[초벌원고]

What does the term buccal corridors means to you? I believe that most orthodontists know that the buccal corridor is defined as the space between the facial surfaces of the maxillary posterior teeth and the corners of the lips when the patient is smiling. Second question, do you intentionally alter the buccal corridors during your orthodontic treatment of adult subjects? In order to accomplish this type of change, one would have to alter the maxillary arch form. If you intentionally constrict or expand the maxillary arch form to either increase or decrease the size of the buccal corridors, would that influence the esthetics of smile? That question was addressed in the study published in the July, 2009 issue of the Angle orthodontist.

[수정원고]

Since esthetics is such a major component of adult orthodontic treatment, I thought that this article would be an excellent one for us to review on this months’ practical reviews in orthodontics. The title of this article is “Effects of Buccal Corridors on Smile Esthetics”. This study was co-authored by Hideki Ioi and two other researchers from the departments of orthodont ics at Kyushu university in Japan and Jacksonville university in Florida. The purpose of this study was to determine the amount of buccal corridors has any influence on smile evaluations between orthodontists and dental students. In order to accomplish this subjective, the authors constructed a series of images that altered the size of the buccal corridors. These alterations were performed using a computer which gradually increased the size of the buccal corridors from 0 up to 25%. One female subject was used as the example and these alterationsions  in the buccal corridors were made to her smiling photograph. 30 orthodontists and 50 japanese dental students were asked to rate the various smiles from least attractive to most attractive using a visual analogue scale. Both female and male panelist were used among the orthodontists and dental students to determine if any gender differences existed.

Ok, I think you get the idea of the experiment. What do these authors find? Question no. 1, were there any gender differences? When the authors compared the responses of orthodontists and dental students combined, they found no differences in responses between males and females to the variations in size of buccal corridors. Question no. 2, did the orthodontists and dental students respond similarly? The answer to that question is in general yes. In both groups, when the buccal corridors increased above 10% up to 20%, there was a gradual decrease in the esthetic readings with the lowest reading or least attractive at 25%. Question no. 3, what was regarded as the most attractive smile? Both groups responded similarly and found that the ideal amount of buccal corridor was between 5% and 10%. In other words, neither of the groups preferred a 0% buccal corridor. So what is this study shown us? Basically, the study is shown that broader arch forms which shows smaller amounts of buccal corridor are preferred by orthodontists and general dentists. Unfortunately, this means that in order to produce the type of esthatic effect, the maxillary arch form would need to be broadened in many patients. But from past studies, we know that arch form is difficult to change long term. So although the study confirms that wider arch forms with smaller buccal corridors are preferred, perhaps this ideal is un-achievable with long term stability in some patients.

If you like to review this article, you can find it in the July, 2009 issue of the Angle orthodontist.

Early Treatment for Class II Division 1 Malocclusion

with the Twin-block Appliance:

A Multi-Center, Randomized, Controlled Trial

O'Brien K, Wright J, et al

Am J Orthod Dentofacial Orthop 2009;135:573-9

March 12, 2010

Dr. Hyun-Ran Jeon

 [초벌원고]

Recent studies comparing the effectiveness of 1-phase versus 2-phase treatment for patients with Class II malocclusions have concluded that in general there is no benefit to having 2-phase treatment. Because two of the largest control studies were done at the University of North Carolina and the University of Florida, some clinicians have questioned results of these studies because they were performed on patients who were treated in the dental school environment.

 [수정원고]

In the May, 2009 issue of the American Journal of Orthodontics and Dentofacial Orthopedics, a study was reported which evaluated the effectiveness of 1-phase versus 2-phase treatment with the Twin-block appliance. This study was titled “Early treatment for Class II Division 1 malocclusion with the Twin-block appliance: A multi-center, randomized, controlled trial” by Kevin O’Brien, et al. It was a multi-center, randomized, controlled trial which evaluated subjects from 14 orthodontic clinics in the United Kingdom and included 174 children aged 8 to 10 years with Class II Division 1 malocclusion. These patients were randomly divided into two groups. The average age at the start of this research investigation for both groups was approximately nine and a half years. Group I was labelled “the early treatment group” and received treatment with the Twin-block appliance. Group II was labelled “the adolescent treatment group” and received no treatment until approximately 12 years of age when full treatment was initiated. As its typical in 2-phase treatment, the patients in the early treatment group had a period of inactivity following the initial Twin-block treatment and later resumed the second phase of treatment at approximately 12 years of age. Basically the two groups represented classic examples of patients receiving 1-phase versus 2-phase treatment. A second set of orthodontic records was taken at the completion of treatment for both groups and results were compared.

What do you think the authors found when they analyzed these results? The bottom line is that results of this study were very similar to the two university studies. The authors concluded that the early treatment with the Twin-block appliance followed by further treatment in adolescence does not result in any meaningful longterm differences when compared with one course of treatment started in the late mixed or early permanent dentition. They also concluded that there are definite disadvantages to the 2-phase approached treatment including increased burdens for the patient in terms of attendance, cost, length of treatment and inferior final occlusal results. This last finding somewhat surprised me. I would have thought that the final occlusal results for the two groups would be similar. The authors said that it was difficult for them to contribute any cost to this difference. However, the patients in the 2-phase treatment group may have experienced more burn out resulting in less cooperation during the final phase of treatment.

This was a well-controlled 10-year study with a large sample of patients which further supports the conclusion that for the treatment of patients with Class II malocclusion, there is no advantage to 2-phase versus 1-phase treatment. You can find this article in the May, 2009 issue of the American Journal of Orthodontics and Dentofacial Orthopedics.

Influence of Patient Financial Account Status on

Orthodontic Appointment Attendance

Lindauer S J, Powell J A, Leypoldt B C, Tufekci E, Shroff B

Angle Orthod 2009;79:755-8

March 19, 2010

Dr. Nam-Soon Park

 [초벌원고]

One of the most frustrating aspects of orthodontic treatment is to deal with patients who continually miss or fail their appointments. Not only this increased overall length of treatment for these individuals but it also can complicate the orthodontic mechanics and the sequence of treatment, which types of patients fail their appointment in your office? Is it possible to predict which patients could potentially miss their appointments? Those questions were posted in an article that appeared in July 2009 Issue of the Angle Orthodontics. Since all orthodontists and especially the staff have to contend with the failed appointments, I thought that this would be an excellent article for us to review.

 [수정원고]

The title of this article is "Influence of patients' financial account status on orthodontic appointment attendance". This study was co-authored by Steven J. Lindauer and several other research college from Virginia Commonwealth University in Richmond, Virginia. The purpose of this study was to determine whether the financial status of the patients account among other factors influences whether a patient is more likely to miss orthodontic appointments. In order to accomplish this goal, the authors evaluated the attendance at appointments of all active patients being treated at Virginia Commonwealth University Orthodontic Clinic over 6-week period. New patients, observation patients, and retention patients were excluded from this survey. What the authors wanted to determine was whether or not those individuals in active orthodontic treatment were compliant with attending appointments. For each individual, the patient's financial status relative to the orthodontic contract, was regarded as either current, overdue, or in collections. In addition, the authors evaluated the age of the patients, their gender and the method by which the appointment had been made, either in person by telephone or by postcard. So this was relatively straightforward study.

What did these authors find? First of all, during the 6-week period, the authors used for assessment, there were about 550 appointments that had been scheduled and evaluated at the orthodontic clinic. Overall, 88% of the appointments were kept, well about 12% were missed or failed. When the authors evaluated whether gender played a role in this differences. The authors found that males were significantly more likely to miss their appointment compared to females. Third, at the appointment had been made by sending a postcard, these individuals also were more likely to miss their appointments compared to those who scheduled in person or by telephone. Forth, the authors assessed the financial status of these individuals. They found that patients who were overdue or in collections were three times more likely to miss orthodontic appointments compared to those who were current with their financial account. Finally, the authors found those individuals who missed their appointment were also likely to miss their subsequent reappointment. So there we have it. A good predictor of failed appointments is financial status of the patients account. Those individuals who were delinquent or in collections are much more likely to miss their appointment.

If you'd like to review this information, you will find it in July 2009 Issue of the Angle Orthodontist.

Assesment of Radiographic Factors Affecting Surgical Exposure and Orthodontic Alignment of Impacted Canines of the Palate: A 15-year Retrospective Study.

March 26, 2010

Dr. Sang-Mi Lee

 [초벌원고]

What clues do you look at on pre-treatment radiographs to determine whether a palatally impacted maxillary canine will respond well to surgical uncovery and orthodontic traction? Is age a factor in your decision? To identify some specific factors that may help us make decisions about impacted canines, researchers in Iran published a result of a retrospective study in the June 2009 issue of Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology.

 [수정원고]

Their study began by identification of 80 patients treated over a 15-year period with a combination of surgical uncovery and orthodontic traction for palatally impacted canines. These 80 subjects had a total of 146 canines that were impacted. The age and gender were recorded from the chart as well as the ultimate treatment outcome: successful movement or non-responsive and extracted. The pre-treatment radiographs were used to determine the angulation of the canine to the mid-line vertical, the amount of overlap of the lateral incisor root and the presence of any obvious root anomalies. The treatment outcome was correlated with these various pre-treatment factors to determine which factors may be important for predicting success.

Here’s what they’ve found. The age range for the subjects was from 12 to 24 years and no correlation was found between age and treatment success. The same was true with gender; not helpful in predicting outcome. The factors that were found to be correlated with the positive outcome were a canine angulation to the midline vertical of less than 45 degrees on a panoramic film, overlap of the lateral incisor root by less than one half and no apparent root anomalies.

The very surprising statistic to me was that they had almost 30 percent of these impacted palatal canines that did not respond to orthodontic traction after 9 months and were removed; that seems like incredibly high rate of failure. Could the population in the Middle East respond differently? Did the surgical technique employed cause bony ankylosis? Or maybe the bone was left in the path of the enamel crown which made tooth movement difficult. I don’t know why the number of failure was so high but it makes me little leery of the rest of the finding.

The clinical application of these study results would be to depend more on radiographic assessment to the impacted canine position rather than the patient’s age, when making a decision about whether to try orthodontic movement for an impacted maxillary canine. But I wouldn’t recommend applying their assessment too rigidly because of the unexplained high rate of failure.

For your reference, the article is called “Assessment of radiographic factors affecting surgical exposure and orthodontic alignment of impacted canines of the palate: A 15-year retrospective study” and you can find it published in the 2009 issue of the Triple-O.

