Skeletal and airway stability after mandibular setback in patients with mandibular prognathism: A systematic review

AimTo perform a systematic review to answer the clinical question “What are the longitudinal skeletal and airway changes after mandibular setback orthognathic procedures?”Materials and methodsA systematic search including computer search of different databases with specific keywords, manual search through three international journals and reference list search was performed. Articles that were reporting the skeletal and airway changes after mandibular setback orthognathic procedures were evaluated with five predetermined criteria.ResultsSix articles with a total of 217 patients entered the final review. All were rated to be of moderate bias risk. Four studies evaluated the skeletal and airway changes using two-dimensional (lateral) cephalometric radiographic imaging, whereas the other two studies used three-dimensional imaging with cone-beam computed tomography. In the two-dimensional studies, skeletal relapses from T0 (immediate postoperative) to T1 (postoperative 1–6 months) ranged from −2.14 mm to 0.30 mm, whereas skeletal relapses from T1 to T2 (postoperative 1 year) ranged from −0.90 mm to 1.23 mm. In the three-dimensional studies, skeletal relapse from T1 to T2 ranged from −0.26 mm to 1.53 mm. All included studies reported that there were no significant skeletal relapses after mandibular setback procedures. Regarding airway changes, airway changes from preoperative to T0/T1 ranged from −0.30 mm to −2.32 mm in the two-dimensional studies. Airway changes from T0 to T1 ranged from −0.70 mm to −1.63 mm, whereas airway changes from T1 to T2 ranged from 0.11 mm to 0.60 mm, respectively.ConclusionsThis systematic review showed there was insignificant skeletal relapse after mandibular setback orthognathic procedures. It was noted a small increase of the airway over the first post-operative year in studies using 2-dimensional radiography. However, such finding was not consistent in studies using 3-dimensional imaging with volumetric analysis of the airway changes.     

双侧扩张肩胛皮瓣在儿童、青少年大面积颌颈部瘢痕修复中的应用：7例报道

目的: 探讨应用双侧扩张肩胛皮瓣游离移植治疗儿童、青少年大面积颌颈部瘢痕的可行性。方法: 回顾2018年8月—2020年12月间,在上海交通大学医学院附属第九人民医院小儿整形病区接受双侧背部扩张皮瓣治疗大面积颌颈部瘢痕的儿童、青少年患者7例。所有患者瘢痕累及范围包括颈部及下颌、前胸部,颈部瘢痕累及颈前区及一侧或双侧颈外侧区,存在不同程度的颈部活动障碍、下颌骨发育不良。手术分为两期,Ⅰ期在双侧背部设计旋肩胛动脉扩张穿支皮瓣并植入扩张器,并行6~14个月的扩张;Ⅱ期行颌颈部瘢痕切除、松解,扩张皮瓣游离移植修复创面,吻合双侧面动、静脉与旋肩胛动脉及伴行静脉,供区创面直接缝合。结果: 7例患者中,出现扩张器植入后切口愈合不良、皮瓣破裂1例,经手术治疗后愈合并完成皮瓣扩张。注水壶堵塞1例,经注水壶外置后完成扩张。皮瓣移植后,1例患者出现皮瓣远端小面积缺血坏死,换药后创面愈合。术后随访6个月~2年,患者颌颈角恢复正常,颈部后伸、前屈、侧曲、旋转明显改善,功能改善满意。2例患者进行皮瓣修薄术及瘢痕条带松解术。结论: 旋肩胛动脉位置恒定,支配的背部皮肤面积大,经扩张后的双侧肩胛皮瓣游离移植可修复儿童、青少年颌颈部大面积瘢痕增生挛缩畸形,供区隐蔽、继发损伤小。     

Three-dimensional virtual planning in mandibular advancement surgery: Soft tissue prediction based on deep learning

The study aimed at developing a deep-learning (DL)-based algorithm to predict the virtual soft tissue profile after mandibular advancement surgery, and to compare its accuracy with the mass tensor model (MTM).Subjects who underwent mandibular advancement surgery were enrolled and divided into a training group and a test group. The DL model was trained using 3D photographs and CBCT data based on surgically achieved mandibular displacements (training group). Soft tissue simulations generated by DL and MTM based on the actual surgical jaw movements (test group) were compared with soft-tissue profiles on postoperative 3D photographs using distance mapping in terms of mean absolute error in the lower face, lower lip, and chin regions.133 subjects were included — 119 in the training group and 14 in the test group. The mean absolute error for DL-based simulations of the lower face region was 1.0 ± 0.6 mm and was significantly lower (p = 0.02) compared with MTM-based simulations (1.5 ± 0.5 mm).ConclusionThe DL-based algorithm can predict 3D soft tissue profiles following mandibular advancement surgery. With a clinically acceptable mean absolute error. Therefore, it seems to be a relevant option for soft tissue prediction in orthognathic surgery. Therefore, it seems to be a relevant options.     

