III类骨面型错牙合患者颞下颌关节CBCT测量分析

目的:采用CBCT影像对I类和III类骨面型青少年及成人错牙合患者的颞下颌关节进行三维测量,探讨不同矢状骨面型错牙合患者颞下颌关节的形态结构差异,以及颞下颌关节随年龄改建的相关规律。方法:选取符合纳入标准的I类骨面型青少年和成人患者各15例,III类骨面型青少年和成人患者各15例,拍摄CBCT影像,在重建后的图像下进行测量分析,比较4组患者的关节窝形态、髁突形态、髁突轴向、髁突及下颌骨生长量。结果:髁突内外径仅年龄组别间有差异。III类骨面型患者的关节结节倾斜角、髁突矢状面倾斜角、关节窝深度小于I类患者。III类骨面型患者的髁突上部高度增长量大于I类患者。结论:III类骨面型患者颞下颌关节的形态结构与I类患者有所差异,且有与I类患者不同的生长型特征。     

两种前牵引技术在上颌发育不足治疗中的颞下颌关节评价

目的:采用CBCT评价前牵引矫治上颌发育不足患者治疗前后的颞下颌关节变化。方法:选取就诊于上海市黄浦区第二牙病防治所正畸科11～13岁骨性Ⅲ类、上颌发育不足的患儿40例,随机纳入种植体牵引组和支架牵引组,每组20例。对患者进行前牵引矫治12个月,治疗前后采用德国西诺德公司OTHOPHOS XG 3D Ceph三合一数字化摄片机拍摄头颅定位侧位片以及两侧处于牙尖交错位的颞下颌关节CBCT,对治疗前头影测量、颞下颌关节前间隙、上间隙、后间隙、颞下颌关节窝深度、髁突前后径、髁突近远中径和髁突倾斜度进行测量分析;另选取平均年龄11～13岁骨性I类未经正畸治疗的15例患儿为对照组,在知情告知下不进行任何正畸治疗,对其1年前后的颞下颌关节CBCT进行测量。结果:种植体牵引组和支架牵引组治疗后CBCT均显示颞下颌关节前间隙显著增大,上间隙和后间隙显著减小,髁状突倾斜角增大,髁状突在关节窝中向后上移位,颞下颌关节深度在治疗前后增大,增长量种植体牵引组较支架牵引组略大,说明前牵引后关节窝有明显的生长改建。结论:采用上颌前牵引矫治上颌骨发育不足的病例中,上颌骨均有明显生长,颞下颌关节深度增加,髁突位置向后上移位,有利于颞下颌关节发育。     

髁突高位切除术对髁突肥大患者颞下颌关节功能的影响

目的 探讨髁突高位切除术对髁突肥大患者颞下颌关节功能的影响.方法 计算髁突肥大患者（共12例）的术前、术后颞下颌关节紊乱指数（CMI）,评价患者颞下颌关节功能的变化.结果 ①术后患者面型改善,X线检查显示术后患者双侧髁突形态及下颌升支高度基本对称髁突表面可见新骨皮质形成.②颞下颌关节功能改善,Fricton颞下颌功能障碍指数和颞下颌关节紊乱指数分别从治疗前的0.131和0.066下降到0.042和0.021（P＜0.05）.结论 髁突高位切除术在改善面型的同时亦可以有效改善髁突肥大导致的颞下颌关节功能紊乱.     

基于CBCT髁状突体积分析的髁状突骨折后TMJ骨性形态测量

目的 探讨采用锥形束CT(CBCT)髁状突体积分析进行髁状突骨折后患者颞下颌关节(TMJ)骨性形态测量的价值。方法 选择2017年1月至2019年5月髁状突骨折患者28例,获取CBCT图像,比较健、患侧手术前后TMJ骨性形态指标(两侧的髁状突体积)。结果 术后患侧髁状突体积大于健侧(P<0.05),并明显小于术前(P<0.05)。结论 单侧髁状突骨折前后的体积变化与健侧有显著差异,这可能是术后TMJ功能评定的新标准。     

有限元方法在术前计划中的应用：颞下颌关节强直治疗方法的选择

目的探讨有限元分析方法在颞下颌关节强直术前计划中的应用价值。方法将1例颞下颌关节真性强直患者的CT图像数据导入Mimics13.1软件进行三维重建,并在模型上虚拟两种不同的手术方式（钢板固定和非钢板固定）,通过有限元分析Abaqus软件建立正常下颌骨及不同虚拟手术的下颌骨有限元模型,定量分析正常下颌骨和颞下颌关节强直患者的髁突应力分布状况。结果未采用钢板固定的虚拟手术模型其髁突应力分布值比正常下颌骨为大,而采用钢板固定虚拟手术者的髁突应力分布值与正常人接近。结论颞下颌关节强直手术可以运用有限元分析方法建立有限元模型并进行模拟手术,对颞下颌关节强直治疗方法的选择具有指导性作用。     