Systems Are the Practice’s Best Defense

April 2, 2010

Dr. Eun-Ji Kim

[초벌원고]

In a difficult economy, dentists all across the country are seeing a decline in production. They are looking for ways to protect their practices and are concerned that they are loosing ground. These two sentences are at the very beginning of an article titled “Systems Are the Practice’s Best Defense” by Roger Levin which appeared in the June 2009 issue of the Journal of the American Dental Association.

[수정원고]

And I think the eco what many orthodontists are feeling these days, the tremendous downturn in economy has effected everyone with very a few if any of us in a position to help turn it around. What the Dr. Levin suggests that we do is to develop systems in our own practices that can best protect the practice against negative effects of economy. He believes key to doing this is implementing a process of system development, in his own words, “Systems rule the practice”. And he suggests that developing excellent practice systems is a process of evolution.

He recommends three steps to build a high performance practice. One, evaluate and redesign outdated systems, two, document all systems, and three, implement robust systems to achieve superior patient service. If you allow your practice systems become outdated, it will result in more built-in inefficiencies which will have an negative effect on your practice. Dr. Levin believes that redesigning systems is the best approach to eliminating practice inefficiencies and suggests specific steps that can be taken to redesign outdated systems. He also suggests that for practice to completely integrate all new systems without interfering with the proper operation of the practice usually takes a year or more. So, if you are thinking of implementing new systems in your practice, it would be good to start now. Dr. Levin suggests that is very important that each new system that you implementing your practice, be documented in writing with each step in the system clearly delineated. He emphasizes that a goal in establishing documented systems is to create the highest levels of efficiency. One thing that Dr. Levin pointed out that impress me was that if your practice has slow down because of the poor economy and your appointment book is not full, it is easy for you and your staff to become inefficient because you can look ahead unfilled appointments coming up on your schedule to give you additional time. If you allowed this to happen, you are building inefficiencies into your system. Dr. Levin emphasizes the importance of implementing robust system to achieve superior patient service because he believes that this is the most effective way to increase the number of new patients in your practice.

He also emphasizes that while many dentists have emphasizes external marketing such as newspaper, television, and radio advertising that these areas of marketing are more short-lived and don’t result in a long term positive effects that developing outstanding patient service can provide.

As was many of the Dr. Levin’s articles, I found his comments to be very timely and practical. The bottom line is that developing a long term successful practice requires developing effective systems. You can find this article which has many more details that I haven’t been able to describe in this review in the June 2009 issue of the Journal of the American Dental Association.

Prospective, multi-center study of the effectiveness of orthodontic/orthognathic surgery care in the United Kingdom

O’Brien K, Wright J, et al.

Am J Orthod Dentofacial Orthop 2009;135:709-714

April 9, 2010

Dr. Hoon Noh

[초벌원고]

Numerous studies have been performed to evaluate the effectiveness of surgical orthodontic treatment. Some of these studies have looked at the effectiveness of different surgical procedures, different types of fixation and relationship of stability to specific types of malocclusion. However, one drawback to most of these studies has been a relatively small sample size. For these reason, My attention was drawn to a study titled "Prospective multi-center study of the effectiveness of orthodontic/orthognathic surgery care in the United Kingdom" by Kevin O’Brien et al which appeared in the June 2009 issue in the American Journal of Orthodontics and Dentofacial Orthopedics. In this observational prospective Cohort study, the authors evaluated 131 patients treated at 13 different maxillofacial clinics in the United Kingdom.

[수정원고]

The patients were evaluated initially and then followed until all orthodontic treatment was completed. The study lasted 5 years. Data for the study were collected before the start of treatment once the patient decided to undergo surgical orthodontic treatment and after all treatment when orthodontic appliances were removed. At the completion of the study cephalomatric radiographs were used to evaluate the patient’s skeletal relationships and facial pattern and Peer Assessment Ratings or PAR scores were used to evaluate occlusal changes. Additionally, the author recorded the number of patient visits and the duration of overall treatment time. The patients in this study received care from 24 orthodontists and 20 maxillofacial surgeons. Based on evaluation of their data, the authors concluded that the surgical orthodontic treatment was successful in reducing overjet and correcting the skeletal discrepancies from most patients.

The authors faced this conclusion on the fact that 44% of the patients had posttreatment skeletal relationships that were within one standard deviation of the normal population mean which would include approximately 67% of the population. They also found that there was no relationship between the specific type of malocclusion that is Cl II or Cl III and treatment results which was a little surprising to me. They also concluded that the effectiveness of treatment was influenced by severity of the pretreatment skeletal discrepancy which to me was not surprising. The most striking finding of the study was the overall treatment time which was almost 33 months. The author suggested that one factor in extending overall treatment time might be the wait between the end of presurgical orthodontic treatment and having surgery which was not specifically recorded. This might well be the primary cause of the extended overall treatment time because is my understading that it is in not unusual in United Kingdom for patients having to wait up to year after presurgical orthodontic treatment is complete to have surgery.

The bottomline of this study appears to be that overall surgical orthodontic treatment was effective. However, I was disappointed that no measure of patient satisfaction was recorded. I complement the office on undertaking this large multi-center study results of which you can find in the June 2009 issue of the American Journal of Orthodontics and Dentofacial Orthopedics.

Occlusal Contact Changes with Removable and Bonded Retainers in a 1-Year Retention Period

Sari Z, Uysal T, et al.

Angle Orthod 2009;79:867-72.
                                                                             

April 16, 2010

Dr. Hyun-Jung Lee

 [초벌원고]

Do you rely on settling after orthodontic treatment to improve the occlusal contacts between posterior teeth in your orthodontic patients? Although as orthodontists we try to obtain ideal contacts between the posterior teeth, sometimes this is simply impossible. But we also know the teeth will continue to erupt as a result teeth that were out of contact at end of orthodontics could erupt into contact. This has been shown in several studies in the past. But here is my question. Will the type retainer used at end of orthodontics enhance or prevent the establishment of better occlusal contacts? Obviously an Essix retainer what prevent settling, but I'm not talking about that type of retainer. If you are to use a removable Hawley retainer in both maxillary and mandibular arches or if you simply bonded lingual retainer from canine to canine in both arches, would there be any differences in the amount of settling or increase in posterior occlusal contacts? Since these are common retainers used by most orthodontists, this could be valuable information for any clinician. So when I found an article in the September, 2009 Angle Orthodontist that discuss this topic, I decided to review it on this month’s issue. The title of the article is “Occlusal Contact Changes with Removable and Bonded Retainers in a 1-Year Retention Period”. This study comes out Turkey and co-authored by Zafer Sari and three other researchers from the department of orthodontics at Selcuk university and Erciyes university in Turkey.

 [수정원고]

 The purpose of this study is to evaluate the number of posterior occlusal contacts in centric occlusion during a 1-year retention period comparing bonded and removable retainers to a control sample. In order to accomplish the subjects authors gathered three groups of subjects. First of all, there was a sample of 20 individuals in who no orthodontic treatment had ever been performed, but who had a normal occlusion. A second group of 25 individuals had complete orthodontic treatment and after bracket removal they had fixed bonded retainers placed from canine to canine in both maxillary and mandibular arches. A third group of 25 orthodontic patients had removable Hawley retainers placed in both arches following orthodontic treatment. When the orthodontic appliances removed in both treated samples, patients were place upright in the dental chair impression material was placed on the mandibular occlusal surfaces and the patients were asked to bite their teeth together in centric occlusion. After this impression material had set, this occlusal registration was removed, placed on a light box, and the authors could then determine if perforations were present in the impression material indicating tooth contacts. These contacts were then counted, at the same procedure during the 1-year at that later of it was also performed. In other words, the impression procedure was performed again in 1-year. Again, the number of occlusal contacts were counted for all three groups, the control, the removable retainer group, and the bonded retainer group. Then the authors compared these three groups to determine if there were any increases on the number of occlusal contacts over the 1-year period.

 What did these researchers find? Question number 1, was there any change in the control group that did not have retainers or orthodontic treatment? Of course the answer to the question would be no. These individuals had a similar number of occlusal contacts at both first and second evaluations taken 1-year apart. Question number 2, what happen to the number of occlusal contacts in both groups of individuals who had had orthodontic treatment? As you would expect both of these groups had an increase in number of occlusal contacts when the end of orthodontic treatment was compared to 1-year post treatment. Question number 3, was there any differences in the number of tooth contacts in the removable retainers compared to the fixed retainer group. And the answer to that question is yes and it was statistically significant. These authors found that those patients who had lingual bonded retainers in the maxillary and mandibular arches from canine to canine had a greater increase in the number of occlusal contacts when compared to those individuals who had removable Hawley retainers in both arches. In other words, there was greater settling of the posterior occlusion when there was nothing placed over or around the posterior teeth. This makes sense, but what does this mean? Well, you depend on settling to improve the posterior occlusion in your orthodontic patients, then wearing a removable Hawley retainer will tend to limit the extent of that settling. Bonded lingual retainers in both arches tend to encourage settling which in this research project resulted in a greater number of occlusal contacts 1-year after orthodontic treatment. If you like to review this study, you can find it in the September 2009 issue of the Angle Orthodontist.

Rotational Resistance of Surface-Treated Mini-Implants

April 23, 2010

Dr. Mi-Young Kim

 [초벌원고]

Have you used mini-implants yet to assist providing anchorage for orthodontic movement? Today most orthodontist have at least tried a few cases in which mini-implants are employed for additional anchorage. If so, you probably encountered some of the problems that can occur with mini-implants. One of these is rotation, one of forces applied to the mini-implant. Since most mini-implants have a smooth or machined surface to avoid osseointegration they can still provide anchorage because the implant were simply not move through the bone. But these mini-implants can rotate in a counter clockwise direction if a forces are applied in that direction. Unfortunately this can result in loosening of the implant. It actually could be more beneficial to have the implant partially integrate with the bone to avoid this rotational dilemma. Could osseointegration actually be more appropriate for mini-implant? That question was addressed in the study was published in the September 2009 issue of the Angle Orthodontist. I’d like to review that study on this month issue of practical reviews in orthodontics. The title of the article is “Rotational Resistance of Surface-Treated Mini-implants". This study comes out of Seoul Korea from the Department of Orthodontics at Seoul National University. The lead author of this research is Seong-Hun Kim.

