Multiple supernumerary teeth usually occur with a syndromic disease, and there are very few occurrences in non-syndromic cases. They frequently occur in the premolar region, while they are rare in the midline region of the maxilla. We report a case of four supernumerary teeth in both the midline region of the maxilla and premolar region of the mandible. The patient was a 12-year-old boy referred to our hospital for examination in July 2020. He had no syndromic disease nor familial tendency. According to panoramic x-ray, eight supernumerary teeth were observed in the midline region of the maxilla and premolar region of the mandible.

　There were four supernumerary teeth in the midline region of the maxilla, and two in each side of the premolar region of the mandible. All eight supernumerary teeth were extracted under general anesthesia. The roots of the four teeth extracted from the midline region of the maxilla were complete. In contrast, the roots of the four teeth extracted from the lower premolar region were incomplete. There was no appearance of new supernumerary teeth in the eight months following surgery.

Odontogenic keratocyst (OKC) rarely extends to the maxillary sinus and pterygoid process. However, residual or recurrent lesions occur more frequently in these sites than at other sites, and removal is often difficult. We experienced a case of recurrent OKC in the maxilla that extended to the maxillary sinus and pterygoid process and was removed via a Le Fort I osteotomy. A 59-year-old woman visited our hospital in August 2020 with the chief complaint of swelling in the posterior right maxilla. The patient had undergone a cystectomy at the age of 56 years, and a cystic lesion was found in the same area three years and two months after surgery, which was diagnosed as recurrent OKC. The lesion partially extended to the posterior sinus wall and the pterygoid process. A cystectomy was performed in September 2020 via a Le Fort I osteotomy. This approach provided a direct view of both the maxillary sinus and the pterygoid process, and the lesion could be removed. The pathological diagnosis was OKC. No recurrence was observed at two years and three months after surgery, and close follow-up is ongoing.

Chondrolipoma is an extremely rare lipoma subtype, and its pathogenesis is unknown. Furlong et al reported two cases (1.6％) out of 125 lipomas in the head and neck region.

　In this report, we describe a case of chondrolipoma arising in the mental region. The patient was referred to our hospital due to a painless mass on the right side of the mandible. A 80 × 50 mm mass of mobile elastic-soft tissue with skin bulge was found in the right mandibular area. T1- and T2-weighted images showed a 42 × 26 × 24 mm mass with internal septal structure in the mental region. The patient underwent tumor enucleation under general anesthesia. Histopathological findings showed mature adipose tissue with no cellular atypia and mixed cartilage components, which led to the diagnosis of chondrolipoma. One year after the surgery, there was no functional impairment and no recurrence.