错(牙合)畸形患者颞下颌关节对称性的锥形束CT研究

目的:探讨错(牙合)畸形对颞下颌关节对称性的影响。方法:选择安氏Ⅰ类、Ⅱ~1类和Ⅲ类患者各20例,拍摄锥形束CT(Cone beam computed tomography,CBCT)并应用Dolphin软件重建并测量左右两侧髁突长轴、短轴、关节结节斜度、髁突长度、关节窝高度和宽度以及关节前、上、后间隙,并进行统计分析。结果:安氏Ⅰ类组左右两侧各测量指标无统计学差异,安氏Ⅱ~1类组的关节上间隙和安氏Ⅲ类组的髁状突长度左右两侧存在统计学差异(P0.05)。结论:CBCT能有效检查出关节形态结构的不对称,不同的咬合状态对关节形态结构有一定影响。     

正颌-正畸联合治疗下颌偏突颌畸形

目的探讨下颌升支矢状劈开截骨术与正畸联合治疗下颌偏突颌畸形的效果。方法对16例下颌偏突颌畸形患者采用下颌升支矢状劈开截骨术（Hunsanck改进术式），截骨段间采用坚强内固定，尽量减少髁状突的移动范围，并适当延长颌间栓结时间，根据情况及时调整手术前、后正畸治疗方案。结果所有患者面型及黯关系均达到满意效果，患者下颌运动范围在术后3个月时已接近术前水平。在术后6个月随防时未发现有骨性复发和新出现的颞下颌关节症状病例，通过对术前和术后6个月的许勒位X线片测量，发现健侧髁状突12侧（75％）向前移位，患侧髁状突10侧（62．6％）向后移位，这些变化均是在生理范围内的调整。结论在正畸科的配合下，采用改良的下颌升支矢状劈开截骨术是治疗下颌偏突颌畸形的有效方法之一。     

人工髁突假体在颞下颌关节重建中的临床应用

目的探讨人工髁突假体应用于颞下颌关节重建的可行性及临床治疗效果。方法 2005年1月-2010年1月,对10例(11侧)患者应用人工髁突假体行颞下颌关节重建手术。男7例,女3例;年龄40～68岁,平均50岁。左侧7侧,右侧4侧。下颌骨肿瘤7例,病程9～24个月,平均15个月。双侧髁突囊内骨折3例,其中交通事故伤2例,高处坠落伤1例;伤后至入院时间分别为2、3、2 d;骨折按照Neff等的分类法:M型及A型1例,M型及B型1例,余1例一侧为M型,一侧为髁突下骨折。结果术后切口均Ⅰ期愈合,无相关并发症发生。患者均获随访,随访时间1～4年,面部对称,咬关系良好;张口度22～38 mm,平均30 mm。双侧颞下颌关节无弹响及疼痛,肿瘤无复发。一侧人工髁突假体就位角度稍差,其余人工髁突假体位置良好,与关节窝和关节结节的关系正常,能正常饮食。结论人工髁突假体应用于肿瘤术后颞下颌关节重建,效果良好;应用于髁突囊内骨折的治疗,其临床效果待进一步验证。     

改良颊侧多曲簧矫治器对颞下颌关节间隙影响的临床研究

目的:探讨应用改良颊侧多曲簧活动矫治器矫治安氏Ⅲ类错牙合伴下颌功能性偏斜患者矫治前后颞下颌关节间隙测量值的变化。方法:混合牙列安氏Ⅲ类错牙合伴下颌功能性偏斜患者20例,采用改良颊侧多曲簧矫治器矫治,矫治前后拍摄颞下颌关节闭口位X线片,测量分析颞下颌关节间隙,用统计软件处理数据。结果:改良颊侧多曲簧活动矫治器矫治安氏Ⅲ类错牙合伴下颌功能性偏斜,矫治前后颞下颌关节间隙测量前间隙(M)、后间隙(N),比较线性百分比=(N-M)/(N+M)×100%、面积计算采用Y/X值变化。颞下颌关节间隙发生改变,M值及N值的变化均较明显。结论:改良颊侧多曲簧矫治器适当的持续加力作用,能引起颞下颌关节适应性改建,关节前间隙增大、后间隙减小,髁突明显后移位。     

