Mandibular alveolar bone necrosis after trigeminal herpes zoster

A 74-year-old Japanese man, who had pharyngeal cancer at the age of 53 years and had been treated with radiation therapy, was examined by his dentist for oral ulcers with severe pain for 2 days. He was referred to our hospital on the following day and admitted on March 7, 2000. Physical examination revealed vesicles and pustules on the right side of the lower lip, chin, cheek, and external ear. Ulceration was noted on the right side of the soft palate, buccal mucosa, and tongue. The mandibular soft tissue was markedly swollen. A diagnosis of trigeminal herpes zoster was made. The patient was treated with intravenous acyclovir, 750 mg daily for 7 days, and oral prednisolone, 20 mg daily for 2 days. The facial and mucosal lesions showed rapid improvement and the patient was discharged on March 16, 2000. Forty-four days after the onset, the patient complained of a dull, throbbing pain in the right mandible. Panoramic tomography of the jaw revealed radiolucent areas without radio-opacities on the mandibular bone (Fig. 1). These findings were not observed on the panoramic radiograph taken before admission. The mandibular right lateral incisor, canine, and left lateral incisor were markedly loose and periodontal attachment tissue was necrotic. Sequestrectomy of the necrotic bone was performed and the affected teeth were removed. Microscopic examination of the sequestered bone revealed eosinophilic, homogeneous bone tissue surrounded by degenerated connective tissue. The osteocytic lacunae were empty. Cavum dentis containing bone marrow had been replaced by necrotic tissue (Fig. 2). Although the change in lacunae could be an artifact of decalcification, these findings suggested that the bone tissue was necrotic. After sequestrectomy, the patient's mandibular pain ameliorated, but he developed post-herpetic neuralgia.