减小后牙▉平面倾斜度对安氏Ⅱ类高角畸形髁突位置影响的研究

目的: 研究在安氏Ⅱ类高角畸形正畸治疗中,减小后牙平面倾斜度对髁突位置的影响。方法: 15例安氏Ⅱ类高角畸形患者,年龄15~30岁。治疗前ANB>5°,下颌平面角FH-MP>32°,磨牙关系为双侧远中关系。常规排齐整平及适当扩弓后,利用多曲唇弓导下颌向前,并使后牙平面平坦化。利用锥形束CT（cone-beam CT,CBCT）测量治疗前、后颞下颌关节前、上、后间隙及后牙平面的改变情况。采用SPSS19软件包对变化量进行t检验;并利用相关性分析,进一步探讨髁突位置改变量与后牙平面倾斜度减小量之间的相关性。结果: 所有患者磨牙尖牙关系均调整到中性,侧貌改善明显,髁突后间隙平均增加(0.88±0.17)mm,变化有统计学意义(P<0.001);髁突上间隙平均增加(0.45±0.20)mm,变化也具有统计学意义(P<0.05)。后牙平面变平坦,POP-SN及POP-FH平均减小3.59°±2.31°及2.31°±3.62°,变化具有统计学意义(P<0.001)。髁突前间隙变化量无统计学意义,髁突位置改变量与后牙平面倾角的变化量之间无显著相关性。结论: 在安氏Ⅱ类高角畸形患者的正畸治疗中,通过正畸减小后牙平面倾斜度,可使髁突的位置发生适当的前下改变,有利于关节症状的改善。     

颞下颌关节结构形态的测量分析

目的 了解颞下颌关节的结构形态,研究咬合运动与关节形态之间的关系,为关节镜手术时确定手术范围以及手术部位与邻近解剖标志之间的关系提供参考。方法 解剖测试7具尸体颞下颌关节髁突和关节窝的大小,前、后斜面斜度,髁突附着关节盘时的斜度,以及关节上腔前后隐窝壁之间的距离和分别至耳屏后缘中点的距离,分析颞下颌关节的结构形态。结果 测量髁突、关节盘、关节窝、关节上腔与邻近解剖标志之间关系的参数值。结论 （1）髁突通过关节盘与关节窝相协调吻合,并增大前斜面斜度,使运动中的髁突在骨性结构不溶的关节窝中趋于稳定;（2）髁突横嵴有一定成角,使髁突在侧向运动中可以与关节窝形成类似点面接触,而具有灵活性;（3）关节上腔前后隐窝壁之间距离,以及与耳屏后缘中点,外耳道软骨的距离,关节窝大小对颞下颌关节内窥镜术者掌握好穿刺深度、范围和方向都是重要的参数;（4）颞下颌关节在人的一生中一直处于不断的改建状态。     

Juvenile porcine temporomandibular joint: Three different cartilaginous structures?

ObjectiveThe temporomandibular joint (TMJ) consists of three cartilaginous structures: the fossa, disc, and condyle. In juvenile idiopathic arthritis (JIA), inflammation of the TMJ leads to destruction of the condyle, but not of the fossa or the disc. Such a different effect of inflammation might be related to differences in matrix composition of the cartilaginous structures.MethodsThe matrix composition of the three TMJ structures was analyzed in juvenile porcine samples and in an in vitro system of cells isolated from each anatomical structure embedded in 3% agarose gels.ResultsThe matrix of all three anatomical structures of the TMJ contained collagen type I and its gene expression was maintained after isolation. The condyle and the fossa stained positive for collagen type II and proteoglycans, but the condyle contained considerably more collagen type II and proteoglycans than the fossa. The disc contained neither collagen type II protein nor expression of its gene, and the disc did not stain positive for proteoglycans. Aggrecan gene expression was lower in the disc compared to condyle and fossa cell-isolates. In general, the cell-isolates in vitro closely mimicked the characteristic features found in the tissue.ConclusionThe collagen type II content of the condyle clearly distinguished this cartilaginous structure from the disc and fossa. Since autoimmunity against collagen type II is associated with JIA, the relatively abundant presence of this type of collagen in the condyle might provide an explanation why primarily this cartilaginous structure of the TMJ is affected in JIA patients.     

