The relationship between temporomandibular joint effusion and pain in patients with internal derangement

ObjectivesThe purpose of this study was to evaluate the relationship between temporomandibular joint (TMJ) effusion and joint pain in patients with internal derangement based on the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD).MethodsA total of 240 TMJs from 120 patients with unilateral painful joints (103 females and 17 males, mean age 29.9 ± 12 years) were evaluated. Clinical assessments were carried out according to the DC/TMD guidelines. Magnetic resonance imaging (MRI) was used to evaluate the degree of effusion in each joint. The radiological and clinical findings were analysed for statistically significant correlations.ResultsAlthough the results indicated a statistically significant association between moderate joint effusion and disc displacement (p < 0,05), there was no statistically significant association between moderate effusion and joint pain (p > 0,05). There were, however, statistically significant associations between marked effusion and both disc displacement and joint pain (p < 0,05).ConclusionTMJ effusion is associated with both disc displacement and joint pain: the effusion increased in direct proportion to the severity of pain and disc displacement. The possibility that there are various aetiologies for the condition should also be considered.     

Diagnostic quality of dynamic high-resolution ultrasonography of the TMJ--a pilot study

The aim of this study was to compare sensitivity, specificity, accuracy and positive and negative predictive value for high-resolution ultrasonography (HR-US) in diagnosing degenerative changes, effusion and disk displacement using magnetic resonance imaging (MRI) as a reference. Over a period of 6 months, 100 patients with TMJ disorders (200 TMJs) were investigated by an experienced radiologist with HR-US and magnetic resonance imaging (MRI). The MRI investigation showed degenerative changes in 190 joints (95%), while an effusion was found in 59 (29.5%) joints. At closed-mouth position a disc dislocation was found in 138 joints (69%) and in maximum-mouth-opening position disc dislocation was diagnosed in 76 joints (38%). In the determination of degenerative changes HR-US showed a sensitivity of 94%, a specificity of 100% and an accuracy of 94%. In the detection of effusion HR-US yielded a sensitivity of 81%, a specificity of 100% and an accuracy of 95%. In the determination of disk displacement at closed-mouth position HR-US showed a sensitivity, specificity and an accuracy of 92% each. At maximum-mouth-opening position HR-US reached a sensitivity of 86%, a specificity of 91% and an accuracy of 90%. The results of the current study imply that HR-US is a valuable diagnostic imaging method of the TMJ which can be used as an alternative method to a MRI-investigation, but is yet not able to replace it. Further studies have to be done to reduce false-negative results.     

Diagnostic efficiency of high-resolution ultrasonography in patients with chronic temporomandibular disorders

Purpose

Temporomandibular disorders (TMDs) affect 8–12 % of the adolescent and adult population, resulting in patient discomfort and affecting quality of life. Despite the growing incidence of these disorders, an effective screening modality to detect TMDs is still lacking. Although magnetic resonance imaging is the gold standard for imaging of the temporomandibular joint (TMJ), it has a few drawbacks such as cost and its time-consuming nature. High-resolution ultrasonography is a non-invasive and cost-effective imaging modality that enables simultaneous visualization of the hard and soft tissue components of the TMJ. This study aimed to evaluate the correlations between the clinical signs and symptoms of patients with chronic TMJ disorders and their ultrasonographic findings, thereby enabling the use of ultrasonography as an imaging modality for screening of TMDs.

Methods

Twenty patients with chronic TMDs were selected according to the Research Diagnostic Criteria for TMDs. Ultrasonographic imaging of individual TMJs was performed to assess the destructive changes, effusion, and disc dislocation. Fisher’s exact test was used to examine the correlations between the findings obtained from the ultrasonographic investigation and the clinical signs and symptoms.

Results

There was a significant correlation between pain and joint effusion as well as between clicking and surface erosion.

Conclusions

The present findings suggest that ultrasonography can be used as a screening modality to assess the hard and soft tissue changes in patients presenting with signs and symptoms of TMDs.

