فهرست مطالب seyed omid keyhan

The aim of this study was to compare bite force in different mandibular angle fracture patterns after reduction and fixation with miniplate osteosynthesis with intact mandibles using finite element analysis (FEA). Subject and Three-dimensional finite element models of human mandible was prepared using CBCT. Simulated intact mandible and 4 different types of angle fractures were fixed with 5 different fixation methods of titanium miniplates. The finite element analysis was performed to determine bite force during clenching in the intercuspal position under loading with full masticatory forces. Bite force in the mandible reduced with 2 miniplates were closer that in the intact mandible. The use of double miniplates on the inferior border of the lateral cortex and external oblique ridge showed the best bite force and the single plate on superior border of the lateral cortex pattern was the worst. This study presented a FEA based indirect method to estimate bite force. Finite element method can be effective tool in maxillofacial researches. Double miniplate fixation method for patients with mandibular angle fracture have a biomechanical advantage over 1 miniplate on the restoration of bite force.

Pain and complications are common after surgical removal of impacted third molars. The present study was undertaken to evaluate the effect of an oleous suspension of calcium hydroxide (OSTEORA) on pain severity and complications after surgical removal of impacted third molars. This clinical trial evaluated 30 patients with an age range of 17‒40, referring to a maxillofacial surgery department and two private clinics in Tehran in 2011‒2012 for surgical removal of bilaterally impacted third molars with the same difficulty index. OSTEORA was used on one side and no material was used on the contralateral side as the control. The effect of OSTEORA was evaluated on pain, healing, hemorrhage, dry socket and infection at different postoperative intervals in a double-blind manner. Data were analyzed with chi-squared and Mann-Whitney U tests (α=0.05). Of 60 samples, 28 were from the maxilla and 32 were from the mandible. Intensity of pain in the study groups at baseline and at follow-up intervals was the same (p value = 0.4). The incidence of hemorrhage at follow-ups was the same in both groups (p value < 0.5). Maxillary healing rates on the 3rd postoperative day in the control and test groups were 3.21±2.39 and 2.42±2.17, respectively (p value < 0.03) and on the 7th postoperative day they were 2.9±2.58 and 2.14±2.28, respectively (p value < 0.03). Healing in mandible in both groups was the same at follow-ups (p value < 0.2). No dry sockets and infection were observed in any subject. Under the limitations of the present study, use of an oleous suspension of calcium hydroxide had no effect on the incidence of hemorrhage and pain after surgical removal of impacted third molars. However, it affected healing of the surgical site, especially in the maxilla.