The importance of multisection sagittal and coronal magnetic resonance imaging evaluation in the assessment of temporomandibular joint disc position

Clinical Oral Investigations - The aim of this study was to evaluate diagnoses of temporomandibular (TMJ) disc displacement by comparing evaluations done on the basis of central sagittal scans...     

Pathologic evaluation of disc dysfunction and osseous abnormalities of the temporomandibular joint

The arthrographic findings in 141 patients with TMJ symptoms were compared with the linear tomographic evaluation to assess the incidence and severity of associated osseous abnormalities. Thirty-nine temporomandibular joints (28%) had significant osseous abnormalities compatible with degenerative joint disease. The incidence and severity of the degenerative changes compared favorably with the arthrographic assessment of the degree of soft-tissue injury. A cause-and-effect relationship between TMJ disc damage and dysfunction and degenerative arthritis is suggested.     

Relationship between temporomandibular joint disc position and configuration on magnetic resonance imaging

Magnetic resonance imaging (MRI) of the temporomandibular joint (TMJ) has been shown to be of great value in the detection of displacements and delineation of the disc configuration in patients suspected of having internal derangements. The present study was conducted in temporomandibular joints of 144 patients in order to investigate whether an association exists between disc position, disc reduction and disc configuration as seen on MRI. Sagittal proton density-weighted MRIs of 288 TMJs (144 patients) were taken with the mouth closed and opened, and the position and configuration of the articular disc were assessed. The results showed that joints with a superior disc position barely demonstrated disc deformation while in joints with anteriorly displaced dises, disc deformation occurred more frequently (p<0.001). Non-reduction of the disc was associated with disc deformation whereas disc reduction was associated with the normal biconcave disc configuration (p<0.001). These data suggest that an association exists between disc displacement and disc deformation and between disc deformation and the degree of anterior disc displacement.     

The evaluation of temporomandibular joint disc position in TMJ disorders using MRI

The purpose of this study was to correlate disc position and the type of disc displacement, intra-capsular effusion and degenerative changes of the condyle as demonstrated in MRI studies. In this study, 126 temporomandibular joints (TMJs) of 63 patients with TMJ disorders were investigated using clinical examination and MRI. One hundred and twelve TMJs were found to have internal derangement as disc displacement. The angle between the posterior margin of the disc and the vertical line drawn through the centre of the condyle was measured on MRI for each TMJ. The positions of the discs were normal, 0 degrees-10 degrees, in 11.11%; slightly displaced, 11 degrees-30 degrees, in 37.30%; mildly displaced 31 degrees-50 degrees, in 15.08%; moderately displaced, 51 degrees-80 degrees, in 7.14% of the TMJs with anterior displacement with reduction (ADDR). The disc position was severely displaced anteriorly, as over 80 degrees, in all TMJs with anterior disc displacement without reduction (ADD), constituting 27.78% of all cases. We found that the smaller the degree of disc displacement the milder the internal derangement and that the intra-capsular effusion was more frequently associated with TMJ with ADDR. The degenerative condylar changes were more severe with an increased degree of anterior disc displacement.     

无症状志愿者颞下颌关节盘位置的磁共振观察

目的 通过磁共振成像了解无症状志愿者颞下颌关节关节盘位置的类型及其与年龄和性别的关系.方法 100名无症状志愿者分5组(11岁～、21岁～、31岁～、41岁～、51～60岁),每组男女各10名;利用Siemens Trio Tim 3.0 T磁共振扫描系统对双侧颞下颌关节进行开闭口斜矢状位扫描,共200侧关节;对每侧关节中间层及其相邻内、外各一层磁共振图像进行视觉诊断.结果 100名无症状志愿者中59名(59.0%)双侧关节盘位置正常.关节盘位置正常、关节盘前移位和隐匿性前移位的关节侧数分别为140侧(70.0%)、14侧(7.0%)和46侧(23.0%),在5个年龄组及不同性别之间的分布比较,差异均无统计学意义(P＞0.05).受试者最大开口度平均为(46.3±5.5)mm,不同关节盘位置的受试者间最大开门度比较,差异无统计学意义(P＞0.05).结论 在无症状志愿者中颢下颌关节盘移位确实存在,其分布与年龄和性别无关;盘移位以隐匿性前移位为主;关节盘移位的影像学表现与临床症状之间不存在确定的相关关系.     