     

Prediction of TMJ arthralgia according to clinical diagnosis and MRI findings

PURPOSE: The aim of this study was to investigate the ability of clinical and magnetic resonance imaging (MRI) diagnoses to predict pain in the temporomandibular joint (TMJ). MATERIALS AND METHODS: One hundred forty-nine patients were examined by 2 calibrated examiners in strict accordance with the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). All patients who presented with a defined clinical RDC/TMD diagnosis were included and underwent bilateral coronal and sagittal MRI of the TMJ. Two raters blinded to the clinical diagnosis interpreted the MRI scans for TMJ pathology. The results were tested against the clinical diagnosis according to the RDC/TMD, including pain-related disability and psychosocial status, for associations to TMJ arthralgia using logistic regression analysis (GENMOD procedure, P < .05). RESULTS: MRI-depicted anatomic changes, such as joint effusions, disc displacement, and osteoarthrosis, were not significantly correlated with the presence of pain in the TMJ. However, a significant relationship between pain on palpation of the masseter muscle origin (P = .0050) and psychosocial factors (P = .0452) and pain in the TMJ was demonstrated. CONCLUSIONS: Pain in the TMJ caused by the anatomic proximity of the muscle masseter origin and the lateral TMJ pole and the possible existence of trigger points in the musculature may lead to a false-positive or a false-negative diagnosis of arthralgia. Additionally, clinicians must consider the psychosocial aspects of pain in ideal treatment planning.     

Predictive value of clinical findings for temporomandibular joint effusion

OBJECTIVE: The aim of this work was to evaluate the predictive value of clinical symptoms for magnetic resonance imaging (MRI) findings of temporomandibular joint (TMJ) effusion. STUDY DESIGN: Sixty-one patients with TMJ pain were assessed by means of a standardized clinical examination and MRI. A calibrated investigator evaluated the presence of 8 clinical indicators (predictors) of TMJ effusion (outcome variable). A logistic regression analysis was performed to detect significant associations between clinical symptoms and MRI findings of TMJ effusion. The accuracy of the final logit to predict effusion was compared with that derived from univariate analysis. RESULTS: A clinical examination based upon the assessment of pain in the TMJ with lateral palpation, with posterior palpation, during motion, and during maximum assisted opening, and the presence of click and crepitus sounds has an accuracy of 78.7% to predict TMJ effusion. Among the single clinical symptoms, the most reliable predictor of TMJ effusion is the presence of pain with lateral palpation (accuracy 76.2%; K =.525). CONCLUSION: The use of a multiple regression approach demonstrated that an extensive clinical assessment which considers 6 main indicators consents to predict accurately the presence of MRI TMJ effusion. Based on these findings, MRI assessment should be reserved for patients in which the exact disc-condyle relationship needs to be evaluated.     

急性和慢性不可复性盘前移位临床对比研究

目的　探讨颞下颌关节紊乱病不可复性盘前移位急性和慢性分类对临床诊断、治疗和预后的指导意义。方法　分析连续接诊的 10 0例不可复性盘前移位病例 (急性 4 5例、慢性 5 5例 ) ,比较两组之间临床主诉、开口度、颞下颌关节功能、髁突和关节盘的影像学改变。结果　急性不可复性盘前移位主诉开口受限 ,下颌运动功能严重障碍 ,大部分病例髁突骨质正常 ,关节盘形态良好 ;慢性不可复性盘前移位主诉多为开口痛和 (或 )咀嚼痛 ,下颌运动受限 ,部分病例伴有咀嚼肌疼痛 ,相当一部分病例髁突骨质吸收破坏 ,关节盘变形、变性 ,关节盘附着松弛、撕裂 ,甚至关节盘穿孔。结论　对急性不可复性盘前移位应早期采取积极的治疗 ,恢复良好的盘 突关系 ,阻止关节盘和髁突的进一步损伤。     

Relationship between temporomandibular joint pain and magnetic resonance imaging findings in patients with temporomandibular joint disorders