Associations between the articular eminence inclination and condylar bone changes, condylar movements, and condyle and fossa shapes

Objectives

The purpose of the present study was to determine the inclination and height of the articular eminence with respect to the condylar bone changes, condyle shape, fossa shape and condylar movements in patients with and without temporomandibular joint (TMJ) dysfunction using cone-beam computed tomography (CBCT).

Methods

The associations between the eminence inclination and the condylar bone changes, condylar movements, condylar shape and fossa shape were evaluated in patients with TMJ disorders and control patients without TMJ disorders. The measurements of the articular eminence inclination were established on central sagittal slices of the TMJ. The central coronal slices were used to determine the condyle and fossa shapes. The types of movements of the condyles were determined on open-mouth images, and mandibular hypermobility or hypomobility was noted for each joint.

Results

There were no significant differences in the eminence inclination and height with respect to the condylar bone changes and condylar movements in the TMJ disorder group. However, there was a significant association between the eminence inclination and the fossa shape in the TMJ disorder group and significant associations between the eminence inclination and both the condyle and fossa shapes in the control group. The articular eminence inclination was steeper in the control group than in the TMJ disorder group.

Conclusions

The eminence inclination was steeper in the control patients than in the patients with TMJ disorders, and was not correlated with the condylar bone changes or condylar movements.     

Relationship between horizontal condylar angle and radiographically detectable morphological changes of the condyle in asymptomatic and symptomatic patients with TMD

BackgroundThe relationship between horizontal condylar angle (HCA) measurements and radiographically detectable morphological changes of the condyle in patients with temporomandibular disorder (TMD) is an area of controversy in dentistry.AimThis study sought to determine the effect of the HCA on radiographically morphological changes in the condyles of asymptomatic and symptomatic patients with TMD.Material & methodsCone beam computed tomography (CBCT) scans were used of patients with 146 temporomandibular joints (TMJ) with and without symptoms of TMD. The reconstructed axial plane was adjusted to depict the condyle in maximum width. The HCA was established and measured as the angle formed between the condylar long axis intersecting with the coronal plane. Each condyle long axial was determined independently from the other joint by two oral and maxillofacial radiologists. The average of the readings from the two examiners was used for statistical analysis.ResultsBased on the clinical symptoms, the mean of the HCA in the symptomatic joint was 27.69°, which was slightly greater than the angle measured in asymptomatic patients of 25.6°; however, this was not a statistical difference. No significant differences existed in the mean of the HCA between the joint with and without radiographic arthritic findings in both groups. In both groups, none of the arthritic findings manifested in the affected joint that had influenced the HCA.ConclusionThe HCA was increased in the symptomatic group but had no direct influence on joint's morphological changes in the asymptomatic and symptomatic patients.     

Comparative analysis of jaw morphology and temporomandibular disorders: A three-dimension imaging study

ABSTRACT

Objective: To investigate the association between volumetric measurements of craniofacial morphology and temporomandibular disorders (TMDs).

Methods: Computerized tomography (CT) scans of 20 individuals aged 18 to 40 with (TMD group) or without TMJ pain (control group) were gathered based on a case-control design. Three-dimensional reconstructions were performed to evaluate the gonial angle, condylar volume, and the distance between the posterior edge of the condyle and the sigmoid notch.

Results: The gonial angle was significantly larger (8% difference) in the TMD group with respect to controls, whereas the condylar volume was significantly higher in the control group (15.2% difference). No significant difference was found in the linear distance.

Conclusion: There is an association between the presence of TMJ pain and some features of craniofacial morphology. Individuals with TMJ pain have a lower condylar volume and a tendency towards hyperdivergent growth.     

