The accuracy of two-dimensional planning for routine orthognathic surgery

Two-dimensional cephalometric planning software should be helpful for prediction of hard tissue outcome after bilateral sagittal split ramus osteotomy (BSSRO) or bimaxillary osteotomy, but transferring two-dimensional data to three-dimensions (including mock operation and surgery) may result in errors. The objective of this retrospective study was to analyze deviations between predicted results and postoperative outcome using cephalometric analyses, and to evaluate this procedure for daily use. Fifty-four subjects (mean (SD) age 26 (8) years) had a BSSRO (n = 21) alone or in combination with Le Fort I osteotomy (n = 33). Predictions were made for each case by cephalometric planning software and mock operations done with study models. Postoperative cephalograms were obtained after 14 days and compared with predicted cephalograms for sagittal (SNA, SNB, ANB,) and vertical (ArMeGo, ML–NSL, NL–NSL) measurements. Mean (SD) differences for all measurements varied between 1.3° (1.1°) and 2.2° (1.6°) for BSSRO; and between 1.1° (1.3°) and 2.2° (1.6°) for bimaxillary osteotomy. There were no significant differences between measurements or operations, indicating that the predictions were accurate. A difference of up to 8.5° could be measured in a single case. Cephalometric prediction therefore remains an accurate tool for planning, particularly maxillary rearrangement in the vertical and sagittal dimension for routine operations. If greater shifts in the transversal dimension are necessary, exact planning should be adapted with three-dimensional planning devices to avoid significant differences.     

Effectiveness of glucocorticoids in orthognathic surgery: an overview of systematic reviews

For decades, short-term glucocorticoids have been advocated to reduce postoperative swelling, pain, trismus, and nausea and vomiting in patients experiencing maxillofacial surgeries. The purpose of this systematic overview was to identify and assess the best evidence regarding the efficacy of glucocorticoid administration in patients who undergo orthognathic surgery. Five databases (Medline, Embase, The Cochrane Library, Web of Science, and Epistemonikos) were searched from their inception to October 2020. The risk of bias assessment was performed using the ROBIS tool, and the quality of the evidence reported was rated using the GRADE approach. Six systematic reviews were identified, of which three were included in this overview (n=527). According to the rating of the overall risk of bias, one achieved a low score and two were rated as high. The quality of the evidence reported ranged from very low to moderate. Corticoids may reduce the incidence of moderate or severe postoperative nausea and vomiting in the early postoperative period (0-6 hours) compared to metoclopramide, but the evidence is very uncertain. Some significant therapeutic effects on neurosensory recovery have been reported, but there was inconsistency across the studies. Finally, based on a moderate quality of evidence, it is possible to establish that the administration of glucocorticoids is likely to reduce oedema in the early postoperative period (0-48 hours) in patients who undergo orthognathic surgery, and to have no significant adverse effects. Further quantitative syntheses based on well-designed and standardised clinical studies are suggested to determine direction and strength of the intervention on the other outcomes.     

Evaluating societal outcomes of orthognathic surgery: an innovative application of the Social Return on Investment methodology to patients after orthognathic treatment

Outcomes after orthognathic treatment are complex, and include improvements to mental and physical health, and psychosocial adjustments. The Social Return on Investment (SROI), a framework that is recognised by the government, explores the wider social value of interventions, but has not yet, to our knowledge, been used to measure the value of surgical procedures. To test its feasibility in a surgical setting and to begin to understand the wider nature of the changes experienced by patients after orthognathic surgery, we designed a pilot study that focused on the first two stages of the six-stage model. We collected data from 16 participants about their perceptions and experiences of the short, medium, and longer term outcomes of their treatment during two qualitative storyboard workshops. A grounded theory-SROI method was used to explore their experiences through a process of constant comparison by which data were analysed for concepts and organised into distinct themes. This produced a theory of change that clearly expressed the short to medium-term and longer term outcomes of orthognathic treatment, and provided an initial framework for the approach. The theory captured several outcomes and showed that the framework can be used effectively to investigate the wider psychosocial changes after orthognathic treatment. It therefore provides a basis on which to develop potential indicators for the assessment and valuation of these outcomes over time. The application of these findings to the selection of patients, engagement, and postoperative care, is briefly discussed.     

