Diagnostic value of 4 criteria to interpret temporomandibular joint normal disk position on magnetic resonance images

Relationships between functional temporomandibular joint space and disc morphology, position, and condylar osseous condition in patients with temporomandibular disorder

OBJECTIVE

To investigate the correlations between joint space and temporomandibular joint (TMJ) components and the compressive states of the disc and condyle subsequent to joint space changes.

MATERIALS AND METHODS

A total of 240 TMJs were categorized according to disc morphology, disc position, and condylar osseous condition. The two-dimensional (2D) and three-dimensional (3D) measurements were compared. The functional joint space (FJS) and disc areas on closed- and open-mouth images (DA-C and DA-O) were also calculated, and the joint space was measured in five directions. Different groups of TMJ components were compared. A spring model was used to simulate the effect of condylar displacement on the disc and condyle.

RESULTS

Disc morphology was strongly correlated with its position. The measurements were equivalent between 2D and 3D methods. DA-C and FJS differed significantly between groups. The DA-C to FJS ratio differed between the Class 2 and Class 3 groups and between disc displacement groups with and without reduction. Altered disc morphology and position were correlated with significant changes in joint space in the 60°, 90°, and 120° directions. Despite minor discrepancies among condylar osseous conditions, reduced joint space was correlated with bone destruction at the corresponding site. The spring model stimulation revealed that condylar displacement caused elevated stresses on the disc and condyle.

CONCLUSIONS

Condylar displacement causes joint space alterations while exerting compressive pressure on both the disc and condyle.

CLINICAL RELEVANCE

Proper condylar positioning within the fossa is recommended to ensure sufficient articular disc accommodation.

Arthroscopic discopexy versus natural course of temporomandibular joint anterior disc displacement: a longitudinal study of clinical and radiological outcomes

The aim of this study was to assess the various outcomes of arthroscopic discopexy compared to the natural course of anterior disc displacement (ADD) longitudinally in the same patients. A retrospective review was performed of 108 patients (152 joints) who experienced the natural course of ADD for a period of time and then underwent arthroscopic discopexy. The outcome was evaluated clinically and by magnetic resonance imaging. The natural course of ADD showed significant deterioration in pain, diet, and quality of life, and also a significant reduction in inter-incisal opening (all P < 0.001), while significant improvements in all clinical parameters were observed at the final postoperative follow-up (all P < 0.001, compared to the last preoperative visit). During the natural course, there was a significant shortening of condylar height, mandibular height, and disc length, and an increase in disc displacement distance (all P < 0.001). Postoperative follow-up revealed the restoration of condylar height and mandibular height, and all discs were significantly repositioned with an increased disc length (unfolded) (all P < 0.001). Bearing in mind the assumption of a low evidence base due to bias resulting from the retrospective non-double-blinded study design and the variable duration of the natural disease course prior to surgery, this study found that the natural course of ADD led to degenerative changes in the joint structures and clinical symptoms, whereas arthroscopic discopexy led to a restoration of the bony structures and the alleviation of clinical symptoms.

Imaging temporomandibular disorders: Reliability of a novel MRI-based scoring system

The aim of this study was to assess the inter- and intrarater reliability of a recently proposed scoring system for temporomandibular disorders (TMD), based upon radiological findings from magnetic resonance imaging (MRI). Patients with clinically suspected uni- or bilateral TMD, and subsequently conducted MRI examination of both temporomandibular joints, were included in this study. MRI data were independently evaluated by two experienced radiologists according to the DLJ scoring system proposed by Wurm et al., which includes assessment of the following categories: articular disk (prefix 'D'), direction of disk luxation (prefix 'L'), and osseous joint alterations (prefix 'J'). 60 patients (49 female and 11 male) were eligible for analysis. No significant differences were found between both observers regarding 'D' and 'L' scores (p = 0.13 and p = 0.59, respectively). Significant differences were found for the assessment of subtle osseous changes ('J0' category: p = 0.041; 'J1' category: p = 0.018). Almost perfect intra- and interrater agreements were found for 'D' and 'L' categories (intrarater and interrater agreements for 'D': κ = 0.92 and κ = 0.84, respectively; intrarater and interrater agreements for 'L': κ = 0.93 and κ = 0.89, respectively). However, the assessment of 'J' categories revealed only moderate interrater agreement (κ = 0.49). The DLJ scoring system based upon MRI findings is feasible for routine clinical TMD assessment, and may help to simplify interdisciplinary communication between radiologists and clinicians.

Condylar erosion is predictive of painful closed lock of the temporomandibular joint: a magnetic resonance imaging study

Background

To assess whether magnetic resonance imaging (MRI) findings of condylar erosion (CE) are predictive of a specific clinical diagnosis of painful closed lock of the temporomandibular joint (TMJ), and to determine the strength of association between CE and types of internal derangement (ID).

Methods

Based upon sample size estimation, this retrospective paired-design study involved 62 patients, aged between 18 and 67 years. Inclusion criteria were the presence of a unilateral clinical diagnosis of arthralgia coexisting with disk displacement without reduction (‘AR and DDwoR/wLO’), assigned according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) Axis I, and the absence of signs and symptoms of TMJ pain and dysfunction on the contralateral TMJ side. Bilateral sagittal and coronal MR images were obtained to establish the prevalence of CE and TMJ ID types of disk displacement with (DDR) and without reduction (DDNR). Logistic regression analysis was used to compute odds ratios for CE and ID types. Confounding variables adjusted for were age, sex, time since pain onset, pain intensity, and type of ID.

Results

In the regression analysis, the MRI items of DDR (p = 0.533) and DDNR (p = 0.204) dropped out as nonsignificant in the diagnostic clinical ‘AR and DDwoR/wLO’ group. Significant increases in the risk of ‘AR and DDwoR’ occurred with CE (3.1:1 odds ratio; p = 0.026). The presence of CE was significantly related to DDNR (adjusted OR = 43.9; p <  0.001).

Conclusions

The data suggest CE as a dominant factor in the definition of painful closed lock of the TMJ, support the view that joint locking needs to be considered as a frequent symptom of osteoarthritis, and emphasize a strong association between the MRI items of CE and DDNR.

A magnetic resonance imaging study on the temporomandibular joint disc-condyle relationship in young asymptomatic adults

The aim of this study was to assess the temporomandibular joint (TMJ) disc-condyle relationship in asymptomatic young adults. Ninety-three volunteers aged 19-23 years without temporomandibular disorder (TMD) symptoms underwent TMJ magnetic resonance imaging (MRI). The condylar centre and apex methods were used to measure and analyse the position of the disc in the oblique sagittal plane, and the reliability of the two methods was compared by calculating the intra-class correlation coefficient (ICC). Furthermore, 18 of the volunteers were randomly selected for three-dimensional (3D) reconstruction of the TMJ structure and the disc-condyle relationship. The 3D TMJ structure was established by semi-automatic segmentation of the condyle and articular disc in ITK-SNAP software; the condylar apex method was then performed. It was found that only 33.3% of the posterior edge of the articular discs were located in the normal 12 o'clock position with respect to the condyle. Moreover, this study suggests that the condylar centre method lacks accuracy when compared to the condylar apex method in regard to the measurement of the TMJ disc-condyle relationship (0 < ICC_cen < ICC_apex < 1). The position of the articular disc (left and right) was more forward in young women when compared to young men. However, there was no significant difference in the TMJ disc-condyle position between the left and right sides in the same individual, although the two joint discs in the same individual were not completely symmetrical.

