The pathogenesis of nonsyndromic cleft lip with or without cleft palate (NSCL ± P) and nonsyndromic cleft palate only (NSCP) may be associated with genetic factors. Although some predisposing genes/loci have been reported, their attributable risk is too small to be clinically meaningful. To clarify the genetic causes and mechanisms of NSCL±P or NSCP, we conducted mutation analysis of target genes using a next-generation sequencing (NGS) approach.The target genes, IRF6, WNT5A, WNT9B, TP63, MSX1, TFAP2A, PAX9, DLX3, DLX4, and MN1, were selected based on previous reports of potential associations with the development of NSCL±P or NSCP from genome-wide association studies and candidate gene analyses. Mutation analysis was conducted using NGS on 74 Japanese trios (patient and parents) and 18 Japanese patients only families.We detected single-nucleotide variants (SNVs) for 7 genes: IRF6, DLX4, WNT5A, TFAP2A, WNT9B, TP63, and PAX9. The SNVs found on IRF6 and DLX4 were missense mutations, whereas those identified on WNT5A, TFAP2A, WNT9B, TP63, and PAX9 were rare variants in the noncoding region; no de novo mutation was identified in the trio samples. The amino acid change on DLX4 was detected within the highly conserved homeodomain and was predicted to have a deleterious impact on the protein function by in silico analysis.The DLX4 missense mutation c.359C>T (Pro120Leu) was found in 1 Japanese patient with NSCL±P and was located in the homeodomain region. This mutation likely plays a role in the development of NSCL±P in the Japanese population.
Pleomorphic adenoma is the most common benign tumor of the salivary glands. Most cases develop in the region of the parotid gland, and few occur in the region of the sublingual gland. We describe our experience with a case of pleomorphic adenoma arising in the region of sublingual gland. Case patient: a 47-year-old man. Chief complaint: a tumor mass arising in the left side of the mouth floor. Facial expression: bilaterally symmetric, non-palpable regional lymph nodes. Present illness: a movable, elastically solid mass, measuring 25 × 14 mm, in the left side of the mouth floor. Findings on magnetic resonance imaging (MRI): on T2-weighted images, a slightly heterogeneous, high signal tumor mass in the left side of the mouth floor. Signal intensity as strong as muscle was observed on T1-weighted images. We diagnosed a sublingual gland benign tumor on MRI and suspected pleomorphic adenoma on fine-needle aspiration. We therefore performed extirpative surgery of the tumor, including the sublingual glands, from the oral cavity in May 2011. The histopathological diagnosis was pleomorphic adenoma. It has been 3 years since surgery, and no systemic or local abnormality has been found. A dequate follow-up for relapse and malignant transformation is considered essential.
Schwannoma is a benign tumor originating from Schwann cells, occurring rarely in the masseter muscle. In this report, we describe a case of schwannoma in the masseter muscle. A 35-year-old man was referred to our hospital because of swelling of the left cheek. A painless elastic hard mass was palpable in the left cheek. No abnormalities were found in the skin, oral mucosa, or cervical lymph nodes. MRI T2-weighted images showed a high signal area with 43×37mm internal nonuniformity and clear boundaries. Although malignant atypical cells were not detected by fine-needle aspiration and incisional biopsy, no definitive diagnosis was obtained. The lesion was diagnosed as a benign tumor of the masseter muscle and resection was performed under general anesthesia. It was located in the masseter muscle without any adhesion to surrounding tissues. No nerves were continuous with the tumor. The tumor was 45×40×30mm in size and was covered with a capsule. Histopathological diagnosis was schwannoma. After the operation, left facial nerve palsy was recognized, but it was completely cured 3 months after the operation. In addition, neither masseter atrophy nor masticatory function was observed. Two years have passed since the operation without recurrence of the tumor.
We carried out a clinical study of 124 patients for facial bone fractures treated in our department over a 5-year period from November 2009 to September 2014, and obtained the following results.1. The average age was 41.7±24 years old and the male/female ratio was about 2:1.2. The majority of the patients were between the ages of 10 and 30, (49.2%) with the peak incidence occurring in those in the 10–19 year-old group (16.1%).3. The majority of the patients visited our department within 3 days of injury (89.5%).4. The majority of patients were referred from the Department of Emergency Care in our medical center (58.9%).5. The most common causes of injury were falls (45.9%) and traffic accidents (34.7%).6. Mid-facial fractures accounted for 51.7% and mandible fractures for 48.3%.7. Sixty-two cases (50%) were treated by open reduction surgery.
Sensory disturbance resulting from denture pressure may be caused by advanced alveolar ridge resorption in a patient with an edentulous jaw. We report our observations of a patient with complete dentures with inferior alveolar sensory nerve disturbance due to alveolar ridge resorption associated with a mandibular canal.The patient was a 65-year-old woman, who had begun using complete lower dentures six years earlier. She had become aware of dysesthesia of an area innervated by the right mental nerve, and also hypoesthesia, and thus consulted the Tokyo Dental College Suidobashi Hospital for oral surgery.Hypoesthesia of the area innervated by the mental nerve, i.e. dysesthesia, and gingival area dysesthesia in response to pressure on the right mandibular molar tooth were noted at the time of the first medical examination. Medical treatments performed included denture adjustment, medications, and rehabilitation guidance to restore sensation. The hypoesthesia disappeared progressively within two months, and the dysesthesia resolved three weeks thereafter. The sensory testing method used for this patient enabled both quantitative assessment of the disorder and evaluation of the recovery process over time. Based on the features of each laboratory procedure, the author considers it to be important to assess perception disorders comprehensively.
The Japanese show protein S deficiency more frequently than other congenital causes of thrombosis. Protein S deficiency is considered the highest risk factor for venous thromboembolism in Japanese patients. Because any trauma, surgery, or infection can cause thrombosis in patients with protein S deficiency, careful oral surgical treatment is essential. Conversely, with few reports of oral surgical treatment for this disorder, many issues remain unclear. We successfully extracted an impacted mandibular third molar in a young patient with this disorder and a history of deep venous thrombosis. The patient was hospitalized for the extraction, and the procedure was performed with consideration of hemostasis and prevention of thrombosis relapse.
