Density of the mandibular ramus (cancellous:cortical bone volume ratio) as a predictor of the lingual fracture pattern in bilateral sagittal split osteotomy.

The aim of this retrospective cohort study was to evaluate the relative amount of cancellous bone in the mandibular ramus as a predictor of lingual fracture patterns after bilateral sagittal split osteotomy (BSSO). The study including 78 consecutive patients (156 osteotomy sites). In preoperative cone-beam computed tomographic (CT) scans, the volumes of cancellous and cortical bone in the BSSO surgical field were estimated. Patients were divided into two groups based on the cancellous:cortical bone ratio. We studied postoperative cone-beam CT scans for lingual fracture lines and subcategorised them according to the lingual split scale (LSS). Generalised linear mixed models (GLMM) were estimated to evaluate the association between the cancellous:cortical bone ratio and the lingual fracture pattern. There was a significant association between the cancellous:cortical bone ratio of the mandibular angle and the lingual fracture pattern after BSSO. Mandibular angles with a relatively small amount of cancellous bone showed significantly more LSS3 fracture lines (OR=1.990, 95%CI 1.043 to 3.796, p=0.043). These mandibular angles also showed more unfavourable fractures (LSS4), although this was not significant (OR=2.352, 95%CI 0.748 to 7.392, p=0.143). The relative amount of cancellous bone in the mandibular angle is significantly associated with the lingual fracture line after BSSO.

Osteoradionecrosis of the mandible: pathogenesis.

Although the precise pathogenic mechanisms are not fully understood, osteoradionecrosis of the mandible is caused by radiation-induced cellular injury, ultimately resulting in a chronic, nonhealing wound. This etiology does not explain the strong predisposition of the mandible to radionecrosis relative to the maxilla, and overlooks the contribution of ischemic necrosis due to radiation-induced disturbances in circulation. In this study, irradiated mandibles with and without osteoradionecrosis and nonirradiated mandibles were examined histologically. Our findings show that osteoradionecrosis of the mandible is an ischemic necrosis due to radiation-induced obliteration of the inferior alveolar artery, while revascularization by branches of the facial artery is disturbed by radiation-induced vascular disease and periosteal damage. The most vulnerable part of the mandible is the buccal cortex of the premolar, molar, and retromolar regions.

[Gardner's syndrome: report of a case]. / Het syndroom van Gardner.

Gardner's syndrome consists of multiple polyposis of the large intestine and soft and hard tissue tumors. The syndrome should be considered in case of supernumerary teeth, odontomas, osteoma and soft tissue tumors. These findings often precede colonic involvement. Careful attention should be directed towards the family history. The importance of this syndrome lies in the great tendency of the polyps to become malignant. Dentist and oral surgeon play an important role in the early detection of this syndrome and thus prevention of malignant degeneration of the intestinal polyps.

Reconstruction of the lower half of the facial skeleton after removal of the mandible at autopsy.

A method for postmortem removal of the mandible without altering the facial appearance of the deceased is presented. The technique is especially developed to avoid damage to the soft tissues of the face.