下颌角弧形截骨术18例临床分析

目的观察双侧下颌角肥大、突出行弧形截骨术的治疗效果。方法18例下颌角截骨术患者,10例同时行颏部截骨加植骨,8例取颊脂垫,2例部分咬肌切除,观察疗效,分析探讨相关问题。结果术后患者面形曲线圆滑,但均有不同程度的肌萎缩。结论下颌角弧形截骨术术前应作阻生智齿预防性拔除,咬肌切除应慎重。     

下颌角弧形截骨术对口腔生理功能影响的研究

目的　研究下颌角弧形截骨术对口腔颌面系统生理功能的影响。方法　 2 3例双侧下颌角肥大患者 ,均接受双侧下颌角弧形截骨术 ,术前和术后 1周、2个月、3个月、6个月测定最大咬合力、最大开口度及最大前伸度。结果　所有患者术后短期内上述三项指标均明显低于正常值 ,但 3个月后 ,恢复至正常范围 ,无明显临床意义。结论　下颌角弧形截骨术对患者口腔颌面系统的功能无明显长期不良影响。     

颏下颌下颈阔肌成形术在下颌角截骨术中的应用

目的通过手术方法预防下颌角截骨手术后下颌软组织松垂,观察手术效果,探讨更有效的手术方式。方法对18例下颌角方大患者同期行下颌角截骨术及颏下颌下颈阔肌成形术,纠正患者下颌角方大及预防颏下颌下脂肪堆积、松垂。结果所有患者术后随访半年至2年,无1例面神经下颌缘支损伤致下唇歪斜;所有患者张口度正常;术后16例患者对术后外形比较满意;1例患者术后感染后取出提升线;1例患者颏下颌下仍较肥厚松垂,效果不明显。结论颏下颌下颈阔肌成形术在下颌角截骨术中同期施行对下颌角方大患者面部轮廓改善效果良好,安全可靠,同时面部神经血管丰富,术者应熟悉其分布走行,重视钝性分离,不断积累手术经验及操作技巧才能达到满意的手术效果。     

方脸综合改形术

目的　探讨方脸综合改形的方法。方法　对71例方脸要求手术改变成椭圆脸型的患者经口内入路,以双侧下颌角弧形截骨整形,颏部成形为主,结合颧骨截骨降低缩窄、颊脂垫部分摘除及其他辅助美容手术,整体重塑面部轮廓。结果　所有患者面型均得到明显改善,术后随访6个月~2年,效果满意。其中术中大出血1例,一侧颏神经损伤2例,口角拉伤5例。结论　以下颌角弧形截骨术、颏部成形术为主,结合其他手术方式对方脸进行综合改形,临床效果良好。     

下颌角弧形截骨术前后肌酸激酶活性的变化

目的论证下颌角弧形截骨术后咬肌是否会发生相应萎缩。方法6月龄山羊12只，分为实验组和对照组，实验组行双侧下颌角弧形截除术，对照组行双侧下颌角区的咬肌剥离，并分别于术前1周和术后3日、1周、1月、2月、3月、6月测定血清中肌酸激酶的活性。结果术后血清中肌酸激酶的活性急剧升高，但是在恢复至术前水平的过程中两组所需时间不同。结论下颌角截骨术后咬肌会相应萎缩，故治疗下颌角肥大无需切除咬肌即能达到良好的效果     

不同下颌角成形术后下颌骨受力的三维有限元分析

目的:运用三维有限元方法分析不同下颌角成形术前后下颌骨的应力应变变化.方法:通过螺旋CT扫描及相关软件进行正常下颌骨、下颌角截除术及下颌角区骨外板截除术3 种下颌骨有限元建模,并利用abaqous软件对3 组模型进行应力应变分析.结果:下颌角截除术后:下颌角区的应力明显增加,而应变减少;髁突颈部的应力增加,应变则无明显变化.在下颌角区骨外板截除术后:下颌骨在下颌角及髁突颈部的应力应变均明显增加,且增幅也明显高于下颌角截除术.结论:下颌角成形术可以对下颌骨的应力应变分布产生影响, 其中下颌角区骨外板截除术会更明显的影响髁突颈部及下颌角区域的应力应变分布.     

