颞下颌关节增强磁共振成像研究

目的：探讨磁共振对比增强剂Gd—DTPA对颞下额关节紊乱病的临床诊断意义。方法：对12名临床诊断为颞下颌关节紊乱病患进行磁共振增强前后扫描，观察影像增强效果。结果：Gd—DTPA对关节盘位置正常的关节闭口斜矢状位前伸部及张口位双板区具有显的增强效果；对可复性及不可复性关节盘前移位张闭口位前伸部及双板区均有明显的增强效果；对冠状位也有明显增强效果。结论：磁共振对比增强剂的增强效果明确，为提高临床诊断准确性及作为磁共振常规扫描的辅助手段提供理论依据。     

基于光谱CT的钙抑制技术评估颞下颌关节紊乱病患者关节盘位置

目的探索钙抑制光谱CT技术在评估颞下颌关节盘位置及测量关节盘后带厚度中的应用。方法对2019年2至7月解放军总医院海南医院放射科门诊就诊的23例颞下颌关节紊乱病患者[平均年龄23岁(12~62岁),男性14例,女性9例]行MRI斜矢状位、斜冠状位质子密度加权成像及光谱CT扫描,共纳入可评估关节45侧,依扫描设备分为MRI测量组及钙抑制光谱CT测量组。采用钙抑制算法对光谱CT进行去钙处理,并重建斜矢状位及冠状位钙抑制光谱CT图像。基于斜矢状位及冠状位图像评估关节盘位置,基于斜矢状位图像测量关节盘后带最大厚度。结果45侧颞下颌关节盘位置在MRI图像及钙抑制光谱CT图像上基本一致。MRI测量组与钙抑制光谱CT测量组所测后带厚度的组内相关系数为0.843(0.712,0.914),Bland-Altman图分析MRI与钙抑制光谱CT测量关节盘后带厚度的差值点[95.6%(43/45)]位于95%一致性界限内。Wilcoxon配对检验提示MRI测量组[2.57(1.76,3.65)mm]与钙抑制光谱CT测量组[2.67(1.74,4.56)mm]差异无统计学意义(P=0.07)。结论钙抑制光谱CT成像可以准确评估关节盘位置及关节盘后带厚度。     

Magnetic resonance imaging of the temporomandibular joint: a study of inter- and intraobserver agreement

Objective The purpose of this study was to estimate the inter- and intraobserver agreement for interpreting magnetic resonance (MR) images of the temporomandibular joint (TMJ).Methods The study was based on MR images of 30 TMJs. The images were interpreted by seven observers for disk configuration, disk position, joint fluid, bone marrow changes, and diagnosis. The observers were not calibrated. Kappa statistics were used.Results The kappa values were, for interobserver agreement of disk configuration, 0.10; for disk position in the sagittal plane with closed mouth, 0.35; for a combination of closed mouth and open mouth, 0.44; for disk position in the coronal plane, 0.17; for joint fluid, 0.36; for bone marrow changes, 0.01; and for diagnosis, 0.39. Intraobserver agreement was generally higher than interobserver agreement.Conclusion Agreement on disk position in the sagittal plane, on presence and amount of joint fluid, and on diagnosis was fair to moderate. Agreement on disk configuration, on disk position in the coronal plane, and on bone marrow changes was poor.     

Influence of friction at articular surfaces of the temporomandibular joint on stresses in the articular disk: a theoretical approach with the finite element method

