成人下颌偏斜患者颞下颌关节对称性研究

目的:了解下颌偏斜患者颞下颌关节形态学差异及相关性。方法:对21例下颌偏斜患者拍摄颞下颌关节中位断层片,选择描述髁突位置及髁突和关节窝形态的15个指标进行测量及统计分析。结果:下颌偏斜患者非偏斜侧的髁突在关节窝中的位置较偏斜侧向前下移位;非偏斜侧的髁突高度、髁突上部高度较偏斜侧高;非偏斜侧的髁突前斜面斜度、关节窝后斜面的斜度较偏斜侧大。双侧髁突前斜面斜度与关节前间隙、关节窝深度呈正相关;髁突上部高度与髁突高度呈正相关;偏斜侧髁突后斜面斜度与关节窝后斜面斜度呈正相关;非偏斜侧髁突后斜面斜度与关节上间隙、关节结节高度呈负相关。结论:下颌偏斜患者双侧颞下颌关节具有形态学差异。双侧髁突形态的变化与其同侧关节窝形态的变化及其在关节窝中的位置具有一定相关性。     

髁状突游离再植治疗颞下颌关节髁突颈部骨折的临床研究

目的:探讨髁状突游离再植重建颞下颌关节治疗髁突颈部骨折的方法与疗效.方法:15例17侧髁突颈部骨折患者行髁状突游离再植鈦板复位固定的治疗,术后定期复查患者颞下颌关节功能和X线片检查.结果:患者术区伤口均一期愈合,追踪1～5年颞下颌关节无疼痛、弹响及明显功能障碍,2例面神经颞支有影响,1例轻度错牙合畸形. 结论:本法操作简单易行、复位准确、固定可靠,并发症少,适用于移位的髁突颈部骨折.     

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.     

SPECT-CT对成人下颌偏斜患者双侧颞下颌关节代谢及形态对称性研究

目的:利用SPECT-CT骨显像对成人下颌偏斜患者双侧颞下颌关节代谢及形态对称性研究。方法:对36例成人下颌偏斜患者行SPECT骨显像,对髁突、下颌升支、下颌角图像进行冠状面、矢状面、横断面采集进行三维重建,计算出放射性计数比值,并通过CT扫描三维重建后同机融合,根据双侧颞下颌关节解剖关系测量偏斜侧及对侧髁突的高度、内外径、后斜面倾斜角及后斜面长度的差异,进行对比观察。结果:颞下颌关节各区域(髁突、下颌升支、下颌角)放射性计数比值均有所不同,偏斜侧的放射性计数比值均低于对侧,且两侧放射性计数比值有显著差异(P＜0.05);偏斜侧髁突高度及内外径均较之对侧减小(P＜0.01);偏斜侧髁突后斜面长度、后斜面倾斜角较之对侧增大(P＜0.01)。结论:SPECT-CT骨显像对成人下颌偏斜疾病的诊断评估起到了至关重要的作用。     

间接性TMJ损伤的生物力学初步研究

目的：研究间接性TMJ损伤时下颌骨不同部位在致伤过程中的生物力学改变情况。方法：采用颏部撞击法对6个新鲜羊头颅以4kg和10kg的压力推动0．845kg的圆柱形钢质抛射体进行撞击，对头颅加速度、双侧下颌骨体部、髁突颈部以及颞骨部的应变变化情况进行检测，应用新研制的生物撞击系统数据采集与分析软件对采集到的信号进行分析。结果：随撞击速度的增加，头颅加速度和各检测部位的应变也随之加大，髁突颈部可产生最大应变，颞骨部应变明显减小，说明颞颌关节的存在可减小颏部撞击伤对颅脑的损伤。在外力作用于颏部时，髁突颈部受到的应力最大，因而较其他部位容易发生骨折。当髁突颈部所受应力超出其自身生理范围时，即发生髁突骨折。结论：撞击速度和下颌骨内应力的变化是衡量下颌部损伤，特别是颞颌关节部损伤的重要生物力学参数。     

成人下颌偏斜患者下颌髁突三维CT形态对称性研究

目的:建立成人下颌偏斜患者CT三维重建模型,测量、分析髁突形态、三维特征,并比较双侧髁突对称性,为下颌偏斜患者临床诊断、治疗提供参考.方法:对20例下颌偏斜患者(18～30岁)的头颅进行螺旋CT扫描,在Mimics 8.13软件工作站上进行三维图像重建和参数测量,对结果进行统计学分析.结果:偏斜对侧髁突高度较偏斜侧增大(P＜0.05);髁突内外径较偏斜侧增大(P＜0.01);髁突后斜面长度、髁突后斜面倾斜角较偏斜侧减小(P＜0.01).结论:下颌偏斜可引起髁突的非对称性改建,故下颌偏斜患者双侧髁突形态不对称.     

