Masticatory myofascial pain: an explanatory model integrating clinical, epidemiological and basic science research

Masticatory myofascial pain (MMP) is a regional muscle pain disorder characterized by localized muscle tenderness in taut bands of skeletal muscles and pain and is one of the most common causes of persistent regional pain. The affected muscles may also display an increased fatigability, stiffness, subjective weakness, pain in movement, and slight restricted ROM that is unrelated to joint restriction. Although the exact etiology of MMP is unclear, recent research has improved our understanding of factors that contribute to the development and progression of MMP. Understanding these factors can help to validate an explanatory model for etiology and treatment of MMP. This model includes peripheral mechanisms from local biomechanical strain leading to the onset of early cases of MMP while central mechanisms associated with psychosocial factors lead to increased chronicity of MMP. As MP persists, chronic pain characteristics often precede or follow it's development. Management of the syndrome naturally follows from this model with therapy to rehabilitate the trigger points (TrPs) while focusing effort on reducing all contributing factors.