双侧升支矢状劈开截骨后退下颌术中去骨的评估研究

目的:评估双侧升支矢状劈开截骨后退下颌术中去除的颊侧骨皮质形状与垂直截骨线的方向和前牙覆变化间的关系,指导临床去骨操作。方法:在头影测量侧位描记图的下颌体部设计3种不同方向的垂直截骨线,用头影测量裁剪预测方法先旋转再后退下颌到术前设计位置,分析最终垂直截骨线与初始垂直截骨线间的角度关系,运用几何学原理计算此角度的大小。评价后退下颌时所需要去除骨皮质大致形状同初始垂直截骨线方向及前牙覆变化间的关系。结果:近心骨段不发生矢状向移位情况下,最终垂直截骨线与初始垂直截骨线间的角度大小与上下颌平面交角保持一致,与初始截骨线的方向和下颌后退的距离大小无关。去除的骨皮质形状与前牙覆变化相关。结论:近心骨段去骨形状与前牙覆变化密切相关,与截骨线方向和下颌后退的距离大小无明显相关。     

下颌骨矢状劈开后退术对咽腔间隙及舌骨位置的影响

目的 :CBCT测量分析下颌后退手术治疗下颌前突畸形,对舌骨位置和气道间隙变化的影响。方法 :选取单纯下颌前突畸形患者50例为研究对象,均接受经口内下颌骨升支矢状劈开截骨术,于正颌手术前1周、术后2周、术后6个月拍摄锥形束CT,测量治疗前后咽腔最窄处的矢状径、冠状径、截面积,同时舌骨点的三维位置,分析咽腔间隙大小及及舌骨体位置变化。测量数值配对t检验。结果:所有患者术后咽腔间隙均呈现缩窄趋势。舌骨发生了后下移位,其中术后2周向后、向下平均移动距离分别为2.64、1.56 mm,术后6月向后、向下移位分别为0.97、0.99 mm。术后2周咽腔的矢状径、冠状径及咽腔间隙分别为11.71 mm、3.05 mm、320.67 mm~2,术后6月时分别为14.64 mm、3.23 mm、414.85 mm~2。即随时间推移,舌骨位置及咽腔间隙有恢复正常范围的趋势。结论:双侧下颌骨升支矢状劈开截骨后退术后,舌骨向后下移位,咽腔气道缩小,有可能导致睡眠呼吸暂停综合征的发生,临床需予以重视。     

双侧下颌升支矢状劈开后退术后骨稳定性评价

目的 探讨影响双侧下颌升支矢状劈开后退术并行坚固内固定后骨稳定性的因素。方法 对进行双侧矢状劈开后退术后的15例患者于术后1周及术后1年摄头影测量侧位片,对其相关角度及线距进行测量,并作统计学处理。结果 下颌矢状劈开后退术1年后的平均复发量为2.5mm,后退量>6mm组与后退量<6mm组两者变化量之间无显著性差异。结论 下颌双侧矢状劈开后退术并行坚固内固定是矫正下颌前突最有效的方法之一。     

下颌升支垂直截骨内固定术治疗髁突高位骨折

目的:比较手术和非手术方法治疗单侧下颌骨髁突高位骨折的临床效果。方法:19例髁突高位骨折患者,其中10例行下颌升支截骨内固定术+颌间牵引术(手术组),其余9例单纯行颌间牵引术(非手术组),随访0.5～1年。结果:手术组和非手术组之间比较,开口度及前伸运动度均无显著性差异(P>0.05);侧方运动度手术组优于非手术组,有显著性差异(P<0.01)。非手术治疗的患者,下颌骨平面不对称,X线片显示髁突的解剖位置欠佳。手术患者,下颌下区存在线形疤痕,但下颌骨平面对称,X线片显示患侧髁突与健侧形态相似。19例中无1例出现明显的颞下颌关节紊乱综合征。结论:采用下颌升支垂直截骨内固定术+颌间牵引术治疗下颌骨髁突高位复杂骨折,兼顾美观和功能,手术简便,不失为一种理想的治疗方法。     

