Drug-Induced Oromandibular Dystonia Presenting as Chronic Temporomandibular Joint Dislocation: A Rare Case Report

Approximately 15%-30% of patients receiving neuroleptic medication for a longer duration develop drug-induced dystonia. There are many variations of oromandibular dystonia (OMD), but the most common one is involuntary jaw-opening dystonia. A rare case of chronic mandibular dislocation under long-term neuroleptic therapy is reported with clinical features, diagnosis, and various treatment modalities. Chronic dislocation leads to changes in associated soft tissue and muscles. Therefore, besides alteration of bony articular surfaces (eminectomy), soft tissue remodeling is required to achieve the perfect balance for temporomandibular joint (TMJ) working and occlusion. Drug-induced orofacial dystonia presenting as chronic TMJ dislocation is rare. Therefore, in long-standing chronic dislocation cases during treatment, biomechanics of TMJ, its complex neurological system, and the physiology of the masticatory system should be considered to customize the treatment plan.