下颌前突畸形的正颌外科矫治

目的 总结正颌外科矫治下颌前突畸形的临床经验。方法 对32例下颌前突畸形患者进行了正颌外科手术，其中12例行双侧SSRO，4例行双侧IORO，10例行双侧IVRO，5例行上下颌前部根尖下截骨，1例行下颌骨体部截骨，同期搭配施行水平截骨颏成形术12例，畸形涉及上颌骨行LeFortⅠ型截骨9例。结果 32例下颌前突畸形患者术后外观及功能均获得满意效果。并发症有术后下颌前突轻度复发4例，明显复发1例，下颌骨升支骨折一侧1例，下牙槽神经一侧断离1例，结论 随访结果显示应用IVRO，SSRO等术式治疗下颌前突畸形只要术式选择及操作得当，能获得较满意效果。文中就手术方法，注意事项及并发症等进行了讨论。     

基于增强现实的下颌角截骨配准技术的研究

目的:通过增强现实技术,将下颌骨的虚拟三维数字模型及术前设计的预截骨平面同时显示在快速成型实体模型上,实现虚拟图像与实体的重叠配准.方法:选取20例下颌骨肥大患者,行三维CT扫描,重建下颌骨三维数字模型.利用上海九院整形设计系统完成术前设计,生成截骨平面,并与下颌骨合并为STL文件.取患者下牙石膏牙模,制作包含下牙咬合板在内的标志物支架,固定于石膏牙模,两者一并扫描.然后将扫描数据和下颌骨三维数字模型数据导入同一三维处理平台,选择右第一磨牙的远中舌尖、第二磨牙的近中舌尖、左第一磨牙的近中舌尖,进行标志物支架和下颌骨的拟合,生成虚拟影像.此时的三维虚拟数字化影像包括标志物、下颌骨及预截骨平面.然后将标志物支架的下牙咬合板固定于下颌骨快速成型模型上,采用增强现实视频检测方法.用视频捕捉器识别到标志物后,将虚拟影像与下颌骨快速成型实体模型进行配准.结果:该技术实现了三维虚拟数字化影像与下颌骨快速成型模型的虚实融合叠加,使下颌骨和术前设计的预截骨平面实时显示在下颌骨实体上.结论:本研究建立的配准方法具有良好的重复性,有望成为下颌角截骨术可视化手术有效的配准途径,为未来增强现实手术应用研究奠定了基础.     

颌下切口下颌升支垂直截骨在髁突高位骨折手术中的应用

目的:探讨应用颌下切口下颌升支垂直截骨术治疗髁突高位骨折的效果。方法:对16例(19侧)下颌骨髁突高位骨折患者采用颌下切口下颌骨升支后缘垂直截骨取出升支后缘骨块将骨折的髁突游离后取出,体外直视下将骨折片与升支后缘骨块复位固定后再回植,行颞下颌关节重建。结果:于术后6、12、24个月复查全部患者的开口度为30～48 mm,平均34.92 mm。所有患者咬合关系良好,无关节疼痛症状。部分病人有轻度开口偏斜,均<3 mm,有1例患者有关节弹响。结论:颌下切口下颌升支垂直截骨是治疗髁突高位骨折的一种可选择方法,具有操作简便、复位准确、近期疗效满意等优点。     

游离腓骨瓣轴向截骨术在下颌角重建中的应用

目的:介绍一种下颌角成形术中,应用腓骨瓣轴向截骨的技术,探讨该方法的适应证和优缺点。方法:16例患者中,良性肿瘤11例(成釉细胞瘤8例,牙源性角化囊肿3例),放射性骨坏死3例,术后继发下颌骨缺损畸形2例,所用游离腓骨瓣长度为10～17cm(平均14.6cm),血管蒂长5～11cm(平均8.2cm)。轴向截骨手术步骤:①按改良方法制备腓骨瓣后,剥离肌袖,解剖分离腓骨瓣截骨线旁血管蒂组织及骨膜,加以保护。摆动锯首先切开腓骨肌面,垂直于骨长轴切至骨髓腔平面;②在伸肌面或屈肌面(肌袖面)沿长轴切割,长度为2～3cm;最后在伸肌面与屈肌面交界处,垂直于骨长轴于内侧面切至骨髓腔平面。③进行骨断端塑形,其2个截骨面骨髓腔接触面的大小依其所成角度而改变,通常塑形角度为120°,使修复下颌角2个腓骨骨块即可成角,又使之轴向截骨片间与钛支架紧密接触,并将钛钉固定在预成钛板支架上。结果:16例患者术后经超声Doppler动态监测,移植骨血供良好,术后3、6个月摄片示移植骨段愈合理想,角部外形恢复满意。结论:应用轴向截骨法重建下颌角缺损,由于增大了骨段间接触面,从而提高了骨的愈合能力,且能减少腓骨骨量的损失,并可在一定范围内延长移植骨的长度。     

Clinical feasibility and efficiency of a 3-dimensional printed surgical template for mandibular angle osteotomy and mandibular angle splitting osteotomy

