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外伤是颞下颌关节强直最主要的病因,但髁突骨折与外伤性关节强直的关系一直存在争议。有研究表明,髁突囊内骨折可引起关节软骨损伤、关节盘移位或破损、关节积血,继发关节纤维化以及骨化,最终导致关节强直。本文从临床和实验角度探讨了髁突骨折与颞下颌关节强直的关系。     

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。     

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.     

Association between hypoplastic condyles and temporomandibular joint disc displacements: a cone beam computed tomography and magnetic resonance imaging metrical analysis

This study investigated the association between hypoplastic condyles and disc displacements without reduction (DDw/oR). Consecutive patients with non-syndromic unilateral condylar hypoplasia were recruited and clinical, cone beam computed tomography (CBCT) and magnetic resonance imaging (MRI) data were acquired. Linear measurements including condylar head width, depth, height and condyle length were determined with CBCT while MRI was used to assess disc position, morphology and displacement. A total of 43 patients were enrolled of which 93.02% had a history of temporomandibular disorders (TMDs) and 83.72% presented with TMD signs and symptoms. Depth and height of the condylar head along with condyle length of hypoplastic joints (6.68 ± 1.67 mm, 4.97 ± 1.25 mm and 14.49 ± 3.02 mm, respectively) were significantly lesser than normal joints (7.77 ± 1.26 mm, 6.35 ± 1.45 mm and 18.20 ± 3.18 mm) (P < 0.001). The prevalence of DDw/oR was significantly higher in hypoplastic joints (79.07% versus 13.95%) (P < 0.001). Joints with hypoplastic condyles had shorter disc lengths (6.99 ± 2.16 mm vs, 8.45 ± 2.26 mm) (P = 0.007). Furthermore, disc displacements were significantly more advanced (8.52 ± 2.84 mm) and severe (76.74% with severe translations) when compared to the contralateral side (4.77 ± 2.97 mm and 32.56%) (P < 0.05). A significant association was observed between condylar hypoplasia and temporomandibular joint DDw/oR with hypoplastic joints exhibiting more severely displaced and deformed discs. DDw/oR coupled with repaired degenerative joint disease may mimic condylar hypoplasia radiographically.     

Association between condylar position, joint morphology and craniofacial morphology in orthodontic patients without temporomandibular joint disorders

The present study investigated condylar position and joint morphology in adolescent patients and elucidated the possible association between the joint structure and condylar position, and craniofacial morphology. Sixty-five adolescent patients were selected as subjects and their tomograms and lateral cephalograms were analysed. No significant differences in joint spaces were found between the right and left temporomandibular joints. Both the condyles in this population were located slight anteriorly in the glenoid fossa. With respect to the association between condylar position, joint morphology and craniofacial morphology, the ramus plane angle also exhibited significant negative correlations with posterior, lateral and medial joint spaces. Furthermore, there was a significant negative correlation between the gonial angle and the anterior joint space. These findings imply that the condyle was likely to show more posterior position in the glenoid fossa when the mandible exhibited clockwise rotation. In conclusion, the condyle in the adolescent subjects showed a symmetrical anterior position relative to the glenoid fossa. In addition, the joint spaces and it ratios were significantly related to the craniofacial morphology associated with vertical dimension. It is suggested that the condylar position may be affected by craniofacial growth pattern.     

Clinical investigation of early post-traumatic temporomandibular joint ankylosis and the role of repositioning discs in treatment