改良切口关节盘锚固术治疗颞下颌关节盘不可复性前移位的临床评价

目的: 评价应用改良切口关节盘锚固术治疗颞下颌关节盘不可复性前移位的临床疗效。方法: 选取2014年9月—2016年9月我院颞下颌关节专科就诊的24例（30侧）颞下颌关节紊乱病患者,采用改良切口颞下颌关节盘锚固术进行治疗, 分析术前、术后6个月不同时期患者的疼痛值、开口度的变化及MRI影像学表现,采用SPSS17.0软件包中的t检验评价手术效果。结果: 治疗前平均开口度为（23.63±3.31）mm(17~29 mm),治疗后平均开口度为（38.00±2.30）mm(32~42 mm),治疗后开口度≥35 mm 的患者占 87.5%（21/24）;疼痛直观模拟标尺（visual analogue scale,VAS）值术前为29.76±23.35（0~80）,术后6个月为3.71±7.91（0~50）,术后6个月的开口度及VAS值均与治疗前有显著差异（P<0.05）。MRI影像学评价有效率达96.67%（29/30侧）,所有病例均无并发症发生。结论: 颞下颌关节盘锚固术能有效治疗颞下颌关节盘不可复性前移位,在复位关节盘的前提下,显著改善开口度和缓解疼痛。     

The changes in temporomandibular joint disc position and configuration in early orthognathic treatment: a magnetic resonance imaging evaluation

This study aimed to examine the effects of chin cup therapy on the temporomandibular joint (TMJ) disc position and configuration with magnetic resonance imaging (MRI). Twenty-five individuals ranging in age from 5 to 11 years were evaluated. The treatment group consisted of 15 subjects (10 females and five males) with prognathic facial structures, while the control group comprised 10 subjects (six females and four males) with an orthognathic facial structure. The magnitude of the chin cup force applied to the mandible was 600 g. Unilateral MRIs of the TMJ were taken in all subjects at the beginning and end of the study. No statistically significant changes in the TMJ disc position and configuration during the treatment and control periods could be seen. The values of the alpha angle measurements were found to be different in the treatment and control groups at the beginning (166.23 +/- 2.15 and 172 +/- 1.97, respectively), and end of the treatment and control periods (160.00 +/- 2.16 and 172.00 +/- 2.68). These findings show that if the chin cup appliance is used at an early age and with appropriate forces, there will be no adverse effect on the TMJ disc position and configuration.     

无症状人群颞下颌关节盘位置的核磁共振研究

目的 观察无症状志愿者颞下颌关节盘的位置,了解无症状人群中是否存在关节盘位置的异常,及其性别、左右侧分布特点.方法 无颞下颌关节病症状及病史的志愿者30名,共60例关节,其中男、女各15名,对其双侧颞下颌关节行开闭口轴位、斜矢状位和斜冠状位扫描,根据扫描结果对关节盘位置进行分类.结果 30名无症状志愿者中,正位关节盘45例,发生率为75%,其中女性20例,男性25例,右侧23例,左侧22例;前移位关节盘7例,发生率为11.67%,其中女性5例,男性2例,右侧5例,左侧2例;外侧移位关节盘6例,发生率为10%,其中女性3例,男性3例,右侧2例,左侧4例;内侧移位关节盘2例,发生率为3.33%,其中女性0例,男性2例,右侧0例,左侧2例;后移位关节盘0例,发生率为0.不同性别比较,差异无统计学意义(P>0.05),左右侧关节比较,差异无统计学意义(P>0.05).结论 无症状志愿者关节盘多为正位,但无症状人群的关节盘移位确实存在,且以前外侧旋转移位最为常见,关节盘移位类型与性别无关,左右侧分布无差异.     

Tomographic assessment of temporomandibular joint osseous articular surface contour and spatial relationships associated with disc displacement and disc length.

The objective of this retrospective study was to determine whether associations exist between osseous temporomandibular joint (TMJ) characteristics and TMJ internal derangement (disc position and deformation) in an adolescent population. Magnetic resonance imaging (MRI) was used to quantitatively determine disc position and length in 335 TMJs in 175 subjects (106 female and 69 male) between the ages of 7.27 and 20.0 years (mean age, 13.08 years). Nine tomographic variables were measured from pretreatment tomograms. Tomographic data were cross-referenced with MRI data. Male and female samples were evaluated separately. Stepwise linear regression identified associations between disc displacement and reduced superior joint space, increased posterior joint space, increased anterior joint space, and reduced articular eminence convexity (male R(2) value, 0.41; female R(2) value, 0.38). Associations between reduced disc length and condylar position and eminence flattening were weaker (male R(2) value, 0.16; female R(2) value, 0.32). This study demonstrates that TMJ internal derangement is associated with functional osseous adaptation within the joint.     

