In clinical practice of oral and maxillofacial surgery, the rate of orthognathic surgeries that improve malocclusions and facial deformities has been increasing. Especially, sagittal splitting method (sagittal splitting ramus osteotomy) has been applied widely to cases of mandibular deformity of not only prognathism or retorognathia but also open-bite or facial asymmetry. The method includes many basic procedures for orthognathic surgery. This article revealed standard elements and procedures of sagittal splitting method; incision and abrasion, osteotomy, bone splitting, reposition of medial segments, fixation of bone segments, inter-maxillary fixation. For safety surgery, adequate diagnosis, appropriative surgical procedures and minimally invasive operations are required.
Sodium butyrate, a histone deacetylase inhibitor, is well known to induce cell differentiation and to inhibit the proliferation of colorectal cancer cells and human glioma cells by inducing cell cycle arrest, differentiation, and apoptosis. However, there are few reports on the antitumor effects of sodium butyrate on human oral squamous cell carcinoma (OSCC) and anticancer-drug-resistant OSCC, and the mechanisms involved. In the present study, three OSCC cell lines (SAS, Ca9-22, and HSC-3), two cisplatin (CDDP)-resistant OSCC cell lines (SAS-SO and Ca9-22-TO), and a control cell line (normal gingival fibroblast Gin-1) were treated with various concentrations of sodium butyrate to evaluate inhibitory effects on cell proliferation and invasion. Cell proliferation was assayed using MT T, and invasion was assayed using Matrigel invasion chambers. The results demonstrated that sodium butyrate inhibited cancer cell proliferation and invasion by both OSCC cell lines and CDDP-resistant OSCC cell lines. In particular, when CDDP-resistant OSCC cell lines were pretreated with sodium butyrate before treatment with CDDP, the susceptibility of cancer cells to CDDP increased and a greater inhibitory effect on cancer cell proliferation was obtained at lower concentrations of CDDP. The mechanism by which sodium butyrate inhibits the proliferation of OSCC cell lines is suspected to involve suppression of cell cycle progression from G1 to S phase as indicated by BrdU-labeling index and flow cytometry, as well as by induction of apoptosis as shown by the appearance of DNA ladder.
We report the history of dental education in the United States of America (USA) as compared with that in Japan. In 1840, the first dental school in the world was founded in the USA as Baltimore Dental school, offering a 1-year course. Dental education in the USA gradually progressed, and it took 77 years to reach a higher education level equivalent to that of college. Qualification of admission to dental school required completion or graduation from 2 years of junior college since 1940, and professional education was confined to a 4-year course. Medical school was also the same system. This higher education system is now internationally adopted, and the dental degree is termed Doctor of Dental Surgery (DDS: Baltimore system) or Doctor of Dental Medicine (DMD: Harvard system). Before the Second World War, Japanese dental schools were at the career college level and consisted of 8 schools, one of which was national and the others were private. After the Second World War, the Japanese dental education system switched to the DDS system in accordance with the instructions of the General Headquarters (GHQ) in 1946. At present, there are a total 29 dental universities, including 16 private, 11 national, and 1 prefectural. Post-dental education, such as specialist or professional courses requires 4 years, and special clinical courses officially authorize individuals. Before and during the second World War, education on oral and maxillofacial surgery, including cancer surgery as well as clinical and basic sciences, was offered by university departments of oral maxillofacial surgery, and most of the chairpersons of these departments had medical doctor (MD) degrees or both MD and DDS. Many professors had been educated in surgical specialties in Europe after the First World War. The European oral maxillofacial surgery system, including plastic surgery, tumor surgery, and bone surgery, has been followed continuously to the present time. In Japan, dental doctors with a single license can perform major surgery for oral and maxillofacial diseases following examination by a specialist.
Acinic cell carcinoma (ACC) usually arises in the parotid gland and rarely occurs in the minor salivary glands. In particular, ACC of the upper lip is extremely rare, and the incidence is 0.94% of all minor salivary gland tumors. ACC of the lips is rare. We report two cases of ACC involving the upper lips. The first patient was a 42-year-old woman with a 7 × 10 mm painless granulomatous mass in the upper lip. As a result of biopsy following a clinical diagnosis of inflammatory granuloma, the lesion was diagnosed as ACC. The lesion was excised surgically. The second patient was a 69-year-old man with an 18 × 30 mm painless mass in the upper lip. The clinical diagnosis was a low grade malignant tumor of the minor salivary glands, and the lesion was excised surgically. The pathological diagnosis of the tumor was ACC. The first case was characterized by solid / lobular and microcystic growth of intercalated ductal and vacuolated cells, whereas the second case showed a mixture of papillary-cystic and solid/lobular growth patterns of acinar and vascuolated cell types. Neither case has shown any evidence of recurrence or metastasis 4 years and 3 years after surgery, respectively.
