[Problems of the treatment of prognathism by sagittal splitting of the ascending mandibular branch].

The author reports 20 years of experience at the Zurich clinic with the treatment of mandibular prognathism by sagittal cutting of the ascending mandibular rami. The original method of Obwegeser and its modifications (1955, 1957) are discussed. After mentioning the indications, the technique of surgery is described, such as it is practised today at the clinic of maxillofacial surgery in Zurich. The classical method applies to tooth bearing arches, while modifications are necessary in edentulous mandibles. Further on, modifications as mentioned in the literature, particularly applying to the soft tissue cuts, the bone cuts, the position of the buccal cut of the cortical bone, the direction of partition, the technique of partition and the fixation of the segments, finally the intermaxillary splinting and drainage are mentioned. It is explained, why in the Zurich clinic the technique of Obwegeser is still prevalently used. The most prominent modifications are the blunt partition of the ramus and the control of the position of the condyle under the radiographic viewer. The use of the modification in the cut of the buccal cortical bone after Dal Pont (1959) was abandoned again.