Comparison of ultrasonography and magnetic resonance imaging in the evaluation of temporomandibular joint disc displacement

The aim of this work was to evaluate the accuracy and reliability of ultrasonography in the diagnosis of temporomandibular joint (TMJ) disc position abnormalities compared with magnetic resonance imaging (MRI). Participants in this study were 41 consecutive patients with signs and symptoms of temporomandibular disorders. All 82 TMJs were evaluated to detect disc position abnormalities by means of ultrasonography and MRI, performed by blinded operators. The accuracy of ultrasonography was evaluated with respect to MRI. Ultrasonography demonstrated good accuracy in the evaluation of disc position, showing a sensitivity of 65.8% and a specificity of 80.4%, resulting in a positive likelihood ratio of 3.35, a negative likelihood ratio of 0.42, and a diagnostic odds ratio of 7.97. The predictive positive and negatives values were respectively 77.1% and 70.2% and the overall agreement between the two radiological techniques was 73.1%. Ultrasonography proved to be accurate in detecting normal disc position and the presence of abnormalities in disc-condyle relationship but not so useful for the distinction between disc displacement with and without reduction.     

Magnetic resonance imaging in the evaluation of temporomandibular joint disc displacement--a review of 144 cases

One hundred and forty four patients underwent magnetic resonance imaging (MRI) for evaluation of suspected internal derangement (ID) of the temporomandibular joint (TMJ). All scans were performed on a state-of-the-art scanner by highly experienced technologists and evaluated by a single Head and Neck/Maxillofacial radiologist. Seventy-nine percent of patients were female and 21% male. Age distribution of the cases was bi-modal with first peak at 20-30 years of age and second peak at 50-60 years of age. Of the 82.5% of cases with disc displacement, 59.5% demonstrated reduction with opening and 40.5% did not reduce. Anterior disc displacement is common (44%) and sideways displacement rare (4%). Antero-lateral displacement was the second commonest type of displacement (29%) probably related to the weakness of the lateral disc attachment.     

Magnetic resonance imaging evaluation of temporomandibular joint disc deformities in relation to type of disc displacement.

PURPOSE: This study was undertaken to assess the relationship between the temporomandibular joint (TMJ) disc deformity and the type of internal derangement. PATIENTS AND METHODS: One hundred thirty-three TMJs of 72 patients (53 female and 19 male) with intracapsular dysfunction were studied using clinical and magnetic resonance imaging examinations. RESULTS: Of the 133 TMJ discs, 41.35% had no deformity, whereas 18% of the discs were folded, 19.55% were lengthened, 9.77% were round, 7.51% were biconvex, and 3.75% had thick posterior bands. The frequency of disc deformity was greater with anterior disc displacement without reduction than in cases of anterior disc displacement with reduction (P <.001). Folded and round discs were most common in cases with TMJ anterior disc displacement without reduction (P <.0001). An increase in length was seen in 56.75% of the cases with anterior disc displacement with reduction, whereas 100% of nonreducing discs were mainly folded or rounded. Crepitation was correlated with folded and round disc deformities, whereas lengthening was the feature of reducing discs associated with early and intermediate clicking. CONCLUSIONS: The results show that the degenerative changes in the TMJ disc are influenced by the degree and the type of disc displacement. The more advanced the internal derangement, the more deteriorated the disc configuration.     

Therapeutic outcome assessment in permanent temporomandibular joint disc displacement

In permanent temporomandibular disc displacement (TMJ-DD) outcome studies many authors claim positive effects of arthroscopic surgery, arthrocentesis and physical therapy. This literature review was undertaken to analyse whether the claimed effects are based on acceptable methodology. The recorded papers were analysed by two independent observers according to (1) method of investigation, (2) therapeutic intervention studied, (3) therapeutic outcome variables used, and (4) claimed effectiveness of the intervention. Agreement between observers was calculated. Twenty-four papers were found in which therapeutic outcome of interventions on temporomandibular disorders were studied. Six studies applied a true experimental design. Each of these six studies compared a different set of interventions. Twenty-two papers used maximal mouth opening (MMO) as an outcome variable, nine studied pain intensity on a visual analogue scale, one paper assessed the mandibular function impairment questionnaire. Kappa for overall agreement concerning the reviewing criteria was 0.82 (P < or = 0.001). No distinguishing effects on MMO, pain or function impairment were reported between arthroscopic surgery, arthrocentesis and physical therapy. Results of methodological sound outcome studies evaluating the effects of arthroscopic surgery, arthrocentesis and physical therapy are needed.     