前牙闭锁性深覆(牙合)颞下颌关节的三维有限元分析

目的：研究前牙闭锁性深覆[牙合]颞下颌关节髁突、关节窝和关节盘的受力情况。方法：利用CT和MRI对软硬组织的不同成像特点，将两者的图像融合并通过改变前牙的覆[牙合]、覆盖关系建立前牙闭锁性深覆[牙合]的几何模型，然后对三维有限元模型进行力学加载，以观察不同组织部位的应力分布情况。结果：三维有限元分析表明前牙闭锁性深覆[牙合]时颞下颌关节的受力情况与正常袷的分布特点相似，但应力值增大，变化范围也有所增加。结论：前牙闭锁性深覆[牙合]颞下颌关节应力值增大，变化范围的增加可能是导致颞下颌关节紊乱综合征的病因之一。     

Weight-bearing radiographs and cone-beam computed tomography examinations in adult acquired flatfoot deformity

BackgroundOptimal characterization of Adult acquired flatfoot deformity (AAFD) on two-dimensional radiograph can be challenging. Weightbearing Cone Beam CT (CBCT) may improve characterization of the three-dimensional (3D) structural details of such dynamic deformity. We compared and validated AAFD measurements between weightbearing radiograph and weightbearing CBCT images.Methods20 patients (20 feet, right/left: 15/5, male/female: 12/8, mean age: 52.2) with clinical diagnosis of flexible AAFD were prospectively recruited and underwent weightbearing dorsoplantar (DP) and lateral radiograph as well as weightbearing CBCT. Two foot and ankle surgeons performed AAFD measurements at parasagittal and axial planes (lateral and DP radiographs, respectively). Intra- and Inter-observer reliabilities were calculated by Intraclass correlation (ICC) and Cohen’s kappa. Mean values of weightbearing radiograph and weightbearing CBCT measurements were also compared.ResultsExcept for medial-cuneiform-first-metatarsal-angle, adequate intra-observer reliability (range:0.61?0.96) was observed for weightbearing radiographic measurements. Moderate to very good interobserver reliability between weightbearing radiograph and weightbearing CBCT measurements were observed for the following measurements: Naviculocuneiform-angle (ICC:0.47), Medial-cuneiform-first-metatarsal-gapping (ICC:0.58), cuboid-to-floor-distance (ICC:0.68), calcaneal-inclination-angle(ICC:0.7), axial Talonavicular-coverage-angle(ICC:0.56), axial Talus-first-metatarsal-angle(ICC:0.62). Comparing weightbearing radiograph and weightbearing CBCT images, statistically significant differences in the mean values of parasagittal talus-first-metatarsal-angle, medial-cuneiform-first-metatarsal-angle, medial-cuneiform-to-floor-distance and navicular-to-floor-distance was observed (P < 0.05).ConclusionModerate to very good correlation was observed between certain weightbearing radiograph and weightbearing CBCT measurements, however, significant difference was observed between a number of AAFD measurements, which suggest that 2D radiographic evaluation could potentially underestimate the severity of AAFD, when compared to 3D weightbearing CT assessment.     

Intraoperative cone-beam CT for image-guided tibial plateau fracture reduction.

OBJECTIVES: A mobile isocentric C-arm was modified in our laboratory in collaboration with Siemens Medical Solutions to include a large-area flat-panel detector providing multi-mode fluoroscopy and cone-beam CT (CBCT) imaging. This technology is an important advance over existing intraoperative imaging (e.g., Iso-C(3D)), offering superior image quality, increased field of view, higher spatial resolution, and soft-tissue visibility. The aim of this study was to assess the system's performance and image quality in tibial plateau (TP) fracture reconstruction. METHODS: Three TP fractures were simulated in fresh-frozen cadaveric knees through combined axial loading and lateral impact. The fractures were reduced through a lateral approach and assessed by fluoroscopy. The reconstruction was then assessed using CBCT. If necessary, further reduction and localization of remaining displaced bone fragments was performed using CBCT images for guidance. CBCT image quality was assessed with respect to projection speed, dose and filtering technique. RESULTS: CBCT imaging provided exquisite visualization of articular details, subtle fragment detection and localization, and confirmation of reduction and implant placement. After fluoroscopic images indicated successful initial reduction, CBCT imaging revealed areas of malalignment and displaced fragments. CBCT facilitated fragment localization and improved anatomic reduction. CBCT image noise increased gradually with reduced dose, but little difference in images resulted from increased projections. High-resolution reconstruction provided better delineation of plateau depressions. CONCLUSION: This study demonstrated a clear advantage of intraoperative CBCT over 2D fluoroscopy and Iso-C(3D) in TP fracture fixation. CBCT imaging provided benefits in fracture type diagnosis, localization of fracture fragments, and intraoperative 3D confirmation of anatomic reduction.     