The present study was designed to assess stress and displacement of the temporomandibular joint (TMJ) disk during jaw opening with different frictional coefficients (micro) from 0.0001 to 0.5 at the TMJ disk and bony component interfaces using three-dimensional finite element (FE) models of individual TMJs based on magnetic resonance (MR) images. An asymptomatic female volunteer and a female patient with anterior disk displacement without reduction were selected, and serial sagittal and frontal slices of their MR images were used for the TMJ reconstruction procedure. The condylar movement was recorded during jaw opening by a Gnatho-hexagraph and used as the loading condition for the subsequent stress analysis of the model. In the asymptomatic subject, relatively high von Mises stresses were observed in the anterior and lateral regions of the disk during jaw opening, and the superior boundary, contacting with the glenoid fossa, exhibited lower stresses than those on the inferior boundary facing the condyle. In the symptomatic subject, although the stress value in the disk was relatively low, the posterior connective tissue exhibited high stress throughout jaw opening. Additional increments in stress values and disk displacement were observed as the coefficient of friction increased, especially in the asymptomatic subject. It is concluded that an augmentation in the friction between the disk, glenoid fossa, and condyle produces an increment in stress and displacement of the disk.     

Correlation between direction and severity of temporomandibular joint disc displacement and reduction ability during mouth opening

The most common temporomandibular joint (TMJ) internal derangement is an abnormal relationship of the disc with respect to the mandibular condyle, articular eminence and glenoid fossa‐disc displacement. The aim of our study was to analyse the correlation between partial/complete disc displacement in the intercuspal position (IP) and its reduction in the open‐mouth position (OMP) in both oblique sagittal and coronal planes on magnetic resonance imaging (MRI) in patients with temporomandibular disorders. Multisection MRI analysis of 382 TMJs was conducted in 191 patients with disc displacement according to the RDC/TMD criteria (148 women, 43 men; aged 14‐60 years). The disc position was evaluated on all oblique sagittal and coronal images in the IP and the OMP. Univariate logistic regression analysis showed that the severity of disc displacement in the sagittal plane is a statistically significant predictor of reduction ability during mouth opening (B = 3.118; P < .001). Moreover, the severity of disc displacement in both planes is also a significant predictor of disc reduction in OMP (B = 2.200; P < .05). In conclusion, reduction ability during mouth opening is associated with the severity of disc displacement in IP, in both sagittal and coronal planes. Multisection analysis of all MR images allows distinguishing the correct disc position from disc displacement and can improve the ability to distinguish between various stages of TMJ internal derangement.     

颞下颌关节的3T磁共振高分辨扫描方法研究

目的：探索3T磁共振对颞下颌关节（TMJ）的成像方法与序列特点,并优化扫描参数。方法：采用Siemens3.0TTrio磁共振扫描机,8通道相控阵头线圈,对25例双侧TMJ分别行张口位、闭口位扫描。其中正常志愿者15例,TMD10例。结果：所有被检查者均一次扫描成功,分别取T1WI,T2WI,PWI以及T2WI,T1WI 3D容积成像,扫描方位以髁突为中心,分别做平行于髁突长轴的斜冠状位,垂直于髁突长轴的斜矢状位扫描,正常志愿者的双侧TMJ在优化后的扫描序列中充分而完整显示关节盘、关节间隙、关节窝、关节盘随张闭口改变而位置变化情况,关节周围软组织与骨组织亦充分清楚显示。10例TMD均完全显示出关节盘移位情况,与临床症状一致。结论：3T磁共振扫描机成像速度快,视野内成像矩阵高,解剖细节显示充分,组织分辨力高,对于TMJ等小关节的结构异常与细微病变的显示充分,是其它医学检查设备无法比拟的。     

颞下颔关节磁共振FIESTA动态成像的诊断价值

目的:探讨颞下颌关节(TMJ)磁共振FIESTA动态成像的诊断价值.方法:对40例患者80侧TMJ进行常规静态磁共振扫描和斜矢状位FIESTA动态磁共振扫描.由2名医师分别对每侧TMJ FIESTA动态扫描时关节盘的位置、髁突的骨质改变和关节腔积液情况进行诊断,并与常规静态磁共振扫描诊断结果进行比较.结果:80侧TMJ磁共振FIESTA动态图像中,对关节盘移位的诊断,72侧与静态磁共振扫描结果相符,准确率为90％;对髁突骨质改变和关节腔积液的诊断,所有病例与静态磁共振结果完全相符,准确率达100％.结论:TMJ磁共振FIESTA动态图像诊断颞下颌关节内紊乱(TMJID)具有一定价值,但单凭动态检查结果不够全面,必须与常规静态磁共振扫描相结合.     

