Association between condylar morphology and changes in bony microstructure and sub‐synovial inflammation in experimental temporomandibular joint arthritis

J Oral Pathol Med (2011) 40 : 111–120 Background: In juvenile idiopathic arthritis involvement of the temporomandibular joints (TMJs) is often associated with mandibular growth deviations. The relation between the growth deviations and severity of the inflammation, condylar shape, the micro‐architecture, and the quality of the bone has not previously been investigated. This paper studies the effect on the bony structures in mandibular condylar development in rabbits with antigen‐induced arthritis. Methods: Included were 42 juvenile rabbits with ovalbumin‐induced arthritis of the TMJs treated with intraarticular saline, intraarticular etanercept or subcutaneous etanercept. A TMJ from each animal was scanned using micro‐computed tomography and structural parameters were calculated. Three‐dimensional reconstructions of the mandibular condyle were scored blindly as normal or abnormal. TMJs were stratified for condylar morphology and were evaluated against data on trabecular structural parameters, inflammation, degree of mineralization, overall mandibular growth, and mineral apposition rate. Results: Abnormal morphology were seen in 15/32 animals available for data analysis. Erosions were an uncommon finding. Abnormal morphology was strongly related to the degree of inflammation. The trabecular separation was larger in group with abnormal morphology than in the group with normal morphology. Abnormal condylar morphology was not associated with overall mandibular growth. No differences were observed in mineral apposition rate. No differences in structural parameters were seen according to treatment modality. Conclusion: We showed that severe inflammation in the TMJs during mandibular development was associated with morphological changes in the mandibular condyle. These changes were predominantly seen at the macro‐morphological level and only very few differences were structural.     

Association between temporomandibular joint disc position evaluated by magnetic resonance imaging and mandibular condyle inclination evaluated by computed tomography

Temporomandibular joint disc displacement is common in the world's population and could be associated with bone and functional characteristics of the temporomandibular joint. The aim of these study was to analyse the association between temporomandibular joint disc position evaluated by magnetic resonance imaging (MRI) and the inclination of the mandibular condyle evaluated by computed tomography (CT). One hundred and seventy temporomandibular joints (TMJ) were retrospectively analysed. The temporomandibular disc position was evaluated by MRI and classified into three types: normal (N), disc displacement with reduction (DDWR) and disc displacement without reduction (DDWoR). The mandibular condyle measurements evaluated by CT included horizontal, sagittal and coronal inclination. ANOVA followed by post hoc Tukey's test was used to evaluate the interaction between condylar inclination and disc position. There was an association between disc position and the horizontal and sagittal condylar inclination (P < .05). There are statistically significant differences in the mean of horizontal and sagittal inclination of the mandibular condyle between the DDWoR and the other disc positions (P = .002 and P = .004). Disc position was not statistical associated with coronal inclination of condyle (P > .05). These results indicate that the inclination of the mandibular condyle may be different in TMJ with various disc position. A more medial horizontal inclination and a more posterior sagittal inclination of the mandibular condyle are associated with DDWoR.     

Natural course of severe temporomandibular joint osteoarthrosis evaluated by a novel condylar remodelling scoring system and quantitative volumetric analysis

Temporomandibular joint osteoarthrosis (TMJ-OA) frequently causes mild, moderate, or severe condylar morphological changes. A novel condylar remodelling scoring system (CRSS) based on three-dimensional cone beam computed tomography images is proposed, which is used to grade condylar morphological changes. In the CRSS, the condyle is divided into 10 regions by 11 reference points. For each increase in the number of regions involved in TMJ-OA, one point is subtracted from the full score of 10. The intra-class correlation coefficients for intra- and inter-observer agreement (range 0.656–0.898 and 0.841–0.906, respectively) indicated that the CRSS had good reliability. Cephalometric analysis showed that the condyles with severe morphological changes were prone to present with a retrognathic and clockwise rotating mandible, shorter ramus height, reduced mandibular length, larger mandibular angle, and maxillary retrusion. Qualitative CRSS evaluation and quantitative volumetric analysis were performed to evaluate the stability of severe TMJ-OA in its natural course (343 condyles). The continuous cortex group showed no remarkable changes with an average follow-up of 2 years. In the discontinuous cortex group, most (74.4%) converted into a continuous cortex during follow-up (mean 2 years).     

