In general, hemopoietic and solid tumor cells are cultured in an atmospheric concentration of O2±5% CO2 although most cells proliferate and differentiate in vivo at lower oxgen tension. Regarding cancer therapy, in vitro culture cell systems still have unsolved technical problems such as unsuccessful colony formation in tumor clonogenic assay. It has also been reported that hypoxia-resistant cells may be the cause of poor respons to chemo-different degrees and radio-therapy. In this study therefore, the effect of different degrees of reduced ambient oxygen tension (1, 5, 10%) on in vitro colony growth was investigated in a double soft agar layer system (modified HTCA method) and in conventional liquid monolayer culture for chemosensitivity testing using 4 cell lines of human oral squamous cell carcinoma. Light and ultrastructural microscopic features were also examined. All cell lines had an optimal oxygen concentration of 5% O2 in colony forming assay, but the optimal value was not clear in liquid mass culture. In regard to colony formation, external growth was observed in 5, 10 and 20% 02 and internal capsular formation including cannibalization-like features was seen in 1% O2. Concerning phase-contrast features, spindle-shaped changes and an increase in degenerated granules were observed at 1% O2. Ultrastructurally, conspicuous degeneration of mitochondria (swollen changes) were seen at 1% O2 and the elongation of many microfilaments were mainly observed at 5 and 10% O2. These findings support the assumption that different oxygen supply processes exist between double soft agar layer colony formation and monolayer liquid cell culture. Therefore, it may be useful to apply low oxygen tension for double soft agar layer colony formation, particularly for clinical specimens of the oral cavity.
We established a cell line (Sa3) from human oral cancer. It was derived from a biopsy specimen of a squamous cell carcinoma in the upper gingiva of a Japanese man. The cell culture was initiated by explant culture, and the cell line has now been growing in vitro for more than 80 passages. The cells had an epitheloid morphology and grew as adherent monolayers. They had a doubling time of 55 hours and colony formation of 34%. Chromosomal numbers ranged from 36 to 76 and the mode was 71. The cell line was tumorigenic in nude mice and histologically identifiable with the original tumor. The cells were sensitive to hyperthermia. Histochemical staining of the cells for lysosomal enzymes and cytokeratin was positive.
The aim of this study was to clarify the factors which influenced the successful of bony bridging following bone grafts into the alveolar cleft with autogenous particulate cancellous bone harvested from iliac bone. The bone bridge build up in the alveolar cleft was assessed by periapical radiographs taken before and 18-23 months after the operation. Successful bony bridging defined as a bone bridge with a vertical height of greater than about 11mm, was observed in 123 of all 202 clefts. The frequency of successful bony bridging decreased with increasing severity of cleft type. Successful bony bridging was achieved in 81.8% of unilateral cleft lip and alveolus patients and in only 45.2% of bilateral cleft lip and palate patients. Moreover, the frequency of successful bony bridging was significantly negatively correlated with the width of the cleft. The present study has clearly shown at least two major determinants of successful bony bridging: 1) the cleft type, and 2) the width of the cleft.
The purpose of this study was to investigate the effectiveness of using guided tissue regeneration (GTR) with an absorbable membrane for the preparation of immediate dental implants. Osseous defects were create in the edentulous region of rabbit mandibles. After implanting cylindrical hydroxylapatite (HA). half of the defects were covered with VicrylR woven mesh and the other half were not. The animals were sacrificed 1, 2, 4 and 8 weeks postoperatively. Non-decalcified specimens, 15 pm in thickness, were prepared, stained with toluidine blue and examined histologically. The following results were obtained: 1. In the non-covered defects, connective tissue existed between the new bone and the upper half of the HA implant by 8 weeks. 2. In the mesh-covered defects, direct bonding between newly formed bone and the HA surface under the mesh, without connective tissue in the upper half, was observed 4 weeks postoperatively. 3. Mononuclear and multinuclear cells were observed around the mesh at 1 week. The structure of the mesh became unclear at 4 weeks and the mesh was completely absorbed at 8 weeks. A tendency to cause tissue reactions was not observed. These results indicate that guided tissue regeneration with an absorbable membrane is useful for the preparation of immediate dental implants.
This report presents rate two cases of foreign bodies (sperm-bags of squid) in the oral cavity, which were found in a 38-year-old male and 49-year-old female. Several small thorn-shaped foreign bodies stuck in the oral mucosa were observed and removed successfully.
We report a case of a life-threatening central hemangioma of the mandible treated with superselective new liquid embolization technique prior to excision. A 24-yearold woman was referred by her dentist for severe hemorrhage from the buccal gingiva of the mandibular left molar region. Angiography showed a vascular lesion mostly fed by the inferior alveolar artery. Five days prior to surgery, superselective embolization was carried out using estrogen alcohol and polyvinyl acetate, which is a newly developed method. Histopathological study showed a cavernous hemangioma of the mandibular region undergoing bone destruction with complete obliteration of large vessels and small arterioles without any signs of hemorrhage. This superselective liquid embolization technique can provide a good modality for the treatment of vascular lesions of the oral and maxillofacial areas.
This paper reports a rare case of odonto-ameloblastoma in the mandible. A 61-year-old male patient had felt a painless bony swelling in the right mandibular molar region. Roentgenographic examination revealed a hen egg-sized, multilocular radiolucent area with two radiopaque masses extending from the right mandibular first molar to the mandibular ramus. It was histologically diagnosed to be an ameloblastoma by biopsy. The patient was treated by segmental mandibulectomy and iliac bone grafting for reconstruction. Histopathological examination of the resected specimen revealed a mixture of hard tissues composed of immature dentin, enamel and cementum adjacent to the tumor nest of the ameloblastoma, arising in the cyst wall and subepithelial connective tissue. Therefore, the lesion was finally diagnosed to be an odontoameloblastoma. There have been no sign of tumor recurrence at 1 year and 8 months postoperatively.
Gout is a chronic metabolic disorder characterized by acute exacerbations of joint pain and swelling associated with elevated uric acid in the blood. The attacks result from deposition of crystals of monosodium urate in and around the joints. However, gout of the temporomandibular joint is rare. The case reported here had a gouty tophus arising on the temporomandibular joint which was associated with trismus.
A 21-year-old woman was referred to our hospital complaining of mobility of the upper left incisor. Her bilateral lower first molar had been removed 2 years ago due to periodontitis. The alveolar gingiva of the upper left incisor region showed tumorous swelling. Radiographic examination revealed irregular resorption of the alveolar bone in the same region. A biopsy was performed, and marked plasma cell infiltration was seen. However, no decision could be made regarding the diagnosis, and periodontitis and extramedullary plasmacytoma were suspected. Immunohistochemical staining for immunoglobulin showed that κ-and λ-positive cells were distributed equally. Due to this polyclonal production, inflammatory disease was suspected. Finally, a diagnosis of juvenile periodontitis was made. Immunohistochemical staining proved to be helpful in the diagnosis of abnormal plasma cell proliferation.