Facial palsy after inferior alveolar nerve block: case report and review of the literature

Bell's palsy is an idiopathic and acute, peripheral nerve palsy resulting in inability to control facial muscles on the affected side because of the involvement of the facial nerve. This study describes a case of Bell's palsy that developed after dental anaesthesia. A 34-year-old pregnant woman at 35 weeks of amenorrhea, with no history of systemic disease, was referred by her dentist for treatment of a mandibular left molar in pulpitis. An inferior alveolar nerve block was made prior to the access cavity preparation. 2 h later, the patient felt the onset of a complete paralysis of the left-sided facial muscles. The medical history, the physical examination and the complementary exams led neurologists to the diagnosis of Bell's palsy. The treatment and results of the 1-year follow-up are presented and discussed. Bell's palsy is a rare complication of maxillofacial surgery or dental procedures, the mechanisms of which remain uncertain.