Akademik Veri Yönetim Sistemi
JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY, MEDICINE, AND PATHOLOGY, cilt.36, ss.1-10, 2024 (SCI-Expanded)
Objective: Mandibular bone defects are a common problem and difficult to manage. A defected area mostly left to heal spontaneously. It does not have a definite protocol in the literature that when the area will be left to heal spontaneously or when it will be supported with materials such as plates, screws, grafts, especially in intermediate-sized defects. In this study, it was aimed to determine a cutoff value by examining the areas where the stresses due to chewing forces are concentrated on the mandible bone and the situations that will create the risk of fracture in intermediate size unicortical and bicortical mandibular defects.
Material and Methods: The bicortical and unicortical mandibular defect models which was the residual bone heights were 6, 8, 10 mm in mandibular corpus region were created. Two different loading scenarios were applied anterior and defected premolar side (151 and 355.2 Newton, respectively). Von Mises, Pmax and Pmin stresses in the defect area and surrounding bone were evaluated by three-dimensional finite element analysis method.
Results: As a result, in bicortical defects residual bone height less than 10 mm and in unicortical defects residual bone height less than 8 mm models were showed higher risk for pathologic fracture. The stress accumulation in the cortical bone is higher than the cancellous bone. In unicortical defects the presence of lingual wall was provided an advantage to reducing fracture risk compared to bicortical defects.
Conclusion:
This study was presented that mandibular resistance decreases significantly when residual bone height is less than 10 mm for bicortical defects and less than 8 mm residual bone height at unicortical defects. In cases of these conditions, it may need additional support like screws, plates, or grafting to prevent fractures. However, further validation through in vivo and in vitro studies is necessary for definitive conclusions.