偏突颌患者颞下颌关节盘冠状向位置的MRI评估

目的研究偏突颌畸形患者双侧颞下颌关节盘-髁突位置在冠状位磁共振图像(magnetic resonance imaging,MRI)上的差异,并分析其关节盘移位程度与偏斜严重程度的相关性。方法对54例骨性Ⅲ类错患者进行标准化临床影像学检查得到闭口斜冠状位MRI,通过计算机软件测量分析其冠状位关节盘内外侧移位情况,应用wilcoxon秩和检验分析各组间颞下颌关节盘-髁位置在冠状位磁共振图像上的差异。结果40例偏突颌畸形患者中,偏斜侧7侧(17.5%)关节盘外侧移位,16侧(40.0%)内侧移位;而40侧偏斜对侧关节盘中,27侧(67.5%)关节盘内侧移位,仅2侧(5.0%)关节盘向外侧移位。14例(28侧)无偏斜骨性Ⅲ类患者中,18侧(64.3%)存在关节盘内侧移位,未发现外侧移位的关节盘。本研究证实了偏斜侧关节盘内外侧位置与偏斜对侧及无偏斜组存在显著性差异(P<0.05),中等到重度偏突颌患者偏斜侧关节盘位置与轻度及无偏斜者之间的差异具有统计学意义(P<0.05)。结论在冠状位磁共振图像中显示,中等到重度偏突颌患者偏斜侧关节盘倾向于向外侧移位,偏斜对侧关节盘倾向于向内侧移位。     

Disk and joint morphology variations on coronal and sagittal MRI in temporomandibular joint disorders

Objectives

This study aims to assess the disk morphology and the condyle position in subjects with temporomandibular (TMJ) disk displacements on sagittal and coronal magnetic resonance imaging (MRI).

Materials and methods

Seventy-four TMJs (from 37 patients) with positive clinical TMD symptoms according to the RDC/TMD axis I protocol were evaluated by 1.5 T MRI. Disk position, disk morphology, sagittal and coronal condyle position, joint effusion, joint space, and coronal condyle angulation were evaluated. Multivariate logistic regression was used to explore the relationship between disk displacement and MRI variables.

Results

Disk displacement with reduction (DDR) was found in 36.48 % and without reduction (DDwR), in 21.62 % of the joints. Disk displacement was anterior in 35.1 %, anterior-medial in 13.5 %, and anterior-lateral in 9.45 % of cases. The thickened posterior band (94.48 OR, p?=?0.001) and the posterior condyle position (4.57 OR, p?=?0.03) were more likely found on sagittal MRI in disk displacements. On coronal slices, the disk displacement was significantly associated with the distance from the most medial condyle point to the midplane (p?<?0.05).

Conclusions

Disk displacement is associated with changes of disk shape, disk dimension, and condyle position on sagittal MRI. A significant variation of the distance from the most medial condyle point to the midplane in disk displacement was found on coronal MRI.

Clinical relevance

Our study highlights the existence of changes on coronal MRI in TMD patients which should be assessed for better understanding of the clinical evolution of temporomandibular disorders.     

Magnetic resonance imaging assessment of positional relationship between the disk and condyle in asymptomatic young adult mandibular prognathism