Comparison of load transfers in TMJ replacement using a standard and a custom-made temporal component

PurposeThe temporomandibular joint (TMJ) is a complex articulation and depending on the available prosthesis models, the ultimate solution for mechanical improvements is a very late total joint replacement (TJR). The objective of the present study is to analyse the importance of the geometry of the fossa component with respect to the load transfer.MethodsTwo finite element models were analysed, a Christensen standard fossa component and a custom-made fossa component, using the same commercial condyle geometry and screw fixation. The biomechanical behaviour of components was analysed only for a 5 mm mouth aperture in incisive teeth.ResultsGeometry was seen to influence strain distribution in the condyle and the fossa. Maximum strain was observed in the screw fixation in the cranium around screws for the Christensen and for the custom-made fossa but in other position. The fossa component has some rotation in commercial models, but both components revealed lower potential for bone integration with maximum micromovements of around 40 μm.ConclusionThe study demonstrates the importance of the geometry of the fossa component as it changes the load transfer in the mandibular condyle and the strain distribution near the screws. The screw positions in the fossa component are influenced by the fossa geometry.     

Relationship Between Habitual Occlusal Position and Flat Bite Plane Induced Occlusal Position in Volunteers With and Without Temporomandibular Joint Sounds

Abstract

The aim of this study was to assess whether temporomandibular joint (TMJ) sounds are associated with the difference between the habitual occlusal position (HOP) and the bite plane induced occlusal position (BPOP). Fifteen dental technician school students who had complete natural dentition, normal occlusion and who exhibited TMJ sounds were compared with fifteen healthy control subjects. HOP was recorded by voluntary jaw closing while in an upright position, and BPOP was recorded after wearing an anterior bite plane for a short period of time. Three interocclusal records were obtained in both positions with a vinyl polysiloxane material, and the recorded maxillomandibular relations were analyzed three-dimensionally and compared. Subjects with TMJ sounds had statistically larger differences between HOP and BPOP than controls (p<.05). Within this study population, an association was found between TMJ sounds and the difference between HOP and BPOP.     

Morphological changes in the temporomandibular joint after orthodontic treatment for Angle Class II malocclusion

Objective: The aim of this study was to examine the morphological temporomandibular joint (TMJ) changes that occur after orthodontic treatment in patients with Angle Class II malocclusion.

Methods: The post-treatment changes in TMJ morphology were analyzed, based on TMJ cephalometric laminographs in 19 patients with Angle Class II malocclusion and labial inclination of the upper incisors after premolar extraction.

Results: The condylar pass angle, articular eminence to the Frankfort horizontal plane angle, and total, upper, and lower heights of the articular fossa increased significantly on both sides after treatment and retention. The anteroposterior width of the articular fossa decreased significantly on both sides after treatment and retention.

Discussion: These results suggest that adaptive bone remodeling of the TMJ occurs during the correction of occlusion with labial inclination of the upper incisors by orthodontic treatment after premolar extraction in patients with Angle Class II malocclusion.     

成人颞下颌关节骨关节病骨性改变与Helkimo指数的关系

目的: 应用锥形束CT（CBCT）研究成人颞下颌关节骨关节病临床症状、体征与关节区CBCT影像学改变之间的联系,为临床诊断提供参考。方法: 选取81例同时具有CBCT影像资料及临床检查记录资料的颞下颌关节骨关节病患者作为研究对象,应用Invivo 5 软件重建影像资料后进行颅面测量并记录。选定关节区图像后,记录颞下颌关节骨性改变,按Helkimo方法整理并记录临床检查结果,应用SPSS 22.0软件包对实验结果进行Spearman等级相关分析。结果: Helkimo指数与颞下颌关节骨关节病髁突骨质变化（P<0.01）及关节窝骨质改变相关（P<0.05）,但与颞下颌关节间隙改变不相关（P>0.05）。结论: 应用CBCT对颞下颌关节骨关节病关节区骨质改变进行观察（包括下颌骨髁突、关节窝骨质）,对临床诊断及判断疾病严重程度有一定指导意义,但是对颞下颌关节间隙改变无提示意义。     

Load transfer in Christensen® TMJ in alloplastic total joint replacement for two different mouth apertures