This study investigated the development of temporomandibular joint (TMJ) ankylosis after condylar fracture and the functional results of surgery that included repositioning of the articular discs. In a total of 18 patients, there were 13 cases of fibrous ankylosis (type I) and 11 of partial bony ankylosis (type II). CT scans for both groups and MRI scans for type I patients were analysed. Intraoperative inspection of the damaged disc, the sites of adhesion or bony fusion, and remaining intra-articular movement was recorded. After release arthroplasty and repositioning of discs, follow-up was for 1 to 3.5 years (mean 2.2 years). Post-traumatic TMJ ankylosis was highly associated with sagittal and comminuted condylar fractures. Type I ankylosis usually formed in the 4th to 5th month post-trauma with mean interincisal opening distance of 18.3+/-5.5mm. Progression from type I to II ankylosis occurred 1 year post-trauma and caused a reduction of 5mm in the range of mouth opening. The disc was displaced for each of the involved joints, and intra-articular adhesions or ossification initiated at the site where there was no intervening disc present. After surgical repositioning of the disc, stable joint function and mouth opening from 30 to 45 mm were obtained in all patients but one (recurrence due to dislocation). Sagittal and comminuted condylar fractures predispose the TMJ to ankylosis, and the displacement of the articular disc plays a critical role. Early surgical intervention to reposition the disc was successful for early trauma-induced TMJ ankylosis.     

髁突矢状骨折手术中关节盘复位的应用

目的 探讨髁突囊内骨折开放手术中关节盘复位及固定方法的选择及疗效评判。方法 选择因髁突骨折接受手术治疗,且随访期超过6个月的36例患者为研究对象,骨折类型以髁突矢状骨折为主;术中采用长螺钉内固定,依据关节盘移位及损伤程度分别对关节盘采用缝合法（22侧）及锚固法（14侧）进行复位。术后1、3、6个月及1年进行随访,选择手术前及手术后6个月为时间点详细记录Fricton颞下颌关节紊乱指数（CMI）相关的各项指标,从临床和颞下颌关节（TMJ）功能两方面评估术后恢复情况。结果 两组患者术后TMJ功能改善,CMI分别从治疗前的0.213±0.162和0.273±0.154下降到0.059±0.072和0.064±0.068（P<0.05）。两组不同关节盘复位及固定方法之间比较,CMI、肌肉压痛指数和TMJ功能障碍指数差异无统计学意义（P>0.05）。结论 2种方法处理关节盘均可以有效地改善创伤导致的TMJ功能障碍,关节盘复位及固定方法的选择以关节盘移位及损伤程度作为参考。     

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.     

渐进性咬合紊乱对大鼠髁突软骨肿瘤坏死因子-α表达的影响

目的探讨渐进性咬合紊乱对大鼠髁突软骨中肿瘤坏死因子- α（TNF- α）表达的影响。方法48只8周龄大鼠，随机分为实验组和对照组各4个时间点，雌雄各半，每组3只。以皮筋弹性力推右侧下颌、左侧上颌第一磨牙近中移动，4周后同样方式推右侧下颌、左侧上颌第三磨牙远中移动，造成渐进性咬合紊乱动物模型，实验2、4、6、8周后处死动物。苏木精- 伊红染色观察髁突软骨组织学变化及软骨厚度变化，免疫组织化学方法检测和阳性细胞面积百分比法分析髁突软骨中TNF- α的表达特点。结果实验4、6、8周组髁突软骨均较对照组增厚（P<0.05），实验组出现以无菌坏死为主的软骨退行性变。TNF- α主要集中表达于髁突软骨的肥大层，实验2、6、8周组表达高于同龄对照组（P<0.05），实验4周组与同龄对照组之间无差异（P>0.05），雌雄变化趋势基本相同。结论TNF- α参与了异常咬合所导致的髁突软骨病理性改建活动，随时间延长，咬合紊乱较重者，髁突软骨的分解代谢活动更加明显。     

Synovial fluid dynamics with small disc perforation in temporomandibular joint

Summary The articular disc plays an important role as a stress absorber in joint movement, resulting in stress reduction and redistribution in the temporomandibular joint (TMJ). The flow of synovial fluid in the TMJ may follow a regular pattern during movement of the jaw. We hypothesised that the regular pattern is disrupted when the TMJ disc is perforated. By computed tomography arthrography, we studied the upper TMJ compartment in patients with small disc perforation during jaw opening–closing at positions from 0 to 3 cm. Finite element fluid dynamic modelling was accomplished to analyse the pattern of fluid flow and pressure distribution during the movements. The results showed that the fluid flow in the upper compartment generally formed an anticlockwise circulation but with local vortexes with the jaw opening up to 2 cm. However, when the jaw opening–closing reached 3 cm, an abnormal flow field and the fluid pressure change associated with the perforation may increase the risk of perforation expansion or rupture and is unfavourable for self‐repair of the perforated disc.     

