Temporomandibular joint internal derangement: detection with 12.5 MHz ultrasonography.

The purpose of this study was to determine whether 12.5 MHz ultrasonography (US) could be used to assess the presence or absence of temporomandibular joint (TMJ) internal derangement (ID). In 48 consecutive patients with TMJ disorders 192 TMJ positions were investigated by US to analyse the functional disc-condyle relationship (DCR). In order to compare the respective findings with those of a diagnostic method offering a high accuracy, coronal and sagittal magnetic resonance imaging was carried out immediately afterwards. With US showing a sensitivity of 0.58 and 0.75, and a specificity of 0.92 and 0.84 for disc displacement with and without reduction, the data revealed US to be marginal in detecting the presence, but sensitive in detecting the absence of the respective types of a TMJ ID. In addition, with a positive predictive value of 0.83 and 0.71, and a negative predictive value of 0.81 and 0.87 for disc displacement with and without reduction, the results indicate that US may be insufficient in establishing a correct diagnosis for the presence or absence of the respective types of TMJ ID. Regarding the diagnosis of absence or presence of TMJ ID, the results demonstrate high-resolution (HR)-US to be sensitive in detecting the absence, and reliable in predicting the presence of TMJ ID. In view of the fact that the 12.5 MHz US technique proved to be a reliable diagnostic aid for the detection of normal, and the prediction of abnormal DCR, the results of this study should be of further interest and encourage research in its potential uses and diagnostic capabilities.

Temporomandibular joint osteoarthrosis diagnosed with high resolution ultrasonography versus magnetic resonance imaging: how reliable is high resolution ultrasonography?

The purpose of this study was to determine whether 12.5 MHz ultrasonography (US) could be used to assess the presence or absence of temporomandibular joint (TMJ) condylar osteoarthrosis. In 40 consecutive patients with TMJ disorders, 80 TMJs were investigated by US to analyse the condylar morphology. In order to compare the respective findings with those of a diagnostic method offering a high accuracy, coronal and sagittal magnetic resonance imaging was carried out immediately afterwards. With US showing a sensitivity of 87%, and a specificity of 20%, the data revealed US to be sensitive in detecting the presence, but insufficient in detecting the absence of osteoarthrosis. In addition, with a positive predictive value of 88%, and a negative predictive value of 18%, the results indicate that US may be valuable in diagnosing the presence, but insufficient in diagnosing the absence of osteoarthrosis. In view of the fact that the 12.5 MHz US technique proved to be a valuable diagnostic aid for the detection and prediction of abnormal condylar morphology, the results of this study should be of further interest and encourage research in its potential uses and diagnostic capabilities.

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.

Cross-sectional characteristics of the masseter muscle: an ultrasonographic study.

Cross-sections of the masseter muscle may now be measured non-invasively using ultrasonography. The purpose of the present study was to determine (1) whether the scanning level may affect cross-sectional measurements and (2) whether measurements made at identical levels may be reproducible. The study included 42 asymptomatic volunteers. Unilateral ultrasonographic investigation was performed with a linear (B-scan) 7.5 Mhz small-part transducer to register cross-sections of the masseter muscle on five different levels. Scans were made on the relaxed and contracted muscle. Measurements were made in two sessions with a time interval of at least 5 min. Statistical analysis consisted of univariate analysis of variance for repeated measurements. Data were analysed for reproducibility by using the method error and measurement error. For the ultrsonographic measurements the main effects of the variables 'session' (P=0.0001), 'level' (P=0.0001), and 'condition' (P=0.0001) were significant. Analysis of simple session-within-level effects revealed a significant difference between the repeated measurements for the most upper level (P=0.022), the upper level (P=0.012), and the most lower level (P=0.0001) of the relaxed muscle. An additional significant effect was found for the most lower level of the contracted muscle (P=0.015). Cross-sections evaluated at the middle (method error=0.31 mm; measurement error=2.0%) and lower level (method error=0.32 mm; measurement error=2.4%) of the contracted muscle were the most reproducible. The conclusion is that ultrasonography is a reproducible method for measuring cross-sections at the middle and lower level of the contracted masseter muscle.

Validation of the clinical diagnostic criteria for temporomandibular disorders for the diagnostic subgroup of degenerative joint disease.

Research is needed to assess the validity of the Clinical Diagnostic Criteria for Temporomandibular Disorders (CDC/TMD). The purpose of this study was to test the reliability of the clinical diagnosis of temporomandibular joint (TMJ) degenerative joint disease (DJD) as compared with the magnetic resonance imaging (MRI) 'gold standard'. The TMJ DJD group comprised 48 joints in 24 consecutive patients who were assigned a clinical bilateral diagnosis of TMJ DJD. The TMJ non-DJD group consisted of 82 joints in 41 consecutive patients without a TMJ-related diagnosis of TMD. Bilateral sagittal and coronal MR images were obtained subsequently to establish the corresponding diagnosis of degenerative joint changes. An MRI diagnosis of osteoarthrosis (OA) was defined by the presence of flattening, subchondral sclerosis, surface irregularities, and erosion of the condyle or presence of condylar deformities associated with flattening, subchondral sclerosis, surface irregularities, erosion and osteophyte. For the CDC/TMD interpretations, the positive predictive of DJD for OA was 67%, and for the presence of degenerative joint changes 88%. The overall diagnostic agreement for DJD was 44.6% with a corresponding K-value of 0.01. Most of the disagreement was due to false-negative interpretations of asymptomatic joints. The results suggest CDC/TMD to be predictive for degenerative joint changes but insufficient for determination of OA. Patients assigned a clinical TMJ-related diagnosis of DJD may need to be supplemented by evidence from MRI to determine the presence or absence of OA.

