Biomechanical configurations of mandibular transport distraction osteogenesis devices.

Mandibular bone transport (MBT) distraction osteogenesis devices are used for achieving reconstruction of mandibular defects in a predictable way, with few complications, less complexity than other alternative surgical procedures, and minimal tissue morbidity. However, selection of appropriate MBT device characteristics is critical for ensuring both their mechanical soundness and their optimal distraction function for each patient's condition. This article assesses six characteristics of currently available MBT devices to characterize their design and function and to classify them in a way that assists the selection of the best device option for each clinical case. In addition, the present work provides a framework for both the biomechanical conception of new devices and the modification of existing ones.

Fracture of mandibular reconstruction plates used after tumor resection.

PURPOSE: We assessed the incidence of fractured plates after primary temporary AO plate reconstruction of the mandible following tumor resection. PATIENTS AND METHODS: One hundred ten patients were retrospectively evaluated according to the extent of the tumor, anatomic location of the reconstruction, type of plate, additional use of radiotherapy or flap surgery (or both), and the incidence of fractured plates. RESULTS: Fractured plates occurred in 8 of 110 patients. Most occurred less than 6 months after surgery. All of the 8 patients had a malignant tumor; 2 had received radiation therapy and 4 had skin flaps placed. The fractured plate was the straight type in 1 patient and the angular type in 7 patients. Among patients who had fractured plates, the average number of remaining teeth was 12.8 in the maxilla and 9.5 in the mandible. CONCLUSIONS: Fractured plates were more common among patients with oral cancer with a segmental defect that did not cross the midline in whom an angular-type plate was used and no bone grafting was performed.