14/10/2023
A virtually unknown but extremely important contributor to temporomandibular joint disorder, is the suprahyoid muscle group. Patients will frequently, either due to stress / anxiety / OCD or simply poor cervical stability "clench" these muscles. Suprahyoid muscle clenching is such a common problem and is especially important to consider when patients develop TMD secondary to stress or head-/neck injuries.
Looking at rough configuration of these muscles, one can see they span from the chin, to the hyoid bone, to the sternum. And, when clenched, it will contribute to retraction, ie. backwards pull of the mandible. As I have written about hundreds of times, retraction of the mandible, especially forced retraction, will compress or even crush the temporomandibular joint and often result in both joint damage / irritation and irritation of the auriculotemporal nerve, which is a part of the trigeminal nerve complex.
Suprahyoidal muscle clenching also tends to result in overloading of the pterygoid muscles, which is a common co-malady seen in patients with TMD.
I will address this by gently palpating the patient's suprahyoid muscles about an inch posterior to the mental protruberance, ie. towards the antrior diagstric and genihyoid muscles. This needs to be done when the patient is off-guard and also in a way where they don't clench up as a guarding mechanism due to feeling uncomfortable (it's an uncommon place to palpate, after all, and especially without giving notice first).
If I find that the patient is suprahyoid clenching, they simply need to assess themselves often and work hard on stopping this poor habit. I will treat the TM joint in tandem with this, working on opening and closing mechanics, pterygoidal strengthening and joitn decompression.