数字化设计矫治伴面部不对称的髁突骨软骨瘤的疗效评价

目的 评价数字化设计在矫治伴有面部不对称的髁突骨软骨瘤患者中的疗效。方法 选取2018年至2021年因髁突骨软骨瘤行手术治疗的患者7例。所有患者均采用数字化设计，术前确定手术方案，术中切除患侧髁突骨软骨瘤，同期行正颌手术矫治颌骨畸形，术后1周行CT检查。选择上颌中切牙近中接触点（UI）、下颌中切牙近中接触点（LI）、上颌第一磨牙近中颊尖（U6-R、U6-L）以及下颌第一磨牙的近中颊尖（L6-R、L6-L）作为标志点，选择眶耳平面（FHP）、面中平面（与FHP垂直并通过鼻根点的矢状面）和冠状面(与FHP垂直且通过蝶鞍点)作为参考平面。在Mimics 21.0中测量比较术前设计与术后1周内复查颅颌模型中测量标志点至参考平面距离，并计算两模型间线性差异。测量咬合平面和下颌平面与眶耳平面和面中平面所成角度差异。结果 所有患者均按照术前计划完成髁突骨软骨瘤切除术及正颌手术，切除骨软骨瘤的同时矫治了面部不对称。数字化设计模型与术后1周重建模型间线性差异与角度差异无统计学意义（P>0.05），两者间线性测量指标差异均小于2 mm，角度测量指标差异小于4°。结论 数字化设计有助于髁突骨软骨瘤患者...     

数字化软件辅助设计在治疗偏颌畸形患者中的应用效果研究

目的　评价数字化软件辅助设计在治疗偏颌畸形患者中的应用效果。方法　选择2016年9月至2018年9月于中国医科大学附属口腔医院口腔颌面外科就诊的偏颌畸形患者18例。所有患者术前完成三维CT检查和牙列石膏模型的光学扫描，将数据分别以DICOM格式和STL格式传送至数字化工作站。在数字化软件中构建坐标系，重建上下颌骨、血管和神经束，并完成正颌外科的手术模拟预测，最后设计并打印患者上颌骨的截骨导板、复位导板和终末咬合导板。所有患者在术后6个月到口腔颌面外科门诊复查并行上下颌骨三维CT检查。利用数字化软件测量术后6个月患者两侧上颌第一磨牙点和尖牙点到眶耳平面和冠状平面的距离，计算非对称率；测量上中切牙点和颏顶点到正中矢状面距离作为术后效果的评价指标。结果　术后6个月患者两侧上颌第一磨牙点到眶耳平面和冠状平面距离的非对称率分别为（1.8 ± 1.0）%和（3.2 ± 1.7）%；两侧上颌尖牙点到眶耳平面和冠状平面距离的非对称率分别为（1.0 ± 0.8）%和（11.0 ± 4.8）%；上中切牙点和颏顶点到正中矢状面距离分别为（0.84 ± 1.05）mm和（1.49 ± 1.23）mm。所有患者均对面型表示满意。结论　数字化软件的模拟设计能够提高手术安全性，确保术中操作的精度，提高患者术后美学效果。因此，数字化软件辅助设计在治疗偏颌畸形患者中的应用具有重要的临床意义。     

下颌偏斜患者正颌手术前后第一至四颈椎三维位置变化的研究

目的探究下颌偏斜患者正颌手术前后第一至四颈椎位置是否发生改变。方法本研究为回顾性研究。选取22例下颌偏斜成人, 收集其治疗前(T0)、正颌手术后1周(T1)、术后6～12个月(T2)拍摄的锥形束CT, 测量第一至四颈椎三维位置。应用秩和检验分析下颌偏斜患者正颌手术前后颈椎位置是否有差异。结果第三颈椎双侧横突至眶耳平面距离之差T1[0.96(-1.25, 2.27) mm]T1[0.96(-1.25, 2.27) mm], 差异有统计学意义(P=0.048...     