Real-time assessment of temporomandibular joint using HASTE sequences: feasibility and comparison with standard static sequences

OBJECTIVE

To test real-time MRI (rtMRI) using HASTE sequences in patients with suspected internal disk derangement (IDD) of temporomandibular joint (TMJ) and to compare these sequences with standard static sequences.

METHODS AND MATERIALS

99 TMJ were studied with both standard sequences (fat-saturated proton density) and HASTE sequences with high temporal resolution. Image quality was assessed using a 4-point Likert scale. Two radiologists analysed both standard and rtMRI sequences separately, randomly and blinded (by a third operator) to patients' names in order to assess inter-observer repeatability. One of the radiologists performed the analysis twice for assessing intra-observer repeatability. The same radiologists evaluated randomly and blinded to the previous assessment both the sequences and decided in consensus which was the most credible. Qualitative scores were compared using Friedman's test while concordance between radiologists and sequences was evaluated using the concordance correlation coefficient.

RESULTS

At image quality analysis, mean score was 3.41 for static MRI and 3.82 for rtMRI, with a statistically significant difference in favour of rtMRI (p < 0.0001). Inter-rater concordance between operator 1 (Op1) and operator 2 (Op2) with regard to the same sequence was high for both static and rtMRI sequences (0.824 and 0.888, respectively). Inter-rater variability of Op1 and Op2 between static and rtMRI sequences was lower (0.647 for Op1 and 0.633 for Op2). Among 71 discordances between sequences, 60 were judged in favour of rtMRI, while 11 were in favour of static MRI.

CONCLUSION

rtMRI with HASTE sequences is a robust technique and provide additional information in assessing IDD compared to static sequences.

Magnetic resonance imaging evaluation of articular disk position after orthognathic surgery with or without concomitant disk repositioning: a retrospective study

OBJECTIVE

The aim of this study was to compare the outcomes of 2 surgical treatment options: one for correction of class II malocclusion skeletal deformity and one for pre-existing temporomandibular joint (TMJ) disorders requiring orthognathic surgery (OS) for correction of dentofacial deformity.

STUDY DESIGN

This retrospective study evaluated patients who underwent OS with maxillomandibular advancement (MMA) with or without concomitant TMJ surgery for articular disk repositioning (ADR). Patients were divided into 2 groups: group I (MMA) was treated with OS only (18 patients); and group II (MMA-ADR) was treated with OS and concomitant ADR (19 patients). The sample consisted of 74 TMJs (mean patient age 29.86 years).

RESULTS

In group I, 38.5% of the disks that were originally in normal position became displaced after OS, and 33.3% of displaced disks with reduction became nonreducing after OS. In group II, 78.9% of disks exhibited normal position in the final evaluation, and 97.3% of patients showed improved disk position after surgery. There was significant symptom improvement in all patients in group II, but no significant improvement in group I.

CONCLUSIONS

OS with ADR appears to produce stable and beneficial results in improving symptoms in patients with displaced disk and TMJ pain.

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

OBJECTIVES

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 only, the most often used in temporomandibular disorder (TMD) patients, with a multisection evaluation done with both sagittal and coronal scans.

MATERIALS AND METHODS

Multisection MRI analysis of 382 TMJs was conducted in 191 patients with disc displacement according to RDC/TMD criteria. Disc position in the intercuspal position (IP) was assessed two times using two different methods. The first method involved a TMJ disc position evaluation on the central slide in the oblique sagittal plane only. In the second method, the TMJ disc position was assessed on all oblique sagittal and coronal images. McNemar's χ² test was used to evaluate the differences between the sensitivities of two methods.

RESULTS

The first method (central oblique sagittal scans assessment) identified 148 TMJs (38.7%) with normal disc position compared with 89 TMJs (23.3%) with normal disc position found by the second method (all oblique sagittal and coronal scans assessment). The sensitivity of analysis in both planes was significantly higher than in the sagittal plane only (p < 0.001).

CONCLUSIONS

The multisection analysis in the sagittal and coronal plane allows to distinguish the correct disc position from disc displacement and thus improve evaluation of TMJ internal derangement.

CLINICAL RELEVANCE

The multisection sagittal and coronal images should be recommended as a standard in MRI of the TMJ disc displacement in patients with TMD to avoid false-negative diagnoses.

Shear Wave Elastography in the Evaluation of Temporomandibular Joint Disorders

We aimed at verifying the usefulness of shear wave elastography in determining the temporomandibular disc stiffness in patients with a temporomandibular disorders (TMDs). The study included 37 patients with confirmed TMDs and 208 healthy volunteers. Patients presented with significantly greater stiffness of the intermediate zone of the disc (region of interest [ROI] 1) and significantly lower stiffness of its anteriorly displaced portion (ROI 3). A receiver operating characteristics analysis indicated that a decrease in the stiffness in ROI 3 less than 8.667 KPa provided 100% sensitivity, 97.3% specificity, 100% positive predictive value (PPV) and 99.5% negative predictive value (NPV) in distinguishing between patients with TMDs and without. Whereas an increase in ROI 1 stiffness to at least 54.33 KPa provided high specificity and NPV, both the sensitivity and the PPV of this predictor equaled zero. Findings suggest that a decrease in anteriorly dislocated disc stiffness less than 8.667 kPa can accurately identify patients with TMDs.

Correlation between pain and MRI findings in TMD patients

INTRODUCTION

Magnetic resonance imaging has been established as the gold standard for assessment of the temporomandibular joint. Apart from an excellent assessment of the soft tissues it has the advantage not to expose the patient to ionizing radiation. There is a lack of literature concerning the correlation between pain intensity and radiological findings of the temporomandibular joint. Moreover there is the question of whether a progressive degeneration of the cartilaginous components is accompanied by an increasing degeneration of the osseous parts of the mandibular joint and vice versa. Therefore, this study aims at analyzing correlations between pain and radiological findings. Furthermore, the link between osseous and cartilaginous degeneration is studied.

MATERIALS AND METHODS

91 patients who attend our outpatient clinic for temporomandibular disorders are included in this prospective study. Apart from a detailed anamnesis and clinical examination - adapted to the Research Diagnostic Criteria for Temporomandibular Disorders -magnetic resonance imaging of both mandibular joints is performed. Pain intensity is measured using the visual analog scale. To assess and grade the radiological findings a classification system is established. The evaluation of the osseous components is based on the classification of osteoarthritis by Kellgren and Lawrence whereas the rating of the cartilaginous components is adapted to the Research Diagnostic Criteria for Temporomandibular Disorders. Correlations are verified by Spearman-Rho.

