We report a case of tooth loss and alveolar bone necrosis secondary to herpes zoster in the region innervated by the third branch of the trigeminal nerve. The patient was a 74-year-old man who was referred to our department with chief complaints of tooth loss and exposure of the alveolar bone in the left mandible. He had a history of herpes zoster of the trigeminal nerve and had spontaneous loss of the left mandibular second premolar and first molar approximately 2.5 months and 1.5 months before his first visit, respectively. Initial examination revealed exposure of the alveolar bone of the two affected teeth, with gingival swelling and flare. In addition, paresthesia was present in the region innervated by the third branch of the left trigeminal nerve, for which a dermatologist had prescribed vitamin B12. Antibacterial treatment with local irrigation was performed after initial presentation. Five weeks after his first visit, we observed the elimination of a sequestrum. Currently, the exposed bone has disappeared, and the patient's disease course has been uneventful. The pathological diagnosis was bone necrosis associated with infection.