The purpose of this study was to evaluate abnormal magnetic resonance imaging (MRI) findings related to temporomandibular joint (TMJ) pain. This study included 245 joints of 152 patients with temporomandibular disorders with anterior disc displacement; of these, 129 joints had joint pain whereas 116 joints had no joint pain. MRI was used to evaluate the reduction of anterior disc displacement, joint effusion, mandible condylar morphology, bone marrow oedema of the mandibular condyle, and signal intensity of the posterior disc attachment (PDA) on fat-suppressed T2-weighted images. The odds ratio (OR) for each MRI variable for the pain group versus the no pain group was computed using logistic regression analysis. Univariate logistic regression analysis showed significant correlations between TMJ pain and all MRI findings. Multivariate logistic regression analysis showed significant correlations with joint effusion (P = 0.03, OR 2.21), bone marrow oedema (P < 0.001, OR 11.75), and signal intensity of the PDA (P < 0.001, OR 6.21). These results suggest that bone marrow oedema, high signal intensity of the PDA on fat-suppressed T2-weighted images, and joint effusion, in descending order of influence, are factors related to TMJ pain.     

高分辨率超声诊断颞下颌关节盘前移位的初步临床研究

目的探讨高分辨率超声（HR-US）诊断颞下颌关节紊乱病（TMD）关节盘前移位（ADD）的可行性。方法对40例TMD患者的40侧关节作HR-US（静态图像和动态图像）与关节造影检查。结果HR-US在显示可复性盘前移位与关节造影显示中等一致性,在显示不可复性盘前移位与关节造影显示高度一致性。结论HR-US在诊断ADD方面显示较强的可行性,可以作为ADD诊断方法在临床上应用。     

An assessment of the usefulness of jaw kinesiography in monitoring temporomandibular disorders: Correlation of treatment-related kinesiographic and pain changes in patients receiving temporomandibular joint injections

BackgroundThe authors conducted a study in patients with temporomandibular joint (TMJ) osteoarthritis to assess whether treatment-related changes in pain levels and chewing ability coincide with a change in jaw kinesiographic (KG) parameters.MethodsThe authors selected 34 patients with a diagnosis of TMJ osteoarthritis that met Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) to undergo a cycle of five weekly arthrocentesis procedures with injections of 1 milliliter hyaluronic acid. They performed a permutation test to assess the correlation between changes across time (from baseline to end of treatment) in two clinical outcome parameters—pain level and chewing ability—and changes across time in the KG outcome parameters.ResultsThe authors observed improvement across time in both chewing ability (F = 8.328; P = .005) and pain level (F = 10.903; P = .002). The authors observed no significant changes in any KG variables. With minor exceptions, no significant correlations were shown between changes in the clinical and KG parameters during the treatment period.ConclusionsTreatment-related changes in pain levels and chewing ability in patients with TMJ osteoarthritis do not coincide with changes in KG parameters.Practical ImplicationsIf one assumes pain variables to be the primary outcome measures in assessing treatment of TMJ osteoarthritis, KG recordings of the jaw are not useful for monitoring TMJ osteoarthritis in the clinical setting.     

Magnetic resonance imaging findings of osteoarthrosis and effusion in patients with unilateral temporomandibular joint pain

The purpose of this study was to investigate the relationship between the presence of temporomandibular joint (TMJ) pain and the magnetic resonance (MR) imaging findings of osteoarthrosis (OA), and effusion. The study comprised 112 consecutive TMJ pain patients. Criteria for including a patient were report of unilateral pain near 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 OA, and/or effusion. Comparison of the TMJ side-related data showed a significant relationship between the clinical finding of TMJ pain and the MR imaging diagnoses of TMJ OA (P=0.000), and TMJ effusion (P=0.000). Further, there was a significant relationship between the MR imaging diagnosis of TMJ OA and TMJ effusion (P=0.000). Use of the Kappa statistical test indicated poor diagnostic agreement between the presence of TMJ pain and the MR imaging diagnosis of TMJ OA (K=0.22), TMJ effusion (K=0.29), and TMJ 'OA and effusion' (K=0.30). The study's findings suggest that while clinical pain is correlated to TMJ-related MR imaging findings, clinical pain in and of itself, is not reliable for predicting the presence of TMJ OA and/or effusion. Validation of MR imaging diagnoses would involve the investigation of cross-sectional and longitudinal evidence to assess decisive differences in terms of prognosis and/or treatment outcome.     

