THE EDITOR'S CORNER
We are not going to resolve the question of the merit of myofunctional therapy in orthodontics in one issue of JCO, but we are presenting in this issue an extensive interview with a world authority on the subject on the orthodontic side, Dr. William Proffit.
It is my contention that orthodontists are better able to understand myofunctional therapy than myofunctional therapists are able to understand orthodontics; and that, in claims made for myofunctional therapy related to orthodontic correction, neither orthodontists nor myofunctional therapists have published evidence which in quality or quantity justifies contentions of reliable success, nor which satisfies the requirements of the scientific method. Dr. Proffit has studied the available evidence and done a substantial amount of research on tongue thrust and has failed to find substantial value in tongue thrust therapy in relation to orthodontic problems.
Some tongue thrusting may be primary, with or without dental effect such as anterior open bite, but most of it appears to be secondary, as an accommodation to environmental conditions.
Myofunctional therapy for the correction of tongue thrust should possibly be considered for those individuals who have had their other basic cause eliminated; who have been treated orthodontically or are being treated orthodontically with indifferent results; who have an obviously strong tongue thrust which seems to the orthodontist to be a strong possible interference with the orthodontic treatment; or with a residual speech problem. You don't treat a tongue thrust just to eliminate the tongue thrust. You don't treat a tongue thrust to pave the way for orthodontic treatment. You don't treat a tongue thrust as a substitute for orthodontic treatment. You treat the cause of the tongue thrust; and you treat the environment of the tongue thrust first, orthodontically.
Myofunctional therapists have a legitimate field of endeavor in speech therapy and possibly in other myofunctional disorders. Neither our patients, nor orthodontics, nor myofunctional therapy itself is served by an attempt to find a role for myofunctional therapy as a routine part of orthodontic service until it can be proven in actual clinical practice that there is orthodontic merit to the procedure. So far, what weight of evidence there is is against it.
There are other myofunctional therapy exercises which must be called to question. Without reference to muscle physiology or anatomy, there have been orthodontists who have looked at a lip and said, "That is a lazy lip. It needs to be toned up". The number of exercises were either left to the patient's decision, done supposedly until the patient tired, done for so few times that they could not possibly have accomplished the purpose, or prescribed for so many that the patient would not do them. There does not appear to have been any correlation made between the strength and duration of the exercise and the result, nor assurance that the exercise was done at all; nor proof that the result was due to the treatment; and the result in any case was assessed subjectively.
Other orthodontists have looked at a lip and said, "That is a short lip. We must lengthen it". Lip stretching exercises were prescribed in which the upper lip was stretched over the incisal edges of the upper incisors. This is a questionable effort when you consider the anatomy of the upper lip. The only muscle in the upper lip from corner to corner which runs in a vertical direction is a thin little muscle called naso-labialis which runs from the orbicularis oris complex to the back of the septum of the nose. You have a better chance of changing that short upper lip with orthodontic procedures to tip the palatal plane down at ANS and bring the nose and lip along with it.
Can you really place an 8-year-old on exercises with instructions to tense one muscle or another seven to ten times three times a day and attribute changes in the next four years to that exercise? Or show what happened with a combination of mechanotherapy and myofunctional therapy to support a contention that myofunctional therapy is effective? Since we now have the capability to separate the effects of growth and the effects of treatment, we should be able to separate the effects of mechanotherapy and of myofunctional therapy, and hopefully that will be done. Until then, there may be as good a case to be made for the idea that natural exercise has more to do with the maturing tone of lip muscles, as speech and eating functions themselves mature and are more carefully and completely performed.
