Dictation - 전남대학교 치과대학 교정과 대학원 세미나

Rebonding of Orthodontic Brackets: Part I, a Laboratory and Clinical Study.

Montasser MA, Drummond JL, Evans CA.

Angle Orthod 2008;78:531-6

March 6, 2009

Dr. Eun-Ji Kim

[초벌원고] When you rebond a bracket that comes loose string orthodontics, does the shear bond strength decrease, stay the same, or increase? Logically, it would seem perhaps the shear bond strength would decrease a bit. But is that true? The study was published in May 2008 the Angle Orthodontist answered that question. This study comes out on the Department of Orthodontics at the University of Illinois in Chicago. The title of the article is “Rebonding of Orthodontic Brackets.” and it is co-authored by Mona Montasser, and Carla Evans. The professors of the study was to determine the shear bond strength of orthodontic brackets that were initially bonded then rebonded two more times after debonding. In order to make this as clinically applicable as possible, the authors used three different bonding materials. The sample for this study consisted of 60 extracted human premolars that were divided into three groups. The three adhesive systems that we used were Rely-a-Bond from Reliance Orthodontics, Transbond XT with a self-etching primer from Unitek Corporation, and M-Bond also with a self-etching primer from Tokuyama Corporation in Japan. In the first group, the typical 37% phosphoric acid was used for etching. In the second and third groups as mentioned already, a self etching primer was used. After bonding of all of the premolar stainless steel brackets, the authors waited 24 hours and then debonded brackets using a testing machine which recorded the shear bond strength, then they performed the same procedures all over again. That is to rebond the brackets in the exact the same fashion, again they waited 24 hours and debonded brackets again. This was followed by a second rebonded brackets again using the same techniques, then the brackets were debonded for third time, and the shear bond strengths were recorded. So what the authors were testing was what basically happen to the shear strength when you repeatedly rebonded tooth with same bonding system.	[수정원고]
What happened? Actually this results were very interesting. First of all, the initial shear bond strength for the Tansbond XT was significantly higher than the initial shear bond strength for the Rely-a-Bond, and the M-bond materials. But what happened with the time? For all of the materials, the shear bond strength increased after successive rebondings. That is right. You heard me correctly. The shear bond strength increased with repeated rebonding. However, the increased shear bond strength was minimal and not statistically significant for the Transbond XT, but the increased shear bond strength for the Rely-a-Bond and the M-bond was statistically significant, and after the third rebonding or second rebonding, the shear bond strength of these materials was at the same level or higher than the Transbond XT, very interesting. I would have not predicted that outcome in the study. As an orthodontist in private practice I have experienced many debonded brackets in my career. But I had always assumed that once bracket were rebonded, the shear bond strength would probably be less. This is exactly the opposite. This authors have shown that all three materials shear bond strength of rebonded brackets tend to increase with time, and that is good news for any orthodontic practitioner. So if you would like review this article on rebonding orthodontic bracket you will find it in the May 2008 issue of the Angle Orthodontist.

Comparison of the intrusion effects on the maxillary incisors between implant anchorage and J-hook headgear Deguchi T, Murakami T, et al. Am J Orthod Dentofacial Orthop 2008;133:654-60 March 13, 2009 Dr. Hoon Noh
[초벌원고] It is not unusual to have a patient present for treatment who has a gummy smile and excessive incisor display due to extruded maxillary incisors. The goal of treatment for these patients is usually to intrude the maxillary incisors and avoid extrusion of the maxillary molars if the patient has excessive anterio-vertical dimension or Class II occlusion. If you have a patient like this and you want to intrude the maxillary incisors, would it be more effective to use a J-hook headgear or maxillary implants? In the study title "Comparison of the intrusion effects on the maxillary incisors between implant anchorage and J-hook headgear" by Toru Deguchi et al. which appeared in the May 2008 issue of the American Journal of Orthodontics & Dentofacial Orthopedics, this question was addressed.	[수정원고]
In this study, the authors use lateral cephalometric radiographs to compare two groups of patients. One group consisted of 8 patients who had maxillary incisors intruded with the help of maxillary implants. And the 2nd group consisted of 10 patients who used J-hook headgears. When the cephalometric radiographs were taken at the initiation of the treatment and just after intrusion of the maxillary incisors were compared, results were interesting. There were significantly greater reductions in overbite in the implant group than in the J-hook headgear group. There was also significantly more root resorption in the J-hook headgear group versus the implant group. The average amount of incisor intrusion for the J-hook headgear group was 1.1 mm whereas for the implant group it was 3.6 mm. I decided to review this article for this month's program not only because I thought the results were interesting, but also because I think it raises some interesting questions.
When intruding the maxillary incisors for this type of patient, it is usually goal of treatment to move the incisors apically and distally while avoiding the contact with the powerful cortical plate which has been shown to cause root resorption. Therefore, to treat these patients, you would ideally like to move the incisors upward and distally to the area of the maxilla containing non-cortical bone. It is difficult to do this with the J-hook headgear because the direction of force is usually below the center of resistance of the maxillary incisors which torques them in the opposite direction that you'd like. It is therefore not surprising that the maxillary implants were more effective simply because they were able to deliver an intrusive force labial to the center of resistance of the maxiallary incisors. If you wanted to use headgear for anchorage to intrude the maxillary incisors, it's much more effective to use high-pull facebow headgear for the short outerbow and the round pressing archwire. This allows you to deliver an intrusive force to the molars which can counteract reciprocal force of the intrusion archwire to the incisors. If you are interested in learning about this technique in more detail, you can find it in an article that I published in the July 1989 issue of the American Journal of Orthodontics & Dentofacial Orthopedics.
The bottomline of this study is not only that the maxillary implants were more effective in intruding the maxillary incisors, but they obviously required no patient cooperation. You can find this article in the May 2008 issue of the the American Journal of Orthodontics & Dentofacial Orthopedics.

Treatment of Skeletal-Origin Gummy Smiles with Miniscrew Anchorage. Lin JC-Y, Yeh C-L, et al. J Clin Orthod 2008;42:285-96. March 20, 2009 Dr. Hyun-Jung Lee
[초벌원고] Think about the treatment options you might have for the following patient. Shally is a 25 year old female with a chief complaint of a gummy smile. She is dentally Class I but has a mild increase in lower face height and some increase in overbite. Normally, you may consider orthognathic surgery to impact the maxilla since that may be the most predictable way to correct the vertical maxillary excess. Although Shally listens to your presentation about the maxillary impaction surgery, she politely tells you that she is not interested in surgery and asks what other options she has. If you have read the May 2008 Journal of Clinical Orthodontics and specifically an article by Lin and colleagues called "Treatment of Skeletal-origin gummy smiles with miniscrew anchorages", you may be talking to Shally about another alternative.	[수정원고]
You may suggest miniscrew anchorages to provide maximal incisor intrusion. The truth is Shally's factitious case is very much like the three case reports presented in this article. All three were female and two were young adults while the other was adolescent. The case reports show significant upper incisor intrusion to reduce the gingival display. Judging by the superimposition presented, the intrusion was several millimeters. In two of the three cases, the miniscrews were placed interdentally in the upper incisor region and direct vertical force of about 50 grams was applied to the incisors from the miniscrews. In the third case, there was not enough interdental space anteriorly to place the miniscrews. So, the screw were placed mesial to the first molars and an intrusion arch was used to deliver the vertical force to the anterior teeth. And an anticipated outcome for the two adult patients was that the several millimeters of incisor intrusion reduced the clinical crown length of the incisors. And in the one case the bone did not remodel after intrusion and ledges of bone were present facial to the incisors. This required the periodontal crown lengthening procedure to be done in order to restore crown length and gingival contour.
The outcomes of the three cases presented were dramatic. The reduction in gingival display was significant with a post-treatment photographs revealing very good esthetic balance of tooth, lip and gingiva at smile. Of course, there was no real change in skeletal position as whatever occurred with maxillary impaction but in these patients it was not a problem. Case selection is very important if you are going to repeat the results presented in this paper. Two of the three patients had a deep dental bite along with the vertical skeletal pattern which left plenty of room for incisor and intrusion without creating an open bite. Trying the same technique on a patient with a gummy smile that already had an anterior open bite would be problematic since it would be hard to compensate the lower incisors enough to allow maximal upper incisor intrusion. The photographs in this article are wonderful especially those showing the periodontal crown lengthening since the excess bone left after intrusion is visible. If you want to find these photos or other details in the article, look in the May 2008 issue of the Journal of Clinical Orthodontics.

Relationship between Personality Traits and Cooperation of Adolescent Orthodontic Patients. Amado J, Sierra AM, et al. Angle Orthod 2008;78:688-91 March 27, 2009 Dr. Da-Nal Moon
[초벌원고] Today, we are in an era of non-compliant appliances. Many of the newly developed orthodontic mechanics in appliances tend to take the patient’s cooperation out of the occasion. In that way, orthodontics can be delivered much more predictively. All orthodontists have few patients that don’t cooperate. But is there a way to determine who will be cooperative prior to placing orthodontic appliance? Is there some sort of questionnaire or test that could be given to teenagers to determine their personality traits and thereby determine their potential level for cooperation during orthodontics. You know that will possible that perhaps non-compliant appliances wouldn’t be necessary or perhaps it’s not possible to predict cooperation.	[수정원고]
That idea to relate personality and cooperation was the subject of an article that appeared in the July 2008 issue of the Angle orthodontist. I thought this was an excellent research question and the findings of this study are very interesting to orthodontists. I’d like to review the study on this issue of Practical Reviews in Orthodontics.
The title of the article is “Relationship between Personality Traits and Cooperation of Adolescent Orthodontic Patients”. This study was conducted at the department of orthodontics at the University of Medellin in Colombia. The senior author is Joaquin Amado. The purpose of this study was to establish the relationship between personality traits of adolescence and his or her cooperation during orthodontic treatment. In order to accomplish this project, the authors designed the descriptive, prospective, comparative study of 70 adolescences between the age of 12 and 16. The sample consisted both males and females so that gender could also be assessed. All subjects were wearing active orthodontic appliances and have been in treatment for at least 4 months. The degree of the patient’s cooperation was assessed by the treating orthodontists using an orthodontic patient cooperation scale and it consisted of 10 patient behaviors that could be assessed during orthodontic treatment. In addition, each of these adolescence subjects was given a personality questionnaire that consisted of over 100 questions to assess their personality as well as questions regarding daily problems that patients could experience. After the results were tabulated for both the personality and cooperation questionaries they were compared using appropriate statistics to determine if there were any correlations between a patient’s personality and their level of cooperation during orthodontics.
I think you get the idea of this study. So, what’s the bottom line? Basically these authors found that the outcomes of cross-tabulation between cooperation variables and the variables of personality didn’t show any statistically significant difference. I guess another way to state this is that the patient’s personality traits do not predict cooperation during orthodontic treatment. In addition, the authors found that age and gender were also not statistically significant variables in relation to compliance during orthodontic treatment.
So there we have it. Giving a potential orthodontic patient a personality questionnaire prior to orthodontic treatment really wouldn’t help you to determine whether or not that adolescent patient will become compliant or cooperative during your orthodontic treatment. So, if you must accomplish difficult tooth movement in a non-compliant patients, then perhaps non-compliant appliances are the most effective way of ensuring that you will achieved desired results in the shortest period of time. If you’d like to review this article that correlate the personality traits and patient’s cooperation, you will find it in the July 2008 issue of the Angle orthodontist.

