How do we treat anterior open bite? A real world study.
One of the most challenging problems that we treat is anterior open bite. This ambitious new study was carried out in the real world of orthodontic practice. I thought that it gave us great information. Everyone should read this paper.
Anterior open bite is one of the most challenging problems that we treat. This is because there is a dearth of scientific evidence on the best method of treatment. Furthermore, any treatment that simply extrudes the incisors, to close down the AOB is particularly prone to relapse. As a result, we use a wide variety of techniques. These tend to be fixed appliance treatment only, orthognathic surgery, aligners, and temporary anchorage devices. However, we do not the factors that may influence our treatment decisions. The AJO published this new ambitious study. A team led by academics at the University of Washington, USA did this research.
Greg Huang et al. Am J Orthod Dentofacial Orthop 2019;156:312-25.
What did they ask?
They did this study to answer this question.
“What practitioner and patient characteristics influence treatment recommendations for adults with anterior open bite”?
What did they do?
This was a very complex and ambitious study. They did the study as part of the National Dental Practice-Based Research Network. This is a network of dental practitioners who carry out practice-based research. Their short mission is
“To improve oral health by conducting dental practice-based research”.
In effect, they do investigations in the “real world” of dental practice. There is no doubt that this is the way forward for dental research. Currently, most orthodontic research is carried out in dental schools. It is, therefore, doubtful that this is totally transferable to the private practice setting. As a result, the findings of these studies are going to be very relevant. This orthodontic team worked with the national study to do this investigation on the treatment of anterior open bite.
The team recruited providers of orthodontic treatment from six regions of the USA. They then collected data on the practitioners and their patients who were having therapy for AOB.
The patients were adults who had an Anterior open bite. The practitioners provided information from their clinical exam, cephalogram and intraoral images. They sent this information to the regional centres for analysis.
They collected the following data on the practitioners
- Years in practice
- Nature of practice
This information was gathered about the patients
- Their age and gender
- Dentofacial characteristics
- ANB, mandibular plane angle, incisor angulation, facial height, overbite and overjet.
They divided the treatment decisions into
- Fixed appliances
- Temporary Anchorage Devices
- Orthognathic surgery
The study team also developed an AOB index (POSI) that recorded the degree of the open bite from the intraoral photographs.
Finally, they did a sophisticated statistical analysis. They did this in several stages, The final step involved identifying any predictors of the treatment decisions.
What did they find?
They found a large amount of clinically useful information. I do not have enough space to cover all the information here. Consequently, I am going to concentrate on the predictors of the treatment.
They obtained data from 91 practitioners, and most of these were orthodontists. They obtained usable data from 347 patients. More than 60% of these patients fell into the most severe grades of POSI.
345 patients were recommended 1 of the 4 main treatments. These were
|Fixed appliances only||146||42%|
When they looked at the predictive models
White and Asian patients were advised Aligners almost 3 times as often as black or Hispanic/Latino patients. Patients with tongue posture habits were 2.4 times more likely to be offered aligners over fixed appliances.
Practitioners from private practices were much less likely to offer TAD treatment than practitioners in an academic setting.
When they looked at predictors for surgery versus any other type of treatment, these were the race of the patient, whether they had insurance coverage, the presence of posterior crossbite, molar discrepancies, size of AOB and increased mandibular plane angle.
What did I think?
This was an extensive and ambitious investigation that provided a great deal of clinical information. As a result, the well-written paper was lengthy and very detailed. I hope that I have provided sufficient information on this work, but I suggest that you read the full article, if you can get access.
I thought that the findings were fascinating. The investigators have written a clear discussion that raised many important points. Again, I shall not go into all aspects of this. However, I thought that it was interesting that the orthodontists did most of the treatments using fixed appliances or surgery. Currently, there is a large amount of interest in the use of TADS and Aligners for AOB. Paradoxically, this interest was not reflected in the findings of this study. This may suggest that there is a time lag for the adoption of these relatively new techniques. Alternatively, they may also not be as popular as some of their proponents would have us believe?
When I looked at the data for surgery vs all the other treatments. I felt that some of the findings, for example, the effect of the skeletal discrepancy on the treatment decision were self-evident. Nevertheless, the influence of insurance coverage on this decision was clearly significant. This means that the treatment decision was influenced by economic factors. As a result, I wonder if we could suggest that the “best treatment” was potentially being denied to patients who would have benefited had they got insurance coverage. But I will concede that this may be the European Socialist in me!
Finally, it was great to see research done in a practice setting. I look forward to seeing the results of the treatment that they carried out. I hope that there are sufficient numbers of similar cases treated by different methods. It could then be possible to make some comparisons on the effectiveness of the different treatments. While this would not provide us with the level of evidence that we may get from a trial. It could be a great way forward for orthodontic research.
If I were starting my research career again, I would be working with these practice-based networks to do research of real value. This is the next step and challenge for orthodontic researchers.
Emeritus Professor of Orthodontics, University of Manchester, UK.