Multicentre study of operating time and inpatient stay for orthognathic surgery

Orthognathic surgery has advanced considerably since its development in the mid-twentieth century, and in most maxillofacial units mandibular and maxillary osteotomies are routine procedures. However, to enable accurate health planning and costing, and to obtain meaningful consent, it is important to have reliable data for duration of operation and inpatient stay. Virtually every aspect of orthognathic surgery has been researched, but we know of no recent studies that have looked specifically at how long the procedures take and how long patients stay in hospital. We retrospectively studied a sample of patients who had had orthognathic operations at six maxillofacial units in the United Kingdom (UK) to assess these measures. We looked at 411 operations which included 139 bilateral sagittal split osteotomies, 53 Le Fort I osteotomies, and 219 bimaxillary osteotomies. The study showed that the mean (SD) operating time for bilateral sagittal split osteotomy is 2 h 6 min (46 min), 1 h 54 min (45 minutes) for Le Fort I osteotomy, and 3 h 27 min (60 min) for bimaxillary osteotomy. The duration of postoperative hospital stay was also measured. Fifty percent of patients spent one night in hospital after bilateral sagittal split osteotomy, whereas 39% and 9% of patients spent two and three nights, respectively. Forty-five percent of patients spent one night in hospital after Le Fort I osteotomy, whereas 34%, 13%, and 2% spent two, three, and four nights, respectively. Forty-one percent of patients spent two nights in hospital after bimaxillary osteotomy, whereas 34%, 21%, and 3% spent one, three, and four nights, respectively. This data provides evidence for national benchmarks.     

Benefits of the enhanced recovery after surgery pathway for orthognathic surgery

The enhanced recovery after surgery (ERAS) protocol was designed to improve patient outcomes and decrease complications, opioid use, and postoperative nausea and vomiting (PONV). The aim of this retrospective cohort study was to examine the effectiveness of ERAS protocols implemented in orthognathic surgeries from 2017 to 2018 at the University of Alabama at Birmingham Hospital by measuring opioid use and PONV. Two groups were identified through chart review, a non-ERAS group (traditional) of patients who had surgery without a protocol and an ERAS group of patients who had surgery with the ERAS protocol. The anesthesia and surgical teams followed a standardized protocol for perioperative management. All procedures were performed by a single surgeon and included single- and double-jaw surgeries and adjunctive procedures. The patient charts were analyzed for postoperative opioid consumption (measured in morphine milligram equivalents, MME) and PONV. IBM SPSS Statistics version 26 was used to conduct the statistical analyses. The ERAS group received less opioids during the postoperative period than the control group (31.2 MME vs 54.6 MME, P =  0.002). The ERAS group also had a lower incidence of PONV, with 1.2 episodes of PONV compared to 2.4 episodes in the non-ERAS group (P =  0.008). This study demonstrates that the ERAS protocol is effective in decreasing postoperative opioid consumption and PONV.     

Efficacy of gastric aspiration to reduce postoperative vomiting after orthognathic surgery: double-blind randomised clinical trial

Orthognathic surgery is a treatment modality indicated to correct dentofacial deformities. Postoperative vomiting can be associated with multifactorial origin mainly correlated to patient-related symptoms, anaesthetic and surgical factors. Swallowed blood has been related to one of those multifactorial vomiting causes. This present study was to compare the efficacy of gastric aspiration after bimaxillary orthognathic surgery. A double blind randomised clinical trial was carried out and patients were divided in two groups (n = 44/39 respectively). There was statistically significant difference between the control and study groups in the overall incidence of vomiting (p = 0.031) A stratified analysis by sex between both groups was performed demonstrating a four-fold eduction in the odds for vomiting events independent of patient gender (OR = 0.24; 95% CI 0.07 to 0.72). Gastric aspiration after orthognathic surgery can reduce the effects of postoperative vomiting decreasing inpatient period and, consequently, hospitalisation costs.     

Neurosensory alterations and function of the temporomandibular joint after high oblique sagittal split osteotomy: an alternative technique in orthognathic surgery

The current most common technique for repositioning of the mandible, bilateral sagittal split osteotomy (BSSO), was first described by Obwegeser and Dal Pont in the early1960s, and has since been modified several times. However, there is always a risk of damaging the inferior alveolar nerve. We have studied 50 consecutive patients who had high oblique sagittal split osteotomy (HSSO) as an alternative to avoid damage to the nerve. The patients were evaluated for sensory alterations and function of the temporomandibular joint (TMJ). Healing of both wound and bone were complete and uneventful in all 50 patients. Mean (SD) sagittal movement of the mandible was 6.6 (2.9) mm and length of the osteotomy line was 11.0 (3.1) mm. No patient had either temporary or permanent alteration in sensitivity. Pinprick tests showed no significant changes between the preoperative and postoperative readings (p > 0.16) or in the chronological results (p > 0.23). No disorders of the TMJ developed. Mean (SD) mouth opening 6 months postoperatively was 41.6 (8.6) mm. The lateral excursion increased postoperatively by 1.86 mm to the left and by 0.76 mm to the right. Protrusion increased by 0.66 mm. HSSO is therefore a suitable alternative to BSSO as it avoids injury to the inferior alveolar nerve without compromising the TMJ. Ossification was uneventful though bony attachment was less than with the classic BSSO.     

