“…Hemimasticatory spasm (HMS) is characterized by intermittent paroxysmal contractions of the unilateral jaw-closing muscles, resulting in brief twitches and/or prolonged spasms ( 1 – 56 ). Involuntary movements can cause muscle pain, tongue or buccal mucosa biting ( 9 , 18 , 21 , 25 , 34 , 35 , 55 ), and temporomandibular joint dislocation ( 6 , 18 , 54 ), resulting in masticatory disturbances or dysarthria. HMS is occasionally accompanied by hemifacial atrophy or localized scleroderma ( 1 , 2 , 7 , 10 , 13 , 15 , 17 , 25 , 43 , 47 , 51 ).…”