Temporomandibular Joint Dislocation

Introduction

Dystonia is a movement disorder that causes sustained muscle contractions, repetitive twisting movements, and abnormal postures of the trunk, neck, face, arms or legs [Fahn et al. 1987]. It may be focal, segmental (multifocal), or generalized and may also be primary or secondary based on their etiology. It may manifest as oculogyric crisis, deviation of eyes in all directions, protrusion of tongue, trismus, lock jaw, torticolis, laryngeal spasm, difficulty in speaking, facial grimacing, opisthotonus, lordosis or scoliosis and tortipelvic crisis. Drug-induced dystonia are secondary dystonias which occur commonly with drugs with antidopaminergic effects such as antipsychotics and metoclopramide [Ropper and Samuels, 2009; Fadare and Owolabi, 2009]. They reportedly arise from a drug-induced alteration of dopaminergic–cholinergic balance in the nigrostriatum (i.e. basal ganglia). Most drugs produce dystonic reactions by nigrostriatal dopamine D2 receptor blockade, which leads to an excess of striatal cholinergic output. High-potency D2 receptor antagonists are most likely to produce...