颌态模型的原理及制作

正畸诊疗中,牙颌模型具有很重要的作用,能真实地记录牙齿、牙槽骨、腭部及基骨的形态和位置,是正畸和正颌外科研究错形成的机理、诊断、治疗设计及比较矫治前后变化必不可少的资料。正畸临床中,常用的记存模型有底面平行于牙列平面的平行模型;另外还有Simon提出的底面平行于眶耳平面的颌态模型。平行模型的制作已经有较多的介绍[2～4],而对颌态模型的介绍较少。本文对颌态模型的原理、作用和制作介绍如下。1颌态模型的原理Simon于1926年提出了用互相垂直的三个平面,即眶耳平面、正中矢状平面、眶平面,来研究牙面关系,并以此提出了著名…     

基于虚拟现实技术的正颌手术模拟预测方法的建立

目的:探索建立基于虚拟现实技术的正颌手术模拟研究方法.方法:将颌面畸形患者CT断层图像利用Simplant软件行颅颌面骨组织三维重建,截骨,构建颅颌面骨树状结构模型.在虚拟环境碰撞模型上行上颌骨Le Fort Ⅰ型截骨、双侧下颌支矢状劈开及颏成形的手术模拟.结果:该系统形成的三维立体虚拟影像,可从任意视角观察,清晰逼真.运用系统工具进行骨组织的旋转、平移等手术模拟操作,实现了操作者与模型的交互作用,图像及触觉感知实时反馈,沉浸感强.应用该方法实现了正颌手术设计、虚拟操作及术后效果预测.结论:颅面三维虚拟正颌手术系统可以行正颌手术模拟及手术操作训练,在虚拟环境下实现图像反馈和力、触觉感知的手术模拟,具有较高的临床应用价值.     

双颌正颌手术治疗严重骨性Ⅲ类错牙合 面部硬组织变化的研究

[摘要] 目的：比较严重骨性Ⅲ类错牙合患者双颌正颌手术治疗各阶段硬组织的变化及其术后稳定性。方法：选择30例严重骨性Ⅲ类错牙合患者进行双颌手术,采用SPSS20.0软件包对治疗前（T0）,手术前（T1）,手术后6周（T2）以及治疗结束时（T3）相关硬组织测量项目进行t检验。结果： T0与T1相比,上下切牙的相应测量项目发生了显著变化（P<0.05）;T1与T2相比,上下颌各硬组织标志点分别向前上和后上移位（P<0.05）,SNA角、SNB角、ANB角、Wit值均发生了显著变化(P<0.05),OP-SN增大显著（P<0.05）,牙合平面发生了逆时针方向的旋转,上面高（N-ANS）、下面高（ANS-Me）变化显著（P<0.05）,垂直比例更为协调,均获得了良好咬合关系;T2与T3相比,上下颌各硬组织标志点分别有轻度的后下、前上移位趋势,但其变化无统计学意义（P<0.05）。结论：双颌手术在上颌畸形治疗、面部垂直比例关系改善、牙合平面倾斜度的改变、咬合关系改变方便效果显著,其术后稳定性较好。     

数字化咬合板与传统咬合板在正颌手术中定位上颌骨的精确性临床研究

目的:通过临床研究分析数字化咬合板与传统咬合板在正颌手术中定位上颌骨的精确性。方法:回顾性收集2017～2022年就诊于南京大学医学院附属口腔医院的成年骨性错(牙合)畸形患者,筛选具有完善术前术后影像学CT数据、牙列模型数据且已完成双颌正颌手术的病例18例,其中8例通过传统咬合板辅助正颌手术,10例通过数字化咬合板辅助正颌手术。根据患者术前术后影像学资料及牙列数据通过Mimics Research 20.0及3-matic Research 12.0软件完成颅骨模型重建以及牙列模型数据的替换,完成正颌手术术前、术后三维(冠状位,矢状位,轴位)方向上实际移动距离的测量。测量三维方向上术前预计移动距离与术后实际移动距离的线性差异。结果:传统咬合板组术前计划与术后实际移动平均线性差为(1.00±0.32)mm;数字化咬合板组术前计划与术后实际移动平均线性差为(0.99±0.38)mm。两种咬合板对指导正颌手术中上颌骨的三维方向的定位无显著差异。结论:数字化咬合板与传统咬合板的使用均可在正颌手术中准确定位上颌骨。     

计算机辅助设计结合三维打印手术导板在面部不对称畸形矫治中的应用

目的本研究旨在观察双颌手术结合三维打印技术制作的定位手术导板在矫治上颌骨垂直向发育过度和下颌前突型不对称畸形的临床应用效果。方法选取14名因单侧上颌骨垂直向发育过度伴发下颌前突的不对称畸形患者,在快速原型技术制作的定位导板的辅助下,于短面侧行上颌Le FortⅠ型骨切开术和下颌支矢状骨劈开术,于长面侧行上颌Le FortⅠ型骨切开术和下颌支垂直骨切开术。分别在手术前、术后7 d、术后1年测量并对比上颌牙合平面偏斜度、下颌支倾斜度、下颌骨偏离度、颏部偏斜度等参数。结果所有患者的颌面不对称均得以矫治并达到满意效果。两侧术前的参数有明显差异(P<0.05),然而术后并无明显区别(P>0.05)。结论计算机辅助技术结合三维打印技术制作的手术定位导板将有助于进一步提高手术可预测性与准确性。     