Recently methotrexate (MTX) has been increasingly administered to patients with rheumatoid arthritis (RA). However, it has been well documented that there is a risk of the development of lymphomas in these patients. We report a case of Hodgkin's lymphoma (HL) of the submental lymph nodes in a 76-year-old man who was receiving low-dose MTX for RA. He presented at our hospital because of severe periodontitis in the right lower gum. A biopsy specimen of the right lower gum showed only granulomatous inflammation. Four months later, the patient developed submental lymphadenopathy. Lymph node biopsy revealed the presence of mixed cellularity type of HL. Immunohistochemistry showed that the large atypical cells were positive for CD30 and Epstein-Barr virus early RNA (EBER) and negative for CD3 and CD20. Radiotherapy was immediately performed, and there have been no signs of recurrence for 30 months after radiotherapy.
Basaloid squamous cell carcinoma (BSCC) of the head and neck, first described in 1986, is a rare malignant disease. The aggressive biologic behavior of BSCC has been strongly associated with distant metastasis. We report a case of BSCC in the head and neck of a 58-year-old man who presented with right lower gingival swelling. The patient had a mass extending from the right lower gingival region to the pharyngeal region with spontaneous pain. Computed tomography and magnetic resonance image revealed a round 65 × 35 mm solid mass infiltrating the right side of the mandible, with cervical lymph node, rib, and lung multiple metastases. A biopsy specimen was taken from the primary tumor, and BSCC was diagnosed. The patient received systemic chemotherapy with docetaxel, cisplatin, and 5-fluorouracil combined with radiation therapy, because disease was advanced. Although the primary tumor and regional lymph node metastasis were successfully controlled, the patient died of multiple lung and bone metastases 12 months after these treatments. In conclusion, systemic chemotherapy with a TPF regimen combined with radiation therapy may be an effective treatment for patients with advanced BSCC of the oral region.
Pleomorphic adenoma is one of the most frequent salivary gland tumors. Pleomorphic adenoma derived from minor salivary glands most commonly occurs in the palate. However, few reports have described pleomorphic adenoma arising in the retromolar region. We describe a rare case of pleomorphic adenoma that developed in the retromolar region. The patient was a 68-years-old woman presenting with a painless mass in the retromolar region. The preoperative results of biopsy at another hospital and imaging examinations showed a pleomorphic adenoma. Under general anesthesia, the tumor mass was removed with adequate surgical margins, including the periosteum. The final pathological diagnosis of the extirpated specimen was pleomorphic adenoma. Follow-up examinations have shown no evidence of recurrence for 1 year 9 months after surgery. To our knowledge, only 5 similar cases have been reported in Japan. Moreover, among 223 salivary tumors treated in our hospital, there were only 2 cases (0.9%) of pleomorphic adenoma of the retromolar region.
We report a case of focal oral mucinosis of the upper gingiva in an infant. A 19-month-old girl was referred to our clinic in 2010 because of a swelling of the left maxillary gingiva. We carried out tumor extirpation under general anesthesia. Histopathological examination showed spindle-shaped fibroblast-like cells in a loose mucoid stroma. We diagnosed this case as focal oral mucinosis. The prognosis of the present case is favorable, with no signs of recurrence after the operation.
Methotrexate (MTX) is a key drug widely used to treat rheumatoid arthritis. However, several reports have recently described cases of MTX-associated lymphoproliferative disorders (MTX-LPD). We report a case of MTX-LPD arising in the maxilla of a patient with juvenile idiopathic arthritis in adulthood. A 40-year-old woman was referred to our clinic for the treatment of pain in the anterior maxillary gingiva. She had had juvenile idiopathic arthritis in adulthood and had received MTX for 4 years. On clinical examination, a swelling was noted at the incisal region of the maxilla. CT imaging showed a diffuse bone defect around the roots of the maxillary incisors. Antibiotic therapy had no effect on the lesion, and a biopsy was carried out. The histopathological diagnosis was diffuse large B cell lymphoma. After discussion with her physician, we suspected MTX-LPD and directed her to stop taking MTX. After stopping MTX, the lesion disappeared.