利用CBCT对不同年龄组下颌偏斜患者髁突进行的三维形态研究

目的建立不同年龄组下颌偏斜患者CT三维重建模型,测量、分析不同年龄组下颌偏斜患者髁突形态三维特征,并比较双侧髁突对称性。方法选择3个不同年龄组:替牙组(8～11岁)和年轻恒牙列组(11～16岁),成人组(18～30岁)的偏颌患者各12例,进行CBCT扫描,采集颅面部DICOM数据,使用Sim plant对骨组织进行三维重建和参数测量,对结果进行统计学分析。结果不同年龄组偏颌患者髁突三维形态存在差异性。替牙组下颌偏斜患者两侧髁突形态无明显差异;年轻恒牙列组髁突高度、髁突内外径、下颌支高度、髁突后斜面长度、髁突后斜面倾角偏斜侧与对侧比较出现了差异,双侧髁突形态发生了非对称性改变;成人组下颌偏斜患者双侧髁突形态发生了明显的非对称性改变,偏斜对侧髁突高度、下颌升支高度、髁突内外径较偏斜侧增大,髁突后斜面长度、后斜面倾斜角较偏斜侧减小。结论下颌偏斜可引起髁突的非对称性改建,从替牙组到成人组,下颌偏斜有从下颌移位向骨骼异常发展的趋势,故下颌偏斜患者应该早期矫治。     

下颌偏斜畸形术后髁突位置改变的研究

目的:观察下颌双侧升枝矢状劈开术Bilateral Sagittal Split Ramous Osteotomy(以下简称BSSRO)矫治下颌偏斜畸形术后髁突位置的变化.方法:通过定位薛氏位片研究BSSRO矫治20例下颌偏斜畸形病例术前、术后1周及术后1年关节间隙的改变.结果:BSSRO术后1周髁突位置发生变化,1年后髁突位置恢复到术前状态,关节弹响症状多数缓解.结论:BSSRO矫治下颌偏斜畸形术后髁状突位置远期无明显改变.     

骨性Ⅲ类错(牙合)患者咀嚼时下颌运动特点的初步研究

目的:研究成人骨性Ⅲ类错患者咀嚼不同食物时的下颌运动.方法: 对成人骨性Ⅲ类错伴下颌偏斜患者14 例,不伴有下颌偏斜患者10 例,以及10 例正常对照组,利用下颌定位仪测量咀嚼运动时双侧髁突运动中心点以及切牙点在矢状向、冠状向、水平向的移动范围的面积比值.结果: 咀嚼软食时,从矢状方向和水平方向看,偏斜组双侧髁突点的运动轨迹与非偏斜组和正常组差异显著(P<0.05),而3 组样本切牙点运动轨迹的差异无统计学意义.咀嚼脆食时, 3 组样本在三个方向上的差异更加明显.咀嚼韧食时,在矢状方向上偏斜组偏斜侧髁突点和切牙点运动面积比值明显高于非偏斜组和正常组(P<0.01),而非偏斜侧髁突点运动面积比值仅明显高于正常组(P<0.05).结论: 成人骨性Ⅲ类错患者下颌运动受食物形态和质地的影响相对较大,下颌偏斜患者尤为明显.     

偏颌大鼠模型的构建及其髁突CT影像和组织学评价

目的:构建下颌偏斜大鼠模型,观察该实验性偏颌大鼠髁突显微CT(micro-CT)影像及其组织学变化.方法:选取12只6周龄雌性SD大鼠,将其随机等量分为对照组和偏颌组,每组6只.偏颌造模方法:将上颌左侧中切牙及下颌双侧中切牙分别粘接金属套筒冠不良修复体,上颌金属套筒冠制备唇向斜面导板,使上下颌切牙有正常方向的覆牙合覆盖关系,下颌金属套筒冠制备与牙长轴呈45°角的近远中向斜面导板,使动物咬合时导板可以引导下颌向右.对照组不做任何处理.2组大鼠饲养12周后取材,对双侧髁突进行micro-CT检测及组织学染色.将对照组双侧髁突测量的数据合并取平均值,将偏颌组分为偏颌组-左侧和偏颌组-右侧,分别与对照组比较.结果:Micro-CT结果显示,对照组大鼠髁突关节面光滑、完整,骨质致密.与对照组髁突相比,偏颌组髁突长度和宽度出现不同程度的增加,但骨小梁有明显的吸收;12个髁突中有3个左侧髁突表面出现陷窝.组织学染色结果显示,对照组大鼠髁突软骨细胞层次分明,而偏颌组大鼠左侧髁突骨性陷窝内有软骨组织或纤维组织充填.组织测量学结果显示,偏颌组双侧大鼠髁突未矿化软骨的中带较对照组有显著增厚(P<0.05),偏颌组左侧髁突未矿化软骨的后带较对照组有明显增厚(P<0.05).结论:实验性偏颌可致大鼠双侧髁突骨和软骨出现非对称性异常改建,偏颌对侧髁突表面可出现局部纤维软骨样组织增厚,在影像学上表现为关节面上缺损样陷窝.     

Condylar fractures of the mandible. I. Classification and relation to age, occlusion, and concomitant injuries of teeth and teeth-supporting structures, and fractures of the mandibular body.

In 123 individuals, 138 fractures of the mandibular condyle were classified with respect to fracture level, dislocation at the fracture level, and condylar head relation to the articular fossa. The age of the patient and the location of the most distal occlusal contact were recorded as well as teeth injuries and concomitant fractures of the mandibular body. The position of the most distal occlusal contact did not influence the dislocation of the condylar fragment. Teeth injuries such as fractures and luxation were found to be associated with condylar head or neck fractures, whereas the concomitant fractures of the mandibular body were mostly seen with the subcondylar fractures. Teeth injuries as well as concomitant fractures of the mandibular body were found more frequently in patients with bilateral than unilateral condylar fractures. Fractures of teeth in the molar and bicuspid regions were most frequent on the condylar fracture side, while the concomitant fractures of the mandibular body were located to the contralateral side. Medial angulation of the condylar fragment with lateral override at the fracture level was the typical fracture in adults, and angulation without override the characteristic fracture in growing individuals. Medical override occurred both in children and in adults and seemed to be the result of more severe trauma to the chin.     

Open Reduction and Rigid Internal Fixation of Mandibular Condylar Fractures by an Intraoral Approach: A Long-Term Follow-Up Study of 15 Patients

PURPOSE: To evaluate the long-term results obtained with open reduction and rigid internal fixation of mandibular condylar fractures by an intraoral approach. PATIENTS AND METHODS: Fifteen patients with 24 mandibular condylar fractures were retrospectively examined with an average follow-up of 23 months (range, 6-63 months). Clinical and radiographic examination was conducted according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD), including an evaluation of maximum voluntary bite force measurements and facial nerve function. Statistical analysis was performed on maximum voluntary bite force measurements and maximum pressure pain threshold. RESULTS: Two patients fulfilled the criteria for a RDC/TMD diagnosis. Myofacial pain (group I) and bilateral arthralgia (group III), combined with a moderate nonspecific physical symptom score, was diagnosed in 1 patient and 1 patient received a diagnosis of disc displacement with reduction (group II). Satisfying radiographic fracture healing was seen in 12 joints. However, miniplate fracture occurred in 3 patients and severe bone resorption of the condylar head was seen in one patient. Minor adjustment of the postoperative occlusion was necessary in 6 patients. No significant difference between maximum voluntary isometric bite force measurements or maximum pressure pain threshold was found between the fracture side and the opposite side in unilateral cases or between the operated and nonoperated side in bilateral cases. None of the patients showed facial nerve injury or visible facial scars. CONCLUSION: Within the limitations of a retrospective study, the present study emphasized that optimal management of dislocated bilateral condylar injuries combined with other fractures of the facial skeleton constitute a challenging issue in maxillofacial trauma. Moreover, open reduction and rigid internal fixation of mandibular condylar fractures by an intraoral approach is a technically demanding surgical procedure associated with a high risk of postoperative complications in these injuries.     

青少年髁突骨折诊治的回顾性分析

目的:探讨青少年髁突骨折的临床特点及治疗方法。方法:对1990-2002年间收治的52例(75侧)青少年(2～18岁)髁突骨折病例的临床和随访资料进行回顾性分析。结果:青少年髁突骨折主要由着力于颏部的间接创伤引起,多为颈部的中高位骨折,大部分骨折断端移位较轻,骨块均是向前下内方向移位。保守治疗和手术治疗都取得了较好效果。主要的后遗症是下颌骨发育不良、开口偏斜和轻度张口受限。结论:着力于颏部的外伤要仔细检查有无髁突骨折。治疗上应尽可能采用保守治疗;对于严重移位而难以复位的、粉碎性的髁突骨折,以及不能进行保守治疗的病例,主张手术复位固定。     

A sheep model of intracapsular condylar fracture.

PURPOSE: An animal model of a condylar head fracture similar to a type B intracapsular fracture in humans was created. The effect of this model on mandibular function and morphological changes of temporomandibular joint (TMJ) structure was evaluated. MATERIALS AND METHODS: Ten sheep were divided into 3 groups, sacrificed at 1 week (2 sheep), 4 weeks (4 sheep), and 12 weeks (4 sheep) after surgery. The right side of the TMJ was considered the surgical group; the left side, the control group. The anterior and posterior attachments of the discs were cut, and an oblique vertical osteotomy was made from the lateral pole of the condyle to the medial side of the condylar neck. The condyle fragment was pushed together with the disc anteriorly, inferiorly, and medially. The lateral side of the condylar stump was sutured to the capsule to limit movement. Preoperative and postoperative body weight, maximum mouth opening, lateral excursions, and x-ray and computed tomography (CT) findings in the 3 surgical groups and the control group were recorded. The SPSS software program was used for all statistical analyses. RESULTS: There were no significant differences in weight loss and left lateral movement among the 3 surgical groups, but maximum mouth opening and the right lateral movement decreased significantly in the 4-week and 12-week surgical groups. X-rays demonstrated severe bone erosion and new bony outgrowth in the lateral side of the condylar stump and a narrowed, indistinct joint space in these 2 groups. Three-dimensional reconstruction of CT images showed changed contours of the condylar stump, condylar fragment and articular eminence in all 3 surgical groups. CONCLUSIONS: This study demonstrates progressive changes toward ankylosis and pathological changes in sheep TMJ over time consistent with what has been found in humans.     

髁突矢状骨折动物模型的实验研究

目的：建立髁突囊内矢状骨折动物模型,观察髁突骨折后不同时间的病理形态改变。方法：对10只绵羊进行实验,右侧关节为手术侧,从耳前区切开皮肤,到达颞下颌关节,切断关节盘前后附着,从髁突外侧嵴到内侧髁颈锯开髁突,建立斜形矢状骨折。髁突碎片和关节盘推向前下内侧,左侧关节为对照侧。分别于术后1周、4周和12周处死2只、4只和4只动物。记录术前和术后每组动物的体质量、最大开口度、侧方活动度,进行X线、CT和组织病理学观察。采用SPSS12.0软件包对数据进行统计分析。结果：各手术组体质量、左侧向活动度未发现显著差异,但是在4周和12周组中,最大开口度和右侧向活动度明显减小。在这2组中,X线检查发现髁突残端外侧有新骨生成,并向外侧生长,同时关节间隙变狭窄和模糊。三维CT检查发现,髁突残端、髁突碎片和关节结节均发生改建。组织病理学观察发现,在4周和12周组动物,关节腔充满纤维组织、软骨和骨组织。结论：该研究表明,此类骨折可以导致髁突骨关节病理改变,颞下颌关节有发展为关节强直的可能。     

Preliminary functional results of endoscope-assisted transoral treatment of displaced bilateral condylar mandible fractures

Temporomandibular joint (TMJ) function was evaluated following endoscope-assisted transoral open reduction and miniplate fixation of displaced bilateral condylar mandibular fractures. The transoral treatment of bilateral condylar fractures was performed in 13 patients from May 2000 to December 2004. Eleven of the 13 patients had additional mandibular fractures. Out of 26 fractures of the condylar process, 11 were located at the condylar neck and 15 were subcondylar. One, 6 and 12 months after surgery TMJ function was evaluated. Anatomic reduction was achieved using an endoscope-assisted transoral approach even when the condylar fragment was displaced medially and in fractures with comminution. Good TMJ function was noted 6 and 12 months after surgery. Mouth opening was measured to be more than 40 mm without deviation. Postoperative range of motion with a satisfying lateral excursion was found. Early rehabilitation and pre-injury TMJ function was achieved following minimally invasive anatomic fracture reduction.     

Bite forces after open or closed treatment of mandibular condylar process fractures.

PURPOSE: This study compared maximum voluntary bite forces in patients who received either open or closed treatment for fractures of the mandibular condylar process. PATIENTS AND METHODS: One hundred fifty-five patients (127 male, 28 female) with unilateral fractures of the mandibular condylar process (91 treated closed and 64 treated open) were included in this study. Maximum voluntary bite forces were measured at 6 weeks, 6 months, and 1, 2, and 3 years after fracture. At each trial, unilateral maximum voluntary bite force was measured at 4 different tooth positions bilaterally using a standard transducer. Electromyography (EMG) of the masseter muscles was also recorded during the bite force measurements, and ratios of the working/balancing side EMG were calculated. Analysis of the data was performed using standard statistical methods. RESULTS: The only significant difference between the 2 samples was in the level of fractures on the condylar process. No patients treated open had fractures of the "head" of the condylar process, whereas there were 11 in the group treated closed. No differences were observed in maximum voluntary bite forces between the 2 treatment groups at any time period, or were there correlations between bite force magnitude and location of the fracture, displacement of the fracture, or any other variable studied. Both groups showed a significant recovery of maximum bite force from the 6-week to the 6-month testing session. For both groups, working/balancing EMG ratios were significantly greater when subjects were biting on the side opposite the fracture. When biting on that side, the working/balancing EMG ratios were higher in the closed treatment group, but the difference did not reach significance. CONCLUSIONS: Maximum voluntary bite forces in patients treated for mandibular condylar process fractures do not differ significantly when treatment is open or closed. Neuromuscular adaptations to the fractured mandibular condylar process occur in both groups.     

翼外肌在髁突矢状骨折愈合过程中对髁突形态改建的影响

目的：本实验的目的是检查翼外肌在髁突矢状骨折愈合过程中,对髁突形态改建的影响。方法：20只1岁龄成年绵羊,随机分为两组,每组10只动物,所有绵羊都用超声骨刀造成髁突矢状骨折,剪断关节盘前后附着并将其推向内侧,其中组1动物切断翼外肌,组2动物保留翼外肌功能。每组动物分别在术后4周（各2只）、12周（各4只）、24周（各4只）处死。处死后行CT检查,CT三维重建观察髁突形态,并解剖颞颌关节（TMJ）以观察髁突形态。结果：组2即保留翼外肌功能组,较组1髁突有更多新骨形成,髁突形态改变更严重。结论：翼外肌在髁突矢状骨折愈合过程中对髁突形态改建的影响起非常重要的作用。     

Changes in growth and morphology of the condyle following mandibular distraction in minipigs: overloading or underloading?

OBJECTIVE: Loading of temporomandibular tissues during mandibular distraction may cause changes in condylar growth and cartilage thickness. This study examines the effects of distraction on the condyle in a large animal model by explicitly measuring growth and in vivo loading. DESIGN: Unilateral mandibular distraction was carried out on 20 growing minipigs divided into three groups. One group underwent distraction but not consolidation, whereas the other two groups were allowed a period of consolidation of either 1 or 2 weeks. Animals received fluorochrome and 5-bromo-2'-deoxyuridine (BrdU) labelling and masticatory strain was measured from the condylar neck. Condylar strain was also recorded in an age-matched sample of eight animals that received no distraction surgery. Immunohistochemical procedures were used to identify dividing prechondroblasts and histological analysis was used to measure mineral apposition rate, count dividing cells, and measure the thickness of condylar cartilage. RESULTS: Strain magnitude, particularly compressive strain, was much larger on the non-distraction side compared to the distraction side condyle. Compared to normal loading levels, the distraction side condyle was underloaded whereas the condyle on the intact side was overloaded. Mineral apposition and cartilage thickness were greater on the distraction side condyle compared to the opposite side. Differences between the sides were most pronounced in the group with no consolidation and became progressively reduced with consolidation time. CONCLUSIONS: Increased mineralisation and cartilage thickness on the distraction side condyle are associated with reduced, not increased loading, perhaps because of disruption of the distraction side masseter muscle.     

Mandibular mechanics following osteotomy and appliance placement II: Bone strain on the body and condylar neck.

PURPOSE: The purpose of this investigation was to determine if the mechanical environment of the mandible is changed by osteotomy and fixation, as assessed by the measurement of bone strain on the condylar neck and mandibular corpus. MATERIALS AND METHODS: Immediately following unilateral mandibular osteotomy and distractor placement, strain gauges were attached directly to the corpus and condylar neck in a sample of domestic pigs. Bone strains were recorded during mastication and muscle stimulation. Comparisons of principal strain magnitudes and orientations were made between sides and between the osteotomy sample and a control database. RESULTS: The animals preferred to chew on the non-osteotomy side. Corpus strains were higher for osteotomy-side chewing but were comparable to the control database, regardless of chewing side. For the condyle, compared with the control database and the non-osteotomy side, the osteotomy side was underloaded in compression. Furthermore, the orientation of compressive strain was highly variable and more horizontally oriented than that of control and non-osteotomy condyles. Stimulation of the masseter and medial pterygoid loaded the mandible to normal levels. CONCLUSION: Masticatory behavior was altered, probably as a combined result of disruption of the occlusion, changes in muscle recruitment, and probable loss of sensory feedback. However, neither these changes nor damage to the muscles explain the decrease and reorientation of compressive strain on the condylar neck. Alternatively, the modified strain pattern could have arisen from positional instability of the proximal bone fragment.