RESULTS

83,5% of all patients are female. Most of the time, both sides are affected (47.25%). Women state an average pain of 5.7 (±2.4), men 3.5 (±2.5). 182 discs are examined and assessed with our classification system. Most discs (n = 71) show no pathological changes. The majority of patients show no dislocation (n = 104). The most common forms of dislocation are anterior dislocations (n = 51). The majority of patients show no changes in the osseous component (n = 115). Weak to moderate correlations are found between disc and bone degeneration. Moderate to strong correlations are found between left and right TMJ.

CONCLUSIONS

The classification system which is designed and applied during the study proves to be a reliable and practical Instrument. A standardized evaluation of pathologies concerning the temporomandibular joint is possible by using this system. Numerous patients attending our outpatient clinic do not show any signs of degenerative dysfunctions in the mandibular joints. Degenerations of the osseous components tend to be connected with degenerations of the cartilaginous components and vice versa. The question remains if in the future new procedures in imaging will be able to record pathologies not yet detected.

Disk displacement, eccentric condylar position, osteoarthrosis - misnomers for variations of normality? Results and interpretations from an MRI study in two age cohorts

Background

Clinical decision-making and prognostic statements in individuals with manifest or suspected temporomandibular disorders (TMDs) may involve assessment of (a) the position of articular disc relative to the mandibular condyle, (b) the location of the condyle relative to the temporal joint surfaces, and (c) the depth of the glenoid fossa of the temporomandibular joints (TMJs). The aim of this study was twofold: (1) Determination of the prevalence of these variables in two representative population-based birth cohorts. (2) Reinterpretation of the clinical significance of the findings.

Methods

From existing magnetic resonance imaging (MRI) scans of the TMJs that had been taken in 2005 and 2006 from 72 subjects born between 1930 and 1932 and between 1950 and 1952, respectively, the condylar position at closed jaw was calculated as percentage displacement of the condyle from absolute centricity. By using the criteria introduced by Orsini et al. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 86:489-97, 1998), a textbook-like disc position at closed jaw was distinguished from an anterior location. TMJ morphology of the temporal joint surfaces was assessed at open jaw by measuring the depth of the glenoid fossa, using the method proposed by Muto et al. (J Oral Maxillofac Surg 52:1269-72, 1994).

Frequency distributions were recorded for the condylar and disc positions at closed jaw.

Student’s t-test with independent samples was used as test of significance to detect differences of condylar positions between the age cohorts (1930 vs. 1950) and the sexes. The significance levels were set at 5%. First, the results from the measurement of the age cohorts were compared without differentiation of sexes, i.e., age cohort 1930–1932 versus age cohort 1950–1952. Subsequently, the age cohorts were compared by sex, i.e., men in cohort 1930–1932 versus men in cohort 1950–1952, and women in cohort 1930–1932 women men in cohort 1950–1952.

Results

In both cohorts, condylar position was characterized by great variability. About 50% of the condyles were located centrically, while the other half was either in an anterior or in a posterior position. In both female cohorts, a posterior position predominated, whereas a centric position prevailed among men. Around 75% of the discs were positioned textbook-like, while the remaining forth was located anteriorly. Age had no statistically significant influence on condylar or on disc position. Conversely, comparison between the age groups revealed a statistically significant decrease of the depth of the glenoid fossa in both older cohorts. This age-dependent changes may be interpreted as flattening of the temporal joint surfaces.

Conclusions

We call for a re-interpretation of imaging findings because they may insinuate pathology which usually is not present. Instead, anterior or posterior positions of the mandibular condyle as well as an anterior location of the articular disc should be construed as a variation of normalcy. Likewise, flattening of articular surfaces of the TMJs may be considered as normal adaptive responses to increased loading, rather than pathological degenerative changes.

Trial registration

Not applicable.

MRI alone versus MRI-CBCT registered images to evaluate temporomandibular joint internal derangement

OBJECTIVE

To evaluate the effect of magnetic resonance imaging-cone beam computed tomography (MRI-CBCT) image registration on inter- and intraexaminer consistency when evaluating temporomandibular joint (TMJ) internal derangement compared to MRI alone.

METHODS

MRI and CBCT images of 25 patients (50 TMJs) were obtained and coregistered using mutual-information rigid image registration via Mirada XD software. Two experienced radiologists independently and blindly evaluated two types of images (MRI alone and MRI-CBCT registered images) at two different times (T1 and T2) for TMJ internal derangement, based on sagittal and coronal articular disc position in relation to the head of the condyle and the posterior slope of the articular eminence.

RESULTS

The intraexaminer consistency with MRI alone (examiner 1 = 0.85 [0.74-0.92]; examiner 2 = 0.91 [0.84-0.95]) was lower than for the MRI-CBCT registered images (examiner 1 = 0.95 [0.91-0.97]; examiner 2 = 0.97 [0.96-0.99]). The interexaminer consistency of evaluating internal derangement with MRI alone (0.52 [0.18-0.73] at T1; 0.71 [0.45-0.84] at T2) was lower than for the MRI-CBCT registered images (0.97 [0.95-0.98] at T1; 0.98 [0.96-0.99] at T2). When disc position classification was dichotomized to normal versus anteriorly displaced, intraexaminer agreement for the two examiners was 0.52 and 0.63 for MRI alone, but was 0.91 and 0.92 for MRI-CBCT registered images. Interexaminer agreement for MRI alone was 0.29 at T1 and 0.42 at T2, but was 0.96 at both examination times for MRI-CBCT registered images.

CONCLUSION

The MRI-CBCT registered images improved intra- and interexaminer consistency in the evaluation of internal derangement of TMJ.

Assessing the reliability of MRI-CBCT image registration to visualize temporomandibular joints

OBJECTIVES

To evaluate image quality of two methods of registering MRI and CBCT images of the temporomandibular joint (TMJ), particularly regarding TMJ articular disc-condyle relationship and osseous abnormality.

METHODS

MR and CBCT images for 10 patients (20 TMJs) were obtained and co-registered using two methods (non-guided and marker guided) using Mirada XD software (Mirada Medical Ltd, Oxford, UK). Three radiologists independently and blindly evaluated three types of images (MRI, CBCT and registered MRI-CBCT) at two times (T1 and T2) on two criteria: (1) quality of MRI-CBCT registrations (excellent, fair or poor) and (2) TMJ disc-condylar position and articular osseous abnormalities (osteophytes, erosions and subcortical cyst, surface flattening, sclerosis).

RESULTS

75% of the non-guided registered images showed excellent quality, and 95% of the marker-guided registered images showed poor quality. Significant difference was found between the non-guided and marker-guided registration (χ(2) = 108.5; p < 0.01). The interexaminer variability of the disc position in MRI [intraclass correlation coefficient (ICC) = 0.50 at T1, 0.56 at T2] was lower than that in MRI-CBCT registered images [ICC = 0.80 (0.52-0.92) at T1, 0.84 (0.62-0.93) at T2]. Erosions and subcortical cysts were noticed less frequently in the MRI-CBCT images than in CBCT images.

CONCLUSIONS

Non-guided registration proved superior to marker-guided registration. Although MRI-CBCT fused images were slightly more limited than CBCT alone to detect osseous abnormalities, use of the fused images improved the consistency among examiners in detecting disc position in relation to the condyle.