髁突囊内骨折与创伤性颞下颌关节强直的研究进展

颢下颌关节强直(TMJA)是口腔颌面外科的一种常见疾病,严重影响患者的面部形态和功能,创伤是其主要发病因素.目前,有关创伤性TMJA的确切发病因素和形成机制尚不完全清楚.研究表明,髁突囊内骨折与之关系密切,特别是当骨折明显移位合并关节面严重损伤、关节盘移位以及下颌骨宽度增加和活动度减小等因素时,更加好发.下面就近年来对髁突囊内骨折与创伤性1MJA的流行病学、囊内骨折的生物力学研究和分类、动物试验和临床研究作一综述.     

Computed tomography of the normal temporomandibular joint

Abstract – A study was made in two parts, retrospective (I) and prospective (II), on two samples of 36 and 17 individuals, respectively, who had temporal bone CT studies for reasons unrelated to TMJ pain and dysfunction. Groups I and II had no radiographic signs of TMJ disease and Group II had neither radiographic nor clinical signs of TMJ disease. Both groups were considered to have normal joints. Joint morphometrics for the two groups (I/II) were as follows; transverse condylar dimensions were 18.5/18.1 mm. Condylar angulation averaged 24°/25° and intercondylar distance averaged 83/83 mm while extra condylar distance averaged 118/118 mm. The condyle in the sagittal plane showed a smooth and rounded form with anterior-superior joint space averaging 1.9/1.7 mm while the central-superior joint space averaged 2.3/2.2 mm. The medial-horizontal joint space averaged 3.9/3.7 mm. The slope of the central portion of the articular eminence averaged 60°/60° in the sagittal plane.     

76例颞下颌关节紊乱病患者许氏位片中髁突位置的分析

目的通过颞下颌关节紊乱病(TMD)患者的许氏位片来分析患者的髁突位置变化。方法选取76例TMD患者为研究对象,男性30例,女性46例,年龄为17～53岁。采用Cohlmia法对76例患者的双侧颞下颌关节(TMJ)的牙尖交错位标准许氏位片进行测量分析。结果76例TMD患者左侧颞下颌关节的PO1(反映髁突矢状向位置)平均值为1.220±0.422,PO2(反映髁突垂直向位置)平均值为0.386±0.085,右侧颞下颌关节的PO1平均值为1.119±0.386,PO2平均值为0.397±0.098,左、右侧髁突位置及关节窝形态的差异均无统计学意义(P>0.05)。结论在颞下颌关节紊乱病患者的许氏位片中,髁突位置变化不明显,诊断意义不大。     

颞下颌关节髁突囊样变的锥形束CT影像特点

目的 利用口腔颌面锥形束CT观察髁突囊样变的影像学表现,探讨囊样变的影像特点并加以分类。方法 收集颞下颌关节锥形束CT影像学表现有囊样变的194例患者,观察并记录囊样变的部位、大小、数量、边缘骨白线、周围骨小梁结构、髁突整体骨质情况。根据髁突整体骨质情况,将髁突囊样变分为Ⅰ型和Ⅱ型,比较其发生的部位、数量、边缘骨白线以及周围骨小梁结构情况。结果 194例患者的198侧关节发现囊样变表现,94例位于左侧关节,96例位于右侧关节,4例位于双侧关节。50.0%（99侧）的囊样变位于髁突前外侧皮质骨下方;囊样变直径最小1.2 mm,最大13.5 mm,平均（3.4±1.5）mm;75.3%（149侧）为单发囊样变;62.6%（124侧）存在完整的骨白线包绕;80.8%（160侧）周围骨小梁结构有骨质硬化。66.7%（132侧）囊样变髁突表现有晚期骨关节病征象,5.1%（10侧）囊样变髁突表现有早期骨关节病征象,28.3%（56侧）髁突除囊样变外无其他明显骨质改变。Ⅰ型和Ⅱ型髁突囊样变在发生部位、数量和周围骨小梁结构方面存在差异,Ⅰ型髁突囊样变较多发和骨质硬化,Ⅱ型髁突囊样变发生于髁突内部或髁突颈部较多。结论 Ⅰ型和Ⅱ型髁突囊样变在发生部位、数量和周围骨小梁结构存在不同,这可能与其病因及形成机制不同有关。     

超声在颞下颌关节功能评价中的应用

颞下颌关节的功能状态关系到口腔颌面外科、正畸科和修复科等的治疗成败,超声作为颞下颌关节功能评价的一种新兴手段,以其无损伤性、经济、有效等特点得到了越来越广泛的应用。下面就超声在颞下颌关节盘位置检查、髁突运动轨迹和颞下颌关节音检测等方面的作用作一综述。     

Sonographic evaluation of the ranges of condylar translation and of temporomandibular joint space as well as first comparison with symptomatic joints

AIM: To assess the normal ranges of condylar translation and width of the lateral temporomandibular joint (TMJ) of a healthy population by sonography and permit comparison of findings made in individual patients using this norm. PATIENTS AND METHOD: Fifty non-orthodontically treated, asymptomatic volunteers (100 joints) were subdivided by Angle classes (I = 20, II = 15, III = 15) and evaluated. Reliability was assessed in 15 of those volunteers. The validity was checked in 8 more patients with temporomandibular dysfunction (TMD), all class II with disc dislocation diagnosed by means of MRI. Sonographic assessment of condylar translation from centric occlusion to maximum opening and during protrusion and mediotrusion was performed with a probe positioned parallel to the zygomatic arch. RESULTS: Translation during opening was 12.7+/-3.2 mm in class I, 12.9+/-3.3 mm in class II and 10.9+/-3.6 mm in class III. Protrusive translation was 7.4+/-2.5 mm/10.3+/-4.4 mm/6.8+/-2.1mm, respectively; and mediotrusive translation was 7.9+/-2.6 mm/10.8+/-3.4 mm/6.7+/-2.4 mm, respectively. Class II had longer and class III shorter condylar translations. The lateral joint space in occlusion and protrusion was wider in class II than in classes I and III. Symptomatic patients had shorter condylar translations than asymptomatic volunteers. CONCLUSION: Patients with class II had a more anteroposterior mobility, class III shorter translation. Significant sonographic differences of condylar translation from the norm did not correspond with clinical findings. This demonstrates the higher sensitivity of sonography for the evaluation of individual condylar translation. It is a sensitive tool for assessing joint function.     

再定位(牙合)垫戴入前后颞下颌关节盘和髁突的位置改变

目的测量再定位牙合垫（ARS）戴入前后关节盘和髁突的位置改变,探讨ARS的治疗机制。方法选择22例单侧或双侧可复性颞下颌关节盘前移位患者进行研究,其中关节盘前移位的关节31侧,设为前移位组;关节盘位置正常的关节13侧,设为正常组。分别在闭口位（ARS戴入前）、对刃位和下颌最少前伸位（ARS戴入后）行磁共振成像扫描,测量不同下颌位置时的2组关节的盘突角度、关节盘和髁突位置的变化。结果1）盘突角度：闭口位时前移位组为54.23°,正常组为9.80°;对刃位和下颌最少前伸位时,前移位组的盘突角度多可回复至正常范围。2）关节盘位置：从闭口位至对刃位或下颌最少前伸位,正常组关节盘位置无明显改变,前移位组关节盘明显向后移动。3）髁突位置：从闭口位至对刃位或下颌最少前伸位,髁突在关节窝中向前下方移动,正常组与前移位组比较的差异无统计学意义（P＞0.05）。结论ARS使髁突向前下方移动,关节盘向后回复。ARS的作用可能是阻止已经向后上方移动而复位的关节盘在闭口过程中再次发生前移位,起到固定作用。     

Micro X-ray computed tomography analysis for the evaluation of asymmetrical condylar growth in the rat

Authors– Nakano H, Watahiki J, Kubota M, Maki K, Shibasaki Y, Hatcher D, Miller AJ Objectives – To investigate the influence of forced lateral bite on mandibular growth, micro X‐ray computed tomography (CT) was used for the purpose evaluating condylar cartilage and cancellous bone formation in 10 male Wister rats (3 weeks of age). Settings and sample population – The rats were divided into two groups – experimental and control. In experimental group, an inclined crown was cemented onto the maxillary incisors to produce 2.5 mm shift toward the left side during mastication. Right–left differences in whole mandibular length, mandibular height, condylar size, trabecular structure of the condylar head and three‐dimensional (3‐D) finite element analysis were assessed using 3‐D images reconstructed from micro X‐ray CT scans when the mice had reached 21 weeks. Measurements and Results – Asymmetrical growth was found in the experimental group, in which the left condylar head became thicker and shorter than the right condylar head during development. When comparing the left and right condyles of the experimental animals, histomorphometric analysis from micro X‐ray CT showed that the bone volume (BV) of the cancellous bone, the surface area of the cancellous bone (BS), the BS/BV ratio, the BV fraction (BV/TV), and the trabecular thickness and trabecular number were less for the right condyle than for the left condyle. Conclusions – These findings suggested that artificial changes in the mastication do influence the growth of condylar head, condylar bone trabecular structure, and mineralization.     

计算机辅助外科技术在颞下颌关节疾病治疗中的应用

计算机辅助外科技术已经在口腔颌面外科诸领域（如创伤重建、正颌外科、头颈部肿瘤的切除与重建等）得到广泛应用。其在颞下颌关节疾病治疗中的应用近年来也有很大的发展,例如在颞下颌关节强直骨球的截除、髁突骨折的固定及髁突良恶性肿瘤的切除等方面。本文就此部分内容做一综述。     

Chondrocyte clusters in the condylar cartilage of an ankylosed temporomandibular joint

A complete condyle specimen from a female patient who had temporomandibular joint (TMJ) ankylosis and associated craniofacial deformities was obtained. Abundant chondrocyte clusters were found in the remaining cartilage of the enlarged condyle. The implications of the clusters in this patient are discussed.     

颞下颌关节骨关节病不同分期的锥形束CT三维位置比较

目的 探讨颞下颌关节骨关节病（TMJOA）患者在不同骨关节病分期髁突三维影像学特征的差异。方法 以2005年马绪臣等提出的骨关节病X线表现分期为标准,将108例TMJOA患者（骨关节病组）的锥形束CT（CBCT）检查结果分为4期,对照组为28例仅存在间隙改变的颞下颌关节紊乱病患者;评价TMJOA CBCT征象不同分期时髁突的矢状面位置,并对2组的髁突水平角进行比较。结果 TMJOA不同分期髁突矢状面位置无统计学差异,但髁突水平角有统计学差异（F=3.872,P=0.005）,进一步两两分析表明,第1期髁突水平角低于第2和3期（P=0.027,P= 0.000）;第2期对照组髁突水平角低于第3期（P=0.004,P=0.047）。结论 TMJOA患者在不同分期时髁突矢状面位置差异不明显,但髁突水平角存在差异,该角度的变化对TMJOA的分期有一定提示意义。     

Assessment of osseous morphology of temporomandibular joint in asymptomatic participants with chewing‐side preference

Chewing‐side preference (CSP) may be associated with temporomandibular disorders. However, little information exists regarding whether CSP will lead to osseous changes of temporomandibular joint (TMJ) in asymptomatic participants. The aim of this study was to investigate the relationship between osseous morphology of TMJ in asymptomatic participants with CSP and without CSP. Of the 121 healthy dentate participants, 35 participants with left CSP, 38 with right CSP and other 48 without CSP were scanned by cone‐beam computed tomography. The dimensions of the reconstructed images of opposing TMJs were compared. Statistical analyses were performed using spss 16.0 software. The results showed that there were no significant differences between the dimensions of bilateral structures of the TMJ (P1 > 0·05) in participants without CSP. However, the posterior–superior, posterior and lateral joint space of the preferred side were smaller than that of the unpreferred side in participants with CSP (P2 < 0·01) and bilateral TMJ in participants without CSP (P3 < 0·01). In addition, width of condylar neck of the unpreferred side both in sagittal and perpendicular to the long axis of condyle views was greater than that of the preferred side in participants with CSP (P2 < 0·01) and bilateral TMJ of participants without CSP (P4 < 0·01). Also, the inclination of articular eminence of the preferred side in view perpendicular to the long axis of condyle was less than that of the unpreferred side (P2 < 0·05). These findings suggest CSP affects osseous morphology of TMJ in asymptomatic participants.     

Radiographic study of articular remodeling in the temporomandibular joint after condylar fractures

abstract — A radiographic follow-up of the temporomandibular joints in patients with condylar fractures revealed a frequent remodeling both of the condylar head and the glenoid fossa. A double contour of the fossa was the typical radiographic sign of remodeling. The occurrence of double contours was associated with displacement of the condylar head.     

Observation of three cases of temporomandibular joint osteoarthritis and mandibular morphology during adolescence using helical CT

Temporomandibular joint (TMJ) osteoarthritis (OA) is a potential cause of craniofacial deformity. If TMJ OA appears during orthodontic treatment, the mandible usually rotates posteriorly, resulting in an unsatisfactory profile, especially in patients with pre-treatment mandibular retrusion. Although it is important to confirm the kind of TMJ pathosis at the start of orthodontic treatment, the relationship between TMJ OA, condylar remodelling and changes in craniofacial morphology remains unclear because of a lack of longitudinal studies. Elucidating this relationship might allow better prediction of post-treatment craniofacial morphology. In the present case reports, helical computed tomography and cephalometry were used to analyse relationships between the pattern and location of condylar remodelling and the changes in craniofacial morphology in three patients with TMJ OA.