The aim of this study was to clarify disk position relative to the condyle and condylar position relative to the glenoid fossa in clinically asymptomatic and orthodontically untreated young adult Class III patients by magnetic resonance imaging (MRI). In addition, the relationship between skeletal Class III morphology and positional changes of the temporomandibular joint (TMJ) components were investigated. The material consisted of 34 bilateral sagittal oblique TMJ MR images (MRIs) and lateral cephalometric radiographs taken in a closed mouth position. The mean age of the patients was 20.71 +/- 0.82 years (range 16-29 years). Only clinically symptom-free subjects were included in this study. Measurements made on the MRIs and lateral cephalographs were used to calculate means and minimum and maximum values. The right and left TMJ variables were compared with the Student's t-test. Correlation coefficients between bilateral TMJ variables and skeletal variables were calculated. In the right TMJ, the disk was positioned anteriorly and the condyle was positioned posteriorly, whereas the left TMJ was normal. A negative correlation existed between the vertical skeletal morphology and the anterior joint space of the TMJ. A positive correlation was found between the left disk position and the vertical skeletal morphology because of the differentiation of the condylar head angle in each side. As a result, clinically asymptomatic Class III patients may be candidates for TMJ derangements. For this reason, clinical and visual examinations should be performed simultaneously to eliminate diagnostic errors before orthognathic treatment.     

Prognostic indicators of the outcome of arthrocentesis: a short-term follow-up study

OBJECTIVES: Arthrocentesis of the temporomandibular joint (TMJ) is purported to be an effective modality in the treatment of patients with closed-lock symptoms. The purpose of this study was to determine whether the clinical findings of disk displacement without reduction associated with pain in the TMJ are related to the discovery of TMJ osteoarthrosis (OA) through the use of magnetic resonance (MR) imaging and whether the presence of OA affects the treatment outcome of patients who undergo arthrocentesis of the TMJ. STUDY DESIGN: The study population consisted of 38 patients with TMJ pain who were assigned a clinical diagnosis of unilateral internal derangement (ID) of the TMJ, type III (disk displacement without reduction), in combination with capsulitis/synovitis (C/S) and an MR imaging diagnosis of disk displacement without reduction in the painful TMJ only. Before the patients underwent arthrocentesis, bilateral sagittal and coronal MR images were obtained to confirm the presence or absence of ID and OA. The preoperative and postoperative levels of TMJ function with respect to pain and mandibular range of motion were evaluated and compared. Multiple logistic regression analysis was used to compute the odds ratios for successful outcomes for OA (n = 24) versus unsuccessful outcomes for TMJs (n = 14). RESULTS: The preoperative data revealed a significant relationship between the clinical diagnosis of TMJ ID type III with C/S and the discovery of OA on MR images (P =.048). At the 2-month follow-up, a clinical evaluation revealed a significant reduction in TMJ pain during function (P =.000); a significant reduction in the clinical diagnoses of ID type III (P =.000), and C/S (P =.000); and a significant increase in the mandibular range of motion (P =.000). The patients with successful outcomes were more likely to be associated with an MR imaging finding of OA than were the patients with unsuccessful outcomes. (10.4 odds ratio; P =.016). CONCLUSIONS: Our preliminary findings suggest that the presence of OA revealed on MR images is related to clinical pain; furthermore, OA proved to be an important prognostic determinant of successful arthrocentesis.     

Differences in temporomandibular joint pain and age distribution between marrow edema and osteonecrosis in the mandibular condyle

This study investigated the differences of age distribution and temporomandibular joint (TMJ) pain between marrow edema and osteonecrosis in the mandibular condyle. Subjects consisted of 35 TMJs in 35 patients with abnormal bone marrow on MR images who were selected from a consecutive series of 527 patients with TMJ disorders. Proton density and T2-weighted MR images taken in the oblique sagittal and coronal planes were used to diagnose condylar marrow abnormalities and divide them into either edema or osteonecrosis. The differences in TMJ pain and age distribution for these two abnormalities were assessed with the one-sided Wilcoxon rank sum test with 0.05 alpha level. The degree of pain was higher in joints with marrow edema than in joints with osteonecrosis (p = 0.033). The mean age was higher in joints with osteonecrosis (p < 0.001). Our results suggest that there is more severe pain in TMJs with marrow edema of the mandibular condyle than in those with osteonecrosis. Since the patients with marrow edema have lower age, it also appears that marrow edema may be a precursor condition for osteonecrosis of the TMJ.     

Transitional joint effusion in the mandibular prognathic surgery patient: intraoral vertical ramus osteotomy versus sagittal split ramus osteotomy.