Selective Alveolar Corticotomy to Intrude Overerupted Molars Oliveira DD, de Oliveira BF, et al. Am J Orthod Dentofacial Orthop 2008;133:902-8 April 3, 2009 Dr. Hyun-ran Jeon
[초벌원고] Let me describe a treatment situation that I suspect you have encountered at some point during your practice. One of your referring practitioners sends an adult patient to you who has missing mandibular molars with significantly overerupted maxillary molars. In order to adequately replace the missing mandibular molar space, it is necessary to intrude the maxillary molars to the appropriate level of occlusion and your referring dentist asks if you can do this.	[수정원고]
When I am presented with situations like this, my first instinct is to consider referring the patient to someone else. If you decide to intrude maxillary molars by leveling it along with the other maxillary teeth, it is likely that you will get some extrusion of the adjacent teeth which is usually not indicated. Using a headgear to intrude maxillary molars is difficult, because it not only requires excellent patient cooperation, but also because it is difficult to get both buccal and lingual intrusive force with headgear. More recently, the use of TADs, or temporary anchorage devices, has been suggested for treating this type of problem. However, the TADs have some placement limitations, and usually require an extended period of time for intrusion, which is not appealing to many adult patients.
Wouldn’t it be nice if you could come up with a simple system to rapidly and effectively intrude the maxillary molars without causing any untold side effects on the adjacent teeth. An article in the June 2008 issue of the American Journal of Orthodontics and Dentofacial Orthopedics describes a system to do this. The article is titled “Selective alveolar corticotomy to intrude overerupted molars” by Dauro Douglas Oliveira, et al. In this case presentation article, the authors presented results of 2 patients, one of whom requires significant intrusion of maxillary first molars and the other, significant intrusion of both maxillary first and second molars. The first happened treatment for both these patients was performing buccal and lingual and horizontal corticotomies around the teeth to be intruded. Next, a full-coverage of maxillary splint was constructed with the acrylic removed from the occlusal surface of the molars to be intruded. J-hook attachments were placed in the acrylic on the lingual of maxillary molars and on the heavy round wire on the buccal surface which was anchored to the acrylic. A sentalloy spring was then attached to each of the J-hooks and stretched to cross the occlusal surface of the molar to be intruded. The case records presented for these 2 patients demonstrated a 4 mm intrusion of maxillary right and left first molars within two and a half months in one patient and a 3 to 4 mm intrusion in four months of both maxillary right first and second molars on the second patient.
The treatment described by the records of 2 patients presented in this article was very impressive. Using the molar intrusion technique that I described, a very difficult treatment situation was treated simply and effectively in a short period of time. After intrusion of the maxillary molars, full bonded orthodontic appliances were placed. However, I can conceive of a situation in which only the molars needed to be intruded with no further orthodontic treatment for which this treatment technique would be even more effective. If you are involved with a case like this and need to intrude overextruded maxillary molars, I would strongly suggest that you read this article which appears in the June 2008 issue of the American Journal of Orthodontics and Dentofacial Orthopedics.

Can Previously Bleached Teeth Be Bonded Safely Using Self-etching Primer Systems? Uysal T, Sisman A. Angle Orthod 2008;78:711-5 April 10, 2009 Dr. Mi-Young Kim
[초벌원고] Today with all of the emphasis on cosmetics and esthetics in dentistry, tooth bleaching has become a relatively common procedure especially for adults. Several of my adult patients have successfully bleached their teeth after orthodontics and the improvement has been quite dramatic. But what if adult patient bleaches their teeth prior to orthodontic treatment? Is it more difficult to bond brackets to teeth that have been bleached? And what if you as a orthodontist use a self-etching primer where there be a decrease in the shear bond strength if the teeth had been bleached prior to bonding of orthodontic brackets? If the teeth have been bleached, should you wait perhaps for sometime to elapse before placing the orthodontic brackets? I found the answers to all of the questions in an article that was published in the July 2008 issue of the Angle Orthodontist.	[수정원고]
The title of this manuscript is "Can Previously Bleached Teeth Be Bonded Safely Using Self-etching Primer Systems?"This article comes out of the Department Orthodontics at Erciyes University in Kayseri Turkey. It’s co-authored by Tancan Uysal and Ayca Sisman. The purpose of their in vitro study was to determine the effect of bleaching on the shear bond strength of orthodontic brackets. In order to accomplish this project the authors gathered 60 mandibular premolars that had intact enamel surfaces. These teeth were divided into 3 groups of 20 premolars each. Group 1 was considered the control group using a self-etching primer the surface was prepared and Transbond XT was used to bond bracket to each of these teeth in this group. In group 2, commercially available carbamide peroxide bleaching gel was applied to the enamel surfaces of the teeth for 4 hours per day for a total of 10 consecutive days. Then these teeth underwent the same preparation of enamel surface with self-etching primer and brackets were bonded to the teeth. In group 3, the same bleaching technique was performed using a carbamide peroxide but after the tenth day of bleaching, the teeth were then stored in artificial saliva for 30 days rather than bonding the brackets immediately. Then after the 30 days the self-etching primer was used just as in the previous groups to bond brackets. In each group a testing machine was used to debracket the teeth and shear bond strength were recorded.
Okay, what do you think these authors found? Question No. 1; Does bleaching with carbamide peroxide affect the shear bond strength using a self-etching primer and Transbond XT? The answer the question is yes and no. Let me explain. In those teeth that were bonded immediately after the ten days of consecutive bleeching, the shear bond strength was significantly lower than in the control subjects. Question 2; Was there any difference if teeth were stored in saliva for 30 days after bleaching and before bonding brackets? The answer of that question is definitely yes. In fact, when the authors compared the shear bond strength of those teeth that were bonded 30 days after the last bleaching episode with those in the control group there was no statistically significant difference in shear bond strength. So what’s the clinical message to those orthodontists who are listening to this review? If the patient has bleached their teeth just prior to your orthodontic treatment, make certain that you postpone bracket placement. Do not bond brackets to teeth that have just been bleached. Wait a minimum of 30 days to allow the surface of the tooth to accommodate. This’ll result in higher shear bond strength for the orthodontic brackets especially when using a self-etching primer.
If you’d liked to review this article that evaluate the effect of carbamide peroxide bleaching on shear bond strength using self-etching primers, you’ll find it in the July 2008 issue of the Angle Orthodontist.

Success Rate and Risk Factors Associated with Mini-Implants Reinstalled in the Maxilla Baek S-H, Kim B-M, et al. Angle Orthod 2008;78:895-901 April 17, 2009 Dr. Uhm Gi-Soo
[초벌원고] Have you tried mini-implants yet? Many orthodontist listening to this review have had opportunity to use mini-implants to enhance anchorage during orthodontic treatment. If you were one of those that have used mini-implants in your patients, have you experienced any failures of these mini-implants especially in the maxilla? If you have used enough of these mini-implants, you know that they failed. So that happens especially in the posterior maxilla, what would you do? Do you place another mini-implant in an exactly the same position? Do you replace an implant in a slightly different but adjacent area? If you do replace the mini-implant, well, this will be likely to fail as well. Is there any difference in failure rate between initially placed and reinstalled mini-implants? The answers to all of these questions would be very important for any orthodontist that’s considering the use of mini-implants in the posterior maxilla. So when I found the study in the September 2008 issue of the Angle orthodontist that provided these answers, I thought it would be an excellent one for us to review.	[수정원고]
The title of this article is “Success rate and risk factors associated with mini-implants reinstalled in the maxilla”. This study is co-authored by SH Baek and four other research colleagues from the Department of Orthodontics at Seoul National University in Seoul, Korea. The purpose of this research project was to objectively determine the success rate of reinstalled mini-implants in the posterior maxilla and to determine any risk factors that would cause failure of mini-implants installed in that region. The sample for this study consisted of 58 patients who had total of 100 mini-implants installed in the posterior maxilla to provide anchorage to retract maxillary anterior teeth. Half of the implants were placed on one side of the maxilla and the other half on the other side. The implants were placed either between the second premolar and first molar, or between the first and second molars in the attached gingiva. If any of these implants failed, they were reinstalled. The replacement implant was either repositioned in the same hole, or was originally placed, or in an area adjacent to that site. If the same hole was chosen, a 4 to 6 week delay occurred before the reinstallation of the mini-implant. If the adjacent side was selected, the mini-implant was placed in that side immediately after removal of the failed mini-implant. The authors then calculated the success rate and the length of time that the implants remained in the alveolars. In addition, they co-related several different variables including gender, age, and type of malocclusion to determine, if there were any risk factors for failure of the mini-implants.
Ok, what did the researchers find? Question No. 1; What was the success rate of the initially placed mini-implants in the posterior maxilla? The authors found that 25% of initially placed mini-implants failed. When these were reinstalled either in adjacent area or in the same position of the original implant, the subsequent failure rate was 33%, which was obviously slightly higher. But when the authors compared these data, there was no statistically significant difference in the success rate between the initially placed and reinstalled mini-implants. Question No. 2; Were there statistically significant differences in the age or site of implantation? The answer to that question is no. Question No. 3; Was there any difference in gender? The answer to that question is yes. Let me explain. Significantly higher success rate were found for females versus males for the initially placed implants. But for the reinstalled mini implants, the success rate was higher for males compared to females. Question No. 4; Were there any differences in the types of malocclusions as it relates to success. The answer to that question was also yes. Basically, the authors found the greater ANB discrepancy, the higher the risk for failure. Therefore, Class I malocclusions showed less failure than Class II or Class III. So now you know, the answers to that questions I originally paused. If you utilize mini-implants in the posterior maxilla based upon the results of this study, you will have perhaps a 25 to 30 % chance of failure of the mini-implant over 6 to 10 month period of time. If you repositioned the failed implant in the same side or adjacent side, you can expect a similar failure rate with time.
Let’s face it. These mini-implants are not perfect. The down side risk is that they may have to be repositioned. But more bitter thing to the patients is generally not significant, and therefore reinstalling failed implant is not a huge problem for either the clinician or the patient. If you would like to review this interesting study on the success rate of reinstalled mini-implants in the maxilla, you can find it in the September 2008 issue of the Angle orthodontist.