 [수정원고]

The purpose of this study was to determine the effect of surface treatment on osseointegration and the resistance of mini-implants to rotational movement. In order to accomplish this project, the authors used two different types of implants. Both the implant systems were similar in size and shape. They measured 1.8mm in diameter and 8.5mm in overall length. But the surface treatment of the implants differed. One of the implants was machined or smooth surface titanium. All the other mini-implants surface had been sandblasted and acid etched to produce rough surface. These two implants were then inserted into a serious experimental animals and allowed to set for 3 weeks. After that time a rotational force was placed in the implant to determine if there were any differences between the machined surface and the rough surface. In addition the authors determine the resistance to removal of the mini-implants at the end of the experiment to determine if one of the surfaces had a greater resistance than the other to removal.

Okay, I think you get the idea of the experiment. Now what did these authors find?. Qusestion No. 1; Did one of the implants surfaces perform better than the other relative to rotational resistance? The answer that question is yes, definitely. The mini-implants who surfaces had been sandblasted and acid etched produce greater resistance to counter-clockwise rotation during the experiment. The machined surface implant did not resist counter-clockwise rotation and turned in that direction during the experimental loading. Question No. 2; What about the removal of the implant at the end of the experiment, did the rough surface implant show greater resistance to removal? The answer of that question is also yes. The removal torque value of the rough surface implant was greater than the smooth surface implant. In implied research, this basically means that rough surface implant had partially integrated with bone producing more rigid fixation. So there we have it. If you have machined or smooth surface implant you'll have problem from time to time with rotational movement depending upon the type of force that's applied to the mini-implant. If you wish to avoid that problem in certain types of orthodontic treatment, you might consider using a mini-implant whose surface has been sandblasted and acid etched to produce rough surfaces which results in partial integration with the bone and eliminates the problem of counter-clockwise rotation. If you interested in reviewing this article, you can find it in a September 2009 issue of the Angle Orthodontist.

Adolescent Patients’ Treatment Motivation and Satisfaction

with Orthodontic Treatment

May 7, 2010

Dr. Lee Kyung Min

[초벌원고]

Has this ever happened to you? Suppose you are doing a consultation with a thirteen year old female and her mother. This young girl has a class I malocclusion with very crowded teeth. Her treatment will involve non extraction therapy with arch expansion and alignment. It shouldn’t be an extremely difficult case. But here’s the problem. This young girl is not at all excited about orthodontics. She really doesn’t want to wear braces on her teeth. How do you motivate your patients in that situation? How do you energize them so they’ll accept orthodontics? Is it important to energize a patient before beginning orthodontic treatment? Will their energy level have any effect on their perception of the outcome of the treatment? And finally will the parents’ appreciation of what’s been done for their child, be affected by the energy level of that patient? All the orthodontics have gone through these scenarios but the answers to these questions would be a great importance to any practicing clinician. So when I found an article that dealt with these subjects I thought it would be very worthwhile for us to review.

[수정원고]

The title of the article is “Adolescent Patients’ Treatment Motivation and Satisfaction with Orthodontic Treatment.” This study appeared in the September 2009 issue of the Angle Orthodontists and was co-authored by Lauren Anderson and Marita Inglehart from the department of Orthodontics at the University of Michigan in Ann Arbor. The purpose of their study was to determine whether an adolescent satisfaction with orthodontic treatment outcome is in anyway correlated with the degree to which that adolescent patient was energized before the treatment began and whether the parents’ assessment of the child’s pretreatment motivation correlated with the posttreatment satisfaction of both parents and child.

Now I know this sounds a bit confusing but let me explain what these researchers did. In order to determine the answers to these questions, the authors gathered information on a group of 75 patients who were had treatment performed in the orthodontic department at the University of Michigan. All of these individuals had their orthodontic treatment completed prior to the age of 21. These subjects were sent a questionnaire. This questionnaire was specifically constructed by a behavioral psychologist so that the responses could elicit information about the pretreatment energy level of the patients as well as the parents’ appreciation of their child’s satisfaction with treatment.

Let me give you an example. Four of the questions were designed to measure the energy component of each of the patients. Three of the questions measured how much the patient focused on posttreatment esthetics. Five of the items on the questionnaire evaluated the focus of the individual patient on posttreatment function. The parents portion of the questionnaire focused on three aspects. One was whether or not their child had been motivated prior to beginning of the treatment. The second evaluated the parents’ perception of their child’s energizing at the beginning of the treatment. And finally the last part of the questionnaire determined the parents’ perception of their child’s focus on their teeth. Now again, I know this sounds a bit confusing but let me explain the results of this study as clearly and succinctly as I can. Basically the results of this study suggest that communicating with patients before treatment about the potential for improvement in esthetics, energizes the young patients prior to orthodontics. This allows them to focus on esthetic outcome during treatment. This study clearly shows that those individuals who are energized in this way at the beginning of the treatment were the most satisfied with the treatment outcome. In addition those children that were energized prior to treatment and focused on the esthetic outcome had parents who were the most appreciative of the outcome. So basically this study documents that the more energized and focused the patients are prior to the treatment, the more satisfied they are with the treatment outcomes and that the focus of most patients is on esthetics and clearly not on occlusal function.

So let’s go back to your consultation with your thirteen year old female and her mother. This child is not happy about having orthodontic appliances. She’s not energized. What would you do to overcome this situation? Based upon the results of this study, the best thing you can do is to try to energize this child by having your focus on how esthetically pleasing her teeth will eventually look at the end of orthodontics. If you can accomplish this, then the child will focus on that thought and perhaps that will help make the treatment more pleasurable for the patient, but will also make the patient and parents more satisfied with the end result. If you’d like to review this study you can find it in the September 2009 issue of the Angle Orthodontists.

Immediate VS Late Orthodontic Extrusion of Traumatically Intruded Teeth
 

Medeiros RB, Mucha JN.

Dent Traumatol 2009;25:380-385                                   
                                                                                

May 14, 2010

                                                       Dr. Mi-Soon Lee

[초벌원고]

Imagine the situation where one of your referring dentists calls and indicates that Jennifer, who you treated two years ago, had fallen and traumatically intruded her upper right central incisor. The dentist suggests that orthodontic extrusion may be required, but it is wondering whether it should be done immediately or later. He has heard that early extrusion may encourage root resorption and/or ankylosis. How do you answer this question of treatment timing for traumatically intruded central incisors? I just read an article dealing with this very question in the August 2009 issue of Dental Traumatology, and would like to share the results with you.

[수정원고]

The article comes from Brazil and is called “Immediate versus late orthodontic extrusion of traumatically intruded teeth". I want to make sure you understand the methodology of this paper because it puts the conclusions in proper perspective. This was a review of the literature in which case reports were combined that met certain inclusion criteria. One of the criteria was that there had to be at least one-year follow-up after extrusion. The authors originally identified 55 publications and this was reduced to 13 after all criteria were applied. So the resulting sample was 22 traumatically intruded teeth in 13 subjects.

The treatment these subjects received was classified as ‘immediate’ if it happened within the first 3 months and ‘delayed’ if done later. The age, gender, complications, treatment time, and treatment success were all recorded. The ‘immediate’ group was compared to the ‘delayed’ group to answer the treatment timing question. Overall, 21 of the 22 teeth were successfully treated although nearly half had some sort of complications such as mild-to-moderate root resorption. 18 of the teeth were treated immediately with extrusion started in average of 2 weeks after the injury. Only 4 were classified as ‘delayed’. Nearly all the teeth required endodontic treatment whether the root was mature or not. The big difference was in treatment time. The ‘delayed’ group required treatment several times longer than ‘immediate’ treatment group.

The limitation of this report was that it was based on a combined series of case reports. We all know that the cases that tend to be published are those that demonstrate successful treatment strategies. So this is likely a biased sample. With that limitation noted, it does seem to indicate that the treatment time is much less when immediate extrusion is done. And that fact combined with a lack of severe root resorption in these cases, indicates that it is a relatively safe procedure. So until we have better evidence, it appears that early extrusion happens faster with no more complications, and is therefore probably the best recommendation. So now when you talk to referring dentist about Jennifer, the patient who has an intruded incisor, you are likely suggest that after soft tissue healing, you should begin orthodontic extrusion immediately.

For additional information about orthodontic extrusion of traumatically intruded incisors, you can find this complete article in the Aug 2009 issue of the journal Dental Traumatology.

Esthetic Analysis of Gingival Components of Smile and Degree of Satisfaction in Individuals With Cleft Lip and Palate

Esper LA, Sbrana MC, et al.

Cleft Palate Craniofac J 2009;46:381-387

June 4, 2010

Dr. Sun-young Lim

[초벌원고]

It can be challenging for me to achieve the smile esthetics that I like in many cleft lip and cleft palate patients. There are so many issues from tooth shape and color to gingival contours, to lip shape and function. All of which impact the smile and all of which are affected in cleft patients. 

[수정원고]

How important are the gingival characteristics in the cleft patients on assessment to their smile? And what is the general level of satisfaction in a group of treated cleft patients with their smile? These questions were addressed by a study that appears on the July 2009 issue of the Cleft Palate Craniofacial journal. The paper is from Brazil and this is called “Esthetic Analysis of Gingival Components of Smile and Degree of Satisfaction in Individuals with Cleft Lip and Palate”.

The subjects were recruited for the study were 45 people from age 15 to 30 who had completed their surgical and dental rehabilitation for unilateral cleft lip and palate. Each of the subjects had three standardized photos taken, at last in a natural smile and in a false smile. The patients were asked to complete questionary that included the subjective rating of their own smile on a nine point scale and also asked questions like “Are you ashamed of your teeth and your smile?” Ratings of the photographs were also done by two panels of three dentists each. They were asked to make an overall rating of each smile using the same nine point scale and also asked to rate several characteristics of the gingival components of the smile.

How do they rehabilitated cleft patients assess the own smiles? And How do they compare with professional’s ratings? The patients rated their own smile was an average 7.6 out of 9 or 84%. This rating was in the esthetically pleasing range of the scale. The dentists rated the same smile as 5.2 out of 9 or 58%. This was a large difference compare the subject themselves and was statistically significant. The professionals noticed many asymmetries with in a gingival tissues as we’d be expected in this group. Interestingly, for those few patients who did not rate their smiles as esthetic. The reason was not because of gingival contours but rather issues of tooth shape, tooth color, tooth position or lip contour.