PURPOSE: The purpose of this study was to examine the cause of joint effusion (JE) appearing postoperatively in the temporomandibular joint (TMJ) of patients with mandibular prognathism on T2-weighted magnetic resonance (MR) images. PATIENTS AND METHODS: MR imaging was performed before and after surgery in 30 TMJs of 15 subjects with mandibular prognathism who underwent intraoral vertical ramus osteotomy (IVRO) and in 20 TMJs of 10 subjects with mandibular prognathism who underwent sagittal split ramus osteotomy (SSRO). The preoperative MR imaging was performed 1 month before surgery, and postoperative MR imaging was performed during maxillomandibular fixation. RESULTS: Preoperatively, none of SSRO and IVRO groups had JE. Postoperatively, 12 TMJs (40%) of the IVRO group and only 1 TMJ (5%) of the SSRO group had JE. As for the TMJs in the IVRO group, on MR imaging, the degree of downward movement of the condyle after surgery was larger in TMJs with JE (3.8 +/- 2.3 mm) than in TMJs without JE (1.8 +/- 1.6 mm). JE diminished within about 4 months after removal of the maxillomandibular fixation. CONCLUSION: JE appearing postoperatively in the TMJ of patients with mandibular prognathism might be relation to the degree of downward movement of the condyle.     

Medical Managed Care for Temporomandibular Disorders and Orofacial Pain

Abstract

This study investigated the differences of age distribution and temporomandibular joint (TMJ) pain between marrow edema and osteonecrosis in the mandibular condyle. Subjects consisted of 35 TMJs in 35 patients with abnormal bone marrow on MR images who were selected from a consecutive series of 527 patients with TMJ disorders. Proton density and T2-weighted MR images taken in the oblique sagittal and coronal planes were used to diagnose condylar marrow abnormalities and divide them into either edema or osteonecrosis. The differences in TMJ pain and age distribution for these two abnormalities were assessed with the one-sided Wilcoxon rank sum test with 0.05 alpha level.The degree of pain was higher in joints with marrow edema than in joints with osteonecrosis (p=0.033). The mean age was higher in joints with osteonecrosis (p<0.001). Our results suggest that there is more severe pain in TMJs with marrow edema of the mandibular condyle than in those with osteonecrosis. Since the patients with marrow edema have lower age, it also appears that marrow edema may be a precursor condition for osteonecrosis of the TMJ.     

Relative odds of temporomandibular joint pain as a function of magnetic resonance imaging findings of internal derangement,osteoarthrosis, effusion,and bone marrow edema

OBJECTIVE: The purpose of this study was to evaluate whether common magnetic resonance (MR) imaging variables such as temporomandibular joint (TMJ) internal derangement, osteoarthrosis, effusion, and bone marrow edema are predictive of the presence of TMJ pain. STUDY DESIGN: The relationship between TMJ pain and TMJ internal derangement, osteoarthrosis, effusion, and bone marrow edema was analyzed in MR images of 338 TMJs in 169 patients with a clinical diagnosis of TMJ pain and dysfunction. Criteria for including a patient with TMJ pain were a report of orofacial pain referred to the TMJ, with the presence of unilateral or bilateral TMJ pain during palpation, function, or unassisted or assisted mandibular opening. The criteria for including a patient with no pain were the absence of TMJ pain during palpation, function, and unassisted or assisted mandibular opening. Application of the criteria resulted in a study group of 129 patients with unilateral TMJ pain, 18 with bilateral TMJ pain, and 22 without TMJ pain. Bilateral sagittal and coronal MR images were obtained to establish the presence or absence of TMJ internal derangement, osteoarthrosis, effusion, and bone marrow edema. Logistic regression analysis was used to compute the odds ratios for internal derangement, osteoarthrosis, effusion, and bone marrow edema for nonpainful TMJs (n = 173) versus painful TMJs (n = 165). RESULTS: For pairwise comparison, the chi(2) test was used; the resultant data showed a significant relationship between the clinical findings of TMJ pain and the MR imaging diagnoses of internal derangement (P =.000), osteoarthrosis (P =.015), effusion (P =.002), and bone marrow edema (P =.016). Of the MR imaging variables considered simultaneously in multiple logistic regression analysis, osteoarthrosis (P =.405), effusion (P =.131), and bone marrow edema (P =.231) dropped out as nonsignificant in the diagnostic TMJ pain group in comparison with the TMJ no-pain group. Significant increases in risk of TMJ pain occurred with disk displacement without reduction in combination with osteoarthrosis and bone marrow edema (3.7:1 odds ratio; P =.000) and with disk displacement without reduction in combination with osteoarthrosis and effusion (2.8:1 odds ratio; P =.000). CONCLUSIONS: The results suggest that TMJ pain is related to internal derangement, osteoarthrosis, effusion, and bone marrow edema. However, the data reemphasize that these MR imaging variables may not be regarded as the unique and dominant factors in defining TMJ pain occurrence.     

