At last, a large study on orthotropics: The first nail in the coffin?
Over the past few years. I have posted several times about orthotropics. This is treatment was invented by Joh Mew in the UK. It is based on the concept that using removable appliances can change the skeletal pattern and muscle function. Unfortunately, while John and, more recently, his son Mike has vigorously promoted orthotropics, high-quality research has not been done on the effects of treatment. Until now, when I came across a well-written MSc thesis from the University of Alberta.
What is orthotropics?
I posted about myofunctional orthodontics and orthotropics in 2015. However, some readers may not be familiar with this treatment. Therefore, I have done a quick, precise
This form of treatment was developed by John Mew in London, South of England. Over the last 20 years I have had discussions with John about this treatment. He has given a seminar to the speciality trainees at Manchester. However, UK orthodontics has not accepted his thoughts and there may be many reasons for this. I do not want to go into them now. However, his son Mike, a speciality-trained orthodontist has joined him and these ideas are being put forward more concisely. Details of this treatment are on their website.
In brief, orthotropics is based on the theory that different forms of removable appliances and relevant muscle training correct the soft tissue behaviour and oral environment. This then results in the development of the skeletal bases and a change in the position of the teeth. I have looked at the evidence that has been published. Unfortunately, I could not find any sufficiently powered prospective studies. They illustrate successfully treated cases in papers, a published book and on their website. However, some of these look a little dated. This is reasonable because John has been working as a single-handed practitioner for many years with limited resources. Nevertheless, there is no doubt that some of the results are impressive.
The first large study on orthotropics
A team from Alberta, Canada did the study. The University of Alberta published the thesis in its depository.
Lead author: Faraz Tavoossi. Supervisor: Manuel Lagravere. Committee Member: Carlos Flores-Mir
What did they ask?
They did the study to:
“ Investigate the skeletal and dental changes that occur using a compliance-based orthotropic treatment approach with orofacial posture exercises aimed at controlling vertical facial skeletal growth in the mixed dentition”.
What did they do?
They did a retrospective investigation.
They analysed the cephalometric radiographs of 102 consecutively treated patients. A general dental practitioner (Dr Wong) treated the patients using the standard orthotropics two-phase approach. His initial phase of treatment was directed at the expansion of the arches using removable appliances and a series of daily exercises that were directed at improving oral posture. The second phase of treatment was done with the Mew Biobloc appliance to train the patients to adopt a closed-mouth posture at rest.
Dr Wong took cephalograms before and after active treatment.
They compared these cases to a ‘Control’ group. This was 75 sets of records obtained from the AAOF Craniofacial Growth Legacy. They matched the patients for age sex and timing of records.
The primary outcome measure was the change in 13 skeletal and dental measurements.
What did they find?
The mean age of the patients at the start of treatment was 8.4 years (range 5.5-11.75). The mean length of treatment was 4.1 years (range 1.6-7.00).
They confined the results of treatment to cephalometric measurements. I will not present and discuss all these here. But these were the main points.
They found the following when they compared the two groups pre-treatment measurements.
- Most of the dental and skeletal measurements were not statistically different.
- The treatment group had a 6.6mm shorter mandibular body length than the control group.
- The treatment group had a 5.4mm shorter initial facial height and 1.39mm shorter ramus height than the control group.
These are clinically significant differences. As a result, we need to consider these differences when we critically review their findings.
When they looked at the effects of treatment, they measured change. These were the important, statistically significant measurements.
- SNA increased by 0.97 degrees in the treatment group but decreased by 0.13 degrees in the control group. This resulted in a difference of 1.09 degrees.
- ANB decreased in both groups, but this was greater by 1.47 degrees in the control.
- Mandibular body length increased in both groups by approximately 8mm.
- There was a statistically different difference in gonial angle reduction. The control group was reduced by 1.2 degrees more than the treatment group.
- The treatment group had a 1.6mm less increase than the control for lower facial heights.
- In the treatment group, the upper incisors proclined 8.5 degrees more than the control. Similarly, the lower incisors were proclined 4.8 degrees more than the control group.
- The treatment group had 1.2mm less overjet and 1.2mm less overbite than the control.
I have interpreted this data as suggesting that the appliances did not change the skeletal pattern of the patients in a clinically meaningful way. Furthermore, they appeared to simply procline the upper and lower incisors.
The authors of the thesis concluded:
“The treatment protocol may not be considered to have produced a clinically meaningful effect on skeletal and dental changes”.
What did I think?
I have looked at many Master theses during my career, and this was one of the better ones. All aspects of the work were well written.
I would also like to acknowledge the work that the dentist, Simon Wong did in collecting these records. Furthermore, he took the step of submitting his records for research. This was in marked difference to John and Mike Mew, who have not subjected such a large sample of cephalometric records for analysis.
I want to congratulate him on his contribution to research in orthotropics. Before Simon submitted these records to Alberta, he had offered to submit them to me for analysis. Unfortunately, I could not do this because I had stopped working in the Dental School and had no access to resources. However, he was encouraged and decided to work with Alberta.
However, we must remember that this is an unpublished Masters thesis. As you know, I do not usually review these. I decided to take this step because the work dealt with a controversial area relevant to our clinical practice. Importantly, I understand that the authors submit will submit these results and others for publication in a refereed journal.
I have looked at this as if I were refereeing a submitted paper. While this is a good piece of research. There are some issues that we need to consider.
- It was a retrospective study and is subject to selection bias.
- The control group was taken from a growth study and is therefore subject to secular change.
- The outcome was confined to cephalometric data, and other outcomes need examining.
Nevertheless, this is an excellent first step, but we must carefully consider the uncertainty these issues introduce.
In summary, this thesis suggests that the orthotropics approach does little. Importantly, It does not influence the skeletal pattern differently from any other functional appliance treatment or even just normal facial growth. All it does is procline the incisors. Notably, this data does not support any of the Mews’ claims for orthotropics.
I know there will be a load of moans and gnashing of teeth from the orthotropic/myofunctional believers. Nevertheless, this is the first research into this treatment. I would like to say that If you really believe in your treatment, why not be as open-minded as Simon Wong and research its effects?
Emeritus Professor of Orthodontics, University of Manchester, UK.