Age-associated changes in viscoelastic properties of the bovine temporomandibular joint disc

To test the hypothesis that compressive properties of the temporomandibular joint (TMJ) disc change with age, we investigated its viscoelastic properties and stress-relaxation behavior under compression. Compressive stress-relaxation tests were performed in different regions of bovine discs of various ages. For each disc, specimens were derived from three different regions (anterior, central, and posterior). For four strain levels (5, 10, 15, and 20%), a stress-relaxation test was conducted over a 5-min period. Values of the instantaneous modulus, E(0), appeared to be larger in the anterior than in the posterior region of the disc, irrespective of age. The E(0) value increased with age, especially in the central region. Values of the relaxed modulus, E(R), also increased significantly with age. There were no regional differences in values of the relaxed modulus. Under stress-relaxation, the relaxation time became longer with age, especially in the posterior region. The results suggest that the compressive properties, instantaneous and relaxed moduli, increase with age, while the relaxation time becomes longer. This implies that the TMJ disc becomes harder with age. Furthermore, the compressive properties of the TMJ disc are region-specific. As a result of the harder disc, it is likely that the TMJ becomes more vulnerable to secondary damage, such as fracture and tissue degradation.     

A histomorphometric and scanning electron microscopy study of human condylar cartilage and bone tissue changes in relation to age

Human condylar cartilage and bone were examined in an autopsy material comprising 20 individuals aged 18–31 years. Histomorphometry (trabecular bone volume and marrow space star volume), scanning electron microscopy and cartilage histology were used to analyse the tissue. Slight, but statistically significant, age-related reductions were found in the thickness of the condylar cartilage and in trabecular volume of the underlying bone tissue. Furthermore, quantitative and qualitative investigations of the turnover activity in the fibrocartilage and the bone tissue, describing the activity of hypertrophic chondrocytes and the trabecular bone tissue demonstrated condylar growth potential in the below 30 years age group. However, the growth activity seemed to decline with age. Although it is expected that there is a decline in growth potential in female condylar cartilage earlier than in the male counterpart, based on other clinical findings, this study does not include enough female samples to conclude that sex-related differences exist. The growth in the condylar tissue was found to be symmetrical (left/right condyle) regarding hypertrophic chondrocytes in the cartilage and trabecular bone volume but not with regard to bone microstructure.     

兔下颌骨髁突软骨年龄相关性改变的组织学研究

目的 探讨不同年龄段兔下颌骨髁突软骨的生理特征变化。方法 选取1、4、12和32周龄健康雌性新西兰大白兔各3只,脱钙处理后进行5 μm 连续切片,苏木精-伊红染色。分别对关节盘所覆盖的髁突表面纤维软骨区域软骨各层厚度进行测量分析。采用SPSS19.0软件包对数据进行统计学处理。结果 髁突软骨全层（P=0.008）、成熟层（P=0.008）和肥大层（P=0.007）在1周和4周组间厚度显著下降,在4~32周内厚度变化不明显。连续各组之间纤维层和增殖层厚度无显著改变;32周组纤维层厚度显著高于1周组（P=0.024）。结论 兔髁突软骨全层、成熟层和肥大层在1~4周内明显变薄,成骨活性大于成软骨活性,为下颌骨生长发育的重要阶段;在4~32周内各层厚度改变不明显,成骨和成软骨活性相对平衡。成年期髁突适应和耐受关节腔微环境变化的能力可能较强。     