The Interpersonal Factor Levin RP. J Am Dent Assoc 2008;139:986-7 April 24, 2009 Dr. Kyung-Min Lee
[초벌원고] Most practice management courses that I have attended discussed different systems to improve practice efficiency. These might include a more efficient accounting system, ways to improve your scheduling or different treatment techniques to improve the efficiency of the treatment that you provide. Most of the presentations that I have listened to in these areas seem very mechanical and impersonal. As orthodontists we are not selling products but rather a service and even if we thought of the treatment that we provide as product, very few patients are in the position to judge the quality of that product. Most orthodontic patients choose a orthodontic practice or decide to accept a treatment plan based on how comfortable they feel with you and your staff. This is why developing good interpersonal skills is more important than the developing efficient management and treatment system. Given the importance of good interpersonal skills, is there a way that you can improve your personal skills and those of your staff?	[수정원고]
An article titled “A Better Practice - The Interpersonal Factor” by Roger Levin which appears in the July 2008 issue of the Journal of the American Dental Association suggests that there is. In this article Dr. Levin states that he believes that the greatest book of interpersonal relationship is “How to Win Friends and Influence People” by Dale Carnegie. Based on some of the principles presented in this book, Dr. Levin lists six specific skills that you and your staff can use to improve interpersonal relations with your patients.
One is to greet every person by name. Begin every conversation by using the patient's name. Two is to compliment the patient and Dr. Levin noted that obviously your compliment must be sincere. Three is to comment on something personal. You and your staff members should try to learn one new personal fact about your patients at each visit. I find it helpful if a patient tells me that they are going to camp or their team is playing in the state finals, to make a note and ask them about that during the next visit. The fourth suggestion is never interrupt the patient. It is only when patients feel that you are truly listening to them and concerned about their questions that treatment acceptance increases. The fifth suggestion is to smile. When you are in the mist of a hectic schedule, it is easy for you and your staff to forget about such a simple thing as smiling. Dr Levin's sixth and last suggestion is to shake hands with all patients whether they are male or female. Of the six suggestions this is the only one about which I have some doubt. It seems to me that shaking hands with patients makes your interaction with them more formal, which is the opposite of what I was usually be trying to do.
Overall however I think the suggestions provided in this article are excellent and I would strongly suggest that you use this article as a basis for discussion during your next staff meeting. You can find it in the July 2008 issue of the Journal of the American Dental Association.

A New Bracket-Placement Device Stockstill JW, Levy-Bercowski D, DeLeon E. J Clin Orthod 2008;42:412-4 May 8, 2009 Dr. Sang-Rhok Kim
[초벌원고] What sort of instrument, or device do you use to position brackets on teeth? A scaler, a perio probe, a boon gauge, or other measuring instrument? There’s been a lot of emphasis lately on computer-assisted bracket location and other high-tech solutions, but what about just a better gadget to help you put brackets on teeth more consistently? It is this type of low-tech device that is featured in a short article in the July, 2008 issue of the Journal of Clinical Orthodontics, called “A New Bracket Placement Device”. Now I have to warn you before I begin that this article is written by the orthodontist that invented the device, so interpret everything accordingly. I will try to describe this new positioning device, called the BracketMaster, to you, but if it is something you are interested in you probably want to take a look at the pictures in the article.	[수정원고]
The device looks, at first glance, like a typical double-ended hand-instrument. In fact, at one end it has a universal scaler that is used to push the bracket firmly against the tooth surface and to remove the excess bonding material. The opposite end is the unique positioning aid. It looks something like a fat perio probe with a piece of orthodontic wire stuck through it perpendicular to the probe near the tip. This wire appears to be about six millimeters long and it is the part of the instrument that is placed in the bracket slot during positioning. This relatively long segment of wire makes it easier to visualize the tip and rotation in the bracket and it is long enough to extend to the adjacent bracket for reference. The fat, probe part of the instrument is scored at three and a half, four, four and a half and five millimeters from the perpendicular wire so it can be used to measure the vertical bracket position relative to the incisal edge or cuspid tip. When placing a molar tube, the author suggests placing one end of the device in the molar tube and using the other end of the wire as a vertical reference against the premolar bracket. The short wire segment can also be useful when re-bonding a loose bracket when in a full-size archwire. If you place the device with the wire segment in the adjacent bracket it will allow proper positioning, just like if you use the archwire itself for placement. This can help avoid unnecessary archwire changes to draw back and pick up a re-bonded tooth. This device can also be used for placing brackets on a model for indirect bonding. This is where I plan to try it first. It seems like the long wire segment may be a problem in crowded areas or with rotated teeth, but if it works for indirect bonding I will try it in the mouth for direct bracket placement.
If you are looking for a new aid to help with precise bracket positioning, but aren’t quite ready for the high-tech computer approach, this instrument may be worth a look. The article in the July 2008 JCO lists the supplier of the instrument, if you want to buy one and as I mentioned, it has several color photographs of the instrument and of its use.

Influence of Different Tooth Types on the Bond Strength of Two Orthodontic Adhesive Systems Öztürk B, Malkoç S, et al. Eur J Orthod 2008;30:407-12 May 15, 2009 Dr. Da-nal Moon
[초벌원고] Not long ago, I did a retrospective review of one hundred consecutive patients from our private practice to look at bracket failure rates. Although I was pleased with the overall low failure rate that was discovered, I was surprised that the most frequently loose bracket was a lower incisor. I decided that this was due to the fact that I often leave lower incisor brackets in occlusal contact when bonding but a recent article published in the August 2008 issue of the European Journal of Orthodontics may offer another explanation.	[수정원고]
The article is titled “Influence of different tooth types on the bond strength of two orthodontic adhesive systems” and it looks at the difference in the bond strength between the various tooth types in the mouth. The authors collected two hundred extracted teeth from people ages 13 to 40 that represented all teeth in the mouth; upper incisors, canines, premolars and molars as well as the same tooth types in the lower arch. There were 20 teeth of each of these ten tooth types and half of each group was bonded with Transbond XT and the other half with Light Bond. The composite was bonded to the tooth surface in the solid cylinder rather than with the bracket to isolate testing to adhesive enamel junction. All the samples were tested in a universal testing machine to measure the sheer bond strength and the results were compared to look for differences between adhesives and between tooth types.
Do you think they found a difference in sheer bond strength between the 2 bonding adhesives? Yes, they did. Light Bond was consistently about 10% stronger than Transbond XT, a measurable difference, but a questionable clinical significance. What about variations between tooth types? Well, actually there was surprising variation and both adhesives tended to show the same pattern. The highest bond strengths were found with upper incisors and lower posterior teeth and the lowest strength tended to be upper molars and premolars along with lower incisors. And unlike the relatively small 10% difference found between adhesives, the differences in tooth type bond strength were more like 30 to 40%. This could partially explain why my informal office study showed that lower incisors with the most frequently lost bracket. Those teeth may have inherently lower bond strength to start with. The other implication of this research is that most bonding studies have been done on human premolars and although using premolars may be reasonable to compare one technique or product against another in relative terms, it may not reliably predict how strongly absolute strength will be on incisors or molars. This is one more reason why laboratory studies do not necessarily correlate with clinical performance.
So the take-home message is that the bond strength to enamel may vary from upper to lower and anterior to posterior. In this test, the upper incisors and lower posterior teeth tested the strongest. If you want to read more about this variation in the sheer bond strength among different tooth types, look for the article by Ozturk et al, in the August 2008 issue of the European Journal of Orthodontics.

A randomized clinical study of two interceptive approaches to palatally displaced canines. Baccetti T, Leonardi M, Armi P. Eur J Orthod 2008;30:381-5 June 5, 2009 Dr. Hyun-ran Jeon
[초벌원고] Imagine the clinical situation where you're seeing 10-year old Angela for the first time. She has only mild developing irregularity of the permanent teeth that are present and is in the late mixed dentition. Her family dentist sent along a panoramic radiograph that suggests palatally displacement of the upper right canine and primary canine is still in place on that side along with all second primary molar.	[수정원고]
What is the best way to handle Angela? Do nothing now? Extract the primary canine? How about extracting the primary canine and using some approach to distalize the buccal segments in the maxilla? This type of clinical question is exactly what a recent study from Italy addressed. The study was authored by Tiziano Baccetti and is called "A randomized clinical study of two interceptive approaches to palatally displaced canines". The reason that this study is very important is that it is the first randomized clinical trial of adequate size to address the question of interceptive treatment for palatally displaced canines.
The authors recruited 75 children in the late mixed dentition that had at least one palatally displaced canine as seen on the panoramic film. The children were randomly assigned to one of three groups. The first group received extraction of the primary canine only. The second group received extraction of the primary canine plus cervical headgear to create space of buccal segments. The third group, and this is important, was a control group that received no treatment. All subjects had panoramic and cephalometric films taken at the start of the study and again 18 months later when the study was complete.
Here's what the authors found. First, the three groups had similar canine positions at the start. So the randomization produced equal groups as we would expect. The control group that received no treatment had successful eruption of the permanent canine in about 35% of the cases after 18 months, about 1 in 3. The treatment group that received extraction of the primary tooth only had successful eruption of canine in about 65% of the children, about 2 in 3. The addition of the headgear raised the success rate another 20%, to about 85%.
These differences were all statistically significant. The effect of the headgear was found to be holding the upper molars from moving forward that 2 millimeters so that they moved mesially in the other 2 groups.
So, if we get back to Angela, the patient with palatally displaced canine in the late mixed dentition, there is no question of the primary canine should be removed. That alone will almost double the chances of spontaneous eruption of the canine. The bigger decision is whether headgear treatment should be started to further increase the chances of success. That is a question you will have to answer after discussing the option with the parents.
The authors of this study suggest that since the effect of the headgear was essentially to hold the upper molars in position, the same results may be seen with some sort of Nance appliance or other simple holding mechanism. For more information on this well-designed randomized clinical trial, look in the August 2008 issue of the European Journal of Orthodontics.

