Trigger point formation and their perpetuation in the Lateral Pterygoid is quite common with this workhorse muscle.
Excerpt from T&S Volume 1
“The lateral (external) pterygoid muscle refers pain deep into the temporomandibular (TM) joint (TMJ) and to the region of the maxillary sinus The pain is strongly associated with functional disorders of that joint. In our experience, trigger points (TrPs) in this muscle are the chief myofascial source of referred pain felt in the TMJ area. The myofascial pain syndrome is easily mistaken for the pain of TMJ arthritis.
Most patients with temporomandibular joint dysfunction suffer primarily from a muscular disorder, such as that caused by active TrPs in the lateral pterygoid muscle. Severe pain in the TMJ region is commonly referred from TrPs in the lateral pterygoid, the medial pterygoid, or the deep layer of the masseter. This TrP pain referred to the TMJ, as well as altered occlusion due to TrP tension with shortening of the muscles, often has caused treatment to be misdirected to the joint and teeth, with frustrating results. This often happens when the critical role played by TrPs in the lateral pterygoid and other masticatory muscles has been ignored or ineffectively treated.
Severe pain referred by TrPs to the maxilla, with the autonomic concomitant of excessive secretion from the maxillary sinus, may likewise be misdiagnosed as sinusitis, so that the patient thinks of the pain as a “sinus attack.”
Patients experiencing tinnitus may have lateral pterygoid TrPs responsible for it.
Myofascial pain on chewing tends to be proportional to the vigour of movement. Clicking sounds in the TMJ area may result from dysfunction of the lateral pterygoid muscles. Although the active range of motion of the jaws may be reduced with active TrPs in the lateral pterygoid muscle alone, the decrease in range (brought about primarily by inhibition due to pain) may not be sufficient for the patient to be aware of it.”
If you suffer from any of the above symptoms, be sure to have your bodyworker/therapist check, and if necessary, treat your lateral pterygoids (both externally and intra-orally) for trigger points.
If TrPs are present, there will be notable tenderness when they’re compressed with the fingertip, but proper treatment is often well worth the effort.
Note: these pterygoid muscles are often affected/stressed from dental work that requires the mouth being open for prolonged periods.