Augmented reality guided condylectomy

An accurate transfer of a 3D virtual planned proportional condylectomy to the patient is challenging due to the limited surgical access. A new clinical workflow that uses augmented reality to assist a condylectomy is presented step-by-step. This AR-based approach has the potential to be implemented in the clinical setting routinely.     

口腔内入路髁突切除术的临床应用研究

目的探讨经口腔内入路行髁突切除术并重建颞下颌关节的可行性。方法经口腔内入路行患侧升支垂直截骨术,将带有髁突的近心骨段取出至体外,切除病变的髁突,再将近心骨段的余部重新植入重建颞下颌关节。自1998年至2006年共完成经口腔内入路的髁突切除术并重建颞下颌关节23例,其中髁突良性肥大2例;髁突骨软骨瘤13例;半侧颌骨肥大畸形6例;髁突陈旧性骨折2例,最大的髁突骨软骨瘤直径达5cm。部分患者同期经口腔内入路行正颌外科手术矫治伴发的面部不对称畸形。结果23例患者均顺利完成手术,术后伤口正常愈合,面颈部皮肤无疤痕遗留,无面神经受损症状出现,面部不对称畸形矫治效果良好。经平均4.5年的随访,术后开口度均达35mm,髁突骨软骨瘤及髁突肥大均未见复发。结论自口腔内入路切除病变髁突并重建颞下颌关节,避免了常规口外入路时,术后皮肤遗留斑痕和易损伤面神经的缺点。     

单侧髁突切除对非手术侧髁突软骨细胞凋亡的影晌

目的研究兔单侧髁突切除对非手术侧髁突软骨细胞凋亡活性的影响．方法24只5-6月龄的日本大耳白兔被随机分为两组：对照组和手术组．手术组通过手术切除-侧髁突建立动物模型,分别于术后2个月、4个月采用TUNEL染色,观察非手术侧髁突软骨中凋亡细胞数的表达．结果对照组相比,手术组单侧髁突切除2月和4月后非手术侧髁突软骨凋亡细胞数均增加（P〈0.05）,但物手术组4月较2月增加明显（P〈0.05）．结论单侧髁突切除可导致非手术侧髁突软骨凋亡细胞数量增加．     

The learning curve of transoral condylectomy; a retrospective analysis of 100 consecutive cases of unilateral condylar hyperplasia

In this study, 100 consecutive scheduled transoral condylectomies for unilateral condylar hyperplasia were included. The safety and surgical performances were assessed, using the operating time, conversion rate and complication rate. The conversion rate learning curve was evaluated with a learning curve cumulative summation (LC-CUSUM).The total conversion rate was 8.0%. The LC-CUSUM for conversion signaled at the 53th procedure, indicating sufficient evidence had accumulated that the surgeon had achieved competence. For procedures 54–100, the conversion rate was 4.0%. The operating time for the transoral condylectomy was 41.5 ± 15.3 min; when a conversion was necessary, the operating time was 101.4 ± 28.3 min (p < 0.05). The estimated operating time in the post-learning phase was 37 min, this was reached after approximately 47 procedures. There was 1 major complication of a permanent inferior alveolar nerve hypoesthesia. The complication rate was not significantly decreased after the learning curve.Within the limitations of the study, it seems that transoral condylectomy for UCH is a safe procedure with several advantages over the traditional preauricular approach. Surgeons starting this procedure should be aware of the potential complications and of the learning curve of approximately 53 procedures.     

Evaluation of treatment with unilateral mandibular sagittal split ramus osteotomy and maxillary osteotomy in patients with condylar osteochondroma and mandibular asymmetry: A retrospective case series