Novel Way to Increase Expansion Capacity of Hyrax Expander Neto JR, Ribeiro ANC, et al. J Clin Orthod 2008;42:528-30 June 12, 2009 Dr. Eun-ji Kim
[초벌원고] Do you ever have the clinical situation, where you find your run out of expasion with an RME? Before the maxilla is expanded as much as your ideally like, what would you do? If I need quite a bit more expansion, I'll usually go through a procedure that involves a removal and remake of the appliance in the office. This works but takes a lot of time and disrupts other office activities. If I'm claws I made just replace the expander with the TPA and try to get the last mm or two by adjusting the TPA. A novel approach to this situation was published in the september 2008 Journal of Clinical Orthodontics.	[수정원고]
A group of orthodontist from Sao Faulo, Brazil submitted the case report that you may want to look at. The case documents the expansion of a 16-year-old female. The Hyrax type expander was constructed with the 13 mm screw, but the expansion was still found be inadequate when the limited the screw had been reached. At this point, the screw and guide pins were still anchored in the body of the screw but any further turning could make the expander unstable as the guide pins come out of the metal screw body. The solution to this clinical problem for the authors was to extend the body of the screw mechanism. They did this by adding composite to the medial edges of the screw body that have been seperated. They first clean the screw body with the sodium bicarbonate prophylaxis air polisher. This allowed total cleaning in and arournd the screw and stabilizing pins. Light cured composite was then added to each side around the screw and stabilizing pins effectively extending the screw body towards the midline. In the photographs, it looks like about 3 to 4 mm of composite was added on each side. After the composite was placed and cured it was contoured and polish with diamons or burs and expasion was continued.
In this case 5 more days two turns per day were completed before expansion was found to be adequate. The photo showed that the composite stay attached to the screw body and provided the stability and guidance for the additional 10 turns of expansion. If this works it could really prove to be a simple way to get more expansion out of high Hyrax type expander with minimal clinical lab time.
Although looks great in the single case report, I’m a bit nervous about the cleaning parts since I don’t have a Prophyjet or other bicarbonate cleaner in the office. It seems like may be possible for the composite to pull away from the screw body and not provided the desired stability. I thought about micro etching the screw body surface but it may be hard to do that without getting unwanted retention of the composite to the threaded screw or the stabilizing pins. At any rate I thought that this was a novel idea and may be worth put it in your data bank. To see the photos of procedure and read the complete description of the technique this article could be found in the september 2008 JCO under the title ‘A practical alternative for increasing the capacity of a maxillary expansion screw.

Bond strength of metallic brackets after dental bleaching Patusco VC, Montenegro G, et al. Angle Orthod 2009;79:122-6 June 19, 2009 Dr. Hoon Noh
[초벌원고] Dental bleaching has become a popular means of improving anterior dental esthetics especially after orthodontic treatment. Once I have completed alignment of an adult dentition, I found it many of my adult patients ask me about the possibility of performing dental bleaching. I usally tell them to discuss this with their general dentist can provide them with the most up-to-date options for bleaching. Basically there are two options. One is to purchase an over-the-counter bleaching kit which allows patient to use carbamide peroxide in a low concentration on nightly basis at home to bleach his or her own teeth. Or the process can be performed more quickly by using hydrogen peroxide at higher concentration in the dental office with additional laser to activate and promote the bleaching process. Both of these can be successful and can produce a very nice esthetic improvememt for the patient. But occasionally I encountered patients who bleach their teeth prior to orthodontic treatment. Is this a problem? Well, tooth bleaching have any effect on the enamel bond strength of our orthodontic brackets. Is there any difference between at home carbamide peroxide bleaching and in office hydrogen peroxide bleaching which regard to shear bond strenth of orthodontic brackets. These are very important clinical questions that can affect any orthodontists. And I’d like to review with you the answers in this following review.	[수정원고]
The title of the article that contain this information is "Bond Strength of Metallic Brackets After Dental Bleaching". This study comes out of university of Goiania in Brazil. It’s co-authored by Virna Patusco and Marcos Lenza from that university. Now, the purpose of this study was to investigate the effects of 10% carbamide peroxide versus 35% hydrogen peroxide bleaching on the shear bond strength of the metallic brackets bonded with light cured composite. The sample for this study consisted of 45 extracted maxillary first premolars that were devided into 3 groups of 15 specimens each. Group 1 was a control group. In group 2 carbamide peroxide bleach was used and in group 3 hydrogen peroxide bleach was used. Let me give you some information about the specific bleaching techniques. With carbamide peroxide the teeth were exposed to bleach 4 hours each day for 14 days. With hydrogen peroxide group, there was 1 exposure for 2 minutes and the laser was used to promote the bleaching technique for about 40 seconds. The teeth were stored for 24 hours in distilled water and then metallic brackets were bonded to the teeth. After an additional 24 hours, the brackets were removed with the testing machine to determine the shear bond strength. OK, I think you should get the idea of the study. What did this researchers find? Does the bleaching technique affect shear bond strength? The answer of that question is yes and no. Let me explain.
First of all, carbamide peroxide at 10% concentration used at home does not interfere with shear bond strength. There was no statistically significant difference between the control group and the group that received the carbamide peroxide bleaching prior to the bonding the brackets. On the other hand, the shear bond strength of those brackets bonded to teeth exposed to hydrogen peroxide were significantly reduced. In fact, the shear bond strength was reduced by more than half. So there we haven't. If the patient has used hydrogen peroxide to bleach their teeth immediately prior to bracket bonding, you could expect to have greater problems maintaining the bond of those brackets to the teeth. Why this hydrogen peroxide interfere with shear bond strength? Actually the high concentration of hydrogen peroxide produce several free radical ions during the bleaching process that remain on the enamel surface and react negatively with the composite bonding material. These free radical ions must disappered from the tooth surface before bonding. Previous research were shown that is imporant dely bracket bonding after bleaching with hydrogen peroxide. Remember in present study the brackets were bonded after 24 hours. So if an orthodontic patient has just completed bleaching with hydrogen peroxide, wait for 1 or 2 weeks before placing the orthodontic brackets. This should enhance the shear bond strength and reduce bracket failure. If you’re interested in reviewing on the affect of dental bleaching on bond strength of metallic brackets, you can find it in the January 2009 issue of Angle Orthodontists.

A Patient with Severe Wear on the Anterior Teeth and Minimal Wear on the Posterior Teeth Spear F. J Am Dent Assoc 2008;30:490-4 June 26, 2009 Dr. Hyun-Jung Lee
[초벌원고] Have you ever had an adult patient presents you with severe wear of maxillary and mandibular anterior teeth and no wear of the posterior teeth? I have seen a number of these patients who are usually referred from prosthodontics and restorative dentistry because they did not have enough space to restore the badly worn maxillary and mandibular incisors. These patients often have severe wear on the lingual of maxillary incisors and the labial of mandibular incisors with no overjet. In most of these cases, I have simply used open loop arch wire to advance the maxillary incisors which creates successful overjet and spaces bewteen these teeth. I, then, distribute these spaces as requested by the restoring dentist and also line the mandibular incisors. The end result is an occlusion that due to the excess of overjet allows adequate space for restorative materials on the labial of the lower incisors and the lingual of the maxillary incisors transferring a very difficult restorative problem to relatively easy one. I have often wondered how these patients could get such severe wear on the maxillary and mandibular incisors but have no wear on the posterior teeth. Being in Iowa, I thought for time that these people might be farmers exposed to a lot of grip while they are working in the fields. However, most of them turned out to be insurance salesmen and business people. Based on my experience with this type of malocclusion, I was attracted to an article by Franck Spear which appeared in October, 2008 Issue of the Journal of Dental association which was titled “A patient with severe wear on the anterior teeth and minimal wear on the posterior teeth”.	[수정원고]
In this article, Dr. Spear who is an excellent restorative dentist and often lectures with Vincet Kokich about combined orthodontic and restorative treatment outlines the different causes of anterior incisor wear with no posterior occlusal wear. The first cause can be an attrition which will present with wear and areas of occlusal contact with the teeth appearing shiny, flat and sharp-edged. Dr. Spears explains tjhat if the patient has the steep condylar eminence, it can eliminate the posterior interferences while allowing wear on the anterior teeth. Acid erosion is another cause of wear on the anterior teeth. In cases of acid erosion, wear is apparent in locations with no occulusion contact such as the facial and lingual surfaces of teeth. Dr. Spear states that the origin of acid wear can be either intrinsic which refers to regurgitated stomach acid or extrinsic which refers to indigested acid. Acid wear can be due to such conditions as volemia, consuming acid beverages, or sucking on acid fruits such as lemons. Greater anterior wear can also be caused by trauma and habits. Dr. Spear notes that it is not uncommon for a restorative dentist to think that is necessary to increase the patients’ vertical dimension in patients who have anterior wear with no posterior wear. However, this is not the case. Because it is the posterior teeth which establish vertical dimension and if they are not worn it is not likely that the patients would need an increase in vertical dimension.
A number of patients with excessive wear on the maxillary anterior teeth have significant overeruption of these teeth and can best be treated with orthodontic intrusion of worn maxillary incisors to allow them to be restored to normal proportions. I thought this was an excellent article with presented the most through analysis of patients who have incisor but no posterior occlusal wear that I have ever read. I would strongly recommend that you read it in its entirely. It appears October, 2008 Issue of the Journal of Dental Association.