So what is this mean to us as an orthodontist? I think it means that at least in cleft patients if we can’t achieve ideal gingival contours and nice gingival symmetry, it may not be the end of the world for the patients. We should still strive to do our best to make gingival architecture esthetic, but maybe we shouldn’t be disappointed we can’t make things perfect. All those you argue that this study was conducted in Brazil, and  therefore may not reflect the esthetic values of other areas. I would have to say that these results confirm my clinical impressions.

The actual paper contains much more information about the professional ratings of the various components of gingival architecture. And you can find these details in the July 2009 issue of the Cleft palate Craniofacial journal. But for me the most important conclusion was the cleft subject themselves were clearly happy with their smiles even with some gingival imperfections.

Effects of Intrusive Force on Selected Determinants of Pulp Vitality

Veberiene R, Smailiene D, et al.

Angle Orthod 2009;79:1114-1118

June 11, 2010

Dr. Nabha Wael

[초벌원고]

Suppose you are about to begin an orthodontic treatment on a 30years old adult male, he has a Class I malocclusion with sever abrasion of his maxillary anterior teeth, as these teeth of warn they’ve overerupted, your treatment plan is to intrude these teeth to move the gingival margins apically so his dentist can add on to the incisor edges with porcelain veneers, this should be a very straight forward treatment plane. But here’s  my question. “What would be the effect of tooth intrusion on the dental pulp of these maxillary incisors, Will this tooth intrusion cause a deleterious effect on the pulp ,will there be any change in response to pulp testing as these teeth are intruded, those are interesting questions that could affect any patient whose undergoing intrusion of teeth?” I found an article in the November 2009 issue of the Angle Orthodontist that answers the questions that I just posed.

[수정원고]

I like to review it for you on this mouth issue of practical reviews on orthodontics. the title of the article is “Effects of Intrusive Force on Selected Determinants of Pulp  Vitality”. This study comes out of Kaunas University Dental School in Lithuania the lead author is Rita Veberiene, the purpose of this study was to determine changes seen in dental pulp during the early stages of orthodontic intrusion with fixed appliances in order to accomplish this project the authors gathered 21 healthy subjects who are about to have orthodontic treatment, in each of these patients the treatment plan involved the extraction of maxillary first premolars, prior to the begging of orthodontic treatment an appliance was used to place an intrusive force on one of the maxillary first premolars, this intrusive force lasted for seven days and the amount of force was calibrated at sixty grams, the opposite or contra lateral first premolar was used as a control and no intrusive force was placed on that tooth, at seven days the force was discontinued, an electrical pulp tester was used to test the responds of the pulp to the electronic stimulus, then the first premolars where extracted and the pulpal tissue was evaluated to determine the presence of an enzymes which indicates cell death, this enzyme is called aspartate aminotransferase ,this enzyme appears in normal cell walls but when the cell undergoes death this enzyme is released into the tissue, so it’s a good measure of cell lyses.

Ok, I think you got the idea of the experiment, now what happened ,remember the questions ,question no.1; Does tooth intrusion for one week at 60 grams of force cause an alteration in the response to the electronic pulp tester? The answer to that question is yes, the author should that after one week of initiation of an orthodontic intrusive load there was an increased response threshold to the electronic pulp tester by about three and half times the normal response, question no.2; What happen to the cells in the pulp? Based upon histological evaluation the authors found a sixty-four percent increase in the presence of aspartate aminotransferase, what’s that means? That’s indicates break down of cells with inter dental pulp, so the author found a positive correlation of an increase of aspartate aminotransferase activity and an increase in the threshold response to the electronic pulp tester in test teeth compared to controlled teeth, now what would be the long term effect of this early response, unfortunately that couldn’t be answered in this current study, remember this intrusive force was for only seven days, perhaps the body over comes this initial response and commodities to this change in the pulp, after all many teeth are intruded during orthodontic therapy, but seldom of ever do we see pulpal necrosis requiring root canal therapy after orthodontics, perhaps these authors will determine in future studies the long term effects of tooth intrusion on pulpal vitality and pulpal health, in the mean time.

If you like to review this present study you will find it in the November 2009 issue of the Angle Orthodontist.

Psychosocial impact of dental esthetics on quality of life in adolescents

Delcides F. de Paula et al

Angle Orthodontist 2009;79:311-316

June 25, 2010

Dr. Nam-soon Park

[초벌원고]

How concerned are adolescent orthodontic patients with their esthetic appearance? You know this is a controversial topic. But they found the study in Nov. 2009 issue of Angle Orthodontists, they give us a fresh look at this question. Today researchers who evaluated behavioral questions such as the esthetic importance of orthodontic treatments use measures of oral health related quality of life in their questionnaires. This was one of those types of studies. The title of the article is “Psychosocial impact of dental esthetics on quality of life in adolescents.” This study comes out of Brazil and the senior author is Dr de Paula from the Federal Univercity of Goias in Brazil. The purpose of this study was to investigate the effect of malocclusion, quality of life, and self-image on the psycho-social impact of dental esthetics in a sample of adolescent subjects.

[수정원고]

A large sample of over 300 adolescents was evaluated. The sample consisted of about 60% females and 40% males with an average age of 16 years. These individuals were given 4 separate questionnaires which helped to depict their feelings about esthetics of their dentitions as well as their reading of the actual malalignment in malocclusion. Then the authors compared these various questionnaires to determine the impact of esthetics on an adolescents assesment of the quality of life. What did these researchers actually find? I believe the results were very interesting.

First of all, about 50% of the subjects had no treatment need or only a slight treatment need. On the other hand, about 10% of the individuals had severe malocclusions. In spite of these numbers, at least one oral health impact on quality of life was reported by 90% of the adolescents and nearly 100% of the subjects showed some level of psycho-social impact on dental esthetics. This is interesting when the reliability of an analysis was evaluated, it showed that internal consistency in these study was considered acceptable. With these studies basically showed was that when the authors evaluated the psycho-social impact of dental esthetics, they found a higher score with those subjects who had greater deviations in dental esthetics. What does this mean? Simply stated, the authors believe that their study reveals that adolescents with their higher dental esthetic index score had greater esthetic impact scores as well.

In other words, adolescents with less attracted dentitions are psycho-socially disadvantaged and have a esthetic concerns. The authors concluded that adolescents attribute high importance to an attractive dental appearance. If you are interested in review in the study you can find it in the Nov. 2009 issue of the Angle Orthodontist.

Treatment Response and Stability of Slow Maxillary Expansion by Using Haas, Hyrax, and Quad-helix Appliances: A Retrospective Study

Thuylinh Huynh, Kennedy et al.

Am J Orthod Dentofacial Orthop 2009;136:331-9
                                                                              

July 2, 2010

Dr. Sang-mi Lee

[초벌원고]

Most orthodontists who identify a posterior cross-bite in the early or late mixed dentition, usually try to correct the cross-bite by expanding the maxillary arch. The Haas expander, the hyrax expander, and the quad-helix appliance are the three appliances that are commonly used to do this. With each of these appliances, expansion can be done either rapidly or slowly. Rapid maxillary expansion is usually defined as two turns or half a millimeter per day whereas slow maxillary expansion is usually defined as one turn or a quarter millimeter of expansion every second day when using either the Haas or hyrax appliances or one molar width of activation for the quad-helix appliance.

[수정원고]

A study titled “Treatment response and stability of slow maxillary expansion by using Haas, hyrax, and quad-helix appliances: A retrospective study” by Thuylinh Huynh, et al, which appeared in the September 2009 issue of the American Journal of Orthodontics and Dentofacial Orthopedics looked at the relative long-term stability of expansion using each of these appliances for slow maxillary expansion. The authors first identified three hundred twelve consecutive expansion patients from whom they selected one hundred sixty subjects as satisfied their inclusion criteria. To evaluate long term expansion stability, they took records at the start of treatment, after expansion with no posterior cross-bite present and a minimum of two years later in a permanent dentition. When they compared the long term expansion stability for each of these appliances, what do you think they found?

The bottom line is the slow maxillary expansion had the stability rate of 85% long term and there was no difference between the three appliances and no sex differences were observed. The average ages prior to treatment, at the end of expansion and at least two years post-treatment were 8, 9, and 13 years respectively. Although there were no differences in long term stability based on the type of appliance used, patients who started expansion earlier and patients who wore a removable retainer post-expansion tended to have slightly greater long term stability.

Although the study did not contain a rapid maxillary expansion group, when compared with previous studies of rapid maxillary expansion stability, the slow maxillary expansion stability appears to be significantly better. I was not surprised that there was no difference between the Haas and hyrax appliances but I was surprised to see that there was no difference when the quad-helix appliance was used. Based on the result of this study, it appears that the use of slow maxillary expansion in the early mixed dentition with a removable retainer placed after active expansion results in good long term stability. You can find this study in the September 2009 issue of the American Journal of Orthodontics and Dentofacial Orthopedics.

Standard of Care: Why It Is Necessary

Riolo ML, Vaden JL

Am J Orthod Dentofacial Orthop 2009;136:494-496
                                                                             

September 3, 2010

Dr. Sang-mi Lee

[초벌원고]

For this month’s program, I’ve decided to review two special articles which appeared in the October 2009 issue of the American Journal of Orthodontics and Dentofacial Orthopedics. Both articles are related to standard of care. The first article is titled:"Standard of Care: Why is it necessary"by Michael Riolo and James Vaden. I suspect that for many orthodontists, the terms,'evidence-based treatment'and'standard of care'have negative connotation. As orthodontists, most of us tend to be very independent and the thought of any outside person or entity telling us how we should practice or what standard of care we should achieve in our practice can sound intrusive.

[수정원고]

I’m reviewing this article and we’ll review the second article later in the program because I believe most orthodontists do not fully appreciate the importance of having a standard of care for orthodontic treatment. In this article, the authors quoted the study by Dr. David Sackett who is a clinical epidemiologist who teaches at McMaster University in Hamilton, Ontario, Canada and has studied clinical medical continuing education and how general practice physicians change their concepts and clinical treatment decisions over time. I found one of Dr. Sachett’s statements to be most interesting. He noted that in medicine, new graduates comprised approximately 4 percent of the pool of physicians next year. 5 percent consist of full-time and part-time clinical teachers and of the remaining 91 percent of all physicians. Fewer than 10 percent takes sufficient advantage of the available information to maintain good understand of the current standard of care in general medicine. He found that most physicians change their treatment perspective because of random experiences with short courses, interaction with peers in hospitals and group practices, study club programs, presentations by salesmen and occasional and superficial reviews of journal articles. For the balance of practitioners, he found that what was taught in the year the physician graduated from medical school was the best indicator of the type of medical care delivered.