Imaging of the temporomandibular joint: An update

Imaging of the temporomandibular joint (TMJ) is continuously evolving with advancement of imaging technologies. Many different imaging modalities are currently used to evaluate the TMJ. Magnetic resonance imaging is commonly used for evaluation of the TMJ due to its superior contrast resolution and its ability to acquire dynamic imaging for demonstration of the functionality of the joint. Computed tomography and ultrasound imaging have specific indication in imaging of the TMJ. This article focuses on state of the art imaging of the temporomandibular joint. Relevant normal anatomy and biomechanics of movement of the TMJ are discussed for better understanding of many TMJ pathologies. Imaging of internal derangements is discussed in detail. Different arthropathies and common tumors are also discussed in this article.

Usefulness of dual echo volumetric isotropic turbo spin echo acquisition (VISTA) in MR imaging of the temporomandibular joint

PURPOSE

We investigated the ability to detect the articular disk and joint effusion of the temporomandibular joint (TMJ) of a method of dual echo volumetric isotropic turbo spin echo acquisition (DE-VISTA) additional fusion images (AFI).

METHODS

DE-VISTA was performed in the 26 TMJ of 13 volunteers and 26 TMJ of 13 patients. Two-dimensional (2D) dual echo turbo spin echo was performed in the 26 TMJ of 13 volunteers. On a workstation, we added proton density-weighted images (PDWI) and T2 weighted images (T2WI) of the DE-VISTA per voxel to reconstruct DE-VISTA-AFI. Two radiologists reviewed these images visually and quantitatively.

RESULTS

Visual evaluation of the articular disk was equivalent between DE-VISTA-AFI and 2D-PDWI. The sliding thin-slab multiplanar reformation (MPR) method of DE-VISTA-AFI could detect all articular disks. The ratio of contrast (CR) of adipose tissue by the articular disk to that of the articular disk itself was significantly higher in DE-VISTA-AFI than DE-VISTA-PDWI (P<0.05) in patients and volunteers with closed or open mouth. In volunteers, the CR between adipose tissue and the disk on DE-VISTA-AFI was marginally significant to that on 2D-PDWI at opened mouth (P=0.071) and not significantly different (P=0.18) from that at closed mouth. Joint effusion could be identified in DE-VISTA-AFI in all 8 joints that had joint effusion in DE-VISTA-T2WI but in only 3 of those joints in 2D-T2WI. The CR of joint effusion to adipose tissue on DE-VISTA-AFI did not differ significantly from that on DE-VISTA-PDWI. However, using DE-VISTA-T2WI in addition to DE-VISTA-PDWI, we could visually identify joint effusion on DE-VISTA-AFI that could not be identified on DE-VISTA-PDWI alone.

CONCLUSION

DE-VISTA-AFI can depict the articular disk and a small amount of joint effusion by the required plane of MPR using the sliding thin-slab MPR method.

Temporomandibular joint (TMJ) disc position in patients with TMJ pain assessed by coronal MRI

OBJECTIVES

To assess the position of the temporomandibular joint (TMJ) disc in patients with TMJ pain and compare it with equivalent published data of asymptomatic volunteers.

METHODS

The oblique coronal closed- and open-jaw MR images from 66 patients with TMJ pain were evaluated. Clinical examination followed the research diagnostic criteria for temporomandibular disorders. In all coronal images, the transverse condylar axis and the medial and lateral edges of the disc were determined using special software. Inter-rater agreement was calculated [two raters; inter-rater correlation coefficient (ICC)]. The presence of osteoarthrosis (OA) was determined by two independent raters. The influence of OA was estimated in patients (generalized estimation equation model). The results were compared with those of healthy volunteers (t-test). Differences between closed and open jaw in patients were analysed with the Wilcoxon matched-pair test.

RESULTS

The ICC was good for the transverse condylar axis (0.987) and the medial edge of the disc (0.799) and fair for the lateral edge (0.355). On average, the disc projected 5.5% to the medial side; laterally, the condyle was partially uncovered by the disc (-16.6%). In the open-jaw position, both the medial and the lateral edges shifted medially (to 17.6% vs -23.6%, Wilcoxon matched-pair test, p < 0.001). OA had no significant influence (generalized estimation equation model, p = 0.952). The disc position differed significantly from asymptomatic individuals (t-test, p < 0.001) who showed a medial disc position and full coverage of the condyle.

CONCLUSIONS

In patients with TMJ pain, the disc seems to be smaller and located less medially than in healthy volunteers. The extent of the medial shift on opening was similar.

Web-based calibration of observers using MRI of the temporomandibular joint

OBJECTIVES

Research diagnostic criteria for temporomandibular disorders (RDC/TMDs) were proposed in 1992 with the aim of standardizing and testing methods for diagnosing TMDs. RDC/TMDs have so far been lacking standardized methods for imaging and criteria for imaging diagnosis of disorders of the temporomandibular joint (TMJ). Criteria for disorders of the TMJ have recently been proposed for MRI. The aim of this study was to publish MR images of the TMJ on the web and to test the agreement of five observers using the criteria.

METHODS

20 cases of MRI of the TMJ were published on the web together with the criteria. The MR images were taken in closed and open mouth positions, and sagittal and coronal views. Five observers diagnosed disc position, disc shape, joint effusion and loose calcified bodies in the TMJ.

RESULTS

In all cases except one, three or more observers agreed upon the diagnosis. All agreed on whether a loose calcified body was present or not. The second best agreement was obtained for disc position in the sagittal view, where all observers agreed in 16 of the 20 cases. For disc position in the coronal view and the evaluation of the disc shape, observer agreement was lower.

CONCLUSION

Criteria were useful in order to standardize and simplify evaluation and thereby probably increase the diagnostic outcome among different observers for MRI of the TMJ. We recommend that the criteria be used internationally to facilitate comparisons between different studies.

How should the articular disk position be analyzed?

PURPOSE

To compare 2 methods used to determine the disk position based on sagittal magnetic resonance images.

PATIENTS AND METHODS

A cross-sectional study of patients with the signs and symptoms of temporomandibular disorders was conducted. The patients' ages and gender distributions were collected. The disk position diagnosis from the clinical examination was considered the primary outcome. Three observers evaluated the presence of anterior displacement on magnetic resonance images according to 2 criteria: method 1 (12-o'clock position) and method 2 (location of the intermediate zone). To assess the intraobserver variability of the 2 methods, the examiners evaluated the same magnetic resonance images at the beginning of the study (time 1) and 40 days later (time 2). The intraobserver agreement was assessed using the observed agreement and the kappa statistic. McNemar's test was used to assess the differences between each method and the clinical examination findings (P < .05). The accuracy, sensitivity, specificity, and positive and negative predictive values were calculated by comparing the diagnosis from each method with that from the clinical examination (considered the reference standard).

RESULTS

The final sample was composed of 20 subjects with a mean age of 33.0 ± 33.7 years; 3 were men (15%) and 17 were women (85%). A statistically significant difference between the 2 methods was found. Method 1 yielded a greater percentage of anterior displaced disks (52.5%). The agreement between the clinical diagnosis and method 1 was lower (70.0%) than that between the clinical diagnosis and method 2 (87.5%). No statistically significant difference was found between the clinical diagnosis and method 2.