Effects of throat packs during orthognathic surgery: a double-blind randomized controlled clinical trial

Throat packs are commonly used in maxillofacial surgeries. However, the evidence to support the benefits of their use is controversial. The aim of this study was to evaluate the effectiveness of throat packs in preventing postoperative nausea and vomiting, and their influence on the incidence of sore throat and dysphagia in patients undergoing orthognathic surgery. This was a prospective double-blind randomized study with 54 patients, who were randomized to two groups: with throat pack (n = 27) and without throat pack (n = 27). Fifty patients (25 in each group) were included in the analysis; 66% female and 34% male, mean age 29.44 ± 8.53 years. Postoperative nausea and vomiting (Kortilla scale), sore throat (visual analogue scale), and dysphagia were evaluated. Statistically significant differences in favour of the without-pack group were found for the variables throat pain at 24 hours (P = 0.002) and dysphagia at 2 hours (P = 0.007) and 24 hours (P < 0.001). There was no difference between the groups regarding postoperative nausea and vomiting (P = 1.00). The results of this study indicate that throat packs as utilized here do not prevent postoperative nausea and vomiting and are associated with worse sore throats and postoperative dysphagia.     

正颌外科矫正牙颌面畸形300例总结

目的为总结正颌外科矫正牙颌面畸形的临床经验,方法对300例牙颌面畸形患者进行了正颌外科手术,其中180例上颌前突和上颌前部发育不足畸形,行上下颌前部根尖下戴骨术;40例上下颌后牙正反锁,行节段性根尖下戴骨术。80例下颌前突畸形分别采用了SSRO、IVRO、SOM等戴骨术结果300例牙颌面畸形术后外观及功能绝大多数获得了满意的效果。其中术后复发11例,明显复发2例;感觉异常4例;术后感染10例。结论随访结果显示应用AMO,SSRO,IVRO,SOM法矫正牙颌面畸形,获得了满意的效果,并能减少复发,感染和局部感觉异常的发病率。文中就此类手术的术前后正畸、手术方法、手术中注意事项等进行了讨论.     

Consent for orthognathic surgery: a UK perspective

Obtaining consent to undertake orthognathic surgery is a legal requirement that starts at the initial visit when treatment is being considered and continues until the operation itself. The process includes discussion of the benefits, risks, and potential complications of the proposed procedure, and any alternative (including doing nothing), but there is no consensus about how much information should be disclosed. Guidance is provided on the basis of case law, which is itself evolving. The purpose of this study was to look at the current practice of obtaining consent for orthognathic surgery by oral and maxillofacial surgeons in the UK to act as a benchmark and potentially to stimulate further debate. We also review common and serious complications that might be included in the process.     

人工智能时代的正颌外科发展

简要回顾人工智能（AI）技术的概念及其在不同时代发展历程,概述AI在医疗领域的应用,回顾综述AI在正颌外科发展的研究进展、存在的问题及可能的发展方向,指出AI在正颌外科的发展充满机遇与挑战并存。     

正颌外科治疗后颞下颌关节改变的X线研究

目的 了解正颌外科手术后颞下颌关节（ｔｅｍｐｏｒｏｍａｎｄｉｂｕｌａｒ ｊｏｉｎｔ，ＴＭＪ）形态的改变，探讨手术方式不同对ＴＭＪ的影响。方法 正颌手术患者５７例，术前、术后１周、１年分别拍摄定位许勒位片用于观察髁突位置及关节形态的变化。结果 ①正颌手术可导致髁突移位，但大多数关节适应后并不发生病变，术后１年髁突位置已调整到术前相似的位置。②手术方式不同髁突位置的变化也不尽相同。③８６．４％的患者关节无明显变化或发生了适应性改建；１３．６％患者关节发生了退行性改变。结论 正颌手术可对ＴＭＪ产生影响，但大部分处于关节的正常适应范围内。     

正颌外科术后患者的满意度调查

本文通过问卷回顾性地调查了126位正颌外科术后1年以上患者的满意度。93．6%的患者对手术后容貌的改变满意;849%的患者愿意向有类似畸形的亲朋好友推荐正颌外科手术;74.8％的患者愿意再选择手术;64.3％以上的患者术后感觉自信心提高,与他人交往更自如,幸福感增强。     

Occlusal comparison of hand-articulation versus digital articulation in orthognathic surgery