Why Do Dentists Refer to Specific Orthodontists? Perspectives of the General Dentist Hall JF, Sohn W, McNamara JA Jr. Angle Orthod 2009;79:5-11 July 3, 2009 Dr. Uhm Gi-Soo
[초벌원고] Are you referring dentists faithful to your practice? In other words, do you referring dentist only refer to your office? Or do they also refer patients to other orthodontists in your community? If they're only referring to your office, why? Is it because of your practice location?, or is it because of the quality of your work?, or perhaps it is because you are playing golf regularly with these referring dentists. You know what constant source of referrals is lifeblood of any orthodontic practice and knowing why dentist refer to you could be some importance especially if this information came from a valid survey that actually questioned a large number of referring dentists. That information can be found in the research article that was published in the January 2009 issue of the Angle orthodontist. I thought this would be an excellent article for us to review.	[수정원고]
The title of the study is " Why do dentists refer to specific orthodontists?". This research comes out of the University of Michigan and it is co-authored by Hall JF, Sohn W, and McNamara JA. The purpose of the study was to test the hypothesis that the quality of the treatment outcomes and the overall patient satisfactions are equal importance in influencing the general dentists when referring a patient to an orthodontist. In order to gather this information, the author established series of 35 questions that were to be distributed to 1000 dentists in the east, north central region of the united states. That included specifically the states of Michigan, Indiana, Illinois, Ohio, and Wisconsin. This questionnaire consisted of five sections. The first section included questions that determined the importance of quality of the orthodontic treatment result in general dentist referral decision. The second section of the survey covered referral criteria other than the quality of orthodontic treatment. The third section consisted of questions related to quality of the occlusion and how important specific aspects of the occlusion were in the decision to refer patients. The forth section included questions about the final orthodontic result other than patients occlusion. And finally the last section included questions about the background of the responded. Of course, for any survey the important aspect is the response rate, and the response rate for this study was 36 %. That is not bad and it did provide the researcher with over 350 questionnaires from which they could drive their data, so the power for the data was quite good. OK, what did the researchers find? Let's take these questions and sections on other time. First of all, what was more important, treatment outcome? or patient satisfaction?, when a general dentist is referring a patient to specific orthodontist. This was interesting. Over 75% of the responding general dentists answered that the quality of the orthodontic outcome was of equal importance to the patients' overall satisfaction with their specific orthodontic experience. When referring dentist were asked to rank most important aspect of orthodontic treatment, they included most often the quality of previous treatment results from that specific orthodontists. In addition the responding dentist replied that the level of communication between orthodontists and general dentists was an important factor. How about specific functional aspect of occlusion? More than 50 % of the responding dentist believe that canine guidance during mandibular excursion, Cl I canine and absence of balancing interferences were strongly important. Finally what other factors were deem to important by general dentist? Nearly 50 % of the responding general dentist regarded the patients' post treatment profile as an important factor in selecting an orthodontist for referral.
So what is the bottom line? It seems that your referring dentists are selecting you as the referral source because of how you treat the patient personally and how well you finish the orthodontic treatment. The occlusion and functional result as well as patients satisfaction are equally important in the mind of referring dentist. You know this information helps us to evaluate why we spend so much time finishing the occlusion properly and why we try to make the orthodontic experience as pleasurable for our patients as possible. If you would like to review this article, you will find it in the January 2009 issue of the Angle orthodontist.

Water and Saliva Contamination Effect on Shear Bond Strength of Brackets Bonded with A Moisture-Tolerant Light-Cure system Scott P, Sherriff M, et al. Eur J Orthod 2008;30:227-32 September 11, 2009 Dr. Hyun-ran Jeon
[초벌원고] How do you combat moisture contamination during bracket bonding? Although this is not a big problem when placing brackets in the anterior region especially in the maxillary arch, moisture contamination can be a big problem when bonding brackets in the mandibular arch especially in the posterior part of the mouth. Some practitioners prefer to use resin-modified glassionomer cement in these areas since these materials are hydrophilic and moisture contamination is simply not an issue. But the shear bond strength of resin-modified glassionomer cement is slightly less than that of light-cured composite. But today there are newer materials that can be used if the practitioner prefers light-cured composite.	[수정원고]
This new materials are moisture-tolerant. Now there are two types. These are produced by Unitek. One of them is a primer which is moisture-insensitive and the other is a light-cured bonding material that is moisture tolerant. But do they work? That question was addressed in the study published in the January 2009 issue of the Angle Orthodontists. Since many of our subscribers prefer to use light-cured composite, I thought you would be interested in hearing this review. The title of article is “Water and saliva contamination effect on shear bond strength of brackets bonded with the moisture tolerant light cure system”. This study comes out of the University of Murcia in Spain. It’s co-authored by Dr. Vincente and three other research colleagues from that institution. Now, the purpose of this study was to evaluate the effects on bond strength when using the new moisture-tolerant systems compared to the traditional light-cured bonding techniques under both dry and moist conditions. In order to make these comparisons, the authors gathered 240 bovine mandibular incisors. These were then divided into 12 groups of 20 teeth each. Basically the authors were planning to test four different bonding techniques under three separate conditions- dry, water contamination, and saliva contamination. Now I don’t want to confuse you but let me explain what these different techniques entailed. Two different primer systems were used. One was a self-etching primer, and the other was a moisture-insensitive primer. The moisture-insensitive primer is used after phosphoric acid etching. Obviously, phosphoric acid is not needed with the self-etching primer. Then two different light-cured composites were used. One was Trans Bond XT, which is very common in many research studies. The other composite was Trans Bond Plus. This is the new moisture-tolerant light-cured composite. So both methods of priming the teeth were combined with both methods of using the composites. And for each, they were subjected to either a dry surface, a water contaminated surface, or saliva contamination. After bonding of the brackets that were restored in water for 24 hours, and then a testing machine was used to remove the brackets and recall the shear bond strength. Okay, so much for methodology. What did these authors find? I’d like to give you the results as succinctly as possible so that you remember the take-home messages. First message: the new moisture-tolerant light-cured composite called Trans Bond Plus, showed excellent shear bond strength with both the self-etching primer and the moisture-insensitive primer. And this shear bond strength did not change significantly in either dry or wet conditions. That’s good news. Second message: if you use the self-etching primer with the traditional Trans Bond XT, the shear bond strength under wet conditions is similar to that seen with the moisture-tolerant composite. That’s also good news. Message number three: when and if you use the moisture-insensitive primer with Trans Bond XT, the shear bond strength is reduced significantly under wet conditions. So there you have it. If you want to enhance shear bond strength under moist conditions, definitely use either a self-etching primer or the moisture-insensitive primer with the new moisture-tolerant bonding material, Trans Bond Plus. This produced the highest shear bond strength. On the other hand, if you are committed to using the traditional Trans Bond XT, then remember to use the self-etching primer and not the moisture-insensitive primer when you are bonding in wet conditions.
If you’d like to review this very involved study but interesting on the effects of moisture contamination on shear bond strength, you can find it in the January 2009 issue of the Angle Orthodontists.

Pain During Tooth Alignment: Self-Ligating vs Conventional Brackets Fleming PS, DiBiase AT, et al. Angle Orthod 2009;79:46-50 September 18, 2009 Dr. Da-Nal Moon
[초벌원고] Have you switched to self-ligating brackets yet? Many orthodontists now use self-ligating brackets routinely. Although there are several reasons that clinicians use self-ligating brackets, one common that’s often heard is that patients have less discomfort with self-ligating brackets compared to conventional brackets, especially during initial alignment of the teeth. But it’s not really true. A study published in the January 2009 issue of the Angle Orthodontists looked at that research question. I think you will appreciate learning the answer to this question.	[수정원고]
The title of the article is “Pain experience during initial alignment with a self-ligating and a conventional fixed orthodontic appliance system”. This randomized controlled clinical trial was co-authored by Dr. Fleming and DiBiase from the orthodontic department at Royal London Hospital in England. The purpose of this study was to test whether any significant difference in pain and discomfort experience could be found during initial alignment with a self-ligating bracket system compared to a conventional, preadjusted, edge-wise bracket system. In addition, the second purpose was to determine if placement of a rectangular wire into the bracket slot was more painful with one or the other of these brackets. In order to gather this information, the authors randomly allocated the group of 46 patients to either a conventional bracket system or a self-ligating bracket system. The sample ranged in age from 11 to 21 years. Brackets were placed on all teeth from first molar to first molar in both arches. After bracket placement, 0.016 nickel-titanium archwire was placed on the brackets. Then the subjects were given response sheets that ask them to rate their tooth pain using a visual analog scale over a period of one week. The assessments were made at 4 hours, 24 hours, 72 hours, and finally at seven days. In addition at some later time during the treatment when rectangular wires were introduced into each of these patients, the subjects were again asked if this was painful using the visual analog scale. As you see the authors could compare the self-ligating and the conventional brackets using this test.
What did these authors find? Question number one: Which of the appliance systems produced the least pain during the first week of an initial alignment? And the answer to that question is “No difference”. That’s correct. The pain response from the subject showed that there was no statistically significant difference in the interpretation of pain from the group that had the conventional bracket or the self-ligating bracket. Question number two: Which sample had the greatest discomfort when an edgewise wire was inserted or removed? The self-ligating bracket produced more painful responses in these subjects. Isn’t that interesting? You know advertisements for self-ligating bracket suggest that pain is reduced during initial alignment and that discontinues throughout treatment. Apparently this might not be true. In this randomized prospective clinical trial, the pain during initial alignment did not differ between conventional and self-ligating brackets. In fact the self-ligating bracket produced greater discomfort when rectangular wires were inserted or removed. So if you are interested in reviewing this study comparing tooth pain with a conventional and a self-ligating bracket, you can find it in the January 2009 issue of the Angle Orthodontists.