计算机辅助合成颞下颌关节镜全景图像

目的：介绍一种颞下颌关节镜全景图像合成的计算机处理系统。方法：将关节镜下所见的图像直接输入计算机并贮存于可读写光盘,对所获得的多幅单个图像使用Ｐｈｏｔｏｓｈｏｐ５．０图像编辑软件进行图像编辑处理。结果;通过此图像处理系统,对多幅单个的关节镜图像进行合成,获得了完整的正常颞下颌关节镜下组织的矢状面积（或）冠状面二维全景图像。结论：颞下颌关节镜全景图像计算机处理系统有助于提高关节镜的综合分析能力,同时也有利关节镜手术的推广。     

Variability of disk position in asymptomatic volunteers and patients with internal derangements of the TMJ

This study determined the variability of temporomandibular joint (TMJ) disk position in medial, central, and lateral aspects of the joint using magnetic resonance imaging (MRI). Subjects had clinical evidence of reciprocal TMJ clicking (N = 123) or restricted mandibular motion (N = 52). Eighty-nine asymptomatic volunteers provided a control group. Disk position was quantified on MRI by measuring the angle formed by a line through the middle of the condyle and perpendicular to the Frankfort plane and a line through the same midpoint of the condyle and tangential to the posterior-most aspect of the disk. The disk position in asymptomatic TMJs varied considerably with a tendency toward farther anterior placement in more lateral images. In 47 TMJs from a total of 52 TMJs (90%), restricted mobility was associated with anterior disk displacement (ADD) without reduction. The disk position demonstrated a mean displacement of 77 degrees without significant differences at the medial and lateral aspects of the condyle. One hundred TMJs from a total of 123 TMJs (81%) with reciprocal clicking demonstrated ADD with reduction. Tomograms revealed larger lateral displacements or rotational displacements in these joints, whereas medial images frequently showed similar ranges of disk positions as compared with asymptomatic TMJs. The results suggest that disk positions of up to +15 degrees on medial tomograms and +30 degrees on lateral tomograms should be regarded as normal variations. Furthermore, multisection analysis of all parasagittal images improved the separation between disk displacement and asymptomatic TMJs.     

Risk factors for temporomandibular joint pain in patients with disc displacement without reduction - a magnetic resonance imaging study

