During intra-arterial perfusion therapy of oral squamous cell carcinomas with bleomycin, circumscribed necrotic areas in the perfused region are observed in a few cases. These are usually located in the acral regions. As the cause, a lesion of the blood vessels with formation of microthrombosis could be demonstrated. Electron-microscopic observations of the blood vessels in five bleomycin-perfused tumor areas demonstrated lesions of the endothelium characterized by swelling of the cells, formation of intracytoplasmatic vacuoles and villous projections into the lumen of the vessel. In arterioles, separation of the endothelium from the underlying tissue, swollen smooth muscle cells and destruction of elastic lamellae were found. These were the pacemakers for the formation of thrombosis. A negative influence of the vascular lesions on the cytostatic effect on the tumor is likely. Vascular lesions also constitute one of the initial factors for the development of the bleomycin-induced lung lesion (bleomycin lung).
Craniofacial anomalies are conventionally investigated by cephalometry using ordinary radiographs and by computed tomography. Both methods have the major disadvantage of trying to demonstrate a complex three-dimensional structure, such as the skull, in two dimensions and they therefore cannot display a true spatial image. We present the principle underlying a three-dimensional display derived from computer tomographic studies and discuss the clinical application in the diagnosis of craniofacial anomalies.
The serial records of 21 patients were analyzed to study the stability of genioplasty performed in the course of orthognatic surgery and to describe its effect on the soft tissue profile. A pre-operative and a post-operative cephalogram as well as a cephalogram one year after surgery of each patient were available. Sagital correction of the chin from 16.5 mm advancement to 1.1 mm reduction and vertical movements between 4.8 mm lengthening and 9.3 mm shortening remained nearly unchanged during the control period. No post-operative movements of the chin fragment were observed except for minor resorptions that can be attributed to an osseous remodelling and rounding of sharp edges. In cases of a long face syndrome a bone apposition from 1 mm to 5.5 mm appeared at the lower edge of the chin. The average of sagittal soft tissue change in relation to the correction of the bony chin was 71%. The individual values ranged from 4% to 145% and the standard error of the estimate was 3 mm. Therefore the planning of the soft tissue profile is rather unreliable. A genioplasty performed with rigid fixation by compression screws or mini plates, preservation of vascular supply and re-fixation of the soft tissue of the chin results in accurately predictable and stable bony contours. On the other hand, the planning of surgery procedures related to the soft tissue profile is--if at all possible--very insecure.
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