Deutsche Zeitschrift fur Mund-, Kiefer- und Gesichts-Chirurgie最新文献

To clarify the compatibility of steel and titanium, mandibular resections were performed on 24 sheep and the defects bridged with titanium plates and steel vs. titanium screws. 6, 12 and 24 weeks after osteosynthesis the implants were removed along with the surrounding bone segment and thin ground sections were prepared using the Donath method. The sections were then studied by light, fluorescence, polarization and scanning electron microscopy. The stability and easy removal are advantages of steel screws rendering them particularly suitable for temporary implantations. Moreover, they are 50-75% less expensive than titanium screws. After 3 and 6 months some minimum friction corrosion was observed at the screw/plate interface of steel screws. None of the specimens, however, showed signs of local tissue damage such as metallosis. From this it may be concluded that at least on a temporary basis a combination of steel screws and titanium plantes seems to be possible.

Size and quality of the medullary space in the mandibular ramus are highly variable. Mean value studies using CT scans show a broad range of variation for vertical measurements of the medullary space. An individual CT scan of the mandibular ramus therefore seems to be necessary to establish the optimum line of osteotomy in preparing a sagittal split osteotomy of the mandible.

The present first part of two of a historical overview on ankylosis of the TMJ and syngnathia covers the period from antiquity to the 2nd half of 19th century. Etiology, case studies and the first therapeutic approaches are documented on the basis of long forgotten and meanwhile hardly accessible original sources.

The treatment of single-walled bone pockets involves a number of problems. Conventional treatment methods fail to bring about permanent success, particularly in the more advanced stages. A new method has been developed and described using a cortico-cancellous graft harvested from the apical region of the teeth with a periosteal pedicle that can be inserted into the highly infection-prone area of a bone pocket. The advantage of this procedure is that the transplant is perfused and thus not subjected to necrosis but highly resistant to infections. Indications, practical procedure and success rates are discussed and illustrated in one example.

Inferior alveolar nerve lesions are amongst the most frequent and most severe complications in the surgical removal of third molars. To avoid nerve lesions, careful preoperative radiographic assessment of the anatomical relationships is mandatory. Whenever there is a close topographical relationship between the third molar roots and the mandibular canal, we perform high-resolution CT scans. The additional information obtained as against conventional x-ray films is demonstrated in case descriptions. The results and possible implications in terms of irradiation exposure are discussed.

A method for the generation of a panoramic image from skeletal scintiscans of the jaws with the aid of a cylindrical projection of emission CT scans ist presented. Based on this "panoramic tomoscintigraphy" the jaw regions, arranged in the order of the arch segments, are evaluated numerically and the quantitative results are presented in a clearly organized form. The relative activity of each segment is computed relative to the corresponding contraletaral segment or to the average activity of the respective jaw. In the case of pathologic findings the respective segments are highlighted in the dental chart. A set of normal values with standard deviations has been generated using this method in 24 patients without evidence of any jaw pathology. Within the framework of the significance limit it was not possible to demonstrate any right/left asymmetry in the metabolic activities of the jaw bone.

45 patients with oral cancer preoperatively received regional intraarterial chemotherapy (RIAC). All patients developed stomatitis or glossitis limited to the region of cytostatic perfusion. Between 1 and 19 days (median 4 days) after RIAC the tumor was removed by hemiglossectomy, partial resection of the floor of the mouth etc. The tissue alterations induced by chemotherapy in these surgical specimens were analyzed histomorphologically. Stomatitis due to RIAC was characterized by necrosis, ulceration and severe epithelial dysplasia of mucous membranes. Approximately 2 weeks after chemotherapy both the inflammatory changes and the dysplasia had disappeared completely. The differences between spontaneous premalignant dysplasia of the oral cavity and dysplasia induced by RIAC are discussed.

The case of a 54-year-old man with multiple basaliomas of the face but without any other symptoms of the Goltz-Gorlin syndrome is described. Obviously, there ist a family history of a tendency to develop basaliomas. One of the patient's three brothers, his mother, her sister and two of his six children were also affected. After removal of the tumor, electron microscopy revealed intranuclear crystal-like structures in some of the epithelial cells of the tumor tissue. The particular geometry of these structures suggests that these are papilloma viruses. The tumor stroma contained fibroblasts, fibrocytes and predominantly myofibroblasts. Tumor explants were cultured in vitro in Dulbecco-Vogt medium using 5 different supplements: 10% fetal calf serum (FCS), 10% fresh human serum with and without PDGF and CL (PDGF-CL, PDGF, CL, NULL). These cultures result in different rates of collagen gel contraction and binding of varying amounts of the "q" fraction of the first complement (C1q): PDGF CL-cells greater than PDGF cells greater than FCS cells greater than NULL cells. The culture of tumor tissue cells in different media thus seems to enhance the dominance of different cell subtypes.

The new short pulse Er:YAG laser system allows effective and careful osteotomy. Bone healing subsequent to Er:YAG laser osteotomy takes the same course in time as secondary fracture healing. By contrast, bone healing after cw CO2 laser application is delayed about two to three weeks.

The tissue oxygen pressure measurements carried out in 33 freshly operated flaps with a newly introduced needle probe show a relation between the pO2-values and the prognosis of the flaps. In the assessment of clinically doubtful flap vitality (pale or blueish appearance) this method allows the clinician to discriminate grafts in need of therapeutic intervention (drugs, leeching, surgery) from those that need not to be treated.