CONCLUSION

The disk position should be judged according to the intermediate zone criterion.

Lateral cephalometric analysis of mandibular morphology: discrimination among subjects with and without temporomandibular joint disk displacement and osteoarthrosis

To assess whether in patients with temporomandibular joint (TMJ) arthralgia cephalometric variables of mandibular morphology may discriminate among the magnetic resonance (MR) imaging-based TMJ groups of 'bilateral presence of disk displacement without reduction (DDwoR) and osteoarthrosis (OA)' and 'bilateral absence of bilateral DDwoR and OA'. Bilateral MR imaging of the TMJ was performed in 45 consecutive TMJ arthralgia patients to identify individuals with the specific structural characteristics of bilateral TMJ DDwoR associated with OA. Linear and angular cephalometric measurements were taken from lateral cephalograms to apply selected criteria of mandibular morphology. A discriminant function analysis was used to investigate how cephalometric parameters discriminate among the TMJ groups of 'bilateral presence of DDwoR with OA' and 'bilateral absence of DDwoR and OA'. Ramus height (Ar-Go) and effective mandibular length (Ar-Pog) produced a significant discriminant function that predicted TMJ group membership (P < 0·001). This function correctly classified 80·2% of original and cross-validated grouped cases. This study supports the concept that cephalometric variables of mandibular morphology discriminate among subjects with and without bilateral TMJ DDwoR and OA.

Test-retest reliability of MRI-based disk position diagnosis of the temporomandibular joint

This study evaluated the test-retest reliability for determining the temporomandibular joint (TMJ) disk position, diagnosed using magnetic resonance imaging (MRI). These assessments were done as a base-line measurement for a prospective cohort study, which examines the risk factors for precipitation and progression of temporomandibular disorders. Fifteen subjects (mean age, 24.2 ± 0.94 years; male/female = 8/7) were recruited from the students of Okayama University Dental School. Sagittal MR TMJ images were taken with a 1.5-T MR scanner (Magneton Vision, Siemens) in close and maximal open positions twice at about 1-week (6-11 days) interval. The images were displayed using 200% magnification on a computer screen with a commercially available image software package (OSIRIS, UIN/HCUG). Three calibrated examiners diagnosed the disk positions using the standardized criteria. The disk position of each joint was classified as normal, anterior disk displacement with or without reduction, and others. The first and second disk position diagnoses were compared, and the test-retest reliability level was calculated using the kappa index. The second disk position diagnosis was consistent with the first in 27 out of 30 joints. The calculated kappa value representing the test-retest reliability level between the first and second disk position diagnosis was 0.812. These results indicated that the test-retest reliability of MRI-based diagnosis of TMJ disk positions at about 1-week interval was substantially high, even though they were not completely consistent.

Quantification of disc displacement in internal derangement of the temporomandibular joint using magnetic resonance imaging

Many measures have been developed to determine the extent of disc displacement in internal derangements of the temporomandibular joint (TMJ) using magnetic resonance imaging. The purpose of this study was to develop a quantitative method of analyzing disc position and to evaluate the positions of the disc in internal derangements of the TMJ (group 1, with reduction; group 2, without reduction). Magnetic resonance images of 150 TMJs in 20 healthy volunteers and 55 patients with internal derangements were evaluated. The anatomical points of interest of the TMJ, including the anterior (DA) and posterior (DP) points of the disc, were marked on parasagittal magnetic resonance images of the TMJ disc taken in both the closed- and the open-mouth positions. All points were recorded using an x-y coordinate system, with reference to a referral line. In the closed-mouth position, the DP in patients in group 1 was situated in a more-anterior direction than the DP in volunteers. The DP in group 2 was located further anterior and inferior than the DP in group 1. However, the position of the DA did not differ between group 1 and group 2. In the open-mouth position, the DP was displaced anteroinferiorly to a greater extent in group 2 than in group 1 (one-way ANOVA, followed by Scheffe's test; P < 0.0001). The distance between the disc points in the closed- and open-mouth positions was also evaluated. Comparison of the disc point position in the closed- and open-mouth positions in symptomatic and asymptomatic displaced TMJ discs revealed no significant difference. In conclusion, most of our results quantitatively support previously reported findings in imaging, surgical, and histopathological studies of TMJ internal derangement. We suggest that our measure of disc position of the TMJ would be useful to assess the status and response to treatment of internal derangements of the TMJ.

Research diagnostic criteria for temporomandibular disorders (RDC/TMD): development of image analysis criteria and examiner reliability for image analysis

OBJECTIVE

As part of the Multisite Research Diagnostic Criteria For Temporomandibular Disorders (RDC/TMD) Validation Project, comprehensive temporomandibular joint diagnostic criteria were developed for image analysis using panoramic radiography, magnetic resonance imaging (MRI), and computerized tomography (CT).

STUDY DESIGN

Interexaminer reliability was estimated using the kappa (kappa) statistic, and agreement between rater pairs was characterized by overall, positive, and negative percent agreement. Computerized tomography was the reference standard for assessing validity of other imaging modalities for detecting osteoarthritis (OA).

RESULTS

For the radiologic diagnosis of OA, reliability of the 3 examiners was poor for panoramic radiography (kappa = 0.16), fair for MRI (kappa = 0.46), and close to the threshold for excellent for CT (kappa = 0.71). Using MRI, reliability was excellent for diagnosing disc displacements (DD) with reduction (kappa = 0.78) and for DD without reduction (kappa = 0.94) and good for effusion (kappa = 0.64). Overall percent agreement for pairwise ratings was >or=82% for all conditions. Positive percent agreement for diagnosing OA was 19% for panoramic radiography, 59% for MRI, and 84% for CT. Using MRI, positive percent agreement for diagnoses of any DD was 95% and of effusion was 81%. Negative percent agreement was >or=88% for all conditions. Compared with CT, panoramic radiography and MRI had poor and marginal sensitivity, respectively, but excellent specificity in detecting OA.

CONCLUSION

Comprehensive image analysis criteria for the RDC/TMD Validation Project were developed, which can reliably be used for assessing OA using CT and for disc position and effusion using MRI.

Analysis of magnetic resonance images of disk positions and deformities in 1,265 patients with temporomandibular disorder

Objectives

To compare MRI manifestations according to gender and age and to identify correlations between clinical manifestations and MRI findings in patients with temporomandibular disorder (TMD) as based on a large series.

Materials and Methods

Fat suppressed oblique sagittal images of the open and closed mouth were acquired, and MRI scanning parameters were applied.

Results

The patients consisted of 946 females (average, 36.6 years old), and 319 males (average, 34.3 years old). In all TMD patients, 945 had symptoms in the unilateral temporomandibular joint (TMJ) and 320 in the bilateral TMJ. There were significant differences in the distribution of disk positions based on age, regardless of gender, in the unilaterally and bilaterally symptomatic groups; however, the results were not significant in the asymptomatic group. There were significant differences with respect to the distribution of disk positions between males and females in asymptomatic group and in the unilaterally symptomatic group, although the bilaterally symptomatic group did not show significant differences in this regard. As regards the disk positions in the joints of the three groups (asymptomatic group, unilaterally and bilaterally symptomatic groups), there were significant interactive effects of disk positions, regardless of gender. There were statistically significant age-related differences in disk deformities in all symptom groups, regardless of gender, except for in the group of males lacking symptoms in either joint. As regards disk deformities among the three groups studies here, there were significant interactive effects for disk positions, regardless of gender.