Three-dimensional clavicular and acromioclavicular rotations during arm abduction using vertically open MRI.

There have been several reports about the clavicular and acromioclavicular motion, but a precise motion has been unknown. The purpose of this study was to analyze the 3D kinematics of the clavicle and acromioclavicular joint during arm abduction, using 3D MR images obtained by a vertically open MRI. Seven subjects participated in this investigation, which included 14 shoulders. From a seated position, we obtained MR images of their shoulder in seven abducted positions of the arm in the coronal plane. We evaluated the 3D movements of each bone in the shoulder using the volume-based registration technique, and analyzed the clavicular positions relative to the lung and the scapular positions relative to the clavicle. During arm abduction, the clavicular motion relative to the lung showed 30.6 degrees retraction, 7.3 degrees elevation, and 33.2 degrees posterior axial rotation. During arm abduction, the scapular motion relative to the clavicle showed 15.6 degrees protraction, 21.5 degrees upward rotation, and 22.2 degrees posterior tilting. This study succeeded in describing the 3D clavicular and acromioclavicular motion including the axial rotation of the clavicle, and it revealed that both motions had large degrees of rotations.     

基于CT三维重建的上颈椎三维活动度在体测量研究

目的:采用CT三维重建的方法测量健康成年人上颈椎寰枕关节、寰枢关节的各个方向上的活动度及其耦合运动,以及颈椎病患者上颈椎最大旋转位的三维活动度,并作对比分析,同时验证所使用的测量方法的可靠性。方法:2014年1月至2015年6月,选取20个健康成年受试者(健康成年组),其中男11例,女9例,年龄22～26(24.0±1.2)岁;26个颈椎病患者(颈椎病组),其中男24例,女2例,年龄36～72(52.8±8.6)岁。采集健康成年人中立位、最大右侧旋转位、最大右侧侧屈位及最大屈曲位、最大背伸位5个位置的及颈椎病患者中立位、最大右侧旋转位上颈椎(含枕骨大孔)的CT图像。利用软件Mimics将所得CT重建为三维图像。在各个椎体(或枕骨)上选取明显的解剖标志点进行标注,根据所标注的解剖标志点建立局部坐标系,局部坐标系即代表了所在椎体的位置及方向。利用Pro/Engineer及MATLAB软件运算出上位椎体(或枕骨)相对下位椎体的活动度及颈部整体三维活动度,并比较颈椎病组和健康成年组差异。因解剖标志点识别有人为差异,选取两名实验员进行3次测量,用组内相关系数(组内ICC)和组间相关系数(组间ICC)验证实验方法的可靠性。结果:可靠性验证结果:组内ICC、组间ICC结果均在0.90以上,测量方法有很高的可靠性;健康成年组上颈椎三维活动度:最大右侧旋转位时,寰枕关节有(-6.8±1.5)°的耦合左侧屈和(8.9±2.0)°的耦合背伸活动,其余3个位置寰枕关节各方向活动度均很小,最大为(5.3±2.6)°;最大右侧旋转位时寰枢关节右旋(37.9±5.1)°,占整个颈椎活动度[(72.4±5.0)°]的52.34%,其余3个位置寰枢关节仍以旋转活动最为突出;上位椎体(或枕骨)相对下位椎体的平移距离均很小。颈椎病患者颈椎整体平均轴向旋转角度[(62.0±3.4)°]较健康成年组明显下降,但寰枕关节、寰枢关节的平均轴向旋转角度比较健康成年组没有明显差异(P0.05)。结论:(1)基于CT三维重建的方法能够很好的描述颈椎的这种复杂的三维运动,并且有很高的可靠性。(2)上颈椎运动是一个复杂的三维运动过程,各个方向活动时均附带有其他方向上的耦合运动。(3)颈椎病患者最大旋转位上颈椎旋转方向的活动度较健康成年人没有明显变化。     

Ultrasonography of the temporomandibular joint: comparison of findings in patients with rheumatic diseases and temporomandibular disorders. A preliminary report.

