistically significant. What if the person were young? Let's look at those individuals between 15 and 20 years of age, just like the patient we are discussing in this review. The relative risk of developing TMD after third molar extraction between 15 and 20 years of age was 1.6. This was obviously higher than the overall sample but when the authors crunched to the numbsers, it was not statistically significant.
Basically, the authors found that with age, the relative risk tends to decrease slightly until 40 years of age when the risk of developing TMD after third molar removal increases to about 2.5. But again, the authors were careful to point out that none of the relative risks reached statistical significance in this sample. So there you have it. Yes, there is a slightly increased risk of developing TMD after third molar extraction, but their risk is relatively insignificant. And really doesn't affect younger person a lot more than if that person had had third molars extracted at an older age. So, back to your patient. When the mother asks whether or not her daughter has an increased risk of developing TMD after third molar removal, you can quote this study. The risk is slightly elevated but it's not statistically significant. If you would like to review this excellent study that evaluates age and third molar extraction as risk factors for TMD, you can find it in a March 2008 Issue of the Journal of Dental Research.

Clinical Effect of CO₂Laser in Reducing Pain in Orthodontics Fujiyama K, Deguchi T, et al. Angle Orthod 2008;78:299-303 January 2, 2009 Dr. Mi-Young Kim
[초벌원고] How do you manage patients who complain about the pain that’s produced after you placed a new heavy archwire? I think the most orthodontists try to comfort the patients and tell them that pain won’t last and let the patient simply tough it out. But what about patients who are very sensitive to this pain? I guess one could recommend non-steroidal anti-inflammatory drugs such as Advil or alternatively Tylenol or Aspirin. But are there any other methods of reducing this unfortunate response to tooth movement? Did you know that in some parts of the world lasers are being used to reduce the pain from orthodontic movement? That’s right. But to be more specific, the carbon dioxide laser is what I am talking about.	[수정원고]
The CO₂ laser is observed by only a thin surface layer of tissue, while as other types of lasers penetrate deeper into tissue, but CO₂ laser does not. In addition, carbon dioxide lasers produce lower temperature. But if you apply CO₂ laser to the gingiva and mucosa over the root of the tooth that’s just undergone activation with an archwire, can you really expect a reduction in orthodontic pain? That question was addressed in the study that was published in the March 2008 issue of the Angle Orthodontist. Since this is such a unique application of lasers and may have some clinical benefit to orthodontists, I thoght this would be great article for us to review. The title of this study is “Clinical Effect of CO₂ Laser in Reducing Pain in Orthodontics”. This study comes out of Kyoto, Japan and was co-authored by Koji Fujiyama and several other research colleagues from the department of orthodontics at Okayama University in Japan.
The purpose of this study was to evaluate the effect of CO₂ lasers when applied for the specific purpose of alleviating orthodontic pain. Then in order to accomplish this subjective, the authors gathered the sample of 90 patients. None of this patients had ever had orthodontic treatment in all teeth including second molars fully erupted. In 60 of these patients, plastic separators were placed between the first and second molars on both right and left sides. Then immediately after placement of separators, the CO₂ laser beam was applied to the soft tissue over the root of the maxillary left first molar from the cervical margin up to the apical level in that area. The application lasted about 30 seconds. No application of laser was applied to the tooth on the right side. Now in addition the authors placed the separators in 30 other subjects but they didn’t receive any laser treatment either. Then these 90 subjects were instructed to mark the level of their pain on the visual analogue scale after 30 seconds, then at 6 and 12 hours, and then daily for up to 7 days after separators placement. This visual analogue scale marked the level of pain that each patients experienced. OK, I think you get the idea of the experiment. It was very straightforward.
So what did these authors find? Let’s first look at the group that did not have any laser treatment. In the control group, the pain level peaked at 24 hours after separator insertion and then was minimal at about one week. Now I think that’s typical. But what happened to those subjects who were treated with the laser? When the authors compared the control and laser irradiated sides of those individuals, they found that there was statistically significant reduction in the perception of pain. This difference lasted from 30 seconds up through day 4 but not thereafter. So it did actually work. But I’m sure this raises a couple of questions in your mind. First of all, if the pain were less, did that mean the laser prevented the tooth from moving? The authors were prepared to answer this question because they have measured the amount of tooth movement that occurred on the control and laser irradiated sides. There was no statistically significant difference in the amount of tooth movement. Question number 2: How does the laser work to reduce pain? In other words, what is the mechanism that causes this reduction in the perception of pain? Actually the authors aren’t certain but they gave several suggestions. Research has shown that lasers appeared to have multiple mechanisms of action including elevating body surface temperature, removing pain-inducing substances through increased local circulation, and by inhibiting the production of inflammatory factors. The precise mechanism for CO₂ laser in this case was actually not evaluated in this study. Because this was simply a subject effect evaluation of pain perception in these patients. But the bottom line is that local CO₂ laser irradiation did reduce pain associated with orthodontic force application. You may be seeing or hearing more about this application of lasers in the future. In the mean time, if you’d like to read this article, you’ll find it in the March 2008 issue of the Angle Orthodontist.

