We examined whether the number and the distribution of blood and lymphatic vessels around tumors correlate with the frequency of lymph node metastasis. Ninety-one squamous cell carcinomas of the tongue of golden hamsters were induced by DMBA. After the development of tumors, the hamsters were divided into two groups: 42 given no additional treatment (Group A) and 49 in which surgical incisions were made in the center of the tumor once a week (Group B). The animals were killed when they showed obvious weakening or a body weight of less than 70g. The tongue tumors, lymph nodes, lungs, and liver were excised and frozen in OCT compound at -80°C until use. Each tumor was divided into anterior, middle, and posterior parts, and each part was graded for histological malignancy on the basis of the Anneroth classification, immunohistochemical characteristics of type P1 collagen (basement membrane staining), factor VIII-related antigen (blood vessel staining), and 5'-nucleotidase (5'-Nase: lymphatic vessel staining). The number of blood vessels and lymphatic vessels were counted per 200 fields in the areas most active for factor VIII and 5'-Nase, respectively. All lymph nodes were inspected for metastasis by examination of subserial, 100-μm interval, H-E-stained sections. Metastatic lymph nodes were histologically detected in 9 (21.4%) of the 42 animals in group A and 21 (42.9%) of the 49 animals in group B. The incidence of lymph node metastasis was significantly higher after repeated incisions of the tongue tumor. No metastasis to the lung or liver was detected. The relations between multiple variables and metastasis were assessed by multiple logistic regression analysis. Surgical incisions, the number of blood vessels, and the number of the lymphatic vessels were found to be significant risk factors for lymph node metastasis. These results indicate that lymphangiogenesis as well as angiogenesis may play an important role in the lymph node metastasis.
Sagittal splitting ramus osteotomy (SSRO) is the most common orthodontic procedure used to correct mandibular deformation. However there is a postoperative risk of neurosensory disturbance (NSD) of the mental nerve. A total of 84 patients underwent preoperative and postoperative bilateral examinations (total: 168 examinations). Subjective symptoms were assessed by interview, and constant-touch was evaluated by tactile-threshold tests with the use of a Semmes-Weinstein pressure aesthesiometer (SW test) and by static two-point discrimination tests (2 PD). Dynamic-touch was examined by vibratory sensibility tests. No significant differences were observed as compared with the preoperative scores on the SW test after 4 weeks. Furthermore, no change in the mean preoperative value on the 2 PD test was observed at the 8th postoperative week. A significant difference was detected between the preoperative score on the vibratory sensation test and the score after 24 weeks. Dynamic-touch assessment suggested that recovery was slow as compared with constant-touch recovery. The majority of patients scored 1.65 (the smallest sensible filament) on the SW test, and 83.2% of these patients showed an improvement in symptoms. A significant difference was noted between symptoms and the dispersion of vibratory sensibility test scores. The vibratory sensibility test could detect sensation recovery by slow regeneration of nerves, but the probability of not detecting sensation was high when only the SW test was used. Sensibility occurs via the function of various sensory units. Thus, a combination of tests should be performed to assess sensiblity associated with perceptual disorders.
Recently, distraction osteogenesis is widely used in the cranial and maxillofacial skeleton. However, the need for a latency period before mandibular distraction remains controversial, with recommendations ranging from 0 to 14 days. We used a rabbit model to determine the ideal latency period for mandibular osteodistraction. We performed a bilateral subperiosteal corticotomy of the mandible and applied an external distraction device. We used 0-, 2-, 5-, and 10-day latency periods. Distraction was done at a rate of 0.5mm per day (0.25mm per 12 hours) for 10 days to elongate the mandible by 5mm after each latency period. Hematoxylin-eosin stain was used for histological observation, and bone was labeled by several fluorescence substances, which can be observed with a fluorescence microscope. In the 0-day latency group, the lengthened region was filled with fibrous tissue. Cartilage-like islands were found along the lengthened region. In the 10-day latency group, the lengthened region was almost completely filled with woven bone. In the 2-and 5-day latency groups, there was a distraction gap, with mineralization zones at the periphery of this fibrous interzone. The primary osteon remodeling zone were located at both ends of the mineralization zones. In the 5-day latency group, newly formed bone was observed around the periosteum. These results indicate that 5 days is the most suitable latency period for mandibular distraction in the rabbit.