Mandibular angle osteotomy (MAO) and mandibular angle splitting osteotomy (MASO) are the two main surgical approaches used to correct a square mandible for a desirable aesthetic appearance. However, there are concerns about the safety and accuracy of both procedures as they may lead to unsatisfactory results such as injury to the nerve. To achieve symmetry and security we designed and evaluated a 3-dimensional printed surgical template, which indicates the outer cortex splitting line of the MASO, and the curved cutting line of the MAO. We operated on 11 patients who had been diagnosed with broad mandibles using the assisted template. The mean duration of osteotomy, degree of numbness of the inferior alveolar nerve, and reduction in the width of the mandible (Go-Go) were recorded. The mandibular curve before and after operation was fitted to evaluate its accuracy. The results showed that mean duration of osteotomy and numbness of the nerve were reduced, and there was no significant difference between simulation and postoperatively. The mean (SD) reduction in the mandibular width was 15.2 (1.6) mm. The template facilitated accuracy and safety in both procedures.     

Volumetric mandibular change after angle ostectomy and outer cortex grinding

Background

Mandibular angle ostectomy is one of the most common surgical procedures for facial contouring in Asian women. However, some patients complain about mandibular angle hypertrophy recurrence after surgery. The present study evaluated volumetric change of the mandible after angle ostectomy and outer cortex grinding.

Intraoral curved ostectomy for prominent mandibular angle by grinding, contiguous drilling, and chiseling

There are several surgical techniques for mandibuloplasty, for example, ostectomy of the lateral cortex around the mandibular angle, angle-splitting ostectomy, sagittal split ramus ostectomy, multistage osteotomy of the mandibular angle. These techniques all have achieved excellent aesthetic results, but they require a high level of skill and are time consuming. From July 1995 to June 2010, a total of 1006 patients underwent intraoral curved ostectomy for prominent mandibular angle by grinding, contiguous drilling, and chiseling in our department. A round bur was used to reduce the outer cortex thickness of the mandible body. The ostectomy line on the mandibular angle was penetrated contiguously using a long-shaft bur drill. A curved-headed chisel approximately 10 mm in width was hammered to separate the redundant mandibular angle. Concurrent procedures such as reduction malarplasty and genioplasty were performed in patients with protrusion of the malar bone and microgenia. A total of 992 patients were satisfied with the final facial contour. The square-shaped appearance was converted to an ovoid, slender, and feminine facial contour from the frontal view. Ninety-three patients underwent postoperative complications. Among the 93 cases, there were 14 patients who were unsatisfied with the final results. The average operative time was 42 minutes for ostectomy of prominent mandibular angle. Intraoral curved ostectomy for prominent mandibular angle by grinding, contiguous drilling, and chiseling is an appropriate technique for correcting lower facial contour. The surgical technique is not complex, and the ostectomy is easy to manipulate. The operation consumes less time. Complications of various degrees are relatively lower, and most of them can be treated effectively. Both surgeons and most of the patients are satisfied with the results.     

Computed tomography morphology of the mandibular ramus at the lingual plane in patients with mandibular hyperplasia

This study investigated the specific morphology of the mandibular ramus at the lingual plane in patients with mandibular hyperplasia using spiral computed tomography. The subjects were 25 patients with mandibular hyperplasia undergoing sagittal split ramus osteotomy and there were 20 patients without dentofacial deformities in the control group. The thickness of the mandible, diameter of the inner mandibular canal, width of the buccal bone marrow space, and the width of the buccal cortex and lingual cortex were measured at the lingual plane, which contained the lowest point of the mandibular foramen. The average thickness of the mandible was 8.5 mm in prognathic patients and 9.6 mm in control patients. The average width of the buccal bone marrow space in mandibular hyperplasia patients was 1.5 mm and 2.5 mm in control patients. The mandibular ramus in patients with mandibular hyperplasia was thinner and the width of the buccal bone marrow space was smaller than in the control patients. The width of the buccal bone marrow space and the thickness of the mandible were significantly positively correlated.     

Anterior mandibular apical base augmentation in the surgical orthodontic treatment of mandibular retrusion

The authors describe a surgical technique alternative to traditional pre-surgical orthodontics in order to increase the apical base in mandibular retrusion (class II, division I). This subapical osteotomy, optimizing inferior incisal axis without dental extractions and a long orthodontic treatment, associated to genioplasty permits to obtain an ideal labio-dento-mental morphology. This procedure avoids in some cases the need of a mandibular advancement and, if necessary, it reduces his entity with obvious advantages.     