Miniscrew Implants: Torsional Strength Increases as Diameter Increases Pithon MM, dos Santos RL, et al. Braz J Oral Sci 2008;7:1563-65 September 25, 2009 Dr. Eun-ji Kim
[초벌원고] It's just before lunch, in your last patient of the morning that scheduled to have miniscrew implant placed between upper right first molar and second premolar to help correct an arch asymmetry. You normally place to a 1.2 mm screw in a interdental locations but as you start putting it in realize the bone is dense and you feel like a half the turn much harder than normal. You worried that the screw might break and so you back it out. How much larger screw do you need to get a significant increase and torsional strength and reduce the possibility of screw breakage? A paper published in April/June 2008 issue of the Brazilian Journal of Oral Sciences gives some insight into this question.	[수정원고]
This study was quite straight forward in done entirely in the laboratory. The purpose was to help find the relationship between screw diameter and torsional strength. A special apparatus was used, that allowed the screw to be twisted to the point of fracture and for this maximum torsional strength to be recorded. The authors tested 3 different diameter screws that were identical in length and composition, so the only vailable was the diameter. The 3 diameter is tested 1.2 mm, 1.4 mm and 1.6 mm. Six samples of each diameter screw were tested to failure.
The result showed the torsional strength increased within increasing diameter. Something I am sure you would've been known without this laboratory test. What surprised me, though, was the amount of strength change with a change of diameter. The 1.2 mm diameter screw failed at about 20 N㎠, still about the torque needed to screw into most normal density bone. Increasing the diameter just two tenths of millimeter to 1.4 mm resulted in a torsional strength that more than doubled. And increasing at another two tenths of millimeter increase the strength another 34 %. What I learn from this is that when dealing with a small diameter screws just a small increasing diameter can result large increasing strength. So, if you think back your patient whom at fell like the 1.2 mm screw was marginly strong enough, it would make sense to increase 1.4 or 1.6 mm screw. That way you can get a huge increased torsional strength with only a small increased diameter. You can be confident that the screw would still easily fit between the root and yet be strong enough to avoid fracture. If you would like more information about the relationship between miniscrew diameter and torsional screw strength, refer to the article by piece on in colleagues in the Brazilian Journal of Oral Sciences.

Effectiveness of Pit and Fissure Sealants in Reducin White Spot Lesions during Orthodontic Treatment Benham AW, Campbell PM, Buschang PH. Angle Orthod 2009;79:337-344 October 9, 2009 Dr. Hoon Noh
[초벌원고] How do you prevent decalcification around brackets during orthodontic treatment? Although most patients tend to clean their teeth well, every orthodontist has a few patient were simply lazy and there are plaque accumulated around the brackets. No matter how much we try to encourage them to clean their teeth, there simply not going to perform good oral hygiene. Unfortunately, these patients end up with permanent decalcification around the teeth which can be extreamly unattractive when the appliance is removed. But in recent study published in the march 2009 issue of the Angle Orthodontist, authors showed how simply using in commercially available pit and fissure sealant painted between the gingival margin and the bracket could reduce white spot lesions significantly. I think this is an excellent clinical tip for any orthodontist to be aware of. So I’d like to review that study for you on this issue practical reviews in orthodontics.	[수정원고]
The title of the article is “Effectiveness of Pit and Fissure Sealants in Reducing White Spot Lesions during Orthodontic Treatment”. This study comes out the orthodontic department at Balyor university and it's co-authored by Adam Benham and Phillip Campbell. The purpose of this study was to determine whether a highly filled resin sealant called Ultraseal XT Plus clear sealant could be used for prevention of white spot lesions. Now we know that the typical use for this product is a pit and fissure sealant to reduce occlusal caries in posterior teeth. The reason that this type of sealant is successful is that it is highly filled in their for resistant to mechanical abrasion. What this study want to do is to determined if commercially available product could be used between the bracket and the gingival margin in a group of orthodontic patients and be successful at reducing white spot lesions. These researchers placed the sealants in 60 healthy at recent patients who were undergoing orthodontic treatment at the orthodontic department at Baylor college of dentistry in Dallas. There were 30 male and 30 female subjects in the group. This patients were between 11 and 16 years of age and had brackets placed on all of the teeth. Between 2 weeks and 3 months after the initial bonding, the authors placed the pit and fissure sealant on the teeth in these subjects. Now in order to access effectiveness of the sealant, this material was not placed on all teeth. The authors divided the sample into either right or left halves of the month and alternately placed the sealant on half the teeth, so each subject could be compared to themselves using what’s called at split mouth research design. The placement of the sealant is really rather straightforward. Phosphoric acid gel is placed on the teeth for 15 seconds and then removed and drid. The Ultraseal pit and fissure sealant is then placed between bracket and gingival margin and it is light-cured for 20 seconds. These sealants remained on the teeth for the duration of the experiment which is about 15 to 18 months. At that time the authors compared the amount of decalcification on the sealed teeth versus the non-sealed teeth in all 60 subjects.
OK, I think you get the idea of experiment. What did these researchers find? Question no. 1, did the sealant work? The answer of that question is yes. In the teeth were sealed, 6 areas of decalcification were noted. In those teeth were not sealed over 20 teeth showed decalcification. Therefore the teeth without the sealants has nerely four times greater number of white spot lesions than teeth that had sealants. Question no. 2, where did most of the white spot lesions occur? In this study, 70% of the teeth with white spot lesions were found in the maxillary arch, and only 30% in the mandibular arch. Question no. 3, which teeth suffer the most from white spot lesions? In this study the authors found on the maxillary laterals and canines without sealants showed the highest incidence of white spots. So there we have it. Pit and fissure sealants are effective. This would be such an easy thing to apply in an orthodontic practice. One would not to need to use the sealants on posterior teeth or perhaps even in the mandibular anterior region. If one or two months after orthodontic treatment began at one of the appointments you simply applied the sealants to maxillary six anterior teeth, think of the possible improvement that one could have in reducing white spot lesions, especially in those patients who have poor oral hygiene.
Anyway if you’d like to review the study the documents improvement in reducing white spot lesions using pit and fissure sealants during orthodontics, you can found it in the March 2009 issue of the Angle Orthodontist.

Treatment Effects of Intraoral Appliances with Conventional Anchorage Designs for Non-Compliance Maxillary Molar Distalization. A Literature Review Kinzinger GSM, Eren M, Doedrich PR. Eur J Orthod 2008;30:558-71 October 16, 2009 Dr. Hyun-Jung Lee
[초벌원고] Assume that you have made a clinical decision that, because of increasing challenges with headgear coopearation in your patients are required Class II correction, you are going to try some molar distalizing appliance that would not require the same degree of compliance. How would you make an intelligent decision which appliance to use? You could use PubMed to find treatment outcome articles for each appliance you are considering. Or you could look for a systematic reivew article like the one published in the December 2008 issue of the European Journal of Orthodontics in which the authors do much of the work for you. The article in the European journal is called ‘Treatment effect of intraoral appliances with conventional anchorage designs for non-compliance maxillary molar distalization. A literature review’.	[수정원고]
Another advantage of this type of systematic review is that the authors put the data in the same form from all the included studies, so it is easier to compare apples to apples. In this case, the authors did a Medline search and initially found 85 papers worthy of further review. After applying their inclusion criteria, there were 22 studies that were ultimately included. The appliances that were representative in this group included the standard pendulum appliance and some modifications, the Jones Jig, the distal jet, some other magnet and coil spring distalizers, and the first class appliance.
The data from each study was reviewed and recalculated, if needed, to provide a standard report of molar distal movement, molar tipping, anchorage loss, vertical effects, and overall molar movement as a percentage of total movement.
The result showed that the standard pendulum appliance consistently showed the most distal molar movement, about 4-6 mm, compared to the 2-3 mm measured for most other appliances. The Chaques said the pendulum also showed the most distal molar tipping, 10-15 degrees. Although the molar movement varied quite a bit among the appliances, the amout of anterior anchorage loss was consistently 1-2 mm for all the appliances. This result add in the pendulum appliance, having about 70 percent of the total measured movement being the molars going back while the others tended to be 50-60 percent range.
Overall, the vertical effects on both of the molars and the anchorage teeth were very small, probably not of clinical significance in most cases. So when I look at this combined data, I see that all these appliances tend to work to some degree. But the pendulum appliance seems to give more molar movement for the same amout of anchorage loss. Obviously there are other factors to consider in choosing an appliance, such as cost, comfort, reliability, and ease of use. However, if you are making the decision based on outcome measurements alone, it would seem that the pendulum would be a good choice.
If you have a interest in this subject, I think you would enjoy looking at the comparative tables in this review article. Each table displays results of the 22 studies in the consistent manner, making for easy comparison. And although the article is somewhat lengthy, it is mostly because of these many summary tables. Remember it is published in the December 2008 issue of the European Journal of Orthodontics.

Stability in Dental Changes in RME and SARME : A 2-Year Follow-Up Sokucu O, Kosger HH, et al. Angle Orthod 2009;79:207-13 October 23, 2009 Dr. Mi-Young Kim
[초벌원고] How would you answer this patient’s question? You are having a treatment consultation with a 35 year old adult female. She has a Class I mildly crowded malocclusion with the bilateral posterior crossbite due to palatal constriction. She definitely needs palatal expansion. But at her age you recommend that she should have surgically assisted rapid maxillary expansion. When you propose the surgical correction the patient agrees to the treatment, but then asks you an interesting question. She wonders if she would have the treatment as an adolescent and have conventional maxillary expansion, would there be a difference in the stability of the treatment result long term? How would you answer that question? Is there any difference in the long term outcome when posterior maxillary dental crossbites are corrected in a teenager as opposed to in an adult?	[수정원고]
That question was addressed in the study that was published in the March 2009 issue of the Angle Orthodontist. I thought this would be an excellent article for us to review. The title of this article is “Stability in Dental Changes in Rapid Maxillary Expansion and Surgically Assisted Rapid Maxillary Expansion Two Years after Treatment.” The study comes out of Sivas Turkey and was co-authored by Dr Sokucu and three other researchers associates from the department of orthodontics and maxillofacial surgery at Cumhuriyet University.
The purpose of this study was to compare the detailed dental changes seen with rapid maxillary expansion and surgically assisted rapid maxillary expansion following orthodontic treatment as well as the stability after two years. The sample for this study consisted of two groups of patients. The first group included 14 subjects with the mean age of about 12 years. The second group consisted of 13 subjects with an average age of around 19 years. Both groups had maxillary posterior constriction and required palatal expansion. In both groups a modified bonded acrylic rapid maxillary expansion appliance was used for the expansion process. It was cemented posterior teeth using glass ionomer cement. Now in both groups the appliance was activated one quadrant turn once a day during the expansion period until the desired opening had been achieved. One week after completion of the expansion the bonded appliance was removed and was used as a removable retention appliance for the next six months. Then a transpalatal arch was used during fixed orthodontic appliance therapy and a maxillary Hawley was used for one year during the retention period. The major difference between this two samples was that in the older group of individuals surgically assisted expansion was used. This consisted of standard horizontal osteotomy from the pyriform aperture to the pterygomaxillay junction bilaterally. In order to determine the changes, dental casts were taken before treatment, at the end of orthodontic treatment and after two years. Intermolar and interpremolar width were measured and compared.
Okay, what do you think these researchers found? Remember the key question. Was there a difference in stability when expansion was performed conventionally versus surgically. And the answer of that question is no. In both groups a significant amount of expansion occurred. When the authors compared the two groups there was no statistically significant difference. The key was in the comparison of the groups after two years. The authors also found that two years post-treatment there were no statistically significant differences in the amount of changes occurred in those subjects that had conventional expansion compared to those had surgically assisted rapid maxillary expansion. So now you have an answer for your patient. When your patient asks you whether or not surgically assisted rapid maxillary expansion will be less stable than conventional expansion performed in a child? Now you know there is no statistically significant difference at least up to two years after orthodontic treatment.
If you’d like to review the study that documents the changes in stability of conventional versus surgically assisted rapid maxillary expansion, you can find it in the March 2009 issue of the Angle Orthodontist.