Changes in position of the hyoid bone and volume of the pharyngeal airway after mandibular setback: three-dimensional analysis

Important aspects of orthognathic surgery are the effects of skeletal movement and changes in the position of the hyoid bone, tongue, soft palate, and dimensions of the pharyngeal airway. Our aims were to evaluate the 3-dimensional changes in the pharyngeal airway and in the position of the hyoid bone after mandibular setback in 30 patients who were diagnosed with mandibular prognathism and were treated by intraoral vertical ramus osteotomy (IVRO). Three-dimensional cone-beam computed tomographic (CT) images were obtained preoperatively, one month postoperatively, and one year postoperatively. The total pharyngeal volume decreased between the preoperative state and one month and one year afterwards. The hyoid bone had moved 2.0 mm posteriorly and 3.15 mm superiorly by one month postoperatively. The position of the hyoid bone was affected by changes in posterior and superior movement of the B point at one month (r = 0.44, p = 0.015 and R = 0.63, p = 0.000, respectively) and also by superior movement of the B point at one year (r = 0.57, p = ?0.001). There was an advantageous relation between posterior positional changes in the B point (mandibular setback), and volumetric changes in the hypopharyngeal and total pharyngeal airway, so maxillofacial surgeons should consider the reduction in airway when planning excessive mandibular setback.     

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。     

下颌骨后退术后舌根和舌骨位置的改变

目的　通过下颌后退手术与舌根和舌骨位置变化相关性研究 ,了解二者关系 ,为临床治疗提供依据。方法　描记 18例接受经口内下颌骨升支垂直截骨术矫治下颌前突畸形患者的术前及术后 1个月的标准颅颌侧位头影测量图 ,测量项目 5项 ,测量数值配对t检验 ,并将下颌骨后退距离与各测量项目变化作相关分析。结果　术后 1个月下颌骨后退的平均值是 10 .2 0mm± 1.31mm ,下颌骨后退术后后气道间隙的宽度显著减小 ,舌骨垂直方向显著降低 ,在水平方向上无显著后移。下颌骨后退距离与舌骨垂直方向变化密切相关。结论　双侧下颌升支垂直截骨后退术后舌骨向下移位 ,舌根后移 ,咽腔气道缩小 ,如果患者同时具有超重、短颈、舌体大等其他危险因素 ,下颌骨后退手术可能导致睡眠呼吸暂停综合征的发生。下颌骨后退距离与舌骨垂直方向变化呈正相关。     

Biomechanical and Finite Element Analysis of Mandibular Vertical Ramus Marginal Resection Designs

This study aims to know the post-surgical Von Mises stress of the mandible after two different vertical ramus marginal resection designs, analyze the results, compare with stress pattern of normal adult mandible without simulation and infer regarding the better of the two. Three groups of 3D finite element models of human adult mandibles were created. Group I (control)—normal mandible. Group II: Mandible with a quadrilateral vertical ramus marginal resection simulated. Group III: Mandible with an arc shaped vertical ramus marginal resection simulated. Finite element analysis (FEA) models were subjected to a point load of 475 N over right and left first molars, along with masticatory loads of masseter, medial pterygoid, anterior belly of digastric and temporalis loads in varying combinations (with and without bilateral temporalis and without right temporalis). The models were analyzed to infer the overall Von Mises stress in (a) the mandible (b) the sigmoid notch (c) postero-inferior resection corners. Results of our present study provides scientific evidence for the common practice of using arc form for marginal resection of vertical ramus of mandible whenever executed. Scientific evidence behind the concept of marginal resection of horizontal ramus is available but only scanty biomechanical evidence using finite element method (FEM) is available behind the same when performed in the vertical ramus, as magnitude and direction of loads in this region vary when compared to the horizontal ramus. The results ratify that incorporating arc shaped design pattern and removal of ipsilateral temporalis load by removal of coronoid, an area prone to stress concentration on loading, significantly decreases the post surgical Von Mises stress and hence would reduce the progressive micro-damage of the mandible after marginal resections of the vertical ramus of mandible.     

