Graduate Program in Biomedical Engineering, The University of Western Ontario.
Schulich School of Medicine and Dentistry, The University of Western Ontario.
J Craniofac Surg. 2021 Sep 1;32(6):2045-2049. doi: 10.1097/SCS.0000000000007630.
Zygomaticomaxillary complex fractures are common in midface trauma, with treatment often involving repair using titanium mini plates. However, the need for plate fixation along the zygomaticomaxillary suture on the infraorbital rim remains controversial. This study utilized a previously reported bite force simulator to investigate craniofacial strain patterns following zygomaticomaxillary complex fracture repairs with and without plating of the infraorbital rim. Osteotomies were made to 6 fresh-frozen cadaveric heads to simulate 2 types of zygomatic complex fractures: a dipod fracture with osteotomies at the zygomaticofrontal and zygomaticomaxillary sutures, and a tripod fracture with an additional osteotomies at the zygomaticotemporal suture. Repairs with and without the use of a titanium mini plate across the infraorbital rim were compared in both dipod and tripod fractures. Physiologically proportional masticatory loads were applied using the bite force simulator by actuating intrinsic muscle lines of action. The outcome metric was facial bone strains measured using uniaxial strain gauges. Mixed-effects linear models did not find a significant main effect on the overall strain pattern with the use of an infraorbital rim plate in both dipod (P = 0.198) and tripod (P = 0.117) fracture repairs. However, statistically significant differences were found locally at the zygomatic buttress (P = 0.019) and the zygomatic arch (P = 0.027) on the fractured side in dipod fractures. This is the first known study that successfully utilized a mechanical simulator to reproduce physiological intrinsic masticatory loads in a fracture fixation study. This new technology opens avenues for future biomechanical investigations on maxillofacial fracture repairs and other surgical treatments.
颧骨复合体骨折是面中部创伤中的常见问题，治疗通常涉及使用钛微型板进行修复。然而，在下眶缘沿颧骨-上颌骨缝线进行板固定的需求仍存在争议。本研究利用先前报道的咬合力模拟器，研究了颧骨复合体骨折修复后有无眶下缘钛板固定时的颅面应变模式。对 6 个新鲜冷冻的头颅标本进行了截骨术，模拟了 2 种颧骨复合体骨折：一种是在颧骨额缝和颧骨上颌骨缝处进行截骨的二足骨折，另一种是在颧骨颞骨缝处额外进行截骨的三足骨折。在二足和三足骨折中，比较了有无眶下缘钛板修复。使用咬合力模拟器通过激活内在肌肉作用线施加生理比例的咀嚼负荷。结果指标是使用单轴应变计测量的面部骨应变。混合效应线性模型未发现眶下缘板在二足（P = 0.198）和三足（P = 0.117）骨折修复中对整体应变模式有显著的主要影响。然而，在二足骨折中，在骨折侧的颧骨支柱（P = 0.019）和颧骨弓（P = 0.027）处发现了局部统计学上的显著差异。这是首次成功利用机械模拟器在骨折固定研究中重现生理内在咀嚼负荷的研究。这项新技术为未来在颌面骨折修复和其他手术治疗方面的生物力学研究开辟了途径。