Esthetic Impact of Premolar Extraction and Nonextraction Treatments on Korean Borderline Patients Lim HJ, Ko KT, Hwang HS Am J Orthod Dentofacial Orthop 2008;133:147-52 January 9, 2009 Dr. Gi-Soo Uhm
[초벌원고] I suspect that as long as I live there will be articles published comparing extraction versus nonextraction orthodontic treatment. There are many anecdotal case study articles published by advocate of nonextraction treatment suggesting that four premolar extraction tends to flatten profiles making them less esthetic. On the other hand, there are articles published by practitioner who applicate the use of premolar extraction when indicated that show that there are no deleterious effects on facial esthetics as a result four first premolar extraction treatment. The primary focus of this study seems to be whether or not premolar extraction has negative effects on profile it is not too often that I see a study which suggests that not only does premolar extraction not have negative effect on profile but actually has a positive effect. For this reason, my attention was drawn to study titled “Esthetic impact of premolar extraction and nonextraction treatments on Korean borderline patients” by Hoi-Jeong Lim et al., which appeared in the April 2008 issue of the American Journal of Orthodontics and Dentofacial Orthopedics.	[수정원고]
In this study, the author evaluated 100 Korean orthodontic patients who initially presented with borderline extraction, nonextraction malocclusion. 50 of the patients were treated with four premolar extraction, and 50 were treated non extraction. The authors constructed pretreatment and posttreatment line drawings of the profiles of the 100 patients. A 200 mm visual analogue scale was used to rate tracing outlines. 100 pairs of tracing were then presented to a panel of 50 dentists and a panel of 50 laypersons to evaluate the degree of esthetic change. When the result was statistically analyzed, the authors concluded that for this sample of Korean patients premolar extraction treatment should greater impact on facial profile improvement than nonextraction treatment, and that there was no significant difference between laypersons and dentists, when evaluated the profile. I found this result interesting and I choose to review this article in this month program for number of reasons. The first is that I am always nervous when I see studies that imply that you can apply simple rule of thumb to determine appropriate treatment for any group of patients. One positive that this study did show was that you can have significant effect on reducing lip protrusion with four premolar extraction treatment plan. On the other hand, if these patients show significant profile improvement with the four premolar extraction plan versus nonextraction treatment plan. I question why this patient for classified as borderline extraction patients in the first place. It appear obvious that most is not all of the patients in the sample started treatment with significant lip protrusion which is not the unusual for the sample of Korean patients.
I thought it would be also interesting that the end of the study, the author noticed that the study have shown that preferred facial profiles are becoming similar between the races, as Korean favor more retruded lip position and Caucasian prefer more protruded lip profiles. For me, the bottom line message of this study is that if you are treating a patient with protrusive lips and you aren't reduce protrusion, you should probably treat the patient with four first premolar extraction, and it doesn't make any difference if this is Korean, Caucasian or member of any other ethnic groups. You can find this article in the April 2008 issue of the American Journal of Orthodontics and Dentofacial Orthopedics.

Oral Mucosal Disease: Recurrent Aphthous Stomatitis Scully C, Porter S. Br J Oral Maxillofac Surg 2008;46:198-206 January 16, 2009 Dr. Kyung-Min Lee
[초벌원고] One of the most frusting things for me is trying to complete fixed orthodontic treatment on a patient that has recurrent aphthous ulcerations. This condition called recurrent aphthous stomatitis or RAS was the subject of a recent review published in the April 2008 issue of the British Journal of Oral and Maxillofacial Surgery. The article is called “Oral Mucosal Disease: Recurrent Aphthous Stomatitis” and I was interested to see if there is any new information that would help me better treat my patients.	[수정원고]
Recurrent aphthous stomatitis has been reported to affect up to 25% of the population and it is much more common in white Americans than African-Americans. It often first presents in childhood or adolescence precisely the time when orthodontic treatment may be recommended. In spite of RAS being a common condition, its cause is still not known. We know that there is lymphocytic infiltration of the epithelium follow by edema, ulceration, and then ultimately healing with new epithelium. The best theory at this time suggests that there is some cross react of immune response against oral bacterium that also then damages the mucosa. Predisposing factors include local trauma or irritation. Something braces can be very good at. Certain systemic factors such as HIV infection or even gluten sensitivity may be involved. Interestingly, although many RAS patients show iron, folic acid, or vitamin B12 deficiency, the use of supplements rarely results in improvement for the patients. Most patients with RAS have the minor form which is characterized by lesions on the non-keratinized mucosa usually less than 5 mm in diameter. The treatment for RAS is not curative but only able to reduce the size or severity of lesions. The most common and effective treatment is often the use of cortical steroid topical medication. Long term use could theoretically suppress adrenal activity but there doesn’t seem to be much evidence of this in RAS patients. Other treatments that can be helpful are the use of benzydamine mouth wash, chlorhexidine, or the use of Aphthasol 5% paste applied to the lesions 2 to 4 times per day. The most effective treatment for RAS seems to be systemic thalidomide but the severe side effects especially the infamous birth defects limits its use. Many other medications are discussed in this review but none that offers much help without severe side effects. The bottom line is that we still don’t know the cause of RAS and our treatments are limited to reducing lesion’s size and severity. At this time the best way to deal with an orthodontic patient with RAS would be to limit the local trauma and to use a cortical steroid or Aphthasol topically for relief. It has been suggested that low level laser treatment could also effectively treat ulcerations but this review did not mention that option at all.
If you’d like a comprehensive review of recurrent aphthous stomatitis, this article from the April 2008 British Journal of Oral and Maxillofacial Surgery would be worth for the reading. It has 170 references and more comprehensive review of RAS management then I was able to share with you.

The Integrated Herbst Appliance - Treatment Effects in a Group of Adolescent Males with Class II Malocclusions Compared with Growth Changes in an Untreated Control Group Hägglund P, Segerdal S. Forsberg C-M. Eur J Orthod 2008;30:120-7 January 23, 2009 Dr. Hyun-Jung Lee
[초벌원고] As I have mentioned several times, I have been using the Herbst appliance more and more in my practice for Class II correction. One limitation of the usual Herbst designs is that they require significant laboratory effort for construction and any breakage during treatment can be difficult to repair in the office. In addition, it can be a challenge to incorporate full fixed appliances with the Herbst and so full appliances are usually placed after the Herbst was removed. To address some of these clinical challenges, orthodontists in Sweden have been using integrated Herbst appliance for Class II correction which attaches to the normal fixed appliances following initial alignment. Does this appliance results in treatment changes similar to other Herbst designs? To provide an answer to this question, Paul Hägglund wen from Sweden published a study of treatment outcomes with this appliance in the April, 2008 issue of the European Journal of Orthodontics.	[수정원고]
This study was done retrospectively on a group of patients that have been treated with a integrated Herbst appliance. To minimize the limitation of the retrospective design, they selected consecutive male patients that met the study criteria. The result was 30 class II males with acceptable records for study that average about 14 years old. The other challenge for authors was to find the suitable control group of Class II patients. Although not a perfect solution, they did manage to get records from Austria of untreated Class II males that serve this purpose. All mesurements were made carefully from lateral cephalometric films and the assessment of the method error was done. Here's what they found. The average time for Herbst to be in place was about 8 months. Overall the treatment results of the integrated Herbst appliance were similar to other Herbst studies with the Class II correction coming from the combination of the skeletal and dental changes. The mandible came forward about 1 degree or 1.5 millimeters and the maxilla was restrained about 1 degree. This maxillary restraint of headgear affect was somewhat larger than other Herbst studies of shown. The incisor change was as expected with some forward movement of lower incisors and uprighting of the upper incisors.
The overall result was an impressive reduction and overjet of 7 millimeters but with a slight Class I skeletal pattern remaining. The authors also found the mandibular plane angle close slightly during treatment which follows the pattern of normal growth. This is different than many Herbst studies which shows some mandibular plane opening and this finding may be due to the many different Herbst design. Overall we can say that the integrated Herbst has treatments effects that are very similar to other Herbst designs. So the selection of the type of Herbst should be done based on what fits best on to your treatment sequence or management plan. This integrated Herbst almost treats the Herbst like mandibular surgery with a time of pre Herbst de-alignment and coordination then the Herbst for Class II correction and finally a period of finishing after the Herbst was removed. To find more about integrated Herbst design, or to look more carefully at the treatment effects that can be expected. Look for this article on the April 2008 issue of European Journal of Orthodontics.