If there is pain in the mandibular posterior teeth, what muscle is the pain deferred?

• A. Anterior temporalis
• B. Middle temporalis
• C. Upper superficial masseter
• D. Lower superficial masseter

Answer: (D)

Muscle-originated referred pain can mimic dental pain because sensory input from jaw muscles converges with dental afferents in the same trigeminal pathways. When a trigger point exists in the masseter, especially in its lower superficial portion, the pattern of referred pain tends to project to the mandibular molar region. This makes a patient feel pain in the posterior teeth even though the teeth themselves aren’t the source.

The temporalis muscle and the other part of the masseter have different referral patterns—temporal muscle trigger points more commonly produce pain in the temple and sometimes anterior teeth, not the posterior molars; and the deep portion of the masseter, while involved in grinding, is less typically associated with posterior-tooth referral than the lower superficial portion. Thus, pain in the mandibular posterior teeth is most consistent with referral from the lower superficial masseter.