These comments reminded me of presentations that I went to numbers of years ago by physicians of University of Vermont, pioneers of concept of problem-based records in medicine. The comment that he made that I’ve never forgotten was that in the United States, the treatment that he received for the medical problem is determined more by the specific medical office that you go into than by the symptoms which you present. The comment like this certainly supports the need for standard of care in medicine. I believe that many orthodontists are resistant to establishing the standard of care because they feel that a standard of care implies that all patients must be treated to an ideal and that they themselves have a number of cases that do not have an ideal finish. Establishing standard of dare does not mean that all orthodontic cases must be treated to an ideal finish. Obviously all of us have patients who have less than ideal finishes for a number of different reasons, such as growth, cooperation, hygiene and financial consideration, and concerns of the patient or the parents.

In this article, the authors note that the one element that defines a profession is that it establishes and enforces its own standards. The authors emphasize that the initial standards for orthodontists should be realistic and achievable for the majority of clinicians or qualified to deliver the type of care under consideration. They further note that without actual data, preliminary standard represent the consensus of professional society representatives or be based on audits of samples of clinicians. If appropriate, these standards can later be changed if research shows that a change is indicated. The bottom line of this article is our specialty has and obligation and the right to develop criteria of standards for care and if we don’t do this, someone else will. You can find this article in the October 2009 issue of the American Journal of Orthodontics and Dentofacial Orthopedics.

When My Child Was Born: Cross-Cultural Reactions

Black JD, Girotto JA, et al.

Cleft Plate Craniofac J 2009;46:545-48
                                                                            

September 10, 2010

Dr. Nam-soon Park

[초벌원고]

The birth of a cleft child can have a big impact on the mother. This reaction can, in turn, affect the way of mother response to the newborn’s needs and therefore negatively affect the child attachment security which is a strong predictor of future self-esteem. As health care providers to this group of children, it is important that we understand the cultural differences that may impact the mother’s acceptance of a cleft child after birth. To help us be aware of this cultural differences a research team from the US published its work in the September 2009 issue of the Cleft Palate Craniofacial Journal under the title “When My Child Was Born: Cross-Cultural Reactions to the Birth of a Child with Cleft Lip and/or Palate”.

[수정원고]

To access the maternal reaction to the birth of a cleft child, the research team used evaluated survey instrument designed to measure this impact. For this study, they specifically used the section of the survey on maternal affect. This survey instrument was translated into severall languages and administered to 110 mothers in four different cultures. This was done in conjunction with medical mission trips, just surgically repair cleft in four different places. The cultures all included words; Thai, Chinese, Columbian and Ugar, small muslam population in China.

The results from this culture were compared to previously published group of American mothers. The primary research question was “Are there cross-cultural differences and maternal reaction to the birth of cleft child?” The result from this study showed that there are significant differences among mothers from different cultures. The Thai mothers had the highest maternal affect score which means the most positive reactions to the birth. The authors attributed this to the Buddhist belief system which may help them accept the situation that they can not change. In the middle of the maternal affect scores, with the Columbian and Ugar mothers who scores similar to the American mothers previously published. The lowest maternal affect scores were found in the Chinese mothers. The authors believe this more profound impact maybe due to the one child policy in China that put significant  financial incentives on family to have only one child. This may make a mother fear like she has lost only chance to have a co-normal child.

Many orthodontist treat cleft patients from a variety of cultures either in their practices or as a part of medical mission teams. The result from this study suggests that there may be some significant differences and how mothers from different cultures react the birth of cleft child. These different reactions can not affect the child psychosocial development and self-esteem.

For more detail information about this study of maternal reaction to the birth of a cleft child, see the September 2009 issue of the Cleft Palate Craniofacial Journal.

Precision of Bracket Placement on Dental Models

Lai ML, Mah J.

J. Clin Orthod 2009;43:524-528
                                                                            

                                                                 September 17, 2010

                                                                     Dr. Mi-soon Lee

[초벌원고]

The difference between precision and accuracy is important to understand. Precision is essentially repeatability, the ability to hit the same position again and again. Accuracy is being able to hit the desired target. If you are shooting several arrows at a target, the precision would be good if the arrows were tightly bunched even if they were not near the bull’s eye. Accuracy is being able to hit the bull’s eye. The ideal bracket placement technique would be accurate and precise, that is the brackets would be placed close to the ideal position again and again.

[수정원고]

A recent publication in the August 2009 JCO reported on the development of a system to measure the precision of bracket placement. And this purpose is reflected on the title of the paper, “Precision of Bracket Placement on Dental Models”. The authors’ desire was to find a way to measure the bracket position on a tooth and be able to describe the position in all three planes of space. In this case an optical method was developed that proved to be useful. Five orthodontists were then asked to participate in the study using this measuring method. They each placed brackets virtually on a computer first to represent their target position and then bonded three cases with a direct bonding method and three with their preferred indirect bonding method. In addition, three cases were bonded using a commercial digital indirect bonding set-up. All bonding by the orthodontists was done on mannequins, trying to replicate the clinical situation.

The purpose of this study was to see how precisely or repeatably the orthodontists could place the brackets using the different methods. The results showed that the precision of bracket placement slightly favored the indirect bonding method, but the differences were not large. The most precise method was the laboratory-based indirect bonding that likely had some technology assistance for placing the brackets during the set-up. Remember, though, that this was not a measurable accuracy. Good precision could be placing the brackets repeatedly in the wrong position. In general, the variation in position was within + or – 0.5 mm, but the variation in angulation was more like + or – 5 degrees, making me wonder why we argue over bracket prescriptions that may vary by just a couple of degrees.

The authors promised provide further studies in the future on accuracy of bracket positioning. It would be nice if that could be done in a true clinical situation on real patients. It is difficult to determine how a study such as this done on mannequins represents what happens on in a real mouth with the tongue and saliva. If you want more details of the study investigating the precision of bracket placement, take a look at this article by Lai and Mah in the August 2009 issue of the Journal of Clinical Orthodontics.   

Root and Pulp Response

after Intentional Injury from Miniscrew Placement

Renjen R, Maganzini AL, et al.

Am J Orthod Dntofacial Orthop 2009;136:708-714
                                                                            

September 24, 2010

Dr. Sun-young Lim

[초벌원고]

If you one of the many orthodontists placing miniscrews as TADs for anchorage. I am sure one of your concerns is the possibility of having the miniscrew penetrate root structure. How much injury would occur if you did contact root structure when placing a miniscrew. If a miniscrew has caused root damage and then left in place what is the likely histologic response? Does this cause external root resorption, ankylosis, pulpal necrosis, repair of attachment or no response? These questions were addressed in a study titled "Root and Pulp response after intentional injury for miniscrew placement" by Rahul Renjen et. al. which appeared in November 2009 issue of the American Journal of Orthodontics and Dentofacial Orthopedics.

[수정원고]

In this study the authors placed a total of 60 self-tapping miniscrews between the premolars and molars of 3 beagle dogs. The miniscrews were placed with intention of inflicting root damage. A full radiography series was take before and after miniscrew placement and the dogs were assessed daily for evidence of infection and stability of the miniscrews. Using radiographs the authors identified 20 sites with evidence of root proximation and these sites were selected for histologic assessment. At 12 weeks another radiography series was taken and each dog was sacrificed. Microcomputed tomography scans were then used to identify evidence of pulpal necrosis or local inflammatory infiltrate and attachment apparatus surrounding each miniscrew was evaluated for evidence of ankylosis, external root resorption or cementum repair.

What do you think the authors found when they evaluate the root of the teeth that have been penetrated by miniscrews.  The bottom line is the results of this study are good news for orthodontists. There was no histologic evidence of inflammatory response either at the root surface or in the pulp. Pulp necrosis, external resorption, and ankylosis were not found, but repair of cementum was seen at each injury site.

There was evidence of continuous cementum repair along the injured root surface, and it was only in cases of severe injury with displacement of root fragments that ankylosis was noted. The authors also noted that each site woven bone was present along the miniscrew threads, which suggest that a degree of osseointegration had occurred with the miniscrews. The bottom line is that only when screws penetrated and splint the roots did negative effect occur ie. ankylosis. It is important to understand that in this study the miniscrews were placed intentionally cause root damage so that the authors could determine the degree of penetration that could be sustained.

Practically when a orthodontist is placing a miniscrew he or she would likely to experience a significant alteration in resistance if the root had been contacted. And also proprioceptive nerve endings in the PDL would transmit the sensation of increased pressure to the patients, unless the patients was under profound anesthesia. Although it is always good to be careful about inferring results from animal studies to humans, I see no reason that similar results would not occur in humans.  Also in most cases miniscrews were placed in orthodontic patients would be in place more than 12 weeks. However I see no reason why these results should not be similar to miniscrews evaluated after longer period of time. It appears that authors do plan to conduct follow up research project with the screws in place for a longer period of time. You can find result this good new study in the November 2009 issue of the American Journal of Orthodontics and Dentofacial Orthopedics.

The Influence of Soft Tissue Thickness on Crestal Bone Changes Around Implants:

A 1-Year Prospective Controlled Clinical Trial

Tomas Linkevicius et al

Int J Oral Maxillofac Implnats 2009;24:712-719
                                                                            

October 1, 2010

Dr. Da-Nal Moon

[초벌원고]

Dose bond loss occur around maxillary lateral incisor implants after they are placed in the maxilla? You know today most referring dentists prefer to use implants to restore can congenitally missing maxillary lateral incisor spaces. But after implant placement in certain situations, there could be some recession of the gingiva causing an unesthetic appearance of the implant crown. This recession is usually preceeded by bone loss around the implant. But not all implants have bone loss after their placement. Is there any way of predicting whether or not your young adult patients will have a greater or lesser chance of bone loss around their maxillary lateral incisor implant? That question was addressed in the study that was published in the International Journal of Oral and Maxillofacial Implants in July 2009.