Stability of Mini-Screws Invading the Dental Roots and Their Impact on the Paradental Tissue in Beagles Kang YG, Kim JY, Lee YJ, Chung KR, Park YG. Angle Orthod 2009;79:248-55 October 30, 2009 Dr. Gi-Soo Uhm
[초벌원고] Do you use miniscrews or temporary anchorage devices to assist you in your orthodontic treatment? Many orthodontists have now utilized miniscrews to assist in difficult types of tooth movement. In fact, many orthodontists are placing their own miniscrews. So let's say you are one of those individuals. You are at the chair. You are placing a miniscrew in the mandibular posterior region between the first molar and the second molar. Unfortunately, you misjudged the angulation of the handpiece and the miniscrew contacts the mesial root of the mandibular first molar. Now what would you do? Should you take it out and try it again? Have you permanently damaged the root of that tooth? Will that miniscrew have higher failure rate because it's touching the root of the tooth? All of those questions are important in the mind of the clinician who has just performed this procedure and now the patient has a miniscrew touching the root.	[수정원고]
Let me give you the answers to all of these questions based upon the study that was published in the March 2009 issue of the Angle Orthodontists. The title of this paper is “Stability of miniscrews invading the dental roots and their impact on the periodontal tissues”. This study comes out of the department of Orthodontics at Kyunghee University in Seoul, Korea. The lead author is Dr. Kang and he was assisted by four other research colleagues from that same institution. The purpose of this study was to determine what happens when a miniscrew contacts the root of a permanent tooth. This study was performed in an experimental animals so that the researchers could histologically evaluate the sites and determine how the root healed after the injury from the miniscrew. So the authors intentionally placed miniscrews that contacted the root of the permanent teeth in these experimental animals. In addition, they placed miniscrews in the alveolar region away from the roots of the teeth as controls. After the miniscrews have been placed, half of them were loaded immediately and the other half were allowed to remain unloaded for eight weeks. After eight weeks the success rates of miniscrews were determined and the histology was evaluated.
What did these authors find? Question number one: when a miniscrew was placed next to the root, what's the percentage of failure of that miniscrew? In this study, the failure rate was 80%. So if you've placed a miniscrew very near the root, chances of failure are high. What should you do? Remove the screw and place it in a different position. Would that help? In this study the failure rate of those screws placed in the alveolus away from the tooth roots was only 8%. Question: did immediate loading of the miniscrew affect stability? And the answer of that question is No. The failure rate for miniscrews that were unloaded or loaded immediately was nearly the same. The authors believed that this information suggests that immediate loading had no negative effect on miniscrew success. So what valuable information can be cleaned from this study? Well first of all, if the miniscrews are placed in good solid alveolar bone, the success rate should be about 92%. Second, immediate force or immediate loading does not appear to have any adverse effect on those miniscrews placed in alveolar bone. If a miniscrew has placed near the root, the orthodontist should remove that screw. Chance of failure in these situations is 80%. Last question: what happens to the root surface when the miniscrew was placed to near the root? Based upon the histology in this study, the authors found that cementoblasts or repaired root surface and none of these roots in the study had periodontal or pulpal involvement secondary to the injury by the miniscrew. That's the good news.
So if you'd like to read this study that documents the effect of miniscrews placed near roots of teeth in experimental animals, you can find it in the March 2009 issue of the Angle Orthodontists.

Changes in the Duration of the Chewing Cycle in Patients with Skeletal Class Ⅲ with and without Asymmetry Before and After Orthognathic Surgery Ueki K, Marukawa K, et al. J Oral Maxillofac Surg 2009;67:67-72 November 13, 2009 Dr. Kyung-Min Lee
[초벌원고] What happens to an individual chewing pattern after jaw surgery? Actually let me be a bit more specific with my question. If a person has skeletal asymmetry and he had a certain chewing pattern prior to jaw surgery because of that skeletal asymmetry, will that chewing pattern change once the jaw asymmetry has been corrected with the jaw surgery? One would assume that if the teeth are in more symmetric relationship because the jaw asymmetry has been corrected then the chewing pattern should also change. But is that really true? That question was addressed in a study that was published in January 2009 issue of the Journal of Oral and Maxillofacial Surgery. Since most orthodontists at least a few times in their careers are required to treat patients with mandibular asymmetry. I thought that this would be a useful review for us to explore in this issue of practical reviews in orthodontics.	[수정원고]
The title of this study is “Changes in the Duration of the Chewing Cycle in Patients with Skeletal Class Ⅲ Malocclusions with and without Asymmetry Before and After Orthognathic Surgery.” This study comes out the department of oral and maxillofacial surgery at Kanazawa University in Japan. The primary author is Koichiro Ueki and his joint by five other research colleagues from that same institution. The purpose of this research project was to examine the chewing cycle after mandibular ramus osteotomy in patients with Class Ⅲ malocclusions with and without mandibular asymmetry. In addition the authors wanted to compare two different surgical techniques, the intraoral vertical ramus osteotomy and the sagittal split ramus osteotomy. Now before getting into the project, let me explain what is meant by chewing cycle. The chewing cycle is defined as a series of mandibular movements consisting of the opening phase, the closing phase, and the occluding phase when the teeth actually come together. This chewing rhythm shows high regularity and is easily repeated in most individuals. It’s simply their chewing patterns. The question is what happens to this chewing pattern when its jaw asymmetry is corrected. In order to answer that question, the authors gathered 34 subjects with an average age of about 23 years who had Class Ⅲ malocclusions. About half the group had skeletal asymmetry and the other half did not. The sample was divided into two groups. One group had inverted ramus osteotomy to correct their malocclusion. The other had sagittal split ramus osteotomy. Prior to jaw surgery, each of the subjects had their chewing cycle recorded. This was done on a special apparatus called sirognathographic analyzing system. Then the chewing cycle was recorded after all orthodontic appliances removed which was well after the jaw surgery had been completed. What did these authors find? Did the chewing pattern change with the alteration in a skeleton especially in those subjects with skeletal asymmetry? And the answer of that question is no. Isn’t this interesting? The authors found no significant differences in the duration of the chewing cycle between preoperative and postoperative values in both the sagittal split ramus osteotomy group and the intraoral vertical ramus osteotomy group. But what about differences between the asymmetry group and the symmetry group? Same answer. No differences were noted in the chewing cycle between the symmetry and the asymmetry groups before and after surgery. So, in conclusion this study suggests that surgical orthodontic treatment does not significantly change the duration of the chewing cycle whether the patient has symmetric or asymmetric alteration during orthognathic surgery.
If you are interested in reading this study, you can find it in the January 2009 issue of the Journal of Oral and Maxillofacial Surgery.

Effects of First Molar Extraction on Third Molar Angulation and Eruption Space Bayram M, Ozer M, Arici S. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009;107:e14-e20 November 20, 2009 Dr. Da-Nal Moon
[초벌원고] Here is the situation. You’re considering extraction of all four first molars because your patient has moderate crowding and poorly adapted stainless crowns on the first molars. The parents relate that the child had deep caries on the molars which was not initially detected and required full coverage restorations. At present, when you look at the panoramic radiograph, the third molars are all present. But there appears to be inadequate space for their eruption. Will remove of the first molars and orthodontic space closure result in enough additional space posteriorly to allow predictable third molar eruption? I’ll share some information with you from the February, 2009, Tripleo that will help answer this question.	[수정원고]
The study is titled “Effects of first molar extraction on third molar angulation and eruption space”. The study was a restrospective clinical study that compared two groups of patients. The first group was 21 adolescents that had four first molars extracted followed by orthodontic treatment. The second group was 20 adolescents treated non-extraction. The before and after panoramic radiographs were used to measure the space available for the third molars and the angulation of these teeth. 31 of the subjects voluntarily returned at the time of third molar eruption so that the eruption status of these teeth could be classified. The authors found that in the non-extraction group, the increase in space for the third molars during treatment and observation was small, generally less than a couple of millimeters. In the first molar extraction group, the increase in space was much larger more like 8 to 10 millimeters. In addition, the angulation of the upper third molars got much better in the extraction group, although this angulation improvement wasn’t apparent in the lower arch. When examined clinically, the first molar extraction group demonstrated complete eruption of nearly all the upper third molars and more than 80% of the lower’s with the remaining teeth judged as being partially erupted not impacted. The non-extraction group differed dramatically in third molar eruption with more than half the third molars classified as impacted. So we get back to our original clinical question of “Will remove of the first molars and orthodontic space closure result in enough additional space posteriorly to allow predictable third molar eruption?”. The answer from this study is definite “yes”. In a case where extraction of first molar may be indicated, chances are very high that the third molars will completely erupt.
The details of the study are available in the February, 2009 issue of the journal oral surgery, oral medicine, oral pathology, oral radiology, and odontology.

Impaction and Retention of Second Molars: Diagnosis, Treatment and Outcome: A Retrospective Follow-Up Study Magnusson C, Kjellberg H. Angle Orthod 2009;79:422-7 November 27, 2009 Dr. Sang-Rok Kim
[초벌원고] How do you manage impacted maxillary or mandibular second molars? These are often challenging. Actually there are differences in the type of second molar impaction that can exist. In some situations the second molar is blocked from erupting by either the first molar or the third molar or because of its angulation in the alveolars. A second situation can exist where the second molar can be impacted but nothing is blocking its path of eruption. In the third situation course one of second molar begins to erupt comes through to gingiva but then stops erupting. All of these are regarded as second molar impactions. But they have very in degrees of treatment success. Because this can be a challenging situation for connections, I’d like to review an article for you that retrospectively evaluates over 125 impacted second molars that will retreated with the variety of methods.	[수정원고]
The title of this articles is impaction and retention of second molars. Diagnosis, treatment and outcome. This study is co-authored by Catherine Magnerson in Hightreen Killberd from the department of Orthodontics at Gothenburg University in sweden. The purpose of their study was to describe both the outcome of treatment in patients with the second molar impaction and to describe the outcome of no-treatment. These authors searched the records of the dental school in Gothenburg and identified the total of 135 impacted second molars in nearly 90 patients. They divided these into groups. About 100 of these impactions were regarded as true impactions were something was blocking the second molar from erupting. About 25 of these were second molars that had failed to erupt but there was nothing blocking their path of eruption. Finally there about five teeth in which the second molar had partially erupted but then had stopped erupting. Once they classified these individuals into various groups, the identified the method of treatment and weather or not it was successful for each of these patients. So what did they find? First of all, 20% of the second molars were left untreated. Of the teeth that were left untreated, about 40% erupted into good inclusion. Now that’s interesting. As orthodontist we may often get a bit over anxious and what to do something to in a impacted second molar that actually may not be necessary. As the study showed a little less then half of those had received no-treatment and actually corrected themselves. Now of those subjects who had true impactions compared to those that were simply unerupted, what was the percentage of treatment versus no-treatment? Actually for those subjects who had true impactions about 90% received uncovering and orthodontic treatment. Those that were simply unerupted were left untreated about half the time. Here’s an interesting finding. Of those impacted second molars they were actually treated only about 40% achieved successful results. This is discouraging. In some of these cases that clinician simply could not upright or erupt the second molar into a good position. The authors identified that most successful treatment was surgical exposure which was successful about 70% of the time. In a few of these subjects the impacted second molar was extracted to allow the third molar to erupt into a better position. But when the authors evaluated the outcome of that treatment plan they found success in only 10% of the cases. So in conclusion, what have these authors shown us? First of all surgical exposure of the second molar with or without extraction of the third molar seems to be the most successful treatment in both jobs. Second, the retained permanent second molars that had begun eruption and then failed to erupt seemed to be the most difficult to treat. These partially retained molars show less stable results then those that were totally impacted. And finally if one assumes that extracting the second molar at allowing the third molar to move forward is a reasonable treatment plan?
This study sadly shows that that was only successful in about 10% of the cases. So the next time you require to treat a patient with an impacted or retain maxillary or mandibular second molar? You may want to refer to this article. You can find it in the May 2009 issue of the Angle Orthodontics.

Are Teeth Close to the Cleft More Susceptible to Periodontal Disease? de Almeida ALPF, Gonzalez MKS, et al. Cleft Palate Craniofac J 2009;46:161-165 December 4, 2009 Dr. Hyun-ran Jeon
[초벌원고] If you see a patient with the cleft lip and palate in your orthodontic office, do you need to be concerned about an increased risk of periodontal disease in the area of the cleft? Do you need to be worried that even though the rest of the mouth seems healthy, the cleft area might be more susceptible? It would be ideal to answer this question with a longitudinal study that looked at the periodontal status of a group of cleft patients over a long time period. But to get a more rapid answer, a cross-sectional study of a representative group of cleft patients of various ages could be conducted. This is the approach taken by a team of researchers in Brazil trying to determine whether teeth close to the cleft are risk of periodontal disease. The actual title of their publication is "Are teeth close to the cleft more susceptible to periodontal disease?" And it is published in March 2009 issue of the cleft palate craniofacial journal.	[수정원고]
Here is how the study was done. All cleft lip and palate patients that presented to a cleft clinic in Brazil were eligible for consideration. There were several reasons for exclusion including orthodontic appliances, partial dentures, smoking, and other congenital disorders. The enrollment continued until 400 subjects had agreed to participate. All subjects were examined by calibrated examiners and recordings were made on all teeth of pocket depth, attachment level, gingival bleeding, and plaque. The type of cleft was recorded as well as the age and gender of each subject. Correlations were used to look for associations between the area of the cleft and measures of periodontal disease.
So do you think that the area of the cleft was more susceptible to periodontal disease than other areas of the mouth? Well, at least in this cross-sectional study, the investigators found that there was no increased prevalence of periodontal disease in the cleft area. There was a very high level of plaque and gingival bleeding both more than 90%, but this was not different in the cleft area than the rest of the mouth. The only positive correlation that was found was with age, there was more periodontal disease in the older subjects. The results of the study would indicate that when you treat a cleft patient, you should expect the same expression of the periodontal disease that you would in a non-cleft patient. The area of the cleft does not appear to be more susceptible to periodontal disease than the other parts of the mouth. This of course does not mean periodontal disease does not occur in the cleft area, only that it seems no more likely to appear there than anywhere else.
I would still rather have some longitudinal data that help answer this question about periodontal disease and cleft areas, but until that study is done we will rely on the data from this study indicating no relationship between the area of the cleft and periodontal disease. This article from Brazil is available for study in the March 2009 issue of the cleft palate craniofacial journal.

“Surgery First” Skeletal Class Ⅲ Correction Using the Skeletal Anchorage System. Nagasaka H, Sugawara J, et al. J Clin Orthod 2009;43:97-105 December 11, 2009 Dr. Da-Nal Moon
[초벌원고] Think about the consultation you’re having with a seventeen year-old young lady and her mother. Nicole is the patient. And she has class III skeletal malocclusion that were required orthognathic surgery to correct. In the course of discussion, you take care to explain that before surgery, her lower incisors will become more protrusive as you decompensate. So she will actually look worse before she looks better. Nicole is not pleased to hear this and says “Isn’t there another way?”. Well, if you read February 2009 issue of the JCO, you might suggest there is another way.	[수정원고]
The article is called “surgery first, skeletal class III correction using the skeletal anchorage system”. And it describes technique for doing surgery as the first step in a surgical orthodontic class III correction. Here is the underlying idea. Because it is so difficult in many cases to decompensate the class III incisors, because the lower incisors must be pushed out into the lip, why not do this surgery first create class II anterior relationship and then work with the soft tissue pressures to procline the lower incisors and retract the uppers. But this will only work if you can be certain you can obtain predicted tooth movement. The authors do this by placing many plates in the upper arch to give skeletal anchorage for final tooth position.
This technique is demonstrated by well-documented case report on a seventeen year-old female. The surgery was done at the beginning by predicting the desired final tooth position and creating a surgical splint to place the mandible appropriately. At the time of surgery, many plates were placed in the upper arch and the upper second molars were removed to facilitate distal movement of the upper dentition. The end result was an excellent correction of the malocclusion with the fully decompensated dentition and the total treatment time of only twelve months. The twelve months normally would’ve been a minimal pre-surgical orthodontic time for such case. The author states several advantages of this approach, patient’s satisfaction since they get their skeletal changes immediately, no need to fight soft tissue for decompensation, rapid treatment time that may benefit from the rapid phenomenon and full incisor decompensation that normally can be a quite challenge. There are also drawbacks. Can you predict the needed final skeletal position with enough accuracy to allow for an excellent result? Can you really accomplish the orthodontic movement to finish the case? In addition, I think it may be more difficult to plan if there are problems in the transverse or vertical planar spaces as well. I believe that as long as the original malocclusion allows proper skeletal positioning, this may be a reasonable approach to try. Planning for skeletal anchorage is important so that you have an absolute reference for your final tooth positioning.
If you’re interested in more information about this alternative of approach to class III surgical treatment, take a look at the clinical records and additional illustrations included in this case report, find in the journal of clinical orthodontics. If nothing else will help you, realize that we are often restrain by your own concept of treatment. And maybe you could offer your patient, Nicole another way.

Multidiciplinary treatment of a mutilated dentition Bilodeau JE. Am J Orthod Dentofacial Orthop 2009;135:S96-S1021 Decemher 18, 2009 Dr. Eun-ji Kim
[초벌원고] During my years of practice, I have found two of the most difficult problem to treat, a mutilated dentitions and posterior open bite. I was therefore attracted to an article, titled mutidisciplinary treatment of the mutilated dentition by John Bilodeau which appeared in the April 2009 supplement 1 issue of the American Journal of Orthodontics Dentofacial Orthopedics.	[수정원고]
In this article, Dr. Bilodeau was in the private practice of orthodontist's Springfield of Virginia, described treatment of 37 year old black woman who was missing the maxillary right and left lateral incisors and the maxillay left canine and both premolars. She was also missing the mandibular right first molar. All four third molars were present. The patient had an almost one hundred percent overbite, excessive overjet, severe protrusion both of maxillary and mandibular incisors and the anterior facial overclosure with redundancy of the lips. When I look at the initial records for this patient, the first thing that came to mind was her treatment would probably require the use of TADs and orthognathic surgery. As I read the case report, I was impressed by the fact that neither TADS nor orthognathic surgery was used to treat this patient who demonstrated an excellent profile and dental improvement.
Dr. Bilodeau treated this patient by extracting the mandibular left second premolar to allows space to retract mandibular anterior teeth and resolve the severe dental protrusion. On the right side, the space for the missing first molar was used to provide space for retraction of the anterior teeth. In the maxillary arch, the two maxillary central incisors were retracted until it came into contact with the right maxillary canine which substituded as a lateral incisor. In the maxillary left quadrant, implants were used to replace maxillay left lateral incisor, canine and first premolar. In mandibular arch the anchorage was prepared for retracting the mandibular anterior teeth by using a J hook high pull head gear attached to solder hooks gingivaly at the contact points between the mandibular canines and lateral incisors. The maxillary anterior teeth were retracted with the support of Class II elastics. I was very impressed not only with the excellent results achieved in this case but by the fact that there were achieved by not using either TADs or the orthognathic surgery. The excellent results were achieved in this case partly due to the fact that the patient willing to wear head gear to support anchorage. It is easy to get into the have assuming that adult patients will not wear headgear. However, patient will present with a very uncitely mutilated dentition are often motivated enough to wear headgear.
In previous issues of practical reviews of orthodontics, I presented a number of case reports by Dr. Bilodeau and I congratulate him for again achieving an excellent results for very difficult treatment problem. If you are planing to start treatment for mutilated dentition or if you are simply interested in learning more about the possibility of treating this type of patient, I would suggest that you read this article in its entity. It appears in the April 2009 supplement 1 issue of the American Journal of Orthodontics and Dentofacial Orthopedics.