The incidence of osteoarthritic change on computed tomography of Korean temporomandibular disorder patients diagnosed by RDC/TMD; a retrospective study

Objective Osteoarthritis (OA) of the temporomandibular joint (TMJ) is generally thought to be an age-related disease like those of other joints. This study aims to investigate the incidence of computed tomographic (CT) OA changes in Korean temporomandibular disorder (TMD) patients diagnosed by the Research Diagnostic Criteria for TMD (RDC/TMD). Materials and methods The clinical records and radiographs of 1038 TMD patients (297 men and 741 women with mean age 31.1?±?17.4 and 34.0?±?16.2, respectively) diagnosed based on RDC/TMD Axis I in 2010 were reviewed. Results The incidence rate of OA changes in TMD patients is estimated to 27.3%, and higher in women than in men (15.5% in men and 32.0% in women) by 2.3 odds (p?p?Conclusions These results imply that the OA changes in young Korean TMD patients are as common as in the old and have no correlation with clinical pain and noise. Considered with high prevalence of TMDs known in the young population, the overall/absolute OA changes in the TMJ can be even higher in the young than in the old population, not like in other joints.     

Temporomandibular disorders in 19-year-old Korean men.

PURPOSE: The purpose of this study was to determine the prevalence and the nature of the relationships between 3 temporomandibular joint disease (TMD) symptoms and symptoms of associated structures. MATERIALS AND METHODS: This study was designed to rule out the effect from the uneven composition of the samples on TMD symptoms. The samples were collected from subjects who were of the same age, gender, district, and race. Nineteen-year old men (n = 27,978) were selected and investigated by means of questionnaires and clinical examinations. The prevalence of each symptom was studied and tried to determine the effects of the TMD-associated signs on the TMD signs. The indices allocated to reflect the TMD signs and symptoms and the others were dichotomized for bivariate analysis. The predictor variables were headache, neck pain, referred pain, stress, past trauma history in the TMJ, past TMJ dislocation, bruxism, and clenching. The outcome variables were mouth opening limitation, TMJ pain on rest, and TMJ pain during function. RESULTS: The incidence of masticatory muscle stiffness was 17.8%; TMJ sounds, 14.3%; headache, 7.2%; neck pain, 13.5%; bruxism, 8.4%; and clenching, 9.9%. Stress occurred in 12.8%, past trauma history in 11%, and previous joint dislocation in 2.5%. The experience of dislocation in the TMJ was found to be the most important risk factor in terms of mouth opening limitation (odds ratio, 4.08, P <.0001), joint pain during function (odds ratio, 5.50, P <.0001), and joint pain in the rest state (odds ratio, 4.63, P <.0001). Referred pain and the experience of trauma in TMJ were the secondary risk factors in terms of joint pain and referred pain and the stress in terms of mouth opening limitation. Considering referred pain can be induced by TMD, stress may be more related to mouth opening limitation (odds ratio, 2.18, P <.0001), and the experience of trauma in TMJ may be more related to pain in the rest state (odds ratio, 2.56, P <.0001) and during function (odds ratio, 2.47, P <.0001). CONCLUSIONS: The prevalence of TMD signs and symptoms as determined by this examination was in accord with the findings in women or mixed samples of other workers. Prior experience of a dislocated disc was found to be the most risky factor in TMD. Stress was related to limitations of mouth opening, and the experience of trauma in the TMJ was found to be related to pain in the joint region. Bruxism may not be a direct risk factor in TMD, and the clenching habit found to be more harmful than bruxism.     