This study analyses load transfer in the fossa component based on two numerical models of total temporomandibular joint (TMJ) implants for two mouth openings. The TMJ articulation is a very complex system with muscles, ligaments and cartilage. Until now, studies of TMJ implants have analysed only condylar behaviour.The finite element models were constructed based on CT scans of a cadaveric mandible and cranium, considering the bone geometry and position. The influence of five principal muscle actions was simulated for two mouth positions, 5 mm and 15 mm openings at the incisive tooth support. Strain distributions into the surrounding bone tissue were analysed in both models in the condyle and fossa components.The results demonstrate that in Christensen^® TJR of the temporomandibular joint the fossa component is the more critical part, presenting more stress near the screw holes and contact regions with the cranium. The most critical region is around the first two screws and the least critical is in the condyle component.For the mandible condyle reconstructed with a Christensen^® prosthesis, the 15 mm mouth opening was more critical, as compression was increased, but for the fossa component the most critical situation occurred with the 5 mm opening. The micromovements observed suggest that the number of screws could be reduced to increase osteointegration of screws in the mandible condyle.     

Chondroblastoma of the Temporal Bone Involving the Temporomandibular Joint,Mandibular Condyle,and Middle Cranial Fossa: Case Report and Review of the Literature

Abstract

Chondroblastoma is a highly destructive tumor, derived from immature cartilage cells, typically occurring in epiphyses of the long bones of adolescents and young adults. Those occurring in the temporal bone and TMJ area are likely to mimic TMJ symptoms. This report describes a unique case in which a chondroblastoma resulted in extensive destruction of the temporal bone, temporomandibular joint, mandibular condyle, and cranial base, including gross intracranial and extracranial involvement. With appropriate surgical management, the outcome for patients with chondroblastoma of the temporomandibular region is quite favorable. This case brings the total reported chondroblastomas to 59 in the temporal bone and eight in the mandibular condyle as of the date of submission of this article for publication.     

Adolescent internal condylar resorption (AICR) of the temporomandibular joint,part 1: A review for diagnosis and treatment considerations

Background: Adolescent internal condylar resorption (AICR) is a temporomandibular joint (TMJ) pathology that develops predominately in teenage females during pubertal growth (onset between ages 11 and 15 years), with a distinct clinical, radiographic, and magnetic resonance imaging (MRI) presentation.

Clinical and imaging presentation: The condition usually occurs bilaterally with: (1) Progressive retrusion of the mandible; (2) High occlusal plane angle facial morphology; (3) Worsening Class II occlusion; and (4) TMJ symptoms such as pain, headaches, noises, etc. MRI imaging demonstrates decreased condylar head size and anterior disc displacement.

Treatment protocol: AICR can be successfully treated when the condyles and discs are salvageable with the following surgical protocol: (1) Removal of bilaminar tissue surrounding the condyle; (2) Reposition the disc with the Mitek anchor technique; and (3) Orthognathic surgery to advance the maxillo-mandibular complex in a counterclockwise direction.

Conclusion: AICR can be successfully treated using the specific protocol presented herein to provide stable and predictable outcomes.     

牙尖交错位紧咬时颞下颌关节接触特征及应力分布的三维有限元研究

目的研究正常人牙尖交错位紧咬时颞下颌关节的接触特征及应力分布情况。方法建立颞下颌关节三维有限元模型,在Marc软件中定义髁突、关节盘和关节窝三者间的接触关系,运用接触模式,采用自动探测的方法求解有限元分析软件。结果牙尖交错位紧咬时,关节盘后带与双板区的交界处和髁突的后斜面首先发生接触,随后髁突的顶部、内侧面与关节盘的后带,髁突的前斜面与关节盘的中间带也发生接触。同一矢状面上Von Mises应力平均值的大小依次为:髁突>关节盘腹面>关节盘背面>关节窝。结论Marc所提供的接触分析模块能较为真实地反映牙尖交错位紧咬时颞下颌关节的接触特征;颞下颌关节各结构通过相互接触及关节盘的缓冲使应力分散和传递,反映颞下颌关节各解剖结构与生理功能之间具有良好的适应性。     

