WORLD JOURNAL OF PLASTIC SURGERY

en Three Different Fixation Modalities following Mandibular Setback Surgery with Sagittal Split Ramus Osteotomy: A Comparative Study using Three-dimensional Finite Elements Analysis تخصصي Special مقالات اصيل Original Article Background: The provision of sufficient stability after maxillofacial surgery is essential for the reduction of complications and disease recurrence. The stabilization of osteotomized pieces results in rapid restoration of normal masticatory function, reduction of skeletal relapse, and uneventful healing at the osteotomy site. We aimed to compare qualitatively stress distribution patterns over a virtual mandible model after bilateral sagittal split osteotomy (BSSO) bridged with three different intraoral fixation techniques. Methods: This study was conducted in the Oral and Maxillofacial Surgery Department of Mashhad School of Dentistry, Mashhad, Iran, from March 2021-March 2022.  The mandible computed tomography scan of a healthy adult was used to generate a 3D model; thereafter, BSSO with a 3mm setback was simulated. The three following fixation techniques were applied to the model: 1) two bicortical screws, 2) three bicortical screws, and 3) a miniplate. The bilateral second premolars and first molars were placed under mechanical loads of 75, 135, and 600N in order to simulate symmetric occlusal forces. Finite element analysis (FEA) was carried out in Ansys software, and the mechanical strain, stress, and displacement calculations were recorded. Results: The FEA contours revealed that stress was mainly concentrated in the fixation units. Although bicortical screws presented better rigidity than miniplates, they were associated with higher stress and displacement readings. Conclusion: Miniplate fixation demonstrated the most favorable biomechanical performance, followed by fixation with two and three bicortical screws, respectively. Intraoral fixation with miniplates in combination with monocortical screws can serve as an appropriate fixation arrangement and treatment option for skeletal stabilization after BSSO setback surgery.   Bicortical, Bilateral sagittal split osteotomy, Finite element analysis, Maxillofacial surgery 43 57 http://wjps.ir/browse.php?a_code=A-10-795-4&slc_lang=en&sid=1 Majid Eshghpour 100319475328460013937 100319475328460013937 No Dental Research Center, Mashhad University of Medical Sciences, Mashhad, Iran Sahand Samieirad 100319475328460013938 100319475328460013938 No Oral and Maxillofacial Diseases Research Center, Mashhad University of Medical Sciences, Mashhad, Iran Zahra Shooshtari 100319475328460013939 100319475328460013939 No Dental Research Center, Mashhad University of Medical Sciences, Mashhad, Iran Abdolrahim Shams 100319475328460013940 100319475328460013940 No Oral and Maxillofacial Surgery Department, Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran Nafiseh Ghadirimoghaddam Shamsa971@mums.ac.ir 100319475328460013941 100319475328460013941 Yes Oral and Maxillofacial Surgery Department, Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran