MR grading of temporomandibular joint fluid: association with disk displacement categories, condyle marrow abnormalities and pain

Signal intensity on fluid-attenuated inversion recovery images of condylar marrow changes correspond with slight pain in patients with temporomandibular joint disorders

OBJECTIVES

Edema and necrosis of the temporomandibular joint (TMJ) have been described in terms of bone marrow signal abnormalities in magnetic resonance imaging (MRI). However, painful joints often show no such signaling abnormalities, making the diagnosis of TMJ disorders difficult in the clinical setting. An association has been suggested between TMJ bone marrow change and TMJ pain, but even when such change results in slight pain, it may be too slight to be visually apparent on MR images. We hypothesized that fluid-attenuated inversion recovery (FLAIR) can be used to detect such minimal changes. The purpose of this study was to determine whether there is an association between signal intensity on FLAIR images and pain in the TMJ.

METHODS

The study included 85 TMJs in 45 patients referred to our department for MRI. The signal intensity on FLAIR images was measured. Pain was evaluated based on the visual analog scale. An unpaired t test and Pearson's product-moment correlation coefficient were used for the statistical analysis. A p value of <0.05 was considered statistically significant.

RESULTS

Signal intensity on the FLAIR images was significantly higher in painful than in nonpainful TMJs, although a significant correlation was not observed between the signal intensity and the pain score.

CONCLUSIONS

The results of this study suggest an association between abnormalities in the marrow of the mandibular condyle and pain. They also indicate that FLAIR imaging is a useful tool in the clinical diagnosis of painful TMJs.

Significance of Frequency-Selective Fat Saturation T2-Weighted MR Images for the Detection of Bone Marrow Edema in the Mandibular Condyle

The objective of this study was to evaluate the utility of frequency-selective fat saturation (FS) T2-weighted images (T2WI) for the detection of bone marrow edema in the mandibular condyle. MR evidence of bone marrow abnormalities was examined on the set of FS T2WI and conventional T1WI or of conventional T2WI and T1WI in 200 patients with temporomandibular joint (TMJ) related pain. Other parameters studied were TMJ effusion, disk displacement categories, and cortical bone abnormalities. The detection rate and area of bone marrow edema by FS T2WI and T1WI were significantly greater than those assessed by conventional T2WI and T1WI. The correlation between bone marrow abnormalities on FS T2WI and T1WI and pain was significantly stronger than with conventional T2WI and T1WI. This study confirms that FS T2WI is useful for the detection of the "edema pattern" in the mandibular condylar associated with TMJ-related pain.

A Longitudinal Study of Magnetic Resonance (MR) Evidence of Temporomandibular Joint (TMJ) Fluid in Patients with TMJ Disorders

It has been reported that joint effusion, the excessive accumulation of joint fluid in and around the joint, is related to temporomandibular joint (TMJ) disorders such as pain and disk displacement. However, there have been no longitudinal studies of this phenomenon. We performed a longitudinal study on the relationship between joint fluid and various pathological disk conditions. The subjects were 17 patients who visited our facility for orthodontic treatment and were diagnosed using MRI as having internal derangement of one or both TMJs (three males and 14 females; age 12-31 years; mean age 20.5 years). MRI was performed before, during, or after treatment for their disorders. We evaluated the relationship between changes in joint fluid in the joint space and the state of the disk, as well as the presence or absence of pain. Joint fluid was evaluated by classifying the extent of high-signal areas in the upper and lower articular cavities on T2-weighted images. The extent of high-signal areas was classified into five levels. Disk displacement and the extent of displacement were evaluated using proton density-weighted images. Statistical analysis was performed using the chi-square test, and differences in the distribution among the groups were examined. Effusion was noted on the first MRI in nine of the eleven joints (81.8%) in which joint fluid decreased on the second MRI (p<0.01). Displacement remained unchanged or worsened in 18 of the 21 joints (85.7%) that showed joint fluid on the first MRI (p<0.01). Pain was alleviated or absent in all joints in which the fluid decreased. These results suggest that joint fluid may be a factor in the outcome of disk recapture treatment as well as in the evaluation of pain.