血管化腓骨肌瓣下颌骨重建中髁突不同处理方法对颞下颌关节功能的影响评价

目的 对髁突采用不同处理方法的血管化腓骨肌瓣下颌骨缺损重建后评价患者的临床及颞下颌关节(TMJ)功能状态.方法 患者41例,其中男性21例,女性20例.41例均为累及下颌升支上部且未超过下颌中线的颌骨良性病损,其中应用腓骨替代髁突法重建24例、游离髁突法重建5例、保留髁突法重建12例.采用Fricton TMJ功能量表评价患者术后的TMJ功能,并进行统计学分析.结果 所有患者均未发生关节强直,术后最大开口度31～53 mm,平均值(42.8±5.7)mm.不同术式患者术后面部外形、进食及语音功能比较,差异无统计学意义(P＞0.05);但患者的TMJ功能指数,即功能障碍指数(dysfunction index,DI)及功能紊乱指数(cramiomandibular index,CMI)间比较,差异有统计学意义(P＜0.01).保留髁突组患者的TMJ功能优于腓骨替代髁突组.结论 保留髁突的血管化腓骨瓣下颌骨重建有助于恢复TMJ功能;以腓骨瓣末端替代髁突进行下颌骨重建时,重建髁突的位置和形态对于TMJ的功能有明显影响.     

前方牵引矫治器不同力值反作用力的三维有限元分析

目的：通过建立包含颞下颌关节的颅颌面三维有限元模型,模拟前方牵引矫治器反作用力的加力方式,分析其在颞下颌关节区、颌骨的应力分布情况以及对各部位节点位移的影响。方法：选择1名健康男性受试者,通过CT扫描得到颅颌面的二维图像数据,借助Mimics、Magics、MSC等专用软件,采用连续、均质、线性、各向同性的线弹性材料,建立包括颞下颌关节和上、下颌骨的颅颌面三维有限元模型。然后在此基础上,根据前方牵引装置的反作用力原理建立加力模型,即采用与平面成后上方37°的施力方向,于下颌最底部加载3~6 N的力值,采用ANSYS10.0有限元分析软件,测定颞下颌关节区、颌骨的应力分布情况以及各部分位移的变化,并对结果进行分析、归纳和整理。结果：在同一角度下,关节窝和髁突头、颈部应力随加载力的增大而增大,下颌最大应力出现在节点力加载部位颏部,上颌最大应力出现在刚性固定面。同时该模型出现微小的位移变化,颅颌面各部分位移随节点力的增大而增大,颅上颌位移由颅底部和平面向颅顶部逐渐减小,下颌骨的位移由前部到后部逐渐减小,并出现顺时针方向旋转。结论：前方牵引矫治器对颞下颌关节区及颌骨产生反作用力的影响,且随着加载力的增大,其产生的反作用力和形变随之增大。颏部可能出现变形,下颌顺时针方向旋转。     

Osseous changes of the mandibular condyle affect backward-rotation of the mandibular ramus in Angle Class II orthodontic patients with idiopathic condylar resorption of the temporomandibular joint

Objective: To evaluate whether osseous changes of the temporomandibular joint (TMJ) condyle affect backward rotation of the mandibular ramus in Angle Class II orthodontic patients with idiopathic condylar resorption (ICR).

Methods: Twenty Japanese women with Class II malocclusion with ICR (ICR group) and 24 women with Class II malocclusion without ICR (non-ICR group) were examined. Pre-treatment panoramic radiographs were used to measure condylar ratios. Pre-treatment lateral cephalograms were used to evaluate maxillofacial morphology.

Results: The ICR group had a significantly smaller condylar ratio, greater backward rotation of the ramus, less labially inclined upper incisors, and a steeper occlusal plane. The increased backward rotation of the ramus in the ICR group was significantly associated with a smaller condylar ratio.

Conclusion: Angle Class II patients with ICR had shorter condylar height attributable to osseous changes of the TMJ condyle, and the shorter condylar height may affect subsequent backward rotation of the ramus.     

