Etiology • Usually secondary to hyperfunction (habitual) • May be related to dystrophic or metabolic disease of muscle • May be idiopathic
Clinical Presentation • Usually bilateral masseter muscle enlargement • Painless, symmetric, evenly contoured • Emphasized when muscle is contracted (ie, jaw is clenched) • Responds to functional or hyperfunctional demands
Diagnosis • History • Muscle biopsy if metabolic disease suspected
Clinical Presentation • Usually bilateral masseter muscle enlargement • Painless, symmetric, evenly contoured • Emphasized when muscle is contracted (ie, jaw is clenched) • Responds to functional or hyperfunctional demands
Diagnosis • History • Muscle biopsy if metabolic disease suspected
Differential Diagnosis • Sialoadenosis • Parotid gland enlargement • Bacterial infection • Viral infection (mumps, ? cytomegalovirus) • Autoimmune condition (Sjögren’s syndrome) • Neoplastic infiltration
Treatment • Dependent upon etiology • Usually relates to defining cause and includes the following:
• Observation • Management of underlying cause when appropriate
Prognosis • Excellent