数字化技术用于25例患者正颌手术效果评价

目的:应用数字化技术辅助正颌外科三维重建测量、术前诊断、手术设计与模拟、导板制作、导航验证和效果评估,探索制订更加科学、合理的数字化诊治方法和流程.方法:选取25例先天性牙颌面畸形患者,术前行颅颌面CT扫描,将CT数据导入Mimics 20.0软件,建立数字化原始模型.确定三维重建测量硬组织标志点并进行测量、分析、诊断...     

骨性Ⅲ类正颌手术前后髁突运动对称性分析

目的测量骨性Ⅲ类错患者正颌手术前后髁突下颌边缘运动的对称性,探讨成人骨性Ⅲ类错患者正颌术后髁突运动功能的恢复情况。方法选取成人骨性Ⅲ类错患者15人,分别在术前、术后6个月、术后9个月,运用下颌三维超声定位技术.ARCUSdigma系统对最大张口和前伸运动时两侧髁突对称性进行分析。结果下颌最大张口和前伸运动时,骨性Ⅲ类患者术前和术后6个月组的双侧髁突运动轨迹在冠状向上不一致,差异有统计学意义(P0.05);术后9个月组双侧髁突三维方向的运动轨迹均较好,与术前相比无统计学差异(P0.05)。结论成人骨性Ⅲ类错患者正颌术后9个月时下颌功能性运动逐渐趋于正常,提示应将正颌手术后正畸时间保持在9个月以上。     

Collaborative treatment for a case of condylar hyperplastic facial asymmetry

Facial asymmetry can be caused by unilateral condylar hyperplasia. In such cases, it may be difficult to achieve symmetry since there is dentoalveolar compensation on the affected side, and the occlusal cant does not correspond to the frontal mandibular deviation. In the case presented, surgical orthodontic treatment and orthognathic surgery planning was accomplished for a patient with facial asymmetry due to condylar hyperplasia. The surgical plan was devised with particular attention to the severe dentoalveolar compensation. In this case, prior to the two-jaw surgery, the occlusal cant and frontal mandibular plane inclination was corrected through impaction of the left molar region by segmental osteotomy. Facial asymmetry and severe dentoalveolar compensation were successfully corrected after a unilateral segmental osteotomy and two-jaw surgery, resulting in a stable occlusal relationship and facial symmetry as well as good jaw function. Collaboration between the orthodontists and maxillofacial surgeons was essential for the successful treatment of the patient.     

Comprehensive virtual orthognathic planning concept in surgery-first patients

The surgery-first concept is becoming increasingly popular in orthognathic surgery since it offers major advantages such as a reduction of treatment duration and an increase in patient satisfaction by eliminating phases of presurgical orthodontic decompensation. Here, we present a novel interdisciplinary pathway of a fully virtual orthodontic-surgical planning concept in a surgery-first setting using a 3D-printed cutting guide and a customised maxillary implant for the Le Fort I osteotomy as well as a CAD/CAM-based stereolithographic final splint. Patient data from cone-beam computed tomography of the skull and a full arch dental scan were processed using the OnyxCeph^3TM software (Image Instruments). A mutual computer-aided surgical simulation was conducted by the orthodontist and the oral and maxillofacial surgeon to determine the three-dimensional maxillary and mandibular movements. In a separate virtual planning session, the surgeon designed a customised maxillary guide and implant for precise intraoperative transfer (Geomagic Freeform Plus software, 3DSystems). A 3D-printed CAD/CAM-based final splint was fabricated by the orthodontist and used for accurate mandibular repositioning. We established a comprehensive virtual interdisciplinary orthognathic workflow and successfully applied this concept with a high level of accuracy in a series of surgery-first patients with different types of dentofacial anomalies. This novel fully computer-based pathway offers a high potential to improve the outcomes of orthognathic surgery and reduce total treatment time in the management of the orthognathic patient.     