Discal attachments of the human temporomandibular joint

BACKGROUND: Despite its clinical significance, the anatomy of the human temporomandibular joint (TMJ) and its relationship to the lateral pterygoid muscle remains poorly described and often misrepresented in standard texts. The aim of this study was to describe how the anterior and posterior attachments of the TMJ disc vary between lateral, central and medial regions of the joint. METHODS: Ten left TMJs were removed en bloc from cadavers and serial sections were made at 3-4mm intervals. Observations were made to ascertain the anterior and posterior attachments of the disc and the joint structures were traced from standardized photographs. RESULTS: Laterally, the capsule and lateral discal ligament merged prior to their attachment at the condylar pole. Medially, muscle fibres, capsule and the disc converged on the medial pole of the condyle. There was no evidence that fibres of the upper head of the lateral pterygoid muscle inserted directly into the disc. The upper head inserted into the condyle either directly at the pterygoid fovea or via a central tendon or indirectly via the capsule. Posteriorly, the superior part of the posterior attachment of the disc attached to the cartilaginous meatus and tympanic part of the temporal bone. The inferior part of the posterior attachment of the disc attached to the posterior surface of the condyle. In four joints, this attachment was folded beneath the posterior band of the disc, creating a wedge-shaped flap that ran medio-laterally. CONCLUSION: This study is in broad agreement with other anatomical TMJ studies but there are two main points of difference. Firstly, a true muscle insertion of the superior head of the lateral pterygoid muscle to the disc was not observed. Secondly, a wedge-shaped flap of retrodiscal tissue was identified between the condyle and the disc.     

Lubricin immunohistochemical expression in human temporomandibular joint disc with internal derangement

J Oral Pathol Med (2011) 40 : 587–592 Lubricin is a chondroprotective, mucinous glycoprotein which contribute to joint lubrication, especially to boundary lubrication and maintains joint integrity. The present investigation aimed to study the immunolocalization of lubricin in TMJ discs from patients affected by anterior disc displacement with reduction (ADDwR) ADDwoR. Eighteen TMJ displaced disc affected by ADDwoR were processed immunohistochemically, with a polyclonal anti‐lubricin antibody, used at 1:50 working dilution. The percentage of lubricin immunopositive cells (extent score = ES) and the extent of lubricin staining of the disc extracellular matrix (ECM), were evaluated. Each sample was scored for histopathological changes. Percentage of immunostained surface disc cells was the same (ES = 4) in both control and ADDwOR cells, being this data not statistically significant (P < 0.05). In pathological specimens the percentages of lubricin‐stained cells was very high with an ES of 4 respect to control specimen, and this difference was statistically significant different (P > 0.05). The extracellular matrix (ECM) of discs at the disc surfaces of both pathological and normal specimens was very heavily stained (++++). Both the ES and ECM staining were not statistically correlated to the TMJ degeneration score according to the Spearman’s rank correlation coefficient. According to our findings, a longstanding TMJ disc injury, affects lubricin expression in the TMJ disc tissue and not its surfaces, moreover, lubricin immunostaining is not correlated to TMJ disc histopathological changes.     

Ultrastructural study of synovitis induced by trauma to the rat temporomandibular joint (TMJ)

BACKGROUND: Electron microscopy was used to examine the histologic effect of trauma on the rat temporomandibular joint synovial membrane. METHODS: Trauma to the TMJ in male Wister rats (100-200 g) was introduced through repeated forced condylar hypermobility. Ultrastructural observations were made 5 days and 6 weeks after the trauma. RESULTS: The early response of the synovial membrane was synovial hyperplasia, type A synovial cell loss, dilation of the r-ER in the type B synovial cells and fibrin deposition on the synovial surfaces. The late response included degeneration of synovial cells with swollen mitochondria and cell projections, and cell fragmentation. Large amount of fibrin deposition on opposing surface layers was also noticed. CONCLUSION: The type A cell loss and fibrin deposition followed by the occurrence of fibrinous materials at opposing surface layers of the synovial membrane suggest that traumatic synovitis causes synovial adhesions.