[수정원고]

I subscribed to this journal because I treat so many adults. I'd like to relate articles to our subscribers regarding important information that one can learn from this specific journal. I thought this would be a good study to review. The title of this article is “The Influence of Soft Tissue Thickness on Crestal Bone Changes Around Implants after one year." This study comes out of Vilnius University in Lithuania. And it's co-authored by Tom Linkevicius and several other research colleagues from the department of prosthodontics. The purpose of this study was to determine if initial gingival tissue thickness has any effect on marginal bone loss around implants that have been placed in humans. In order to test this question, the authors placed total of 50 implants in 20 patients. At the time of placement, the authors measure the thickness of the gingiva right over the placement site. The patients were classified as either having thick or thin gingiva. Those individuals with 2mm or greater gingival thickness were considered to have a thick biotype. Those with less than 2mm were considered to have a thin biotype. After 4 months, the implants were restored with crowns. Then these individuals were evaluated one year later with radiograph to determine if bone loss had occurred. The authors compared the thick and thin biotypes to determine if there were any differences in the amount of bone loss.

I think you get the idea. What would these researchers find? Remember the initial question. Does initial tissue thickness have any effect on future bone loss around single tooth implants? And the answer of that question is yes, definitely. The authors found that the average bone loss around individuals with thin gingiva was greater than 1.5mm after one year. But when the authors evaluated those individuals with thick gingiva biotype, they found that the average bone loss around those implants was only about a quarter of a millimeter. So there is your answer. It may be possible to predict which individuals will have bone loss and tissue recession around their implants placed in the esthetic zone. So if your patients in the future has a thicker biotype and that patient would be receiving implants to replace missing maxillary laterals, you may have a better chance of maintaining the bone support around these implants because of the thicker tissue biotype. If you are interested in reading this study, you will find it in the July 2009 issue of the International Journal of Oral and Maxillofacial Implants.

Maximizing Facial Esthetics in a Brachyfacial Class II Deep-Bite Case

Badii K, Uribe F, Nanda R.

J Clin Orthod 2009;43:591-99.
                                                                          

October 8, 2010

Dr. Eun-Ji Kim

[초벌원고]

I have had several occasions in the last few years where oral surgeons treating a Class II deep-bite patient with mandibular advancement surgery want the upper and lower arches leveled completely before surgery so that they inter-digitate ideally. Not only this is approach often take a long time because leveling the lower arch in a brachycephalic patient is often difficult, it produces a poor esthetic result since the lower face height is not increased as much as desired.

[수정원고]

A recent case report published in the JCO demonstrates how proper orthodontic planning can maximize the esthetic result in this type of patient. And this case report would be a good vehicle for discussion with the oral surgeon who insists on leveling prior to surgery. The article comes from the University of Connecticut, and it is called “Maximizing Facial Esthetics in a Brachycephalic Class II Deep-Bite Case”. The primary point of this article is that when an increase in lower face height is desired with mandibular advancement, the lower arch should be leveled after surgery. This concept is not new, but as I mentioned seems to sometimes be forgotten.

The manner in which proper planning and execution can maximize the esthetic outcome is demonstrated in a 14-year-old Class II female undergoing mandibular advancement surgery. Prior to treatment, she exhibited a deep overbite and increased lower curve of Spee. An examination of her initial profile revealed the reduced lower face height and an exaggerated mentolabial fold. To prevent lower arch leveling prior to surgery, the lower arch curve was maintained by initially segmenting and then stepping the lower archwire. Once the arch alignment was completed, the subject underwent mandibular advancement surgery. As planned, when the surgery was done, it required the distal segment of the mandible to rotate downward as it went forward to place the incisors into proper overbite. This resulted in a tripod occlusion where the teeth contacted only on the incisors and second molars. The tripod position was stabilized during initial healing with a surgical splint. Following splint removal, there was a lateral open bite of about 6 mm on each side. This open bite was closed rapidly by a combination of segmental lower arch mechanics to elevate the premolars and first molars and posterior box elastics. The finished result was an excellent Class I occlusion, but importantly, this was combined with the desired increase in lower face height. The increase in face height allowed normalization of the mentolabial fold and proper incisor display.

I would suggest that you keep a copy of this article handy to use for discussion with the oral surgeon that insists on having the arches leveled prior to surgery. The article is well-documented with many photographs and makes it easy to understand the concept of post-surgical leveling to increase face height. The excellent photographs will also help you understand this concept, if it is not clear. To find the article for review or for sharing, look in the September 2009 issue of the Journal of Clinical Orthodontics.

Secondary Alveolar Bone Grafting: Outcomes, Revisions, and New Applications

Goudy S, et al.

Cleft Palate Craniofac J 2009;46:610-612
                                                                         

October 15, 2010

Dr. Hyun-Ran Jeon

 [초벌원고]

Although secondary alveolar bone grafts are necessary in cleft patients to provide in intact dental arch for final orthodontic treatments, their success rate is now 100%. In an attempt to improve the success rate of secondary bone grafts, clinicians at the university of Iowa have been using demineralized bone matrix along with iliac crest bone for alveolar bone grafting in hopes of taking advantage of additional bone-induction factors. These clinicians recently reported on a retrospective study of secondary alveolar bone graft success with and without demineralized bone matrix to determine whether this addition is proving useful. Their report appears in the November 2009 issue of the Cleft Palate Craniofacial Journal in an article called “Secondary Alveolar Bone Grafting; Outcomes, Revisions and New Applications”.

 [수정원고]

 Here's how the study was done. All secondary alveolar bone grafts done in Iowa in the last 20 years were included a total of 103 patients. Records were reviewed to determine that a type of cleft, the age at alveolar grafting, complications after surgery, the need for additional grafting procedures, and the use of the demineralized bone matrix. The need for revision was compared between unilateral and bilateral grafts and between those that received demineralized bone matrix and those that didn't. The result showed that the average age at the time of grafting was about 9 years, which make sense based on grafting prior to canine eruption. The overall revision rate was about 1 and 4 but was higher almost 1 and 3 in bilateral clefts. The inclusion of demineralized bone matrix did not affect the revision rate in this group. In other words, the bone matrix did not appear to improve the success in the way that the clinicians has hoped. About 1/3 of the unilateral clefts subjects that required revision had a postoperative infection or trauma documented in the record. And this number was almost 2/3 in the bilateral group.

Although the authors had admit that the study was unable to demonstrate the benefit to the bone matrix, they also suggest that the sample size was relatively small and so further study with more patients could change the results. The bottom line is that at this point in time there doesn't seem to be any benefit to including demineralized bone matrix in the secondary bone grafting protocol.

For more information about success rates of secondary bone grafting in cleft children, details of the study from the university of Iowa can be found in the November 2009, Cleft Palate Craniofacial Journal.

Root Contact during Drilling for Microimplant Placement

Cho U, Yu W, Kyung HM

Angle Orthod 2010;81:130-136
                                                                         

October 29, 2010

Dr. Hoon Noh

[초벌원고]

Do you use mini-implants to help provide anchorage for your orthodontic mechanics? Today I think that many orthodontists would answer “yes” to this question. Now for my second question. Do you place these implants yourself? I’m not certain what percentages are, but I know several of my colleagues who do place their own implants. Third question, what’s the likelihood that you place mini-implant too near the root of adjacent tooth causing damage to their root? Hopefully wouldn't cause these problem. But if you only place a few mini-implants from time to time, would you have a greater likelihood of damaging a root during mini-implant placement compared to a surgeon who places these devices routinely. Those questions were addressed in the study of published in January 2010 issue of the Angle Orthodontist. I found it’s to be an extensive and fascinating study.

[수정원고]

The title of this article is “Root Contact during Drilling for Mini-implant Placement”. This study comes out of South Korea. It’s co-authored by Dr. Cho and two other research colleagues from one of the dental schools in Daegoo, South Korea. The purpose of the study was to investigate the frequency and pattern of root contact that occurs during the drilling for orthodontic mini-implant placement with a primary emphasis on the influence of 2 factors, surgery site and the clinician’s expertise.

First of all, the authors created dental cast that had 6 sites for implant placement. These dental casts had plastic teeth with roots on them that were in the position on maxillary right and left first molars and second premolars, mandibular right and left first and second molars, and maxillary and mandibular right and left central incisors. These are common sites for implant placement. Because these plastic teeth had roots, the authors could then determine whether or not the implant contacted these roots. Then the authors enlisted two groups of individuals. The experienced group consist that 8 orthodontists who have had more than 2 years experience surgically placing mini-implants. The inexperienced group consisted of 20 general practitioners who were just finishing their undergraduate dental training. Both groups were asked to place series of mini-implants into the 6 different locations on the dental cast. Now to simulate an actual clinical situation, the dental cast were mounted into a mannequin that had cheeks and lips so that there were restrictions just as in the oral cavity. Both experienced and inexperienced groups placed about 200 microimplants. Then the plastic teeth were removed from each of the dental casts so that they could be examined to determine if the mini-implant damage the root surface. Now damage was classified into minor, moderate, severe depending upon how close were into the surface of the root that mini-implant had penetrated.

OK, I think you get the idea of the experiment. What are these researchers find? Remember the primary question. Is there any difference in potential root damage between an experienced and an inexperienced surgeon placing a miniscrew? And the answer of that question is yes, definitely. These researchers showed that the inexperienced operators generated a statistically higher frequency of root contacts at over 20% compared to the experienced group who had a frequency about a half that much all around 10%. In addition the authors found that both groups most of the root contacts occurred in the posterior region. Question No.2. Was there a more susceptible site among the two groups? And the answer of that question is yes. The maxillary right first molar and the mandibular left first molar regions were the most common in both experienced and inexperienced practitioners.

So now you have the answer. If you are inexperienced surgeon and you are planning to place mini-implant your patients, you have a 20% risk of damaging an adjacent root. So what is everything to mean? Out of every five miniscrews that you place, one of those will probably cause root damage. Now if you refer to a surgeon who has experience, the risks reduced one in ten. So you make the choice. Do you place your own mini-implant yourself or not? Perhaps looking at the research might assist you in making that decision. If you’d like to review this study you will find it in January 2010 issue of the Angle Orthodontist.