Effect of scanning level and muscle condition on ultrasonographic cross-sectional measurements of the anterior masseter muscle.

With the disadvantage of computed tomography showing cumulative biological effects and magnetic resonance imaging posing a problem in clinical availability and cost, several authors described the technique of ultrasonography to measure non-invasively local cross-sectional dimensions (LCSDs) of masseter muscle sites. However only few studies addressed the issue of 'technique-related factors for intra- and inter-observer reliability' to gain more consistent testing and diagnosis. The purpose of the present study was to determine (1) whether the scanning level and/or the muscle condition may affect LCSD measurements and (2) whether measurements made at identical levels may be reproducible. The study included 35 subjects with signs and symptoms of temporomandibular disorders. Bilateral ultrasonographic investigation was performed with a linear (B-scan) 7.5 Mhz small-part transducer to register LCSDs of the anterior masseter muscle on three different levels. Scans were made on the relaxed and contracted muscle. Measurements were made in two sessions with a time interval of at least 5 min. Data were analysed for reproducibility by using the intra-class correlation coefficient (ICC) and the method error (ME). Scanning level and muscle condition had a significant effect on muscle measurements (P = 0.000). There was no difference in LCSD between the right and left muscle (P = 0.531). Measurements recorded at a given site were consistent across the testing sessions (P = 0.058). The scanning level with highest reproducibility was halfway between the origin and insertion (ICC = 0.92; ME = 6.2%). The data suggest that ultrasonography is a reliable method for measuring LSCDs of the anterior masseter muscle.

Validation of the clinical diagnostic criteria for temporomandibular disorders for the diagnostic subgroup - disc derangement with reduction.

Research is needed to assess the validity of the clinical diagnostic criteria for temporomandibular disorders (CDC/TMD). The purpose of this study was to test the reliability of the clinical diagnosis of temporomandibular joint (TMJ) internal derangement type (ID)-I as compared with the magnetic resonance imaging (MRI) 'gold standard'. The study comprised 168 TMJs in 84 patients, who were assigned a clinical TMJ-related diagnosis of ID-I (disc displacement with reduction) in at least one TMJ. Bilateral sagittal and coronal MR images were obtained subsequently to establish the corresponding diagnosis of the disc-condyle relationship. For the CDC/TMD interpretations, the positive predictive value (PPV) of ID-I for disc displacement with reduction (DDR) was 44%, and for the presence of an ID 69%. The overall diagnostic agreement for ID-I was 47.6% with a corresponding K-value of 0.05. Most of the disagreement was the result of the false-positive interpretations of ID-I, and false-negative interpretations of an 'absence of ID'. The results suggest CDC/TMD for ID-I to be insufficient reliable for determination of ID and/or DDR. Patients assigned a clinical TMJ-related diagnosis of ID-I may need to be supplemented by evidence from MRI to determine the functional 'disc-condyle relationship'.

Ultrasonographic assessment of local cross-sectional dimensions of masseter muscle sites: a reproducible technique?

Local cross-sectional dimensions (LCSDs) of masseter muscle sites may now be measured non-invasively using ultrasonography. The purpose of the present study was to determine (i) whether the muscle site may affect LCSD measurements and (ii) whether measurements made at identical sites may be reproducible. The study included 17 patients who had signs and symptoms of temporomandibular disorders (TMD). Bilateral ultrasonographic investigation was performed with a linear (B-scan) 7.5 MHz small-part transducer to visualize the antero-superior, antero-inferior, medio-superior, medio-inferior, postero-superior, and postero-inferior sites of the masseter muscle. Measurements were made in two sessions with a time interval of at least five minutes. Data were analysed for reproducibility by using the intraclass correlation coefficient (ICC) and the method error (ME). Muscle site had no significant effect on muscle measurements (P = 0.090). Measurements from the various side-related sites did not differ significantly (P = 0.425). Measurements recorded at a given site were consistent across the testing sessions (P = 0.605). The muscle site with highest reproducibility was the medio-inferior site (ICC = 0.92; ME = 6.4%). The data suggest that ultrasonography is a reproducible method for measuring LSCDs of the masseter muscle.

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.

High-resolution ultrasonography of the TMJ: helpful diagnostic approach for patients with TMJ disorders ?

PURPOSE: The purpose of this study was to investigate patients with a clinical diagnosis of internal derangement to determine the diagnostic value of static high resolution ultrasonography (HR-US) when compared with magnetic resonance imaging (MRI). PATIENTS: Sixty-six patients (132 temporomandibular joints [TMJs]) with a clinical diagnosis of internal derangement were investigated by HR-US and MRI. METHODS: MRI and HR-US investigations were performed by experienced radiologists. The sonograms were done with a real-time 12-Mhz linear-array scanner. The HR-US interpretation errors were re-evaluated retrospectively by the same radiologist knowing the MRI results by comparing these with the 'prospective' and 'retrospective' diagnoses. The prospective and retrospective diagnoses were also compared with each other. RESULTS: Eighty-seven of the 132 TMJs had a disc displacement proved by MRI in the closed-mouth position. At maximum mouth opening, 54 TMJs had a disc displacement. The prospective interpretations showed a sensitivity and specificity of 78% each, accounting for an accuracy of 78%. At maximum mouth opening, HR-US resulted in a sensitivity of 61%, a specificity of 88% and an accuracy of 77%. The retrospective interpretations yielded a sensitivity of 90%, a specificity of 84% and an accuracy of 88% in the closed-mouth position. At maximum mouth opening, HR-US showed a sensitivity of 73%, a specificity of 95% and an accuracy of 86%. CONCLUSION: HR-US is suitable for the detection of disc displacements in the TMJ. However, further studies may be warranted to reduce the proportion of false-positive interpretations, thereby avoiding the application of unnecessary treatment.