Le FortⅠ型骨切开上颌骨整体后退术矫治骨性Ⅱ类上颌骨前突畸形

目的：探讨Le Fort Ⅰ型骨切开（Le Fort Ⅰ osteotomy）上颌骨整体后退术在矫治骨性Ⅱ类上颌骨前突畸形中的价值。方法：对16例骨性Ⅱ类上颌前突患者（上颌骨前突伴下颌骨后缩14例,其中同时伴颏后缩6例;单纯上颌骨前突2例）进行外科-正畸联合治疗。患者治疗前头影测量∠ANB为7.0°～13.1°,平均9.3°。行Le Fort Ⅰ型骨切开上颌骨整体后退术,其中14例同期行双侧下颌支矢状骨劈开术（bilateral sagittal split ramus osteotomy,BSSRO）前移下颌骨,6例行颏成形术（genioplasty）前移颏部。结果：本组行LeFortⅠ型骨切开上颌骨整体后退4～8mm,14例BSSRO下颌骨前移4～7mm,6例颏成形术颏前移6～8mm。1例一侧腭降动脉术中损伤断裂,经结扎处理,无感染及骨块坏死。16例患者伤口均一期愈合。术后及正畸结束后∠ANB为1.6°～3.5°,平均2.9°。结束治疗后随访6～24个月,牙弓形态及[牙合]曲线正常,牙排列整齐,咬合关系良好,外形明显改善,疗效满意。结论：对于骨性Ⅱ类上颌骨前突畸形患者,Le Fort Ⅰ型骨切开上颌骨整体后退术是一种安全、合理、有效的正颌外科术式。     

Single stage surgery for contouring the prominent mandibular angle with a broad chin deformity: En-bloc Mandibular Angle-Body-Chin Curved Ostectomy (MABCCO) and Outer Cortex Grinding (OCG)

BackgroundVarious surgical options are reported to address the Asian 'squared face', characterized by a prominent mandibular angle (PMA) associated with an oversized chin deformity; but shortcomings lie in the requirement of multi-stage procedures with the risk of further revision surgery. We have developed a single-stage “Mandibular Angle-Body-Chin Curved Ostectomy (MABCCO) and Outer Cortex Grinding (OCG)” surgical technique to shorten the period of the surgical treatment and minimize the inherent surgical risks in the multi-staged procedures.MethodsA retrospective study involving patients (n = 36) presented with prominent mandibular angle and an oversized chin who underwent the operation described from 2010 to 2012 with at least 12 months of follow-up. The surgical and aesthetic outcomes were evaluated through clinical assessment, photography, imaging analysis including preoperative and post-operative patient satisfaction rates.ResultsAll the patients were satisfied with the improvement in their appearance following surgery; specifically the 'smoothness' of the mandibular inferior border with no 'second mandibular angle'. The width of the mandible was reduced with G–G distance reduced from 119.9 mm ± 3.9–109.7 mm ± 3.5 (p < 0.05). A significant preoperative and post-operative gonial angle (G-A) was found at the left (110.7° ± 9.6 vs 139.9° ± 11.5, p < 0.05) and right side of mandible (111.3° ± 10.7 vs 140.7° ± 11.8, p < 0.05). There was no iatrogenic inferior alveolar nerve or mental nerve injury and a stable aesthetic outcome beyond the first year.ConclusionWe demonstrated favourable surgical and aesthetic outcomes with our single-stage en-bloc curved osteotomy surgical technique to reshape the prominent mandibular angle with a broad chin deformity with no increased in surgical risks but a high satisfaction rate and stable outcomes.     

Biomechanical effect of asymmetric mandibular prognathism treated with BSSRO and USSRO on temporomandibular joints: a three-dimensional finite element analysis

Asymmetric mandibular prognathism is a clinically common skeletal dentomaxillofacial deformity. Unilateral sagittal split ramus osteotomy (USSRO) is an effective alternative procedure to bilateral sagittal split ramus osteotomy (BSSRO) for some patients. However, the biomechanical effect of temporomandibular joint (TMJ) of USSRO has not been fully studied. This study aims to evaluate the stress distribution changes in the TMJ of asymmetric mandibular prognathism treated with BSSRO/USSRO, to validate the clinical feasibility of USSRO. Nineteen patients with mandibular prognathism patients who were treated with BSSRO (n = 12) and USSRO (n = 7) had preoperative and postoperative computed tomographic scanning. Preoperative and postoperative 3-dimensional finite element analysis (FEA) of functional TMJ movements were made on one BSSRO patient and one USSRO patient. In all patients, the ANB angle and mandibular deviation were significantly improved postoperatively. There was no significant difference in the postoperative ANB angle and mandibular deviation between the BSSRO group and the USSRO group. In two preoperative FEA models, the maximum stresses of non-deviation side TMJ structures were greater than the deviation side during functional movements. The unbalanced stress distribution was corrected postoperatively in both BSSRO/USSRO FE models. Both BSSRO/USSRO can improve the ANB angle and mandibular deviation. The bilateral TMJ structure in patients with asymmetric mandibular prognathism had unbalanced stress, which could be significantly improved with the USSRO as effectively as BSSRO.