OBJECTIVE: The objective of the study was to compare findings from ultrasonography (US) of the temporomandibular joint (TMJ) in patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA), and temporomandibular disorders (TMD). STUDY DESIGN: US assessment of the temporomandibular joints was bilaterally performed in 68 patients (22 with RA, 11 with PsA, and 35 with TMD). All the TMJs were assessed for the presence of disc displacement, effusion, and changes of the condylar profile, and the prevalence of such abnormalities was compared across the 3 groups of patients. To confirm generalizability of results, US findings were also compared with those of magnetic resonance (MR), taken as the standard of reference. RESULTS: Prevalence of disc displacement and changes in condylar profile were similar between patients with rheumatic diseases and temporomandibular disorders, while effusion was significantly more present in TMJs of TMD patients. Sensitivity of US to detect TMJ abnormalities was acceptable, while specificity was low for condylar alterations. CONCLUSIONS: Temporomandibular joint involvement in patients with rheumatic diseases seems to be similar to that described in subjects with temporomandibular disorders. Ultrasonography confirmed to be an accurate technique to detect disc displacement and effusion within the temporomandibular joint, but not to detect condylar abnormalities.     

Assessment of bone segmentation quality of cone-beam CT versus multislice spiral CT: a pilot study.

OBJECTIVES: The objective of this study was to quantitatively assess the quality of jawbone models generated from cone beam computed tomography (CBCT) by comparison with similar models obtained from multislice spiral computed tomography (MSCT). MATERIAL AND METHODS: Three case studies were performed involving images of anthropomorphic head phantoms and real patients acquired with 3 CBCT (NewTom 9000 DVT, Accuitomo 3D, and i-CAT) and 2 MSCT scanners (Somatom VolumeZoom and Lightspeed). Bone was segmented from the CBCT and MSCT images using global thresholding. CBCT vs MSCT segmentation differences were assessed by comparing bone thickness measurements at anatomically corresponding sites, identified automatically by CBCT to MSCT image registration. RESULTS: There was a statistically significant difference between the MSCT and CBCT segmented bone thicknesses, varying from 0.05 +/- 0.47 mm (i-CAT) up to 1.2 +/- 1.00 mm (3D Accuitomo, posterior maxilla). CONCLUSIONS: An automated, reproducible, and observer-independent method has been developed to assess the quality of CBCT bone models using MSCT as a clinically established method of reference. Our validation method is generally applicable in cases where no geometric ground-truth is available.     

数字化正颌外科中相关配准问题的研究进展

随着数字化技术在医学各个领域的迅猛发展,数字化正颌外科的流程也逐步趋向于完善,配准问题是关系到其精确性的重要环节,通常包括:石膏模型光学扫描时,单颌模型与咬合状态模型的配准;锥形束CT(CBCT)数据与石膏模型扫描数据的配准;CBCT三维重建软组织与三维面像的配准。该文就数字化正颌外科中相关配准问题展开综述。     

前交叉韧带的生物力学研究

目的研究前交叉韧带（ACL）在维持膝关节前后稳定和旋转稳定中的作用。方法标本取自新鲜尸体的5只膝关节，分别在ACL完整和切断的情况下对标本施加股四头肌力和腔股关节作用力，采用应变计测量技术和计算机图形处理技术对受载膝关节位移和转角进行测量和图像重建。结果在负载作用下，ACL切断与否对膝关节内、外旋角度的影响很小，但对腔骨前后位移的影响很大。结论ACL是维持膝关节前后稳定的重要结构。     

In vitro stability study of an improved implant system for minimally invasive transforaminal approach

Calf specimens from the L3-4 and L5-6 levels were used for in vitro stability testing of a new transforaminal lumbar interbody fusion (TLIF) implant. Results were compared with those of the conventional posterior lumbar interbody fusion (PLIF) technique using two cuboid spacers. The specimens were loaded with pure moments of 10 Nm in flexion, extension, lateral bending, and axial rotation without any axial preload. They were allowed to move freely and unconstrained in all directions. In extension the PLIF implants showed slightly higher degrees of stiffness than the TLIF implant. While the conventional PLIF technique results in an increased range of motion by a factor of 2.5 after implant insertion, the TLIF approach prevents segmental destabilization in axial rotation. The facet joint arthrodesis using resorbable pins reveals biomechanically interesting results and will therefore be investigated in further studies.     

CT三维图像重建在关节内骨折诊断中的应用

目的 探讨螺旋CT三维图像重建显示关节内骨折的价值。方法 在20例关节内骨折患者中应用Hispeed螺旋CT机进行扫描,再将资料通过Windows工作站应用成像软件进行表面遮盖法三维成像,或再以关节解体技术充分显示损伤的关节面,细致观察关节损伤情况。结果 CT三维图像重建能清晰显示所有病例的关节内骨折及损伤细节情况,结合关节解体技术,能逼真地显示关节损伤的立体形态。所示结构清晰,与临床实际相符,无失真现象。结论 螺旋CT三维重建技术,结合关节解体技术和图像旋转技术,能显示关节内骨折的细节,术前应用有利于选择手术入路及内固定方法,减少手术创伤和失误。