Anamnestic Index Severity and Signs and Symptoms of TMD

Abstract

The aim of this study was to determine the frequency and to characterize the symptoms and clinical signs of temporomandibular disorders (TMD) related to each severity category of Fonseca’s anamnestic index in a sample of Brazilian young adults (mean age 21.61±1.91 years, 87% females and 13% males), by the application of an anamnestic index proposed by Fonseca (1992) and by clinical examination considering mandibular range of motion and tenderness to palpation of stomatognathic system structures. A significant number of participants were classified with mild TMD (43.2%) and moderate TMD (34.8%). Pain frequency during mastication, temporomandibular joint (TMJ) pain, and TMJ sounds were shown to be good predictors of TMD severity. Neck pain, headache, difficulty during mouth opening and lateral deviation, and tenderness to palpation of masticatory sites and during protrusion accompanied the TMD severity but failed to demonstrate differences between moderate and severe groups, showing a poor ability to determine TMD severity progression. This study suggests that not only the frequency of signs and symptoms of TMD should be determined, but also symptom severity and its relationship to the presence of clinical signs in order to discriminate patients with real treatment needs in nonpatient samples.     

The use of pseudo-dynamic magnetic resonance imaging for evaluating the relationship between temporomandibular joint anterior disc displacement and joint pain

The relationship between temporomandibular joint (TMJ) pain and the magnetic resonance imaging (MRI) finding of articular disc displacement is debated. The purpose of this study is to investigate the correlation between TMJ pain and anterior disc displacement (ADD) using pseudo-dynamic MRI. A retrospective review of MRI studies was carried out on 130 TMJs in 65 patients presenting unilateral TMJ pain. The contralateral asymptomatic joints served as the control group. Bilateral oblique sagittal and coronal MRIs as well as pseudo-dynamic studies in the oblique sagittal plane were obtained. The disc–condyle relationship was divided into three subtypes (normal disc position, ADD with reduction, and ADD without reduction), based on the pseudo-dynamic MRI findings. Fisher's exact test was used to determine whether the TMJ pain was linked to ADD. The results showed that TMJ pain was significantly related to ADD (with and without reduction) compared to the group with a normal disc position (P = .0001). A significant correlation was found between TMJ pain and the ADD subtype without reduction, as compared to the ADD subtype with reduction (P = .0156). These data suggest that a displaced disc, particularly in the subtype without reduction, is an important source of pain.     

Signs of temporomandibular disorders in tinnitus patients and in a population-based group of volunteers: results of the Study of Health in Pomerania

The literature has documented a controversial discussion on the possible relationship of otogenous symptoms and craniomandibular dysfunction since the 1920s. Therefore, an investigation was conducted which consisted of two parts: a case study with population-based controls and a cross-sectional study. The aim of the first study was to screen a group of patients suffering from acute or chronic tinnitus for temporomandibular disorders (TMD) in comparison with a population-based group of volunteers without tinnitus. To this end, 30 patients (13 females and 17 males, age 18-71 years) suffering from acute hearing loss associated with tinnitus, isolated acute tinnitus, and chronically transient tinnitus were examined for symptoms of craniomandibular dysfunction. The results were compared with those of clinical functional analysis from 1907 subjects selected representatively and according to age distribution from the epidemiological 'Study of Health in Pomerania' (SHIP); the occurrence of tinnitus was ruled out in these control subjects. Statistical analysis was performed with Chi-square and Mann-Whitney U-tests. Sixty per cent of the tinnitus patients and 36.5% of the control subjects exhibited more than two symptoms of TMD (P = 0.004). Tinnitus patients had significantly more muscle palpation pain (P < 0.001), temporomandibular joint (TMJ) palpation pain (P < 0.001), and pain upon mouth opening (P < 0.001) than the general population group. No statistical differences were found in TMJ sounds, limitation of mandibular movement, or hypermobility of the TMJ. Furthermore, 4228 subjects of the population group examined in the epidemiological study were screened for co-factors of tinnitus with the help of a multivariate logistic regression model which was adjusted for gender, age, and a variety of anamnestic and examined data. Increased odds ratios (OR) were found for tenderness of the masticatory muscles (OR = 1.6 for one to three painful muscles and OR = 2.53 for four or more painful muscles), TMJ tenderness to dorsal cranial compression (OR = 2.99), listlessness (OR = 2.0) and frequent headache (OR = 1.84) A relationship between tinnitus and TMD was established in both examinations. Tinnitus patients seem to suffer especially from myofascial and TMJ pain. A screening for TMD should be included in the diagnostic survey for tinnitus patients.     