Validity of temporomandibular disorder examination procedures for assessment of temporomandibular joint status

INTRODUCTION

This hypothesis-generating study was performed to determine which items in the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) and additional diagnostic tests have the best predictive accuracy for joint-related diagnoses.

METHODS

One hundred forty-nine TMD patients and 43 symptom-free subjects were examined in clinical examinations and with magnetic resonance imaging (MRI). The importance of each variable of the clinical examination for correct joint-related diagnosis was assessed by using MRI diagnoses. For this purpose, "random forest" statistical software (based on classification trees) was used.

RESULTS

Maximum unassisted jaw opening, maximum assisted jaw opening, history of locked jaw, joint sound with and without compression, joint pain, facial pain, pain on palpation of the lateral pterygoid area, and overjet proved suitable for distinguishing between subtypes of joint-related TMD. Measurement of excursion, protrusion, and midline deviation were less important.

CONCLUSIONS

The validity of clinical TMD examination procedures can be enhanced by using the 16 variables of greatest importance identified in this study. In addition to other variables, maximum unassisted and assisted opening and a history of locked jaw were important when assessing the status of the TMJ.

Clinical diagnoses and MRI findings in patients with TMD pain

The aim of this study was to compare the findings on magnetic resonance imaging (MRI) in temporomandibular disorders (TMD) pain patients with clinical diagnoses of myofascial pain or arthralgia/osteoarthritis in combination with myofascial pain according to the Research Diagnostic Criteria for TMD. The temporomandibular joints of 60 consecutive patients, 19 with myofascial pain and 41 patients with arthralgia/osteoarthritis in combination with myofascial pain were examined clinically and with MRI. Overall the most common MRI findings were different kinds of disc displacements and structural bone changes, which were found in both pain groups. However, disc displacements were found significantly (P=0.002) more often in the group arthralgia/osteoarthritis in combination with myofascial pain. One hundred and four joints were found to have no clinical diagnosis of disc displacements, but 64 of these joints had findings of disc displacements on MRI. Joint fluid was found in both pain groups. Patients having a combination of disc displacement and joint fluid were significantly (P=0.047) more common in the pain group arthralgia/osteoarthritis in combination with myofascial pain. In conclusion, the MRI findings of different kinds of disc displacement and structural bone changes were common in TMD patients. The clinical diagnoses for subdivision into myogenous only or combined arthrogenous and myogenous pain groups were not confirmed by MRI.

Sonographic investigation of the temporomandibular joint in patients with juvenile idiopathic arthritis: A pilot study

OBJECTIVE

To evaluate whether there are any correlations between the clinical parameters of temporomandibular joint (TMJ) arthritis and pathologic ultrasound (US) findings of the TMJ in patients with juvenile idiopathic arthritis (JIA).

METHODS

We conducted prospective clinical and US investigations of the TMJs of 48 patients with JIA. The US investigation was performed by a 12-MHz high-resolution transducer, which was positioned parallel to the ramus of the mandible overlying the zygomatic arch in a closed-mouth position and maximum open-mouth position.

RESULTS

Patients with > or = 5 peripheral affected joints showed significantly more sonographically diagnosed destructive changes in the TMJ than did patients with <5 affected joints. There was no significance between the number of affected peripheral joints and disc dislocation in the closed-mouth position. In the maximum open-mouth position, there was a significant correlation between the number of affected peripheral joints and disc dislocation. Patients with a JIA duration >23 months had a significantly higher rate of disc dislocation and destructive changes. Patients with a JIA duration >60 months had a significantly higher rate of destructive changes of the TMJ than patients with a disease duration <60 months, but no statistical significance was found concerning disc dislocation.

CONCLUSION

The significant correlation between pathologic sonographic findings, duration of JIA, and the number of affected peripheral joints make the technique interesting for use as a diagnostic screening method.

Dental attrition models predicting temporomandibular joint disease or masticatory muscle pain versus asymptomatic controls

AIMS

To determine whether patients with temporomandibular joint disease or masticatory muscle pain can be usefully differentiated from asymptomatic controls using multifactorial classification tree models of attrition severity and/or rates.

METHODS

Measures of attrition severity and rates in patients diagnosed with disc displacement (n = 52), osteoarthrosis (n = 74), or masticatory muscle pain only (n = 43) were compared against those in asymptomatic controls (n = 132). Cross-validated classification tree models were tested for fit with sensitivity, specificity, accuracy and log likelihood accountability.

RESULTS

The model for identifying asymptomatic controls only required the three measures of attrition severity (anterior, mediotrusive and laterotrusive posterior) to be differentiated from the patients with a 74.2 +/- 3.8% cross-validation accuracy. This compared with cross-validation accuracies of 69.7 +/- 3.7% for differentiating disc displacement using anterior and laterotrusive attrition severity, 68.7 +/- 3.9% for differentiating disc displacement using anterior and laterotrusive attrition rates, 70.9 +/- 3.3% for differentiating osteoarthrosis using anterior attrition severity and rates, 94.6 +/- 2.1% for differentiating myofascial pain using mediotrusive and laterotrusive attrition severity, and 92.0 +/- 2.1% for differentiating myofascial pain using mediotrusive and anterior attrition rates. The myofascial pain models exceeded the > or =75% sensitivity and > or =90% specificity thresholds recommended for diagnostic tests, and the asymptomatic control model approached these thresholds.

CONCLUSION

Multifactorial models using attrition severity and rates may differentiate masticatory muscle pain patients from asymptomatic controls, and have some predictive value for differentiating intracapsular temporomandibular disorder patients as well.

The efficacy of magnetic resonance imaging in the diagnosis of degenerative and inflammatory temporomandibular joint disorders: a systematic literature review

OBJECTIVE

To evaluate the evidence for the efficacy of magnetic resonance imaging (MRI) in the diagnosis of disk position and configuration, disk perforation, joint effusion, and osseous and bone marrow changes in the temporomandibular joint.

STUDY DESIGN

A PubMed literature search with specific indexing terms and a hand search were made. Two reviewers assessed the level of evidence of relevant publications as high, moderate, or low. Based on this, the evidence grade for diagnostic efficacy was rated as strong, moderately strong, limited, or insufficient.

RESULTS

The literature search yielded 494 titles, of which 22 were relevant. No publication had a high level of evidence, and 12 had moderate and 10 low levels of evidence. The evidence grade for diagnostic efficacy expressed as sensitivity, specificity, and predictive values was insufficient.

CONCLUSION

That evidence is insufficient emphasizes the need for high-quality studies on the diagnostic efficacy of MRI, incorporating accepted methodologic criteria.

