A 66-year-old man was referred to our department because of poor healing of the socket of the right maxillary first molar, which was extracted 5 months previously. The socket showed incomplete epithelization, and alveolar bone was partially exposed. Panoramic radiographs and CT images showed a round bone defect around the socket. The clinical diagnosis was maxillary cyst, and a cystectomy was performed under local anesthesia.The histopathological diagnosis was Langerhans cell histiocytosis. Bone scintigraphy showed no accumulation in other sites. After the operation, healing of the wound was completed and there has been no evidence of recurrence.