Destructive psoriatic arthritis of the temporomandibular joint: a clinical case,an overview of the pathophysiology and its differential diagnoses

Abstract

Background Clinical assessments and uniplanar images in temporomandibular disorders are not always entirely reliable. This predicament is especially important when clinicians need to determine the nature of temporomandibular joint disease, particularly when clinical features are not helpful in determining the diagnosis.

Clinical presentation A 63-year-old female patient presented with mild pain in her right TMJ. During routine imaging exams, a destructive monoarticular arthritis was noticed, producing multiple erosions of the mandibular and temporal condyles. In addition, attrition of the ceiling of the glenoid fossa was observed, generating a communication with the endocranium. Only the presumptive biological behavior revealed on TMJ imaging and the appearance of the psoriatic plaques later during follow-up helped the authors to narrow the differential diagnosis.

Conclusion The clinical case presented illustrates the difficulties in diagnosing an erosive, seronegative TMJ destruction, suggestive of a systemic arthritis.     

颞下颌关节盘前移位患者关节骨形态与矢状向关节盘位置的关系

目的　利用磁共振成像（MRI）技术和锥形束CT（CBCT）分析颞下颌关节盘前移位患者矢状向关节盘位置与关节骨形态的关系。方法　对97例患者的178个颞下颌关节（TMJ）进行回顾性分析，根据矢状向MRI上关节盘的位置分成4组，即对照组（关节盘无移位）、轻度组（关节盘轻度前移位）、中度组（关节盘中度前移位）和重度组（关节盘重度前移位）。然后利用Mimics 20软件基于CBCT数据进行TMJ的相关形态学参数测量，包括髁突线性尺寸（宽度、长度和高度）、髁突体积和表面积，关节窝的深度和长度，关节结节倾斜角，关节前、上、后间隙等，并对各组矢状髁突位置进行评估。使用方差分析、非参数检验和卡方检验等比较关节形态及位置参数的组间差异，采用相关性分析探索矢状关节盘位置与关节测量参数之间的相关性。结果　髁突的线性尺寸、关节窝深度、关节倾斜角、关节间隙和矢状髁突位置分布在4组间差异有统计学意义，而关节窝长度在4组间差异没有统计学意义；相关性分析显示：髁突的线性尺寸、髁突的体积及表面积、关节窝的深度、关节结节倾斜角和关节上间隙与关节盘矢状位置之间存在显著负相关，而关节后间隙与矢状关节盘位置之间存在显著正相关。结论　TMJ骨形态与不同矢状关节盘位置之间存在相关性，应警惕临床看到的关节骨形态的退行性改变可能是患者存在关节盘前移位的标志。     

Treatment of a Case of Skeletal Class II Malocclusion with Temporomandibular Joint Disorder Using Miniscrew Anchorage

Abstract

At the present time, there are no reports in the literature on the treatment of temporomandibular joint disorder (TMD) by intrusion of molars using mini-screws. This case report describes the treatment for a female patient, aged 19 years seven months, with a TMD and an excessive lower anterior facial height. Overjet and overbite were +5.0 mm and +0.5 mm, respectively. The patient had a history of orthodontic treatment in which her first premolars were all extracted. During the first orthodontic treatment, a clockwise mandibular rotation was observed as a result of the increase of posterior dentoalveolar height. She had temporomandibular joint (TMJ) pain during mouth opening and complained of difficulty in eating due to masticatory dysfunction. The pretreatment Schüller views of both TMJ showed a posterior condyle position. In order to correct the overjet, molar relationship and the mandibular condyle position, a miniscrew was inserted into the palatal region of the upper first molar to intrude the upper posterior teeth. As the upper molars were intruded, the overjet was decreased, and a class I molar relationship was achieved by a counterclockwise mandibular rotation. After one year of treatment, an acceptable occlusion was achieved, and the condyle moved into centric position in the glenoid fossa. The patient’s teeth continued to be stable, and she had no pain in TMJ after a retention period of three years. The result of this treatment showed that molar intrusion using miniscrew anchorage is effective for treatment of a TMD patient with a posterior condyle position.