Esthetic perception of facial profile changes in Class II patients treated with Herbst or Forsus appliances

ObjectiveTo evaluate the esthetic perceptions of orthodontists and laypersons for facial profile changes after orthodontic treatment using Herbst or Forsus appliances.Materials and MethodsPre- and posttreatment facial profile contour images of 20 Class II patients treated with Herbst (group H; n = 10) and Forsus (group F; n = 10) appliances were analyzed by 30 orthodontists and 30 laypersons, who graded them from 1 (unattractive) to 10 (very attractive) using a visual analog scale. Two assessments were carried out with a 15 day-interval. In the first evaluation, 40 images were presented in a random sequence. In the second evaluation, initial and final facial profile images of each patient were randomly presented side by side. To compare groups in relation to treatment method, Mann-Whitney tests were used. To evaluate differences between time points, Wilcoxon tests were used.ResultsIn the first evaluation, there was a significant difference between initial and final images only for group H, for both laypersons (P = .017) and orthodontists (P = .037). There was also a significant difference between laypersons and orthodontists in their ratings of posttreatment Herbst appliance profiles (P = .028). There was no significant difference between initial and final facial profile images for group F and no significant differences between or within evaluator groups in their ratings of initial or final Forsus appliance profiles. In the second evaluation, there was a significant difference between appliance groups only for laypersons, who considered cases treated with the Herbst appliance more attractive than those treated with the Forsus (P = .031). Laypersons also considered Herbst profiles more attractive than did orthodontists (P = .047).ConclusionsClass II malocclusion treatment using the Herbst appliance may produce a more esthetically improved facial profile silhouette compared with Forsus appliances. The magnitude of perceived changes may not be considered clinically relevant.     

Evaluation of border movement of the mandible before and after orthognathic surgery using a kinesiograph

PurposeThe purpose of this study was to examine the changes in the mandibular border movement between class II and class III jaw deformity patients before and after orthognathic surgery, by using the same device.Subjectsand Methods: Eighty one patients (28 in class II and 53 in class III) who underwent sagittal split ramus osteotomy (SSRO) with Le Fort I osteotomy using absorbable plate fixation and 27 controls with normal occlusion were enrolled. Mandibular border movement (observed using a kinesiograph) was recorded with a mandibular movement measure system (K7) before surgery, and at 6 months and 1 year after surgery. Time-course changes of 5 components of the mandibular border movement (MVO: Maximum vertical opening, CO to MAP: Maximum antero-posterior movement from centric occlusion, MLDL: maximum lateral deviation left, MLDR: maximum lateral deviation right, CO to MO: centric occlusion to maximum opening) were compared between classes II, III and controls statistically. The relationship between lateral cephalometric measurements and the components of mandibular border movement was also examined.ResultsThere was a significant difference in CO to MAP (P = 0.0025) and CO to MO (P < 0.0001) between class II and class III in the time-course change.In class III, mean and standard deviation of MVO were 44.5 ± 6.7 mm before surgery and 39.8 ± 6.8 mm after 1 year. Mean and standard deviation of CO to MAP were 25.2 ± 6.8 mm before surgery and 21.5 ± 7.9 mm after 1 year. Mean and standard deviation of CO to MO were 53.4 ± 9.0 mm before surgery and 47.3 ± 8.4 mm after 1 year.In class II, mean and standard deviation of MVO were 38.8 ± 5.8 mm before surgery and 36.2 ± 7.4 mm after 1 year. Mean and standard deviation of CO to MAP were 18.0 ± 6.3 mm before surgery and 17.8 ± 7.4 mm after 1 year. Mean and standard deviation of CO to MO were 43.1 ± 7.5 mm before surgery and 39.6 ± 10.5 mm after 1 year.In MVO, CO to MAP and CO to MO, the values after 1 year did not significantly reach the pre-operative values in class III (P = 0.0001, P = 0.0007 and P < 0.0001), although there was no significant difference between pre-operation and after 1 year in class II.In CO to MO, class II (mean and standard deviation 39.6 ± 10.5 mm) and class III (mean and standard deviation 47.3 ± 8.4 mm) still remained smaller values than control (mean and standard deviation 52.7 ± 9.2 mm) after 1 year (P < 0.0001 and P = 0.0095).ConclusionThis study suggests that bi-maxillary surgery can have more influence on the reduction in the range of mandibular border movement including vertical or antero-posterior motion than lateral deviation motion, in both groups. The difference in the time-course change in the mandibular border movement between the groups might depend more on the mandibular length than on the movement direction of the mandible by surgery such as advancement or setback.     