Our experience with ambulatory oral and maxillofacial surgery at Kyoto University Hospital is described. From January through December 2000, 42 patients underwent oral and maxillofacial surgery under general anesthesia at our day surgery unit. The procedures included exodontia, open and closed reduction of mandibular fractures, TMJ surgery, tumor resection, implant surgery, cystectomy, preprosthetic surgery, and removal of salivary stones. All procedures were safely perfomed without complications. Perioperative and postoperative management, including the use of anesthesia is described and discussed.
Previous association studies of nonsyndromic cleft lip with or without cleft palate in Caucasian have strongly suggested that transforming growth factor alpha (TGFA) plays a role in clef ting. However, this remains controversial. Purpose: The aim of this study was (1) to analyze and reconfirm the role of TGFA in Japanese and (2) to summarize the results of previous genetic studies of nonsyndromic cleft. Method: We studied TFGA Taq I and two newly detected polymorphism makers for TGFA. Results and conclusion: Highly significant associations were found between the haplotypes of the two new TGFA makers in Japanese. Our haplotype data support the role of TGFA in facial clef ting. In additon, genetic studies in Japanese are limited; thus, future work is awaited.
A case of desmoplastic ameloblastoma is reported. The patient was a 77-year-old woman, who visited our hospital because of painless expansion of the anterior region of the mandible. Radiograms and CT scans revealed a mixed radiolucent-radiopaque lesion, which was poorly defined and associated with large cystic radiolucent areas. The lesion was excised, followed by the curettage of the underlining intact bone, under general anesthesia. Histologically, the lesion was composed of enamel organ-like tumor nests scattered in prominent fibrous connective tissue. Some tumor nests showed microcyst formation and transition to larger cysts. TGF-β was strongly expressed especially by tumor cells at the periphery of tumor nests, unlike conventional types of ameloblastomas. The postoperative course has been uneventful for 6 months. Clinical and radiographic characteristics of this tumor are discussed.
We report a solitary fibrous tumor arising in the oral cavity. A 27-year-old woman had been aware of a tumor in the right side of the mandible since January 1998. The tumor was found by her dentist on dental therapy, and she was referred to our department on March 19, 1999. On palpation a spherical tumor 1.5 cm in diameter was found in the gingivobuccal fold of the right mandibular premolar. It was a painless movable tumor and there was no adhesion to the skin or perceptional anomaly. The teeth adjacent to the tumor had no anomaly. Echography and computed tomography showed a clearly demarcated tumor. The tumor was enucleated under local anesthesia on April 7, 1999. Histopathologically and immunohistochemically, it was diagnosed as a solitary fibrous tumor. The patient, who has been followed up on an outpatient basis, has had no recurrence and is making good progress.
Hand-Schüller-Christian disease is a non-tumorous disease of the reticuloendothelial system characterized by the three features of bone defects, diabetes insipidus, and ocular proptosis. This disease has no definite cause and is generally called histiocytosis X, together with eosinophilic granuloma and Letterer-Siwe disease. A 39-year-old man with extensive Hand-Schüller-Christian disease in the mandible, skull, and ilium was treated surgically for the mandible and with steroidal pulse therapy for the skull and ilium. After therapy, regeneration of the mandible and skull was observed without recurrence, and the patient showed satisfactory progress.
Anaphylaxis associated with dental treatment is usually induced by local anesthetics, latex gloves, antibiotics, and antiphlogistics, but is rarely caused by intracanal medication containing paraformaldehyde. A 49-year-old woman presented with urticaria about 3 hours after root canal treatment of 4 1 with paraformaldehyde. On the next day, she underwent root canal treatment again with paraformaldehyde, a generalized pruritic rash, facial swelling, dyspnea, and dysphagia developed. These symptoms resolved within 24 hours after administration of hydrocortisone. Laboratory examinations of the blood showed a high IgE RAST value against formaldehyde, and a scratch test revealed intensely positive reactions. From these results together with her anamnesis and clinical history, we diagnosed her symtoms as anaphlaxis caused by paraformaldehyde.