Computer prediction of hard tissue profiles in orthognathic surgery

The purpose of this retrospective study was to analyze the accuracy of computer predictions by CASSOS (Computer-Assisted Simulation System for Orthognathic Surgery) 2001 software (2000 SoftEnable, Technology). Forty adult patients who had undergone orthognathic surgery were evaluated. Pre- and postsurgical lateral cephalographs were scanned into the computer, and 71 landmarks for each cephalograph were digitized. Digitization error was assessed from repeated digitizations. A customized cephalometric analysis consisting of 14 measurements was used in this study. Predicted and actual postsurgical hard tissue landmarks were compared using the Student t test. Results showed good correlation between repeated digitization for all measurements. There were no statistically significant differences in 10 of the 14 measurements. The differences that were statistically significant were in angular measurements for SNA angle, upper incisor to maxillary plane angle (U1-MxP), interincisal angle (U1-L1), and upper incisor to anterior cranial base angle (U1-SN). The greatest mean difference measured was the interincisal angle (U1-L1) which, although statistically significant, was clinically insignificant. This investigation showed that CASSOS 2001 software provides accurate hard tissue prediction for orthognathic surgical procedures.     

Evaluation of the accuracy of virtual planning in bimaxillary orthognathic surgery: a systematic review

The purpose of this research was to evaluate the accuracy of virtual planning in bimaxillary orthognathic surgery in bone by comparing the mean linear and angular measurements of the surgical plan with the actual surgical result. Electronic databases, MEDLINE via PubMed, Web of Science, SCOPUS, the Cochrane Library, grey literature, and the American clinical trials registry (www.ClinicalTrials.gov), were accessed as search engines. The studies consisted of publications on the assessment of accuracy in virtual planning in bimaxillary orthognathic surgery between 2010 and 2020. After application of the eligibility criteria, 26 articles were included, and their quality was evaluated using the methodological index for non-randomised studies (MINORS) tool and Cohen's kappa statistic in the MedCalc program (MedCalc Software Ltd). Evidence obtained by comparing the planning and surgical results, both in the maxilla and mandible, showed that there is great accuracy in virtual planning in bimaxillary orthognathic surgery.     

An integrated orthognathic surgery system for virtual planning and image-guided transfer without intermediate splint

Accurate surgical planning and transfer of the planning in orthognathic surgery are very important in achieving a successful surgical outcome with appropriate improvement. Conventionally, the paper surgery is performed based on a 2D cephalometric radiograph, and the results are expressed using cast models and an articulator. We developed an integrated orthognathic surgery system with 3D virtual planning and image-guided transfer. The maxillary surgery of orthognathic patients was planned virtually, and the planning results were transferred to the cast model by image guidance. During virtual planning, the displacement of the reference points was confirmed by the displacement from conventional paper surgery at each procedure. The results of virtual surgery were transferred to the physical cast models directly through image guidance. The root mean square (RMS) difference between virtual surgery and conventional model surgery was 0.75 ± 0.51 mm for 12 patients. The RMS difference between virtual surgery and image-guidance results was 0.78 ± 0.52 mm, which showed no significant difference from the difference of conventional model surgery. The image-guided orthognathic surgery system integrated with virtual planning will replace physical model surgical planning and enable transfer of the virtual planning directly without the need for an intermediate splint.     

The effects of orthognathic surgery on mandibular range of motion

A prospective study of 55 orthognathic surgical patients was done to determine the effects of surgery on mandibular range of motion. None of the patients had oral physiotherapy during the course of the study. Nineteen patients had mandibular osteotomies, 21 had maxillary osteotomies, and 18 had two-jaw operations. Maximal interincisal opening (MIO), right and left lateral excursion, and protrusive measurements were obtained preoperatively and at six or more months following surgery. MIO was significantly reduced in both categories of mandibular osteotomies. A sagittal split osteotomy to advance the mandible was associated with the greatest mean reduction of 29%, while a vertical subcondylar osteotomy to set the mandible back had a mean reduction of 10%. Likewise, decreases in MIO were noted with combined surgical procedures. Le Fort I and sagittal split osteotomies were associated with a mean decrease in MIO of 28%, while Le Fort I and vertical subcondylar osteotomies had a mean decrease of 9%. Minimal change in MIO were noted with isolated maxillary osteotomies. These results are similar to the findings of other investigators and indicate the critical need for a sound postoperative rehabilitation program following orthognathic procedures to prevent hypomobility.     