功能矫治前徙下颌对颞下颌关节盘-突-窝位置关系影响的MRI研究

目的研究安氏Ⅱ类1分类错[牙合]患者功能前徙下颌后颞下颌关节（temporomandibular joint，TMJ）盘-突-窝位置关系的改变，探讨功能矫治对TMJ结构产生的影响。方法25例安氏Ⅱ类1分类错[牙合]患者（男性10例，女性15例），平均（11．1±1．1）岁（8．1～13．0岁），接受Activator功能矫治，平均疗程10．9个月，矫治效果满意。治疗前后分别对患者TMJ进行MRI扫描检查并用配对t检验进行盘-突-窝位置关系的定量对比分析。结果治疗前后左侧TMJ髁突前缘与关节窝拐点的距离（Ca-Tm）[分别为（-0．1±1．5）mm和（-0．6±0．9）mm]、右侧TMJ关节前间隙（Ca-Ca′）[分别为（2．3±0．8）mm和（1．8±0．5）mm]的差异有统计学意义（P〈0．05），反映髁突向前移位。反映双侧关节盘在关节窝中位置的各测量项目治疗前后的差异均无统计学意义（P〉0．05）。反映双侧关节盘相对于髁突位置的各测量项目治疗前后的差异均无统计学意义（P〉0．05）。结论功能矫治安氏Ⅱ类1分类错[牙合]在促进下颌发育、改善患者[牙合]-颌一面畸形的同时，不会对TMJ功能产生不利影响，相反可能有助于改善患者治疗前存在的不良的TMJ功能状态。     

Effects of growth factors on temporomandibular joint disc cells

The effects of growth factors on cartilaginous tissues are well documented. An exception is the temporomandibular joint (TMJ) disc, where data for growth factor effects on proliferation and biosynthesis are very limited. The purpose of this study was to quantify proliferation of and synthesis by TMJ disc cells cultured in monolayer with either platelet derived growth factor-AB (PDGF), basic fibroblast growth factor (bFGF) or insulin-like growth factor-I (IGF), at either a low (10 ng/ml) or high (100 ng/ml) concentration. Proliferation was assessed with a DNA quantitation technique, collagen synthesis was measured via a hydroxyproline assay, and GAG synthesis was determined with a dimethylmethylene blue dye binding assay at 14 days. Overall, the most beneficial growth factor was bFGF, which was most potent in increasing proliferation and GAG synthesis, and also effective in promoting collagen synthesis. At the high concentration, bFGF resulted in 96% more cells than the control and 30 to 45% more cells than PDGF and IGF. PDGF and bFGF were the most potent upregulators of GAG synthesis, producing 2-3 times more GAG than the control. IGF had no significant effect on GAG production, although at its higher concentration it increased collagen production by 4.5 times over the control. Collagen synthesis was promoted by bFGF at its lower concentration, with levels 4.2 times higher than the control, whereas PDGF had no significant effect on collagen production. In general, higher concentrations increased proliferation, whereas lower concentrations favoured biosynthesis.     

Magnetic resonance imaging of partial temporomandibular joint disc displacement

Unilateral magnetic resonance imaging (MRI) of the symptomatic temporomandibular joint (TMJ) was performed on 55 patients. The position of the articular disc in relation to the condyle was established on sagittal images. Particular attention was paid to partial or complete anterior positioning of the disc. MRI was correlated with clinical and, in 33 cases, surgical findings. The concept of partial anterior displacement may be useful in relation to treatment planning.     

A comparative assessment of mandibular condylar position in patients with anterior disc displacement of the temporomandibular joint.

PURPOSE: The purpose of this study was to determine whether the position of the mandibular condyle in patients with anterior disc displacement (ADD) is different from that of a control group with normal joints using a novel method to quantify the irregular shape of the temporomandibular joint (TMJ). MATERIALS AND METHODS: Twenty-six magnetic resonance images of TMJs with ADD were evaluated and compared with 14 normal joints. The position of the condyle was determined by using 2 different methods: 1) measuring the horizontal and vertical normalized distances in millimeters between the geometric centers of the glenoid fossa and the condyle and 2) calculating the anteroposterior joint space ratio. RESULTS: Using the first method, the horizontal distance between the centers of the condyle and the glenoid fossa was 14.0 +/- 11.1 in the ADD group and 5.3 +/- 10.9 in the control group (P <.001). The vertical distance was 64.7 +/- 22.7 in the ADD group and 68.3 +/- 32.9 in the control group (P =.015). The ratio of the horizontal and the vertical condylar displacement in the ADD group was 2.4. Using the second method, the anteroposterior joint space ratios in the ADD group and in the control group were 1.7 +/- 0.5 and 1.2 +/- 0.4, respectively (P =.001). CONCLUSION: This study found that condyles of patients with ADD were situated more posterior and superior in the fossa than those in the control group. Moreover, in the ADD group, the posterior condylar displacement was noted to be 2.4 times greater than the superior condylar displacement.