Masticatory Myofascial Pain: An Explanatory Model of Regional Muscle Pain Syndromes

SUMMARY

Objectives: To review the current clinical status of masticatory myofascial pain [MMP].

Findings: Masticatory myofascial pain is a regional muscle pain disorder that is consistent with regional muscle pain disorders in other parts of the body. It is characterized by localized muscle tenderness in taut bands of skeletal muscles with associated regional and referred pain. The affected muscles may also display an increased fatigability, stiffness, subjective weakness, pain in movement, and slight restricted range of motion that is unrelated to joint restriction. Understanding these factors that contribute to the development and progression of MMP can help to validate an explanatory model for etiology and treatment of MMP. This model includes peripheral mechanisms from local repetitive biomechanical strain leading to the onset of early cases of MMP while central mechanisms associated with systemic and psychosocial factors lead to increased chronicity of MMP. Management of the syndrome naturally follows from this model with therapy to rehabilitate the trigger points while focusing effort on reducing both regional and central contributing factors.

Conclusions: Pain in the masticatory muscle region should be evaluated thoroughly seeking evidence for MMP. The historical and examination features can help to make a prospective diagnosis based on established clinical criteria. Treatment of this condition, based on a painful muscle model, can be very rewarding.

KEYWORDS:

• Myofascial pain
• muscles
• pain
• etiology
• mechanisms