ABSTRACT
The purpose of this study is to evaluate the tissue response in applying of various bone substitutes included toothash-plaster mixture, resorbable hydroxylapatite (HA) and demineralized freeze-dried bone and to show the clinical usefulness of toothash-plaster mixture for the repair of craniomaxillofacial bone defect. For this experiment, 100 Sprague-Dawley rats weighing 200gm or more were used. There were four experimental groups: group I, toothash-plaster mixture; group II, demineralized freeze-dried bone; group III, resorbable HA; and group IV, control group. A full thickness, round bone defect measuring 10mm in diameter was created in the midcranium, and the substitutes cited above were embedded in the experimental rats based on their group assignment. Blood clot was filled in the rats assigned to the control group. Experimental rats were sacrificed on the 1st, 3rd, 5th, 8th, 12th and 24th week after implantation and stained with the hematoxylin-eosin, Masson's Trichrome, using Van Gieson's stain method, and were examined under light microscope. The results were as follows: 1. In all the groups, prominent inflammatory reaction and the infiltration of multinucleated giant cells were noted during the early stage. Gradual healing decreased this reaction. 2. Among the rats in the experimental group II, which were given demineralized freeze-dried bone implants, active formation of new bone traveculae manifested. Chondroid tissues appeared, and it was suggested that the defect was filled with newly formed bone by virtue of osteoinductive activity. On the 12th week after the experiments, most of the defect was filled with newly formed bone trabeculae. 3. In experimental groups I and III, it was noted that HA manifested a healing process similar to that characterized by the toothash-plaster mixture, but inflammatory reaction was more prominent in experimental group I. Active osteoblasts were observed along the periphery of osteoid tissues, while newly formed bone trabeculae appeared adjacent to the implanted materials three weeks later. Formation increased to the extent that newly formed bone trabeculae fused directly with the host bone. Increase in new bone ingrowth into the filling materials was revealed by both experimental groups. 4. In the control group, new bone formation adjacent to the host bone was observed, but most of the defect was filled with mature connective tissue 24 weeks after the experiments.
Subject(s)
Animals , Rats , Bone Substitutes , Connective Tissue , Durapatite , Giant Cells , Osteoblasts , Osteogenesis , Rats, Sprague-Dawley , VirtuesABSTRACT
We had experienced a case of traumatic myositis ossificans arising in right masseter muscle, inferior to zygomatic arch occurred on 25 year old male. He had some trauma on the site one year ago and visited with complaint of mouth opening limitation and swelling. Palpable mass with facial disfigurement was noted. and several ovoid radiopaque masses were revealed on C.T. examination. On histopathologic examination, multiple bone trabeculae with osteoblasts in its periphery was noted in connective tissues and invaded to neighbouring muscles, but any chondroid components were not revealed.
Subject(s)
Adult , Humans , Male , Connective Tissue , Masseter Muscle , Mouth , Muscles , Myositis Ossificans , Myositis , Osteoblasts , ZygomaABSTRACT
The ameloblastic carcinoma is an extremely rare, aggressive odontogenic neoplasm of the jaws. It is described as an ameloblastoma in which there is histologic evidence of malignancy in the primary or recurrent tumors, regardless of whether it has metastasized. We report an aggressive case of ameloblastic carcinoma of the mandible. A 68-year-old man with the complaint of the left facial swelling and intermittent pain was referred to our hospital. Serial images of panoramic radiograph, computed tomograph, and magnetic resonance imaging showed an ill-defined destructive radiolucent lesion of the left mandible. The lesion had typically aggressive behavior with extensive local destruction of bone and extended to the adjacent soft tissues. Bone scan revealed increased uptakes in the left mandibular body and ramus regions. Histological features were generally resembled with those of an ameloblastoma but with cytologic features of epithelial malignancy.
Subject(s)
Aged , Humans , Ameloblastoma , Ameloblasts , Jaw , Magnetic Resonance Imaging , MandibleABSTRACT
The ameloblastic carcinoma is an extremely rare, aggressive odontogenic neoplasm of the jaws. It is described as an ameloblastoma in which there is histologic evidence of malignancy in the primary or recurrent tumors, regardless of whether it has metastasized. We report an aggressive case of ameloblastic carcinoma of the mandible. A 68-year-old man with the complaint of the left facial swelling and intermittent pain was referred to our hospital. Serial images of panoramic radiograph, computed tomograph, and magnetic resonance imaging showed an ill-defined destructive radiolucent lesion of the left mandible. The lesion had typically aggressive behavior with extensive local destruction of bone and extended to the adjacent soft tissues. Bone scan revealed increased uptakes in the left mandibular body and ramus regions. Histological features were generally resembled with those of an ameloblastoma but with cytologic features of epithelial malignancy.
Subject(s)
Aged , Humans , Ameloblastoma , Ameloblasts , Jaw , Magnetic Resonance Imaging , MandibleABSTRACT
Subject(s)
Animals , Rats , Anesthesia , Anesthesia, Local , Constriction , Epinephrine , Hemostasis , Lidocaine , Mandibular Nerve , TongueABSTRACT
The purpose of this study was to identifu the preventive and the preventive and the progressive inhibitory effects of enamel demineralization with fluoride releasing light-and self-cured orthodontic sealants(FluoroBond), in vitro, under the polarizing light microscope and the scanning electon microscope. The polarizing light microscopic group was subdivided into seven groups(Group A-Group G). The scanning electron microscopic group was also subdivided into seven groups(Group A'-Group G'). For polarzing light microscopic evaluation, longitudinal sections were made longitudinally by Maruto cutter(Maruto Co., Japan) and Maruto grinding machine(Maruto Co., Japan). Sections were examined and photographed by the polarizing light microscope(Olympus Optical Co., Japan) using crossed polars and with the enamel rod longitudinal axis oriented at 45degrees to the extinction position. For scanning electron microscopic evaluation, the specimens were coated with a highly conducting layer of gold palladium in a model Hus-4 high0vacuum evaporator* and examined in an ISI-100B scanning electron microcpe** operated at 20kV. The results of this study were as follows : 1. The mean deoths of artificial carious lesions under a polarized light microscope were Group A(5.08microgram), Group B(47.82microgram), Group C(8.42microgram), Group D(7.20microgram), Group E(85.41microgram), Group F(60.38microgram), Group G(60.13microgram). 2. There were statistically significant differences in Group B compared with Group A, C, and D(p<0.05), and also, in Group E compared with Group F and Group G(p<0.05). 3. Light-and self-cured orthodontic sealants had the preventive effects of enamel demineralization. 4. Light-and self-cured orthodontic sealants had the progressive inhibitory effects enamel demineralization. 5. The time progress of demineralizing agent no ingluecse on the samples of light-and self-cured orthodontic sealants under the scanning electron microscope. 6. There was no difference between the specimens of light-and self-cured orthodontic edalants both in the polarized light microscopic group and in the scanning electron microscopic group. *Hitachi Ltd, Tokyo, Japan **International Scientific Instruments, Santa Clara, Calif.