Accuracy of maxillary repositioning surgery using CAD/CAM customized surgical guides and fixation plates

The advent of three-dimensional imaging and computer-aided surgical simulation (CASS) have brought about a paradigm shift in surgical planning. The aim of this study was to assess the accuracy of maxillary repositioning surgery using computer-aided design and manufacturing (CAD/CAM) customized titanium surgical guides and fixation plates. Thirty consecutive adult patients, 13 male and 17 female, with a mean age of 29.2 years and 25.5 years, respectively, requiring Le Fort I maxillary osteotomy, with or without simultaneous mandibular surgery, were evaluated retrospectively. All orthognathic surgeries were performed by one experienced surgeon. The pre-surgical and post-surgical volumetric imaging were superimposed to assess the linear and angular differences between the planned and actual positions of the maxilla following surgery. With the use of the CAD/CAM titanium surgical guides and fixation plates, all surgical movements were within 2 mm and 4° of the planned movements, which is considered clinically insignificant. The overall root mean square error between the planned and actual surgical movements was 0.38 mm in the transverse dimension, 0.64 mm in the anteroposterior dimension, and 0.55 mm in the vertical dimension. In regard to the centroid of the maxilla, the absolute angular difference of the maxillary centroid was 1.06° in pitch, 0.47° in roll, and 0.49° in yaw. Maxillary repositioning surgery can be performed with high accuracy using CAD/CAM titanium surgical guides and fixation plates.     

Effects of orthognathic surgery on pharyngeal airway and respiratory function during sleep in patients with mandibular prognathism

The aim of this study was to determine changes in overnight respiratory function and craniofacial and pharyngeal airway morphology following orthognathic surgery. The subjects were 40 patients in whom mandibular prognathism was corrected by orthognathic surgery: a one-jaw operation in 22 patients and a two-jaw operation in 18 patients. Morphological changes were studied using cone beam computed tomography immediately before surgery and at more than 6 months after surgery, and the apnoea–hypopnoea index (AHI) was measured with a portable polysomnography system. Pharyngeal airway volume was decreased significantly after surgery, especially in the one-jaw operation group. AHI was not changed significantly after surgery in either group, although AHI in one patient in the one-jaw operation group was increased to 19 events/h. There was no significant change in pharyngeal airway morphology in that patient, but he was obesity class 1 and was 54 years old. In conclusion, some patients who are obese, have a large amount of mandibular setback, and/or are of relatively advanced age may develop sleep-disordered breathing after mandibular setback; a two-jaw operation should therefore be considered in skeletal class III patients who have such risks because it decreases the amount of pharyngeal airway space reduction caused by mandibular setback surgery.     

Severe unilateral scissor bite and bimaxillary protrusion treated by horseshoe Le Fort I osteotomy combined with mid-alveolar osteotomy

This report describes an orthognathic surgical case employing horseshoe Le Fort I osteotomy (HLFO) combined with mid-alveolar osteotomy and bilateral sagittal split ramus osteotomy (BSSRO) for a patient with severe unilateral scissor bite and bimaxillary protrusion. A female patient (aged 26 years, 2 months) presented with a chief complaint of dysmasesis caused by scissor bite on the right side. The clinical examination revealed difficulty in lip closure and a convex profile. Overerupted right maxillary premolars and molars and lingual tipping of the right mandibular premolars and molars were indicated before treatment. After 3 months of presurgical orthodontic treatment, two-jaw surgery involving a combination of HLFO with mid-alveolar osteotomy and BSSRO was performed. A good interdigitation in the right side was established by superior-posterior-medial movement of the dento-alveolar segment of the maxilla. Next, both the maxilla and mandible were moved superiorly and posteriorly to correct the improper lip protrusion, thereby improving the patient''s profile. Our results suggest that this new orthognathic surgery technique—achieved by combining HLFO with mid-alveolar osteotomy and BSSRO—is effective for adult patients exhibiting severe unilateral scissor bite and bimaxillary protrusion.     

Simultaneous repositioning of the maxilla, mandible, and chin. Treatment planning and analysis of soft tissues

There is a clinical, biologic, and biomechanical foundation for simultaneous surgical repositioning of the maxilla, mandible, and chin in a significant proportion of adult and adolescent patients. The restoration of normal jaw function, optimal facial esthetics, and long-term stability are the sine qua non of successful orthognathic surgical procedures to simultaneously reposition the jaws. The key to the achievement of these objectives is to carefully and systematically analyze facial esthetics, establish esthetic priorities, and then coordinate and implement them through the use of cephalometric planning and occlusal studies. By meticulous and precise surgical technique, properly programmed, coordinated, and sequenced with efficient presurgical and postsurgical edgewise orthodontic therapy, and systematic postsurgical neuromuscular rehabilitation, the maxilla, mandible, and chin can be simultaneously repositioned with relatively few postoperative complications or sequelae. This article purposes to elucidate on the indications for two-jaw surgery and describe a simplified clinical-cephalometric analysis for orthognathic surgery. Representative case reports are presented and discussed to illustrate the esthetic, orthodontic, and surgical treatment objectives. The basic problems involved in diagnosis and treatment planning of patients who require two-jaw surgery are discussed as well.