The aim of the study was to describe an approach where condylar resection with condylar neck preservation was combined with Le Fort I osteotomy and unilateral mandibular sagittal split ramus osteotomy (SSRO).Patients with a unilateral condylar osteochondroma combined with dentofacial deformity and facial asymmetry who underwent surgery between January 2020 and December 2020 were enrolled. The operation included condylar resection, Le Fort I osteotomy and contralateral mandibular sagittal split ramus osteotomy (SSRO). Simplant Pro 11.04 software was used to reconstruct and measure the preoperative and postoperative craniomaxillofacial CT images. The deviation and rotation of the mandible, change in the occlusal plane, position of the “new condyle” and facial symmetry were compared and evaluated during follow-up. Three patients were included in the present study. The patients were followed up for 9.6 months on average (range, 8–12). Immediate postoperative CT images showed that the mandible deviation and rotation and occlusion plane canting decreased significantly postoperatively; facial symmetry was improved but still compromised. During the follow-up, the mandible gradually rotated to the affected side, the position of the “new condyle” moved further inside toward the fossa, and both the mandible rotation and facial symmetry were more significantly improved.Within the limitations of the study it seems that for some patients a combination of condylectomy with condylar neck preservation and unilateral mandibular SSRO can be effective in achieving facial symmetry.     

Cone–beam computed tomographic analysis of maxillary and mandibular changes after high condylectomy combined with orthodontic treatment for active unilateral condylar hyperplasia

Our aim was to evaluate the efficacy of high condylectomy combined with orthodontic treatment for active unilateral condylar hyperplasia in 25 affected patients, by an analysis of the maxillary and mandibular changes on cone–beam computed tomography (CT). High condylectomy was the sole operative treatment. Variables that reflected the canting of the occlusal plane, the height of the maxillary complex, the buccolingual angulation of the maxillary first molar, the height of the ramus, the total length of the mandible, and the deviation of the chin were measured and compared between the two sides and between time intervals: preoperatively (T1) and the end of treatment (T2). The differences between time intervals in the deviation of the chin (p < 0.001) and the canting of the occlusal plane (p < 0.001) were significant, but there were no significant differences in the height of the ramus (p = 0.476) and the total length of the mandible (p = 0.838) between the affected and unaffected sides at T2. There were significant differences between time intervals in the buccolingual angulation on the unaffected side and the height of the maxillary complex on the affected side (p < 0.001). Facial asymmetry was corrected and the occlusal plane was improved. In conclusion, high condylectomy as the sole operative treatment combined with orthodontic treatment can provide an alternative method for correction of facial asymmetry associated with active unilateral condylar hyperplasia.     

髁状突或髁状突软骨缺损对生长期大鼠下颌骨生长发育的影响

目的:观察髁状突切除术和髁状突软骨全层削刨术对生长期大鼠下颌骨发育的影响,为临床治疗儿童发育期髁状突病变提供理论指导。方法:36只大鼠平均分为3组,髁状突切除组、髁状突软骨全层削刨组和正常对照组,分别于术后6、12周处死后测量下颌骨大体标本并做髁状突中份软骨组织学观察。结果:同正常对照组比较,术后6、12周髁状突切除组下颌升枝高度(H)、下颌体高度(M)、下颌体长度(L)都明显缩短;两手术组间H和L差异显著(P<0.01);两手术组的修复组织大部分为纤维软骨样组织。结论:下颌骨的生长发育是内部生长中心发育和外部功能刺激双重作用的结果。     

髁突高位切除术对下颌骨位置的影响

目的:探讨髁突高位切除术后下颌骨的位置变化。方法:收集武汉大学口腔医学院就诊的髁突肥大患者10例。患者术前均接受临床及影像学检查及双侧髁突Tc99-MDP计算机体层扫描(SPECT)检查。所有患者均接受髁突高位切除术,平均随访时间9.6月。下颌骨位置变化评价方法:1)矢状位:比较侧位头影测量上测量术前术后SNA、SNB及ANB角的变化。2)冠状位:比较正位头影测量术前术后上、下颌切牙点至Y轴的距离。结果:侧位头影测量显示术后SNA无显著变化(P>0.05),SNB显著减小(P<0.05),ANB显著增加(P<0.05)。正位头影测量显示上切牙点至Y轴的距离无显著变化(P>0.05),下切牙点至Y轴的距离显著减小(P<0.05)。结论:髁突高位切除术后下颌骨在矢状位及冠状位上发生向后和向患侧的移位,此种移位有利于髁突肥大所致偏颌畸形的矫正。