Correlation among the changes observed in temporomandibular joint internal derangements assessed by magnetic resonance in symptomatic patients

PURPOSE

The objective was to assess possible correlations among the anatomy and position of the articular disc, the morphology of the articular eminence and of the condyle, and the presence of joint effusion.

MATERIALS AND METHODS

Magnetic resonance images of 142 joints of symptomatic patients were assessed. The articular disc was classified as normal, elongated, or folded; displacement was classified as normal, anterior with reduction, anterior without reduction, or posterior, lateral, or medial; the condyle was classified as rounded, convex, flattened, or angulated; and the articular eminence was classified as box, sigmoid, flattened, or deformed.

RESULTS

The most frequent forms of the articular disc, articular eminence, and condyle were normal, box, and flattened, respectively. Associations were confirmed between the form of the articular disc and its anterior and lateral positions; between the form of the condyle and an anterior position of the disc; and between the form of the articular eminence and the form of the disc. The form of the articular eminence was the only variant that was not associated to the presence of joint effusion.

CONCLUSIONS

Magnetic resonance imaging allowed the clear observation of articular structures, without attributing a cause-and-effect relation. The prevalence of changes observed was associated with the diagnosis of internal derangement and was statistically proved.

Diagnostic imaging for temporomandibular disorders and orofacial pain

The focus of this article is diagnostic imaging used for the evaluation of temporomandibular disorders and orofacial pain patients. Imaging modalities discussed include conventional panoramic radiography, panoramic temporomandibular joint imaging mode, cone beam computed tomography, and magnetic resonance imaging. The imaging findings associated with common diseases of the temporomandibular joint are presented and indications for brain imaging are discussed. Advantages and disadvantages of each imaging modality are presented as well as illustrations of the various imaging techniques.

Clinical assessment of patients with orofacial pain and temporomandibular disorders

Accurate diagnosis of chronic pain disorders of the mouth, jaws, and face is frequently complex. It is common for patients with chronic orofacial pain to consult multiple clinicians and receive ineffective treatment before a correct diagnosis is reached. This problem is a significant public health concern. Clinicians can minimize error by starting the diagnostic procedure with a careful, accurate history and thorough head and neck examination followed by a thoughtfully constructed differential diagnosis. The possibility that the patient has symptoms of a life-threatening underlying disease rather than a more common dental, sinus, or temporomandibular disorder must always be considered.

Clinical and magnetic resonance imaging findings of the temporomandibular joint in patients with rheumatoid arthritis

Background

The aim of this study is to evaluate temporomandibular joint (TMJ) involvement in patients with rheumatoid arthritis by magnetic resonance imaging (MRI), jaw clenching force, mouth opening, and Fonseca’s questionnaire, and to establish the relationship between these findings and clinical, radiologic, and laboratory activity parameters that are unique to rheumatoid arthritis.

Methods

Included in the study were 30 RA patients and 30 healthy volunteers. Jaw clenching force of the entire cases was measured with Istanbul Bite Force Recorder (kg) and the mouth opening was measured with a ruler (cm). Additionally, hand grip forces of patients with rheumatoid arthritis were measured with hand dynamometer (kg). Hand and feet graphs and TMJ MRIs of patients were obtained. MRI findings were classified as normal, mild, medium, and severe. DAS28 and sharp scores of patients were estimated. Sedimentation rate (ESR), C-Reactive protein (CRP) and rheumatoid factor (RF) were checked in the patient group and Fonseca’s questionnaires were filled in.

Results

A significant difference was not observed between age, gender, and level of education of the groups. Jaw clenching force and mouth opening were established as significantly low in RA group compared to the control group (P < 0.001). A significant correlation was found between jaw clenching force, hand grip force, mouth opening, questionnaire, and MRI findings with the disease duration sharp score, DAS28, and hand grip force of the RA group (P < 0.05). However, a significant correlation was not established with ESR, CRP, and RF (P < 0.001).