Daily Chewing Gum Exercise for Stabilizing the Vertical Occlusion

N. MASUMOTO, et al.

Journal of Oral Rehabilitation 2009; 36:857-863

November, 05, 2010

Dr. Nabha Wael

[초벌원고]

The availability of mini screws has allowed us to treat more anterior open bite patients by vertically restraining or even intruding molars once this result is been obtained, maintaining this vertical molar position is important to prevent the open bite from returning investigators in Japan were curious to determine whether  daily  gum  chewing exercises could impact occlusial force on contact area in a way that could benefit open bite retention, the results of this investigation where published in the December 2009 issue of the journal of oral rehabilitation

[수정원고]

The title of the paper is “Daily chewing gum exercise for stabilizing the vertical occlusion”, let me give you a brief over view of how this research project was designed: 35 healthy adult dental students where recruded as the study subjects, these subjects had no significant malocclusion and were not recent orthodontic patients ,the occlusial force contact area and pressure where measured using the  occluser, an occlusial film that the subjects bit down on for three seconds at maximum pressure, following initial occlusial  measurements, the patients where issued a four week supplying of chewing gum and instructed to chew for at least ten minutes before or after meals three  times a day, following the four weeks of chewing exercise the occlusial  measurements were repeated and then the  measurements where done a third time four weeks after the exercise was discontinued ,the researchers used repeated trials at each  step to verify reducibility ,and also had five control subjects who did not participate in the chewing exercises but had the occlusial measurements done, the results showed no change in occlusial measurements in the control subjects as would be expected,  in the gum chewing exercise group the occlusial force on contact area increased significantly after four weeks of exercise and the balance of context tended to move forward when measured again four weeks after the exercise was completed ,the measurements of  occlusial force area had pretty  much returned to their base line levels.

There are some questions about the study design, the use of dental students as a subjects and the funding coming from the chewing gum company, a primary question for me is whether the increase in occlusial force with exercise demonstrated on these dental students  would also be seen in a group of patients treated for open bite with more vertical skeletal patterns?, and more importantly would it lead to greater stability of open bite correction?, I have to admit am a pet sceptical that this simple protocol could lead to long term improvements in stability, on the other hand there is  very  little  risk to using gum chewing exercise 30 to 45 minutes per day, the authors also surveyed the participants about their willingness to comply with ungoing gum chewing as exercise but I found a little value in this because of the dental students status of the subjects.

If you want to see these survey results or just get more details about this gum chewing study, look in the December 2009 issue of the journal of oral rehabilitation.

Oral Contraceptive Pill Use and Abnormal Menstrual Cycles

in Women with Severe Condylar Resorption: A Case for Low Serum 17β-Estradiol as a Major Factor in Progressive Condylar Resorption

Gunson MJ, Arnett GW, et al.

Am J Orthod Dentofacial Orthop 2009;136:772-9

November 12, 2010

Dr. Mi-Young Kim

[초벌원고]

Some patients particularly women have been shown to undergo severe condylar resorption with or without orthodontic treatment which can result in severe open bite or retrognathia. If you see a patient like this what would you do? A recent article addressed this question. The article is titled “Oral Contraceptive Pill Use and Abnormal Menstrual Cycles in Women with Severe Condylar Resorption: A Case for Low Serum 17β-Estradiol as a Major Factor in Progressive Condylar Resorption” by Michael Gunson and William Arnett, et al. which appears in the December 2009 issue of the American Journal of Orthodontics and Dentofacial Orthopedics.

[수정원고]

In this article the authors evaluated 27 women with no history of autoimmune disease who presented for orthognathic surgical correction for their skeletal deformity secondary to severe condylar resorption. The patients were selected for this study solely on imaging evidence of severe condylar resorption either currently active or active in the past. All subjects gave a history of spontaneous regressive change in their dental occlusion and development of a more retrusive chin position. Because severe condylar resorption is more severe in women versus men, researchers have suspected that the cause of the disease maybe related to the sex hormones. After having identifying the sample of 27 women with severe condylar resorption sex hormone dysfunction was evaluated and serum levels 17β-estradiol were measured. 17β-estradiol is an estrogenic hormone produced by ovaries and used in treating estrogen deficiency in women. It is mostly used as a hormonal replacement in menopausal women and is also used to treat hot flushes and prevent osteoporosis.

Of the 27 women with severe condylar resorption that were evaluated in this study, 26 had either laboratory findings of low 17β-estradiol or a history of extremely irregular menstrual cycles. Sixteen of the 27 had both low 17β-estradiol and irregular periods. Of the 27 women, 25 showed abnormally low levels of serum 17β-estradiol at midcycle, and the other 2 were at the low end of normal. The authors then identified 2 subjects of the women with the low 17β-estradiol levels. The first group did not produce estrogen naturally, a process called ovarian failure. The second group had low 17β-estradiol levels secondary oral contraceptive use. Of the 19 oral contraceptive pill users, all 19 reported that chin regression and open-bite changes occurred after starting oral contraceptive pill use. And 9 of the 19 reported condylar resorption symptoms within the first 6 months after starting use of the pill. Of the 27 women examined with severe condylar resorption, 17 had a history of irregular menstrual cycles. Seven of the 17 women with irregular menstrual cycles had episodes of frank amenorrhea that is no cycle at all, which corresponded temporally with their symptoms of condylar resorption. In trying to explain relationship between low 17β-estradiol had been shown to be a potentiator of osteoprotegerin which help to protect bone in the face of local and systemic inflammatory factors. Therefore when levels of 17β-estradiol are deficient, osteoprotegerin is not produced allowing local and systemic inflammatory factors to inhibit new bone formation or promote resorption of bone. With 26 of 27 women in the sample presenting with finding low 17β-estradiol or a history of extremely irregular menstrual cycles I think these results are very impressive.

So the answer to the question I asked at the start of this review is that if you encounter female patient with severe condylar resorption you should immediately check for history of either birth control pill use or extremely irregular menstrual cycles. You can find this article in the December 2009 issue of the American Journal of Orthodontics and Dentofacial Orthopedics.

Cementum, Pulp, Periodontal Ligament, and Bone Response After Direct Injury With Orthodontic Anchorage Screws: A Histomorphologic Study in an Animal Model

Volong Dao et al

J Oral Maxillofac Surg 2009;67:2440-2445

November 26, 2010

Dr. Kyung-Min Lee

[초벌원고]

Do you use miniscrews to enhance orthodontic anchorage? If so, do you place your own miniscews? Today many orthodontists place miniscrews or mini-impalnts. After all, the procedure is rather simple. The problem is that the miniscrews could injure the roots of adjacent teeth. This root damage could be extensive in some situations. What actually happens to the root surface when it’s injured? Although several studies have been published in humans, most of these studies don’t involve biopsies or block sections to actually analyze the root surface. But a study that I’ve found in the November 2009 issue of the Journal of Oral Maxillofacial Surgery did an extensive evaluation in experimental animals on what happens to the actual root surface, pulp, periodontal ligament and adjacent bone when intentional injury is caused to roots with the miniscrews. I thought this would be an excellent article for us to review. The title of this article is “Local Response After Direct Injury With Orthodontist Anchorage Screws.” This study is co-authored by Dr. Dao and several other researchers from the department of oral and maxillofacial surgery at Albert Einstein College in New York.

[수정원고]

The purpose of their study was to evaluate the repair of the periodontium after iatrogenic root injury with titanium screws. In order to accomplish this subjective, the authors used three experimental animals. A total of 60 self-drilling and self-tapping miniscrews were manually inserted into the maxilla and mandibles of these animals with specific intention of injuring the adjacent roots. These miniscrews were allowed to remain in these animals for a period of twelve weeks. At that time, radiographs were taken and block sections of the maxillas and mandibles were evaluated so that the root surface could be examined histologically. What did these researchers find when the microscopic analysis was performed? First of all, five of the sites showed direct screw penetration into the pulp chamber of the associated root. But there was never any pulpal necrosis in any of these five teeth. In fact, at every injury site, the authors found continuous cemental repair in the area of the external portion of the root. The authors never observed external or internal root resorption in any histologic specimen. Also, necrosis and inflammatory changes were not seen in the periodontium of any of the damaged roots. Now the authors did observe ankylosis of the socket wall with the tooth in one case where there was severe injury and displacement of the root fragment. Lastly the authors found that woven bone could be observed at all miniscrew-bone interfaces which was consistent with osteointegration.

So what the bottom line? In this study, the authors report that even in case of severe root injuries, there was no evidence of pulpal necrosis or inflammatory infiltrate at least up to twelve weeks in their animal models. So the authors believe that if the person placing the mini-implant follows the careful surgical protocol, that self-tapping, self-drilling screws cause little chance of severe root damage even when they are positioned close to adjacent roots. If you are interested in reviewing this information, you can find it in the November 2009 issue of the Journal of Oral and Maxillofacial Surgery.

Regression of Post-orthodontic Lesions by a Remineralizing Cream

Bailey DL, Adams GG, et al.

J Dent Res 2009;88:1148-1153
                                                                         

December 3, 2010

Dr. Hyun-Jung Lee

[초벌원고]

What is the most disappointing thing you see when remove brackets from teenagers? I don't know about you but for me it's white spot lesions or decalcifications. That patient's tooth alignment could be perfect, and the occlusion could be ideal. But if the patient has white spot lesions that is visible when that patient smiles, I regard this as an esthetic failure. The literature on improvement or correction, or elimination of this white spot lesions is full of techniques that frankly don't work very well. For the most part, these are permanent scars. But in the study of published in the December, 2009 issue of Journal of Dental Research has identified a new remineralizing cream that has the potential to perhaps improve these white spot lesions. The title of the article is "Regression of post-orthodontic lesions by a remineralizing cream". It's co-authored by doctor Suzuki and several research colleagues from Tohoku university in Sendai, Japan. Since these types of problems affect all orthodontists. I thought this would be a great article for us to review.

[수정원고]

Now first of all, let's talk about the basics. Why do most remineralizing solutions fail? You see in order to remineralizing enamel, the solution must have calcium and phosphate ions that are available on the tooth surface for a long enough period of time, that they could be incorporated into the enamel surface. Unfortunately when most solutions containing these ions are placed intraorally, they have limited effect due to their low solubility. But recently, researchers have shown that if these calcium and phosphate ions suspended in a complex called casein phosphopeptide-amorphous calcium phosphate complexes that these calcium and phosphate ions are stabilized. Thereby preventing them from transformation into crystalline phases and maintaining a supersaturated solution of these ions. If this solution is then applied to the teeth with decalcification lesions, perhaps remineralization is possible. At least that's the theory was tested in this research project. The authors gathered 45 patients who would participated in this experiment. They were randomly assigned into one of two groups. Now all subjects were selected from 10 private orthodontic practices, and all of these individuals were scheduled for orthodontic appliance removal. These subjects had total of over 400 white spot lesions. They were divided into two subgroups. One group received a placebo cream, and the other group received the remineralizing cream containing the calcium phosphate complex. Each group was asked to apply the cream in the morning and the night for 12 consecutive weeks. Then reevaluated at 4, 8, and 12 week intervals to determine the effectiveness of the remineralizing cream on the white spot lesions.