The aim of the present study was to develop measurement methods to evaluate occlusal differences in digitally-articulated and hand-articulated models in final occlusal planning for orthognathic surgery. A total of 10 (five class II and five class III) previously treated orthognathic cases were analysed by three oral and maxillofacial surgeon investigators, creating a total of thirty cases. Investigators used physical models to create a preferred hand-held final occlusion, which were then scanned and saved utilising a Trios 3® scanner (3Shape). Models were digitally disarticulated and sent back to investigators after a period of at least a month for digital articulation. Novel measurements of dental roll, pitch, and translational differences were performed by an independent engineer using Materialise 3-Matic® software. Statistical analysis was used to evaluate translational differences, the effect of deformity, and inter-investigator variation. A mean (SD) translational difference of 1.58 mm (1.14) mm was seen between the thirty digital and hard-articulated cases analysed. Minimal difference was seen in roll and pitch between hand articulation and digital articulation. A significant translational difference was seen in class III cases compared with class II (p = 0.0006) but not in roll or pitch. There was no significant difference seen between investigators related to translation (p = 0.18), roll (p = 0.09), or pitch (p = 0.17). Digital articulation yielded similar results to hand held in this pilot study. Using measurement techniques described in larger cohorts, its accuracy can be validated using currently available technology.     

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...     

The specific psychosocial effects of orthognathic surgery

This study was to test the validity of patients' opinions and provide a more accurate method than previously reported of assessing the specific psycho-social effects of orthognathic surgery. Questionnaires were used preoperatively and postoperatively providing a longitudinal sample, while those patients who only completed questionnaires either before or after surgery provided cross-sectional samples. Different questionnaires were used to provide data on a 'Body Satisfaction Scale', 'Fear of Negative Evaluation', 'Social Avoidance and Distress', and a 'General Health Questionnaire'. The results indicate that surgery produced an improvement in body image, particularly in the evaluation of facial attractiveness.     

正颌外科治疗对颞下颌关节功能影响的研究

目的　观察正颌手术后颞下颌关节病各种症状及体征的变化 ,比较不同固定方式及手术方式对于颞下颌关节的影响。方法　正颌手术矫治的连贯患者 46例 ,术前 1周内及术后 1年记录患者的颞下颌关节情况。结果　全组Helkimo主诉症状指数 (Ai) ,临床指数 (Di)的差异无显著性 ,术后最大开口度与下颌前伸度皆减小 ,但只有 1%差别 ,无明显临床意义。单双颌手术及升支的 3种术式之间比较 ,各项症状与体征的变化差异无显著性。结论　正颌外科治疗对颞下颌关节的影响不大 ,不同的术式间对颞下颌关节的影响无明显不同     

计算机辅助模型外科设计及虚拟[牙合]板的临床应用

目的：通过计算机辅助软件进行正颌手术模型外科设计，经快速原型技术制作[牙合]板，探讨该[牙合]板的临床应用价值。方法：15例颌面畸形需要正颌手术的患者均进行全头颅三维CT扫描（层厚0．625mm），将DICOM格式的CT数据输入电脑软件Simplant CMF（Materialise Medical，Leuven，Belgium）。通过软件对头颅模型进行上下颌骨的分离、截骨线的设计、截骨、骨块移动等操作，收集并输出数据，经快速原型机制作[牙合]板（虚拟[牙合]板）。同时，每例患者还进行传统石膏模型外科以及传统[牙合]板制作。术中首先利用虚拟[牙合]板进行骨块的移动和固定，然后应用传统[牙合]板检验骨块的新位置，验证虚拟[牙合]板的临床实用性。结果：15例患者中．4例单颌手术（双侧下颌支矢状劈开术）、10例双颌手术（LeFortⅠ型整体截骨术＋双侧下颌支矢状劈开术）以及1例双颌手术（LeFortⅠ型分块截骨术＋双侧下颌支矢状劈开术）。手术中，12例患者的虚拟[牙合]板完全符合临床要求。3例患者（包括1例双侧下颌支矢状劈开术和2例LeFortⅠ型整体截骨术＋双侧下颌支矢状劈开术）的虚拟[牙合]板与传统[牙合]板之间有部分偏差，遂通过传统[牙合]板进行骨块的重新固定。结论：计算机辅助设计可完成LeFortⅠ型整体（或分块）截骨术和双侧下颌支矢状劈开术的模型外科，虚拟[牙合]板基本可实现传统[牙合]板的功能。通过对软件的进一步熟悉、更多病例的积累，计算机辅助模型外科可能取代传统的石膏模型外科。     

正颌外科手术的麻醉特点及技术改进(附168例病例报道)

总结168例正颌外科手术的麻醉特点及技术改进,为临床提供指导。方法：选择正颌外科手水患者168例,观察其插管方式、麻醉方法、术中生命体征及术后呼吸道管理。结果：168例均经鼻腔盲探插管成功,采用静吸复合麻醉顺利完成手术。术后78例保留气管导管,平均为72h。拔管后无一例发生呼吸道梗阻及其它并发症。结论：鼻引导管为正颌外科手术所需经鼻盲探插管技术提供保证。而术后保留气管导管,不仅避免了常规气管切开的各种不利因素,同时保证呼吸道的通畅及生命安全。