The influence of third molars in the line of mandibular angle fractures on wound and bone healing.

OBJECTIVES: The objective of this study was to evaluate postoperative complications after removal or retention of the third molar in the line of mandibular angle fractures. MATERIALS AND METHODS: This retrospective study included the data of 98 patients with a molar in the line of a mandibular angle fracture treated with internal reduction and mini-plate fixation at our department over 9 years. Patients were classified into two groups: tooth removal during osteosynthesis (n = 45) and tooth retention (n = 55). The primary target criterion was the incidence of minor (outpatient treatment, local measures) and major (surgical revision, rehospitalisation) complications. Time between trauma and surgery was 1.4 days (range 0 to 12), and the average follow-up 291 days (range 66 to 863). RESULTS: Regarding the eruption status, 26 of 52 (50.0 %) impacted third molars, 11 of 19 (57.9 %) incompletely erupted and 8 of 27 (29.6 %) completely erupted molars had been removed during open reduction. Overall, 17 (17.3 %) patients had postoperative minor (n = 7) or major (n = 10) complications, in detail 10/45 (22.0 %) patients after tooth removal and 7/55 (13 %) patients after tooth retention (p = 0.286). Complication rates between impacted and incompletely erupted third molars (impacted molars 15.0 %, incompletely erupted molars 10.0 %) did not differ significantly, but completely erupted molars had a complication rate of 26.0 %. CONCLUSIONS: Mandibular angle fractures with a completely erupted third molar show the highest complication rate after open reduction and osteosynthesis. Retention of a non-infectious third molar facilitates open reduction and does not increase the complication risk. CLINICAL RELEVANCE: The study helps with the decision of removing or retention of a third molar during surgical treatment of a mandibular angle fracture.

[Maxillary and mandibular fractures. Treatment concepts in maxillofacial surgery]. / Frakturen von Maxilla und Mandibula. Kieferchirurgische Behandlungskonzepte.

Maxillary and mandibular fractures are a relatively frequent occurrence due to the exposed location of the jaws and are caused mainly by acts of violence, traffic and recreational accidents. Mandibular fractures can be treated conservatively with dental splints and intermaxillary fixation. Since Michelet, miniplate osteosynthesis via intraoral access has become the method of choice. Champy showed that the monocortical fixation of miniplates at the level of the linea obliqua results in stable osteosynthesis, despite postoperative micro-movements in the fracture gap, and postulated the principle of dynamic compression. Dislocated fractures of the mandibular collum are treated with stable osteosynthesis via an intra- or extraoral approach, while fractures of the mandibular joint are usually treated conservatively and early functional rehabilitation is favored. For mandibular fractures, the principle of load-bearing and load-sharing should be considered, i.e. in the case of sufficient bone and uncomplicated fractures, the bone can bear most of the force, such that miniplates are sufficient (load-sharing). If bones are weakened by atrophy or in the case of infected, comminuted or defect fractures osteosynthesis plates must bear the load alone (load-bearing).

Bone formation and degradation of a highly porous biphasic calcium phosphate ceramic in presence of BMP-7, VEGF and mesenchymal stem cells in an ectopic mouse model.

INTRODUCTION: Angiogenesis and mesenchymal stem cells (MSCs) promote osteogenesis. The aim of the present study was to evaluate whether bone morphogenetic protein (BMP-7) promoted osteoinduction could be enhanced by combining it with vascular endothelial growth factor (VEGF) or MSCs in highly porous biphasic calcium phosphate (BCP) ceramics. MATERIALS AND METHODS: BCP ceramic blocks were implanted in an ectopic site in 24 mice (BMP-7 vs. BMP-7/VEGF; BMP-7 vs. BMP-7/MSCs and BMP-7 vs. Control; each group n=8). Specimens were analysed 12 weeks after surgery by environmental scanning electron microscopy (ESEM) and Giemsa staining. RESULTS: In all implanted scaffolds, newly formed bone was observed, even in the control site. No statistical differences in the amount of new bone were found in the presence of BMP-7 compared to BMP-7/VEGF (p=1.0) or BMP-7/MSCs (p=0.786). ESEM revealed a degradation of the scaffolds. A higher degradation was observed in areas where no bone-implant contact was present compared to areas where the ceramic was integrated in newly formed bone. CONCLUSIONS: Neither VEGF nor MSCs enhanced BMP-7 induced bone formation under the selected conditions. The present ceramic seemed to be osteoinductive and degradable, making this material suitable for bone tissue engineering.