Without getting into any further detail on the chemistry, I think you probably understand experimental protocol. The question is what happened. Did this material actually work? And the answer to that question is "Yes, definitely". Based upon the analysis of three calibrated reviewers, the group that received the remineralizing cream demonstrated a significant reduction in white spot lesions compared to the placebo. Again, the authors believed that the reason for the success of this cream is that the complex is able to localize and stabilize calcium and phosphate ions at the tooth surface in a bioavailable form that can promote remineralization of enamel to subsurface lesions in the mouth. This thereby restores the white opaque appearance of the lesions to translucency. So there you have it. This new calcium phosphate complex contained in this remineralizing cream is successful. Now there were no bland names given in the article. So I don't really think this remineralizing cream is yet available for clinical use. But in the future watch for this material to appear in the market. This could be away to improve those ugly white spot lesions in our patients who don't have very good oral hygiene. If you'd like to review this article, you can find this in the December, 2009 issue of Journal of Dental Research.

Miniscrews in Orthodontic Treatment: Review and Analysis of Published Clinical Trials

Crismani AG, Bertl MH, et al.

Am J Orthod Dentofacial Orthop 2010;137:108-113

                                                            December 10, 2010

                                                            Dr. Biao Yan

 [초벌원고]

I assume that you are either using or considering the use of miniscrews as temporary anchorage devices for your patients. Assuming this, I would like to ask you some questions. What success rate can you expect to achieve using miniscrews? Would you expect to have a higher success rate in either the maxilla or the mandible? Would you expect to have a higher success rate in males or females? Would your success rate be influenced by the age of the patient? Would the length and diameter of the miniscrew that you use influence the success rate? Would it make any difference if you used a surgical flap or a flapless technique to place the miniscrew? Would it make any difference if you immediately loaded the miniscrew or waited for a healing period before placing forces on the screw? I believe the questions that I have asked are all very practical and clinically related. My next question would be “How would you find the answers to these questions?”. The best way would be to review the results of published clinical trials that met specific research criteria. Fortunately, this has already been done for you in an article titled “Miniscrews in Orthodontic Treatment: Review and Analysis of Published Clinical Trials” by Adriano Crismani which appeared in the January 2010 Issue of the American Journal of Orthodontics and Dentofacial Orthopedics.

 [수정원고]

In this article, the authors conducted a MEDLINE search and identified 734 articles related to miniscrew placement. They then limited the articles to those published in either English or German. Those that involve human clinical trials, delimitated any case reports or case series articles, eliminated studies with fewer than 30 miniscrews and required that the studies had additional data on factors related to patient, miniscrew, surgery and loading available for correlation with the miniscrew success rates. Of the 734 articles they found 14 articles that match all the criteria for this study. Based on the review of these articles, they reached the following conclusions. The mean overall success rate was approximately 83% and was higher in the maxilla than in the mandible. There was no difference in success rates based on sex. However, greater success in patients over 30 years of age was observed. Related to the length and diameter of the screws, these studies indicated that screws under 8mm in length and 1.2mm in diameter had lower success rates and should be avoided. There was no advantage due on a delayed loading period nor was there any advantage to doing flap surgery prior to placement of the miniscrews. I thought it was impressive that out of 734 articles only 14 met the rigid criteria for this study. Because the authors took the time to sort out these articles, you can have more confidence in the results that were reported and you now have answers to the questions that I asked at the start of this review. You can find this excellent article in the January 2010 Issue of the American Journal of Orthodontics and Dentofacial Orthopedics.

Prevalence of Temporomandibular Disorders in Obstructive Sleep Apnea Patients Referred for Oral Appliance Therapy
 

 [초벌원고]

Let me tell you what happened to me last week. A 45-year-old male was referred to me for orthodontic treatment. He has a class I crowded malocclusion that will require non-extraction orthodontic therapy. But as a part of my usual routine, I had him fill out health history. This individual is generally very healthy. But in the health history, he circled two items. One was ‘Have you ever been treated for sleep apnea?’ He circled ‘Yes’. The other was ‘Do you have pain in your jaws?’ He also circled ‘Yes’ for that question. So this 45-year-old with a routine class I malocclusion has obstructive sleep apnea and temporomandibular pain.

 [수정원고]

Here is my question. Is this typical? Are they related? How often do individuals with sleep apnea have temporomandibular joint symptoms. That question was addressed in the study that was published in the October 2009 issue of the Journal of Orofacial Pain. I thought this was very interesting and ruminating study and I would like to review it for you. The title of this article is “Prevalence of Temporomandibular Disorders in Obstructive Sleep Apnea Patients Referred for Oral Appliance Therapy.” This study comes out of federal university of Parana in Brazil and the senior author is Dr. Paulo A. Cunali.

The purpose of this interesting research project was to evaluate the prevalence of pain associated with TMD in obstructive sleep apnea patients who have been referred for oral appliance therapy. These researchers assembled sample of ninety subjects, half male and half female. All have been referred for oral appliance therapy because of moderate obstructive sleep apnea syndrome. All subjects have been diagnosed in an overnight sleep clinic to have between 15 and 30 apneic episodes per hour. Now this is regarded as moderate obstructive sleep apnea. In addition, these individuals had the body mass index that was above the acceptable range. So basically, these were all subjects with moderate to severe obstructive sleep apnea. Then the author performed temporomandibular exam on the subjects to determine the presence of signs and symptoms of TMD. Finally, they correlated what they found on the TMD exam to determine the incidence of these symptoms in these subjects. So this was a very straight forward study design.

What did these researchers find? Of the 90 patients that were evaluated with moderate obstructive sleep apnea syndrome, a little over half or 52% presented with some sign or symptom of TMD. Of these subjects, 75% had chronic pain related to the TMD. The most common TMD diagnosis for this group was myofacial pain with or without limited mouth opening and arthralgia or joint pain. What have these researchers shown us? Based upon the analysis, the authors believed that the prevalence of pain associated with TMD and the impact of this dysfunctional pain were high in obstructive sleep apnea patients who have been referred for oral appliance therapy.

As a result, these researchers suggest that the standard TMD evaluation be performed for all subjects who present with oral obstructive sleep apnea in order to determine if supportive TMD therapy should also be used for the sleep apnea subjects while their undergoing oral appliance therapy. So if you would like to review the study that relates TMD with obstructive sleep apnea, you will find it in the October 2009 issue of the Journal of Orofacial Pain.

Randomized Clinical Trial of Acupuncture for Myofacial Pain of the Jaw Muscles

Shen YF, Younger J, et al.

J Orofac Pain 2009;23:353-359

December 24, 2010

Dr. Sang-Mi Lee

[초벌원고]

How do you manage adult orthodontic patients who have myofascial pain? In my training and clinical experience, I found that the occlusal splints tend to work successfully on most adult subjects if they wear the appliance. But we all know that there are some patients who simply do not response favorably to wearing a occlusal splint for muscle pain. What would you recommend next? Obviously, medications could be a possibility but have you ever considered recommending acupuncture?

Now some of you would probably consider this a silly question but an article, that was published in October 2009 issue of the Journal of Orofacial Pain reported on some interesting results that were achieved with acupuncture in a sample of subjects with patients with myofascial pain of the jaw muscles. I’d like to review it for you on this month’s issue of practical reviews on orthodontics. The title of this study is “Randomized Clinical Trial of Acupuncture for Myofascial Pain of the Jaw Muscles”. This study comes out of the Department of Oral and Maxillofacial Surgery at the University of California in San Francisco and it was co-authored by Dr. Yoshi Shen and three other research associates.

[수정원고]

The purpose of their investigation was to evaluate the effectiveness of acupuncture in treating symptoms associated with myofascial pain of the jaw muscles. In order to accomplish this subjective, the authors gathered the sample of twenty eight subjects who had been diagnosed with bilateral chronic myofascial pain of the jaw muscles. All subjects were over the age of eighteen and had pain at least four times a week in the jaw muscles for at least a period of twelve weeks. The average pain severity was at least four on a ten point scale for at least one hour per day. Then the sample was randomly divided into two groups. One group received acupuncture and the other group received a sham acupuncture procedure.

Let me describe the acupuncture technique. A single acupoint was used for all of the participants. This area is located between the thumb and the index finger – this is the area where the radial nerve innervates and this acupoint is commonly used for head and neck pain. In the real acupuncture subjects, an acupuncture needle was inserted into the left hand to a depth of about ten to twenty millimeters. This remained in place for fifteen minutes. After the first five minutes, the acupuncture was restimulated by performing quick quarter turns at the needle for fifteen seconds. Now in the sham group, the skin was pricked by the needle but it was not penetrated. Just before the acupuncture and sham acupuncture were performed, all subjects were asked to clench their teeth continuously for two minutes in order to produce pain in their jaw muscles. They were then asked to fill out a visual analog scale that rated the degree of the pain prior of the acupuncture. Then immediately after the acupuncture and sham procedure were performed, the subjects were asked again to evaluate their pain level on a visual analog scale. These two pain assessments were then compared. So I think you get the idea of these experiments. What happened was acupuncture effective? The answer to that question is yes, definitely. In the sham group, only one of the twelve participants responded favorably with minimal reduction in pain. In the real acupuncture group, four individuals responded minimally and eight responded with the major reduction in symptoms. So in other words, the acupuncture was effective at reducing the pain in a short term.

How does this study relate to others that have been performed in this area? The current study was prospective but another study that was recently published was a retrospective review of over one hundred patients treated for facial pain with acupuncture. That study found that about seventy percent of the sample benefitted from acupuncture.

You know, I had not heard of this type of approach to reducing myofascial pain. Now the authors were very honest in their study and they recognized that there were several limitations. First of all, the sample was small at only twenty eight subjects. Second, in most acupuncture treatment, there are several acupoints that are addressed or stimulated at anyone sit in. And finally, there was no long-term assessment of the relief of myofascial pain in this sample. But at least this study showed that there was some significant obvious short-term positive effect. Perhaps, we will learn more from these researchers in the future regarding the use of acupuncture to help in treating patients with myofascial pain. If you are interested in reviewing this study, you will find it in the October 2009 issue of the Journal of Orofacial Pain.