We assessed the relation between the procedure used for mandibular resection and the pattern of tumor invasion to the jaw in 176 patients with lower gingival carcinoma at the First Department of Oral & Maxillofacial Surgery, Tokyo Dental College from 1988 through 1998. The results were as follows: 96 patients (55%) received marginal resection of the mandible, 74 (42%) received segmental resection of the mandible, and 6 received hemimandibulectomy. The tumors in the patients who underwent marginal reresection were classified into two categories: invasion to the periostium (11 patients, 11%) and invasion to the cortical bone and marrow (23 patients, 24%). The tumors in the patients who underwent segmental resection were classified into two categories: invasion to the periostium (48 patients, 65%) and invasion to the cortical bone and marrow (26 patients, 35%). Local recurrence (soft tissue) occurred in 14 of the 80 (18%) patients who underwent segmental mandibulectomy patients and in 14 of the 96 (14%) who underwent marginal mandibulectomy.
Matrix metalloproteinase (MMP) activity in synovial fluid (SF) was studied with respect to age, sex, clinical findings, and MR images, to clarify factors related to MMP activity in SF of patients with closed lock of the temporomandibular joint (TMJ). Synovial fluid was obtained from 54 patients (58 joints) with TMJ closed lock. MMP-2, 3, and 9 activities in SF were detected by an MMP activity assay system with specific substrates for each enzyme. There were no significant correlations of MMP-2, 3, or 9 activity with age, sex, joint pain, or range of mouth opening. In addition, no significant correlations were found between MMP-2, 3, or 9 activity and the degree of disc deformity, or between MMP- 2 or 3 activity and the degree of bone changes. MMP-9 activity significantly increased in SF isolated from joints with severe bone changes (p<0.05). These results indicate that increased MMP- 9 activity is related to degenerative changes in the TMJ.
Elderly persons and patients with bone disease such as osteoporosis or osteopenia have a high risk of lumbar spine compressive or femoral fractures because of low bone mineral density. In the field of oral and maxillofacial surgery, they also have a high risk of mandibular fractures and seem to have delayed healing once a mandibular fracture occurs. To investigate the healing of mandibular fractures in rabbits with low mineral density, we performed ovariectomy (OVX) and fed the rabbits a low-calcium diet (including 0.15% calcium) and compared bone mineral density (BMD) of the mandible in the experimental rabbits with that in a control group. Furthermore, we examined the healing of mandibular fracture both histologically and radiologically. The BMD of the mandible decreased 22.6% as compared with the control group within 1 month, but did not change appreciably thereafter. Radiological examination of mandibular fractures showed no difference between the experimental and control groups after 1 and 2 weeks, but radiolucency was higher in the experimental group after 4 and 8 weeks as compared with the control group. Histological examination revealed that bone newly formed at the edge of the fracture margin at an early stage and rapid bone formation was observed after 2 to 4 weeks in both groups. However, the experimental group had slightly poorer and slower bone formation than the control group. These findings suggest that healing of mandibular fractures is delayed in the presence of low mineral density.
To determine whether there are paths for fracture lines, along which the cortical bone of long bones tends to split, a rabbit femur was split with a chisel and the course of the fracture line was investigated. Macroscopic observation of the rabbit femur confirmed that the course of the fracture line of the split bone has a constant direction. Microscopic cross-sectional observation showed that the fracture line ran along the curve of the cementing line, haversian lamella, or both. Microscopic examination of longitudinal sections showed that the course of the haversian canal was nearly parallel to the long axis of the bone. Furthermore, small cavities in the bone were also arranged parallel to this direction. We thus confirmed that the fracture line tends to occur along lamellar structures or areas with weak physical and bond strength.
Based on the experimental results obtained by splitting a rabbit femur, the mandible in a human cadaver was split by the sagittal splitting technique. In addition to macroscopically and microscopically examining the course of the fracture line, three-dimensionally reconstructed images were studied. Macroscopic examination showed that the course of a fracture line was nearly constant. On microscopic examination, we confirmed a trend for the course of the fracture line to be along the cementing line or the curve of the haversian lamella, or both. The three-dimensionally reconstructed images showed that the fracture surface was nearly parallel to the direction of the haversian canal. These findings indicate that the course of fracture line is influenced by the structures composing lamellar bone, such as the haversian canal, haversian lamella, interstitial lamella, and cementing line. These structures may account for the preferred path of fracture lines in the bone. Furthermore, we confirmed that the direction of the chisels used for sagittal splitting was appropriate.
Basal cell adenocarcinoma was added to the classification of the World Health Organization in 1991 and is considered the malignant counterpart of basal cell adenoma. It is a rare salivary gland tumor and is most often found in the parotid gland, with only two cases reported in a minor salivary gland. To our knowledge, all basal cell adenocarcinomas have been treated by surgical excision, and their outcome has been comparatively good. We report a case of basal cell adenocarcinoma arising in a minor salivary gland in the upper lip. The patient was a 56-year-old man who presented with a right upper lip mass. The mass was found to have widely infiltrated the maxillary alveolus, nasal floor, and the right wing of the nose. We successfully treated it with radiation (66.4 Gy), hyperthermia (8 times), and chemotherapy (5 -FU, CDDP), without lowering of the patient's quality of life.