Herbst appliance therapy and temporomandibular joint disc position: A prospective longitudinal magnetic resonance imaging study

INTRODUCTION

The objective of this prospective study was to verify changes in the position of the temporomandibular joint (TMJ) disc by means of magnetic resonance images (MRIs) in adolescent patients treated with the Herbst appliance.

METHODS

Twenty consecutive Class II Division 1 patients treated with Herbst appliances were selected for the study. MRIs were analyzed at 3 stages: immediately before Herbst treatment (T1), 8 to 10 weeks after appliance placement (T2), and at the end of the 12-month Herbst treatment, immediately after appliance removal (T3).

RESULTS

Class I or overcorrected Class I dental-arch relationships were observed after Herbst therapy. The qualitative evaluation showed that each patient had the disc within normal limits at T1. At T2, a slight tendency toward disc retrusion because of mandibular advancement was observed, but, at T3, the disc returned to normal, similar to T1 values. By using a quantitative evaluation, parasagittal MRIs (central, medial, and lateral slices) of the TMJs showed that there was no change of disc position from T1 to T3, except in the central slice, which had a retrusive position of the articular disc at T3.

CONCLUSIONS

During the 12-month period of Herbst appliance treatment, mild changes in the position of the disc occurred in patients whose articular discs were within normal limits at T1. These changes were within normal physiological limits when evaluated in the short term.

Sensitivity and specificity of a new MRI method evaluating temporo-mandibular joint disc–condyle relationships: an in vivo study

The aim of this study was to evaluate sensitivity and specificity of a new method to locate temporo-mandibular joint (TMJ) disc using magnetic resonance imaging (MRI) and analyze disc-condyle relationships, in asymptomatic subjects and patients with disc displacement. Twenty-nine sagittal MRI of 16 subjects, 8 asymptomatic volunteers and 8 subjects with anterior disc displacement, were carried out during controlled opening from intercuspal position up to a 25 mm opening. Selected sections were analyzed with a graphic computerized system of coordinates. The total surface area (TS) of disc section was separated into anterior surface area (AS) and posterior surface area. Areas were determined by computer. Two trained examiners drew images at random. The reliability of AS/TS ratio index was evaluated in a previous study. AS/TS ratio sensitivity (Se) and specificity (Sp) were calculated closed mouth, 5 mm open and 25 mm open mouth. Best sensitivity (Se=0.63) and specificity (Sp=0.81) were obtained when MRI was realized with closed mouth and 25 mm open mouth. Lower sensitivity was observed when MRI was performed either with closed mouth (Se=0.54) or 25 mm open mouth (Se=0.18). Lower specificity was observed with 5 mm open mouth (Sp=0.68). In conclusion, it was confirmed as well that MRI of anterior disc displacement should be performed with closed mouth and opened mouth. Thus, further studies are required to assess disc displacement and mechanical alterations and to evaluate the risk of direct damage on TMJ tissues.

Proposed graphical system of evaluating disc–condyle displacements of the temporomandibular joint in MRI

The aim of this preliminary study was to standardize the reading of magnetic resonance imaging (MRI) of the temporomandibular joint (TMJ). The MRI was conducted on a control group of eight subjects. In this study, the analysis of joint relationships was limited to the oblique sagittal plane, during the movement of controlled opening. The sections were analyzed by a computer-assisted quantitative method of graphical evaluation. The total surface area (TS) of the disc section was divided into an anterior surface area (AS) and a posterior area (PA), in accordance with a line joining the center of the condyle (C) to the center of the articular tubercle of the temporal bone (T). The disc-condyle relationships in the chosen plane of section were evaluated by the AS/TS ratio. If TS remains relatively constant, the AS/TS values on average decrease from 0.5 to 0.3 between the closed mouth position and the 25 mm open position. The results show good intra-observer reproducibility (p=0.26), evaluated by Wilcoxon's test. In conclusion, this protocol enables the displacement of the disc-condyle assembly during mouth opening to be described. Observed on a larger sample, the AS/TS would be able to show a range of variability in functional disc positions.

Conservative therapy in patients with anterior disc displacement without reduction using 2 common splints: a randomized clinical trial

PURPOSE

We performed a comparative evaluation of different types of splint therapy for anterior disc displacement without reduction (ADDWR) of the temporomandibular joint.

PATIENTS AND METHODS

Seventy-four patients agreed to participate (65 females and 9 males). All patients were examined using a clinical temporomandibular joint disorder examination protocol, including muscle palpation, mandibular range-of-motion measurement, and joint sound detection. Additionally, the patients marked their pain (during chewing, mandibular movements, and rest position) and limitation levels on a visual analog scale. Bilateral magnetic resonance images were acquired, confirming ADDWR in at least one joint. After clinical examination and imaging, randomized splint therapy was provided: 38 patients received a centric splint, while 36 received a distraction splint. After 1, 3, and 6 months of therapy, outcome was evaluated using the Wilcoxon signed rank test for matched pairs. Success after 6 months was defined as improvement in active mouth opening of greater than 20% and pain reduction (on chewing) of at least 50%. Success was statistically verified using logistic regression test.

RESULTS

The improvements in mouth opening were significant in both groups. The improvements in pain on chewing, pain during other functions, pain at rest, functional limitation on chewing, and other functions were also comparable in both groups. However, the logistic regression test suggested that patients using centric splints were treated more successfully than the others (confidence interval, 1.014 to 8.741, odds ratio = 2.785).

CONCLUSIONS

Centric splints seem to be more effective than distraction splints. Therefore, before the surgical treatment of ADDWR, centric splints should be used instead of distraction splints.

Temporomandibular joint disk position assessed at coronal MR imaging in asymptomatic volunteers

PURPOSE

To assess the normal position of the temporomandibular joint (TMJ) disk relative to the condyle by using coronal magnetic resonance (MR) imaging in asymptomatic volunteers.

MATERIALS AND METHODS

This study was approved by the review committee for human research, and all subjects signed an informed consent form. Thirty symptom-free volunteers without histories of TMJ disorders underwent standardized clinical examinations. Afterward, bilateral sagittal oblique and coronal oblique MR images were acquired with the patient's mouth opened and closed. The coronal oblique opened- and closed-mouth images were analyzed by using computer software. The medial and lateral edges of both the TMJ disk and the condyle were marked for these imaging examinations by using the section through the posterior 3 mm of the disk. To eliminate the effect of different magnifications and/or distortions, the distance between these points was measured automatically and divided by the largest mediolateral dimensions of the condyle. To assess the reliability of the measurements, four observers evaluated the position of the disk in the coronal plane. To assess the changes in position of the posterior 3 mm of the disk in the coronal plane in the closed- and opened-mouth positions, the Wilcoxon signed rank test for matched pairs was used. Interobserver measurement reliability was evaluated by using interclass correlation coefficients (ICCs).

RESULTS

Analysis of the coronal closed-mouth disk position revealed a medial position of the TMJ disk relative to the condyle in 11 (21%) of 52 analyzed joints. In the opened-mouth position, the medial location of the disk was more frequent: 29 (85%) of 34 analyzed joints exhibited a medial position of the disk relative to the condyle in this plane. This increasingly medial position of the disk was statistically significant (P < or = .001). Measurement reliability assessment revealed sufficient results (ICC > or = 0.7).