Temporomandibular dysfunction post-craniotomy: Evaluation between pre- and post-operative status

ObjectiveTo identify risk factors associated with post-operative temporomandibular joint dysfunction after craniotomy.MethodsThe study sample included 24 patients, mean age of 37.3 ± 10 years; eligible for surgery for refractory epilepsy, evaluated according to RDC/TMD before and after surgery. The primary predictor was the time after the surgery. The primary outcome variable was maximal mouth opening. Other outcome variables were: disc displacement, bruxism, TMJ sound, TMJ pain, and pain associated to mandibular movements. Data analyses were performed using bivariate and multiple regression methods.ResultsThe maximal mouth opening was significantly reduced after surgery in all patients (p = 0.03). In the multiple regression model, time of evaluation and pre-operative bruxism were significantly (p < .05) associated with an increased risk for TMD post-surgery.ConclusionA significant correlation between surgery follow-up time and maximal opening mouth was found. Pre-operative bruxism was associated with increased risk for temporomandibular joint dysfunction after craniotomy.     

Evaluation of the relationships between contrast-enhanced magnetic resonance characteristics and joint pain in patients with temporomandibular disorders

Objectives

To evaluate the correlations between temporomandibular joint (TMJ) pain and both conventional and gadolinium-enhanced magnetic resonance (MR) imaging characteristics in patients with temporomandibular disorders (TMDs).

Methods

T1-weighted, T2-weighted, and fat-suppressed contrast-enhanced T1-weighted MR imaging were performed in 80 TMD patients with the main complaint of TMJ pain. A kappa statistical analysis was performed to calculate the interobserver agreement between two of three radiologists. The relationships between TMJ pain and various MR findings were analyzed by multiple comparison test, Spearman’s rank correlation test, Chi-square test, Student’s t test, and multivariate logistic regression analysis.

Results

Significant correlations were observed between anterior disk displacement without reduction, joint effusion, and TMJ pain (p < 0.01). The degree of contrast enhancement of the posterior disk attachment was correlated with the severity of TMJ pain, especially spontaneous pain (r = 0.725, p < 0.01), while no correlation was observed in the masticatory muscle pain group. The correlation tended to be higher in the latero-central portions than in the medial portion of the mandibular condyle, although no significant difference was seen.

Conclusions

It has been suggested that fat-suppressed contrast-enhanced MR imaging techniques facilitate better understanding of the sources of TMJ pain, but not masticatory muscle pain, and could reflect TMJ synovial inflammation. The severity of TMJ pain was closely correlated with the degree of contrast enhancement. The above-mentioned correlation had a tendency to be higher in the latero-central portions of the mandibular condyle.

     

Comparison of algometry and palpation in the recognition of temporomandibular disorder pain complaints

AIMS: To determine the construct validity of algometry and to compare it with that of palpation, and to compare tenderness of masticatory muscle sites and the temporomandibular joint (TMJ) on palpation and on algometry. Methods: Two hundred fifty subjects, 148 with temporomandibular disorder (TMD) pain complaints, underwent a standardized blinded physical examination that included pain-intensity measures on palpation and pressure pain threshold measures on algometry of masseter muscle sites, temporalis muscle sites, and the TMJ. Results: Logistic regression analysis indicated that the recognition of TMD pain complaints based on pressure algometry was comparable to that of palpation (R2 = 0.22 and R2 = 0.21, respectively). The masseter muscles were most tender to palpation and algometry, followed by the TMJs and the temporalis muscles. Conclusion: Construct validity of algometry in the recognition of TMD pain complaints is comparable to that of palpation, and differences in tenderness on palpation and on algometry are found between masticatory muscle sites and the TMJ.     