What factors affect the attachment of the inferior alveolar nerve to the buccal plate following sagittal split osteotomy?

PurposeThis study aimed to assess the factors that can possibly affect the positioning of the inferior alveolar nerve (IAN) in the proximal or distal segment following sagittal split osteotomy (SSO).Materials and methodsThis was a prospective cohort study. The patients were assigned according to the position of the IAN: the IAN was attached to the buccal plate in group 1 (27 SSOs), while it was in the distal segment in group 2 (83 SSOs).ResultsThe mean of the buccolingual thickness of the proximal segment at the vertical cut of the osteotomy (BLTP) was 5.0 ± 0.62 mm in group 1 and 4.16 ± 0.72 mm in group 2. The mean of the distance between the IAN and the external cortical bone at the distal of the second molar before the osteotomy (IANB) was 0.5 ± 0.24 mm in group 1 and 1.24 ± 0.45 mm in group 2. There were significant differences for the mean BLTP and IANB between the two groups (P = 0.001).ConclusionIt seems that the thickness of the buccal plate of the proximal segment, the distance from the IAN to the external cortical bone, the osteotomy technique, and the presence or absence of impacted third molars may be associated with the positioning of the IAN following SSO.     

下颌骨前突患者下颌管走行及临床价值探讨

目的：：运用锥形束CT(cone-beam CT,CBCT)分析正常人群和下颌骨前突患者下颌神经管轨迹,为临床手术方案的制订和操作时避开重要神经血管提供帮助。方法：选取28例骨性Ⅲ类下颌骨前突患者（男10例,女18例）、20例正常对照组患者（男12例,女8例）,使用CBCT拍摄下颌管影像,从下颌孔至第一磨牙区分为5个平面,在每个层面分别测量下颌管内外径、下颌骨厚度、下颌管至颊舌侧骨皮质及下颌骨下缘的距离。采用SPSS 17.0软件包对测量结果进行统计学分析。结果：下颌骨前突患者自下颌支到下颌角前部逐渐增厚,继续至下颌第一磨牙区逐渐变薄。下颌神经管的内外径自下颌支到下颌体部逐渐变细。颊侧骨皮质厚度自下颌支区域逐渐增厚,到下颌体部继续变薄。下颌骨前突患者与对照组患者下颌管的对比分析显示,骨髓腔宽度与下颌支厚度有显著差异,且具有显著相关性。结论：CBCT能够精确显示下颌神经管的走行及与周边结构的关系,下颌骨前突患者与对照组患者下颌支厚度的差异主要由颊侧骨髓腔宽度造成。     

颌骨肿物为始发症状的肾透明细胞癌:2例报告及文献复习

肾透明细胞癌(renal clear cell carcinoma, RCC)早期即发生远处转移,但极少转移至头颈部。本文基于2016—2018年间联勤保障部队第940医院2例以颌骨肿物为始发症的RCC病例,回顾RCC的发病特点及临床表现,分析颌骨病变的临床、影像学及病理特点,为减少误诊误治提供参考。     

黏膜下注射曲马多对下颌智齿术后疼痛的疗效

目的：评估黏膜下注射曲马多缓解下颌智齿术后疼痛的有效性。方法：选取拔除智齿的患者40例,采用随机数字表法分成实验组（A组：曲马多注射组）和对照组（B组：生理盐水注射组）。采集患者在术后1、2、6、24、48 h由视觉模拟疼痛量表（VAPS）评定的分值。采用具有一个重复测量两因素一元定量资料方差分析统计。结果：A组术后疼痛评分显著降低,在2、6、24 h差异有统计学意义（P=0.006,P<0.001,P<0.001）。术后48 h无统计学意义（P=0.061）。结论：曲马多黏膜下注射对下颌第三磨牙术后早期疼痛控制有明显疗效。