CONCLUSION

At both closed- and opened-mouth MR imaging, a medially located TMJ disk seems to be within the normal range of variation. The disk seems to shift even more medially when the mouth is opened.

Characterization of Patients With Disc Displacement Without Reduction Unresponsive to Nonsurgical Treatment: A Preliminary Study

PURPOSE

Arthrocentesis and arthroscopic lysis and lavage have been described as effective treatment modalities for temporomandibular joint (TMJ) disc displacement without reduction (DDw/oR). More commonly, nonsurgical intervention is offered as the desired first-line treatment; however, a certain group of DDw/oR patients receiving nonsurgical treatment may remain unresponsive, thereby prolonging suffering and treatment dissatisfaction. The purpose of this study is to characterize these nonresponders by evaluating the characteristic pretreatment findings peculiar to this group.

PATIENTS AND METHODS

This retrospective study was based on the review of pretreatment clinical and magnetic resonance imaging (MRI) findings of 52 DDw/oR patients who were treated with stabilization appliance, jaw-stretching exercise, and nonsteroidal anti-inflammatory medication. On the last treatment visit, each patient was classified as either a responder (R) or nonresponder (NR) based on the satisfaction or dissatisfaction with the treatment received, respectively. Pretreatment data were then examined and analyzed by logistic regression to identify which clinical and MRI findings were specifically related to the NR group.

RESULTS

Logistic regressions indicated that NR had significantly higher odds ratio for pretreatment pain-free mouth opening of less than 30 mm (odds ratio [OR] = 7.385), "stuck" disc (OR = 4.521), and unchanged disc shape during mouth opening (OR = 4.050). Multiple logistic regression analyses revealed that these factors combined gave the highest likelihood ratio of 15.90 ( P = .001), indicating a strong possibility that these factors are associated with the NR group.

CONCLUSIONS

Nonresponders can be characterized by their pretreatment pain-free mouth opening (<30 mm) in combination with MRI confirmation of "stuck" disc and unchanged disc shapes during mouth opening.

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.

The effect of quality of temporomandibular joint MR images on interrater agreement

OBJECTIVES

Effects of calibration on interrater agreement in evaluating magnetic resonance (MR) images of the temporomandibular joint (TMJ) have already been examined. The objectives of the present study were to assess to what extent the quality of MR images of the TMJ influences interrater agreement and to evaluate interrater agreement with respect to image quality assessment.

METHODS

Two non-calibrated medical radiologists and two general dentists evaluated sagittal images of 100 TMJs for both a rating of the image quality and the performance of five diagnostic tasks. The agreement between these raters with respect to the diagnoses was evaluated. Additionally, two additional raters, calibrated during a 5 h training including the evaluation of 70 MR images, also evaluated the diagnostic aspects and the image quality, on the basis of objective criteria. The agreement between the subjective diagnoses of the non-calibrated raters and the objective diagnoses of the calibrated raters was evaluated. Afterwards, the subjective and the objective quality assessments were compared using kappa statistics.

RESULTS

When good quality images were evaluated, higher kappa values were obtained for all diagnostic categories by the non-calibrated raters (mean Deltak for making diagnoses >0.1). This finding was confirmed by the value obtained for the agreement between the non-calibrated and the calibrated raters. The non-calibrated raters were in good agreement (k=0.67, standard error +/-0.09) with the calibrated raters for assessment of image quality.

CONCLUSION

The present study shows that it is possible even without calibration to obtain a better interrater agreement when higher quality MR images of the TMJ are evaluated.

Temporomandibular joint pathosis in patients with myofascial pain: a comparative analysis of magnetic resonance imaging and a clinical examination based on a specific set of criteria

OBJECTIVE

We sought to determine the prevalence of joint diseases in patients with either of 2 forms of myofascial pain (with and without limited mouth opening) and to verify the accuracy of temporomandibular joint-related clinical diagnoses through the use of magnetic resonance imaging (MRI).

STUDY DESIGN

On the basis of the results of a clinical examination carried out according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD), 61 patients were divided into 2 subgroups. The first group consisted of 36 patients who had myofascial pain with limited mouth opening (MPLO), whereas the other 25 patients were diagnosed with myofascial pain without limited mouth opening. MRI was carried out on all patients. The clinical joint-related diagnoses from RDC/TMD were compared with MRI results.

RESULTS

Patients with MPLO often had joint diseases that were not detected by means of a clinical examination alone. The kappa statistic was used to compare MRI and clinical diagnoses, confirming poor agreement in patients with MPLO (kappa=0.13) and acceptable agreement in patients with myofascial pain without limited mouth opening (kappa=0.72).

CONCLUSION

Restricted mandibular mobility is frequently associated with temporomandibular joint diseases that were not identified during a clinical examination. Therefore, an adaptation of the classification scheme used for the RDC/TMDs may result in the improvement of the sensitivity of clinical joint-related diagnoses, especially in patients with MPLO.

Are high-resolution ultrasonographic signs of disc displacement valid?

PURPOSE

The study goal was to define the positive predictive value (PPV) for the diagnosis of disc displacement of the temporomandibular joint (TMJ) with the use of high-resolution ultrasonography (HR-US).

MATERIALS AND METHODS

The HR-US reports for 29 patients aged 19 to 62 years who had a prospective clinical diagnosis of TMJ internal derangement were correlated with magnetic resonance results.

RESULTS

For the prospective HR-US interpretation, the PPV for disc displacement was 97% at the closed-mouth position and 88% at the maximum-mouth opening position.

CONCLUSION

The PPV for the HR-US diagnosis of disc displacement is high.

Comparing methods for diagnosing temporomandibular joint disk displacement without reduction

BACKGROUND

Research is needed to assess the validity of the Clinical Diagnostic Criteria for Temporomandibular Disorders, or CDC/TMD. The authors conducted a prospective, double-blind study to determine whether applying the specific CDC/TMD diagnosis of TMJ internal derangement, or ID, type III would demonstrate good agreement with diagnoses obtained by MRI.

METHODS

The study comprised 138 TMJs in 69 subjects who had a clinical diagnosis of unilateral TMJ ID type III (disk displacement without reduction). The authors obtained bilateral sagittal and coronal MRIs to establish the corresponding diagnosis of disk-condyle relationship.

RESULTS

For the CDC/TMD interpretations, the positive predictive value of ID type III for disk displacement without reduction was 86 percent, and for the presence of an ID it was 91 percent. The overall diagnostic agreement for ID type III was 78.3 percent with a corresponding K value of 0.57. Most of the disagreement was due to false-positive interpretations of an absence of ID.

CONCLUSIONS

The results suggest that using CDC/TMD for ID type III is predictive for the presence of an ID but is not sufficiently reliable for determining disk displacement without reduction. Parameters other than the functional disk-condyle relationship may need to be addressed to account for the biological plausibility of this entity.

CLINICAL IMPLICATIONS

A clinical TMJ-related diagnosis of ID type III may need to be supplemented by evidence from an MRI to determine the functional disk-condyle relationship. Investigation of longitudinal evidence, including risk factors, history and response to treatment, appears to be warranted.