Morphological and positional assessments of TMJ components and lateral pterygoid muscle in relation to symptoms and occlusion of patients with temporomandibular disorders

Disc displacement is accepted as one of major findings in temporomandibular disorders (TMD). However, the associations of disc positions with morphological and positional changes of temporomandibular joint (TMJ) components and lateral pterygoid (LP), TMD clinical symptoms, and occlusion have rarely been discussed quantitatively. In this study, the morphological and positional changes of TMJ components and LP were assessed by means of magnetic resonance imaging (MRI) and tomography of the TMJ in 41 TMD and nine control (CN) subjects. Disc positions in TMD subjects were divided into normal position (NP) and anterior displacement with and without reduction (ADR+ and ADR-, respectively). From MRI scans and tomograms, the morphological and positional changes of TMJ components and LP were measured and compared among CN, NP, ADR+ and ADR- groups. Correlations between these measurements and the scored clinical symptoms and occlusal factors were analysed in TMD subjects. The results indicated that: (1) TMJ osseous structures and LP showed no significant difference among CN and the three TMD groups, except for a posterior seat of condyle and shorter/steeper condylar movement during jaw opening; (2) disc length and inclination were significantly shorter and steeper, respectively, in ADR+ and ADR-; (3) disc positions were not specified by clinical symptoms and occlusal factors, except for the dominant TMJ sounds in ADR+; (4) an uncoordinated movement of the condyle/disc complex was found in ADR+ and/or ADR-; (5) TMJ osseous structures and the disc were weakly associated with clinical symptoms and occlusal factors. However, the LP showed negative associations with palpable pain for both the TMJ and jaw muscles and the static occlusal factors. These findings suggest that TMJ internal derangements are more related to the positional changes or spatial relationships of TMJ components but less to the individual morphologies of TMJ osseous structures, disc and LP, as well as specific clinical symptoms and occlusal factors, which might be in disagreement with a large body of previous statements.     

Correlation of different MRI characteristics of anterior disc displacement with reduction and without reduction

The aim of this study was to evaluate the correlations between magnetic resonance imaging (MRI) findings in anterior displacement with reduction (ADDR) and anterior displacement without reduction (ADDWR). Two hundred patients with temporomandibular disorder (TMD) symptoms were examined clinically by a clinician experienced with this disorder. There were 130 joints with ADDR and 45 joints with ADDWR; 88 patients were identified according to the clinical and MRI diagnoses of both observers. The MRI characteristics such as position, signal intensity, morphology of disc, degenerative changes, effusion, scar tissue, avascular necrosis, and condylar hypermobility were evaluated in the individual with ADDR and ADDWR. The Chi-square test was used to determine the correlation between MRI characteristics in the ADDR and the ADDWR. There were significant relationships between degenerative changes and increased signal intensity, degenerative changes and side-way displacement, effusion and the deformation of the disc, effusion and subluxation, increased signal intensity and subluxation, elongation deformation and increased signal intensity, and elongation deformation and side-way displacement in ADDR. There were significant relationships between degenerative changes and effusion, degenerative changes and decreased signal intensity, scar tissue and avascular necrosis, deformation of disc and increased signal intensity, as well as deformation of disc and decreased signal intensity in ADDWR. These MRI findings also correlated with the clinical findings, however, this correlation appears to be a synergistic pattern rather than a set of clear-cut relationships. The correlations between these MRIs and different clinical findings such as pain and dysfunction also must be evaluated. Existing correlations must be considered in the diagnosis and treatment planning of TMD, and signs and symptoms of TMD should be monitored after treatment.