We describe a rare case of sialolipoma of the palate. A 75-year-old Japanese man was referred because of a palatal mass, which measured 1.2×1.2 cm and was soft and painless. The mass had first been noticed 3 years previously and thereafter had slowly increased in size. It was removed for a clinical diagnosis of pleomorphic adenoma. The entire surgical specimen was processed for microscopic examination. Histologically, the tumor was well demarcated. It showed an admixture of adipose cells and glandular components and was traversed by delicate fibrous septa. The glandular component consisted of elongated tubules and some acinar cells. No cartilage or bone was observed. The tumor was diagnosed to be a sialolipoma. Sialolipomas are newly categorized uncommon tumors of the salivary gland, comprising an intimate admixture of mature fat cells and glandular elements. The tumor is well-circumscribed. Although few cases have been reported, sialolipoma tends to occur in the major salivary glands. Only a few palatal cases of sialolipoma have been reported. The patient is presently doing well 21 months after undergoing the operation.
We report a case of florid cemento-osseous dysplasia of the maxilla. The patient was a 71-yearold woman who had had a painless swelling in the left maxillary gingiva for 2 years. Since a radiographic examination by her dentist showed radiopacity in the left side of the maxilla, she was referred to the Department of Dentistry and Oral Surgery, Ishikawa Prefectural Central Hospital. A tumor with an ulcer measuring 20×28 mm was found in the left side of the maxillary gingiva. A radiographic examination showed radiopacity with an impacted tooth in the left side of the maxilla and maxillary sinus. The tumor was resected with the patient under general anesthesia. Histopathological examination of the surgical specimen showed loose, fibrous connective tissue with many areas of lobulated masses resembling cementum around the impacted tooth. The tumor was diagnosed as florid cemento-osseous dysplasia. There was no evidence of recurrence 10 months after the operation.
A rare case of osteomalacia with an oronasal fistula developing after sequestrectomy is presented. The patient was a 45-year-old woman who was referred to our hospital because of an intractable ulcer at the midline of the hard palate. She had an edentulous maxilla and wore a poorly fitting complete maxillary denture. Oral examination showed ulceration with a sequestrum under the prosthesis. Removal of the sequestrum extending from the oral cavity to the nostrils resulted in an oronasal fistula of the hard palate. The case was finally diagnosed as osteomalacia based on the results of radiographic and serum chemical examinations. In this patient, continuous pressure caused by the poorly fitting maxillary denture induced the sequestrum in the hard palate, which was thin and fragile because of osteomalacia.
A 19-year-old man had methicillin-resistant Staphylococcus aureus (MRSA) infection involving multiple facial injuries, including multiple maxillofacial bone fractures, caused by attempted suicide. The infection associated with the mandibular compound fracture was treated by open reduction, fixation, and chemotherapy with antibiotics. However, 4 months after the operation, pyoderma caused by MRSA infection occurred and later progressed to eczematous lesions with severe itching. Pyoderma was treated by powder consisting of zinc oxide, talcum, and dermatol containing 2% acrinol and 0.2% promethazine hydrochloride. Autosensitization dermatitis developed all over the body and was treated with a mixture of povidone iodine gel and betamethasone. One month after the treatment the eczema disappeared and MRSA infection was cured completely.
Multiple odontogenic keratocysts in a sister and brother are reported. Case 1: A 14-year-old boy with diffuse swelling of the left buccal region visited our clinic. There were three radiolucent lesions in the jaws. The three lesions were diagnosed as odontogenic keratocyst by biopsy. All cysts were extirpated with the patient under general anesthesia. As of about 4 years 10 months after the operation, we have found no sign of recurrence. Case 2: A 13-year-old girl with swelling and spontaneous pain of the right side of the mandible visited our clinic. Four cystic lesions were found in the jaws on radiographic examination. The lesions were histopathologically diagnosed as odontogenic keratocyst. All cysts were extirpated with the patient under general anesthesia. Three years 2 months after the operation, a recurrent cyst, which arose in the left side of the maxilla, was removed. These cases cannot be diagnosed as basal-cell nervous syndrome because only multiple jaw cysts were present.
To examine the occurrence of intermittent lock, we investigated the correlation between the frequency of intermittent lock of the temporomandibular joint and magnetic resonance imaging (MRI) findings. The subjects consisted of 25 patients (25 joints) with unilateral intermittent lock who were treated from April 1994 through March 2000 at our department. MRI examination of the joint was performed on the affected side. We divided the patients into two groups: a high-frequency group consisting of 15 patients who had symptoms of intermittent lock every day and a low-frequency group consisting of 10 patients who did not have symptoms every day. The results showed no statistical difference between the two groups in clinical findings such as age, sex, clicking side of the joint, duration of intermittent lock, method of unlocking, muscle pain on palpation, degree of maximal mouth opening, distance between the maxillary and mandibular tooth midline, or the degree of overbite and overjet. However, the two groups differed significantly in the degree of anterior disc displacement as assessed by MRI.
We report a case of pseudoaneurysm (PA) originating in a facial artery after intraoral vertical ramus osteotomy. The case was treated by embolization. A 30-year-old man had undergone Le Fort I type osteotomy and intraoral vertical ramus osteotomy. Abnormal bleeding occurred during intraoral vertical ramus osteotomy on the right side of the mandible. The bleeding was stopped by gauze packing. The swelling after the operation decreased gradually, and he was discharged and followed up as an outpatient. Seventeen days after the operation, right acute buccal swelling recurred. Initially, an infection was suspected, and curettage was performed. Subsequently, severe bleeding from the inferior border of the mandible was recognized. A right external carotid angiogram revealed a PA in the facial artery, which was confirmed to be the cause of hemorrhage. The PA was successfully treated by embolization therapy with platinum microcoils.