下颌前突患者下颌支矢状劈开截骨术后髁突运动轨迹的改变

目的:研究双侧下颌支矢状劈开截骨术对下颌前突患者髁突运动轨迹的影响。方法:采用ARCUSdigma下颌三维运动轨迹描记仪,以髁突运动中心为参考点,研究30例正常受试者、14例下颌前突患者手术前后开口、前伸和左右侧向髁突运动的轨迹。用SPSSV11.0统计软件包进行配对t检验和成组t检验。结果:下颌前突患者术前、术后、正常组左侧髁突的运动轨迹与右侧基本相同,左侧髁突与右侧的开口、前伸和侧方运动范围无显著性差异(P>0.05)。术前组与正常组髁突运动轨迹差别较大,术前开口、前伸和侧方运动范围均小于正常组(P<0.05);术后与正常组髁突运动轨迹接近,术后开口、前伸和侧方运动范围与正常组无统计学差异;术前与术后组髁突运动轨迹差别较大,术前开口、前伸和侧方运动范围均显著小于术后组(P<0.05)。结论:下颌前突患者手术后,随着术后正畸治疗及咬合自我调整,建立了正常的咬合引导关系,使下颌功能运动趋向正常。     

Changes in the sensitivity of cutaneous points and the oral mucosa after intraoral vertical ramus osteotomy

In this study we investigated the changes in the sensitivity of cutaneous points and the oral mucosa that occur after intraoral vertical ramus osteotomy (IVRO). Additionally, postoperative changes in the sensitivity and the relationships between neurosensory disturbance and factors associated with IVRO operations were evaluated. An objective evaluation of the neurosensory status of cutaneous points and the oral mucosa of each patient was completed preoperatively and at 1, 2, 4, 8, 12, and 24 weeks postoperatively. The other variables studied for each patient included sex, age, magnitude of mandibular setback, and the amount of haemorrhage that occurred during surgery. In addition, the relationships between neurosensory disturbance and factors connected with IVRO operations were evaluated. We found that at cutaneous points, contributing factors such as sex, age, the magnitude of mandibular setback, and haemorrhage were associated with an increased risk of neurosensory disturbance after IVRO. However, these factors were not associated with that in the oral mucosa. In conclusion, we demonstrated the changes that occur in the sensitivity of cutaneous points and the oral mucosa after IVRO, the postoperative changes in sensitivity, and the relationships between neurosensory disturbance and factors connected with IVRO operations.     

Changes in cross-sectional measurements of masseter,medial pterygoid muscles,ramus, condyle and occlusal force after bi-maxillary surgery

Purpose

The purpose of this study was to examine changes in masseter and medial pterygoid muscles, ramus, condyle and occlusal force after bi-maxillary surgery in class II and III patients.

夜间打鼾青少年安氏Ⅱ类错患者应用SGTB功能矫治前、后上气道的变化

目的: 使用SGTB功能矫治器治疗安氏Ⅱ类打鼾合并下颌骨后缩的患者,比较治疗前、后患者上气道的三维变化以及舌骨位置变化。方法: 选择25例下颌骨后缩伴打鼾患者,采用 SGTB矫治器治疗,于治疗前、后分别拍摄锥形束 CT（CBCT）,应用 Dolphin 11.95 软件进行气道三维测量,分析并比较功能矫治前后患者上气道的变化。利用Mimics 17.0软件对下颌骨进行三维重建,比较治疗前、后下颌骨及舌骨位置的变化。采用SPSS 16.0软件包进行数据处理。结果: 治疗后,患者上气道总体积、鼻咽体积、口咽体积均较治疗前增大,差异有统计学意义（P<0.05）;治疗后,患者会厌顶平面（TE）上气道的截面积较治疗前增大,会厌顶平面、会厌底平面横径均增大,差异均有统计学意义（P<0.05）。治疗后,患者舌骨位置较治疗前水平前移2 mm,具有统计学意义（P<0.05）。结论: SGTB功能矫治器治疗能显著增加下颌骨后缩儿童上气道体积,改善患者呼吸阻塞情况。