Digital Study Of The Zygomatic Arch Based For Osteotomy Reduction Of A Prominent Zygomatic Arch

ObjectiveOsteotomy reduction of a prominent zygomatic arch can effectively reduce the width of the middle face and adjust facial contours.However,there is a lack of research on the reduction of the prominent zygomatic arch at home and abroad.The purpose of this study is to analyze the osteotomy reduction of a prominent zygomatic arch from the following aspects.1.Construct 3D models of the zygomatic bone and zygomatic arch region,measure the anatomical morphological data of the zygomatic arch bone,analyze the anatomical morphological characteristics of the zygomatic arch bone,and judge the effect of the anatomical morphological on the degrees of zygomatic arch reduction.2.Digital surgery was used to simulate the degree of reduction of the zygomatic arch during osteotomy with different initial arch positions.To analyze the value of simulated surgery in predicting the outcome of individualized surgical reduction of a prominent zygomatic arch.3.To introduce a digital method of locating the osteotomy position of the zygomatic arch during surgery and analyze the accuracy of this method.Materials and MethodsComputed tomography data were obtained from the electronic records of patients who had prominent zygomatic body and zygomatic arch.The data were imported into modeling and analysis software Mimics.According to the purpose of the experiment,the corresponding measurement system was established,and the construction and analysis of the experimental model were completed in this system.1.In the 3D models,a vertical cut of the zygomatic arch was done,and anatomical morphological characteristics of the zygomatic arch were obtained through bone data measurement and morphological observation.2.In the 3D models,a wedge-shaped cut of the zygomatic bone was pushed inward,and the osteotomy position of the zygomatic arch was taken as a variable to simulate the reduction malarplasty.The reduction effect was calculated from the simulated movement of the fracture end of the zygomatic arch from internal pushing forces.3.Locating the simulated osteotomy position of the zygomatic arch before the osteotomy reduction surgery,applying the digitally modeled osteotomy position of the zygomatic arch during the surgery,and locating the actual osteotomy position of the zygomatic arch after the surgery.The accuracy of the experimental method was verified by matching the preoperative simulation data with the postoperative osteotomy data.Results1.There exists a stabilization area of bone morphology and enlargement area of bone morphology in the posterior margin of the zygomatic process.In people with prominent zygoma,The anterior edge of the stabilization area was located in front of the articular tubercle point(95% CI: 15.12 to 17.16 mm).The posterior edge of the stabilization area was located in front of the articular tubercle point(95% CI: 7.11 to8.24 mm).The posterior edge of the enlarged area was located in front of the articular tubercle point(95% CI: 3.17 to 3.94 mm).2.The observed reductions were similar for osteotomy in the middle and posterior regions of the zygomatic process.We refer to this area as the "stable internal pushing osteotomy area".Osteotomy in the root of the zygomatic process,behind the stable internal pushing area,resulted in a continuous increase in the reduction of the zygomatic arch.We refer to this area as the "high-efficiency internal pushing osteotomy area" The anterior edge of the stable internal pushing osteotomy area was located in front of the articular tubercle point(95% CI: 10.64 to 11.89 mm).The posterior edge of the stable internal pushing area was located in front of the articular tubercle point(95% CI: 7.8 to 9.13 mm).The posterior edge of the high-efficiency internal pushing area was located in front of the articular tubercle point(95% CI 4.7to 5.73 mm).3.A Wilcoxon rank sum test was performed to compare the cases osteotomy position obtained by preoperative simulation with the actual postoperative position.There was no significant difference in zygomatic arch osteotomy position between the preoperative simulation and the real postoperative position(Z=-1.867,P=0.062).Conclusion1.There exists a stabilization area of bone morphology and enlargement area of bone morphology in the prominent zygomatic arch.2.Stable and high-efficiency internal pushing areas were detected above the zygomatic arch.The simulation showed that osteotomy in these areas can provide different degrees of zygomatic arch reduction.3.The digital method to locate the zygomatic arch osteotomy can be used with accuracy to achieve the proper osteotomy position.