The purpose of this study was to evaluate whether the magnetic resonance (MR) imaging variables of temporomandibular joint (TMJ) internal derangement, osteoarthrosis and/or effusion may predict the presence of pain in patients with a clinical disorder of an internal derangement type (ID)-III. The relationship between TMJ ID-III pain and TMJ internal derangement, osteoarthrosis and effusion was analysed in MR images of 84 TMJs in 42 patients with a clinical unilateral diagnosis of TMJ ID-III pain. Criteria for including a TMJ ID-III pain patient were report of orofacial pain referred to the TMJ, with the presence of unilateral TMJ pain during palpation, function and/or unassisted or assisted mandibular opening. Bilateral sagittal and coronal MR images were obtained to establish the presence or absence of TMJ internal derangement, osteoarthrosis and effusion. Using chi-square analysis for pair-wise comparison, the data showed a significant relationship between the MR imaging findings of TMJ ID-III pain and those of internal derangement (P=0.01) and effusion (P=0.00). Of the MR imaging variables considered simultaneously in the multiple logistic regression analysis, osteoarthrosis (P=0.82) and effusion (P=0.08) dropped out as non-significant in the diagnostic TMJ pain group when compared with the TMJ non-pain group. The odds ratio that a TMJ with an internal derangement type of disk displacement without reduction might belong to the pain group was strong (2.7:1) and highly significant (P=0.00). Significant increases in risk of TMJ pain occurred with 'disk displacement without reduction in combination with osteoarthrosis' (5.2:1) (P=0.00) and/or 'disk displacement without reduction in combination with osteoarthrosis and effusion' (6.6:1) (P=0.00). The results suggest that TMJ pain is related to internal derangement, osteoarthrosis and effusion. However, the data re-emphasize the aspect that these MR imaging variables may not be regarded as the unique and dominant factors in defining TMJ pain instances.     

Normal and pathological anatomy of the TMJ viewed by computerized panoramic arthroscopic images

The individual single images obtained to document TMJ arthroscopy are often difficult to interpret. The aim of this paper is to make available a new computer-aided image process system to reformat the panoramic arthroscopic images of the temporomandibular joint (TMJ). Arthroscopic images were input directly into a computer and memorized into a magneto optical disk. Using Photoshop 5.0 (Adobe Systems, Inc., Mountain View, CA) software for Windows 98 (Microsoft Corp., King County, WA) the images were edited and adjusted to compound sagittal and/or coronal panoramic images of normal articular surfaces as well as pathology of TMJ disorders. Normal TMJ sagittal and coronal two-dimensional composite panoramic arthroscopic images were achieved. The panoramic images of some intracapsular disorders (including disk displacement, osteoarthrosis, adhesion, and disk perforation) were also obtained. The computerized arthroscopic panoramic images are a new technique that may aid in the understanding of TMJ anatomy and TMJ disorders.     

Magnetic resonance imaging findings of internal derangement in temporomandibular joints without a clinical diagnosis of temporomandibular disorder

The purpose of this study was to assess the prevalences of magnetic resonance (MR) imaging findings of internal derangement (ID) in temporomandibular joints (TMJs) without a specific clinical diagnosis of temporomandibular disorder (TMD), and to investigate whether in this TMJ group the variable of pain may be linked to MR imaging findings of ID. The study comprised 109 patients, who were assigned a clinical uni- or bilateral TMJ-related diagnosis of 'absence of TMD'. Bilateral sagittal and coronal MR images were obtained subsequently to establish the prevalence of TMJ ID. An MR imaging diagnosis of ID was found in 99 (55.9%) of the 177 TMJs investigated. About 30.3% of the closed mouth-related TMJ positions characterized by disc displacement presented with anterior disc displacement, while 27.3% had anterolateral and 25.3% anteromedial disc displacement. Analysis of the data revealed the presence of TMJ pain to be associated with significantly more MR imaging diagnoses of disc displacement without reduction than disc displacement with reduction (P < 0.05), while there was no significant difference in the prevalences of ID and those of absence of ID (P > 0.05). Using chi-square analysis, no significant relationship was found between the presence of TMJ pain and the MR imaging diagnosis of TMJ ID (P=0.93). Use of the kappa statistical test indicated poor diagnostic agreement between the presence of TMJ pain and the MR imaging diagnosis of ID (kappa=0.01). The results suggest TMJs with a clinical diagnosis of 'absence of TMD' to be associated with a high rate of IDs, while in these instances the clinical variable of TMJ pain may have no effect on prevalences of MR imaging diagnoses TMJ ID. The data confirm the aspect of clinical diagnostic criteria as an unreliable instrument in predicting MR imaging diagnoses of TMJ ID.