Temporomandibular joint dysfunction (TMD or TMJD), also known as temporomandibular joint dysfunction syndrome or temporomandibular disorder, is a vast and complicated subject. Some aspects of diagnosis and treatment of TMD are very controversial. Doctors disagree over fundamentals such as the definition of "centric relation," and what the normal position of the condyle should be. The factors causing it and and effectiveness of various treatments are the subject of much debate.
That being said, TMJ problems occur when the condyles are not in the correct position or not moving correctly. Similar to that of a person who develops back pain when they have bad body mechanics (movement). When the teeth fit in a certain way or when the patient chews in a way that the condyles do not like, that is when TMJ problems appear.
Patients who have TMJ problems can experience pain or they can have no pain at all. During orthodontic treatment a patient’s bite can worsen or improve the TMJ position - this is fairly common.
At the end of treatment is when TMD should be analyzed and treated if needed. However, at any point during treatment you may elect to refer to a specialist for consultation and/or management if uncertainty or unique problems arise.
What do I do if my patient complains of TMJ pain or issues?
It has come up with some patients undergoing clear aligner treatment, that the Chewies that are occasionally recommended caused a fulcrum point in the patient's occlusal plane and resulted in joint stress and positional changes and consequently worsened the TMJ position.
(The definition of fulcrum is: "the point on which a lever rests or is supported and on which it pivots". In this application of the concept, the Chewie interposes between the occlusal tables and becomes an effective pivot point (fulcrum). Depending on the patient and where it is placed, the position of the condyle in the fossa may change and become stressed. A dental example of an occlusal fulcrum is a high filling.)
If this occurs with a patient, we advise a conservative joint management approach, as described below:
- Discontinue Chewies and ask the patient to help seat the trays by pushing up/down with fingers instead.
- Ensure the clinical TMJ exam is complete including joint films (CBCT) and radiologist report. (You need to rule out degenerative joint disease and pathology.)
- Continue to clinically monitor patient's TMJ signs and symptoms at every visit. If pain or limitation of jaw movement is noted consider staying with the last passive aligner until symptoms resolve with conservative therapy (Motrin, no gum chewing, soft diet, limit wide openings, etc.)
- Consider a one year TMJ radiographic examination - if no changes from baseline, go to 3-5 year radiographic follow-up.
With the above actions are taken, the best case scenario and most probable is that the TMJ issues (joint popping or pain) will diminish. If the problems do not persist, continue on with the patient's aligner treatment.
Steps #2-4 above apply to any aligner patient with TMD.
If the issues persist we would recommend going back to step 3 above.