Conclusions

Jaw clenching force, mouth opening, and Fonseca’s questionnaire can be used as parameters pointing to TMJ involvement in patients with RA. Yet, further studies in which TMJ involvement is followed up since the onset of the disease are of necessity.

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

OBJECTIVES

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

CLINICAL RELEVANCE

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

Magnetic resonance characteristics of temporomandibular joint disc displacement in elderly patients

OBJECTIVES

The purpose of this study was to evaluate the MR characteristics of temporomandibular joint (TMJ) disc displacement in elderly patients.

METHODS

Of the MR images of 1660 TMJs in 847 patients with disc displacement who underwent MRI for suspected temporomandibular disorders, 301 TMJs in 154 patients aged over 50 years were studied as an elderly group. These MR images of the elderly group were compared with those of a control group (1359 TMJs in 693 patients aged under 51 years) concerning disc displacement with or without reduction, joint effusion and osteoarthrosis.

RESULTS

The incidence of disc displacement with osteoarthrosis was significantly different between the elderly (41.9%) and the control (19.8%) groups (p = 0.000). Logistic multivariate regression analysis demonstrated that the osteoarthrosis was a significant variable (odds ratio = 2.94, p = 0.000).

CONCLUSIONS

This study suggests that MR characteristics of TMJ disc displacement in elderly patients includes osteoarthrosis.

Magnetic resonance imaging of the temporomandibular joint in the rat compared with low-powered light microscopy

OBJECTIVE

High magnetic field magnetic resonance imaging (MRI) was applied to the temporomandibular joint (TMJ) in the rat. The purpose of this study was the depiction of the internal structure of the TMJ, including the articular disc, articular cartilage, and the upper and lower joint cavities. We also proposed MRI settings and slices suitable for imaging the TMJ in the rat.

METHODS

Temporomandibular joints from one female and eight male Sprague Dawley rats (5-8 weeks old) and four male Wistar-Hamamatsu rats (7-8 weeks old) were used. Using scout images, the horizontal plane was defined as being parallel to the body of the basisphenoid bone underneath the base of the brain. The coronal plane was defined as a slice vertical to the horizontal plane and vertical to the longitudinal fissure of the cerebrum. The sagittal plane was defined as a slice vertical to the horizontal plane and parallel to the longitudinal fissure of the cerebrum.

RESULTS

T(1)-weighted MR images with a spatial resolution of 75 μm were obtained for 5 min. The temporal bone and mandibular condyle were depicted as lower signal intensity images and the articular disc was depicted as an intermediate signal intensity image. In accordance with Gd-DTPA-enhanced MR or T(2)-weighted MR images, the articular disc, articular cartilage, and the upper and lower joint cavities could be assigned clearly.

CONCLUSION

These MRI findings closely agreed with those observed with haematoxylin-eosin staining under light microscopy, suggesting that MRI is a useful method for analyzing the complex structure of the TMJ in the rat.

Usefulness of cone beam computed tomography in temporomandibular joints with soft tissue pathology

OBJECTIVE

the aim of the study was to evaluate the usefulness of cone beam CT (CBCT) in temporomandibular joints (TMJs) with soft tissue pathology.

METHODS

106 TMJs of 55 patients with temporomandibular disorder (TMD) were examined by MRI and CBCT. MR images were used for the evaluation of disc displacement, disc deformity, joint effusion and obscurity of temporal posterior attachment (TPA). CBCT images were evaluated for the presence or absence of osseous abnormalities. The chi(2) test was used to analyse the association between MRI and CBCT findings.

RESULTS

MRI of 106 TMJs revealed disc displacement, disc deformity, joint effusion and obscurity of the TPA in 68, 73, 28 and 27 joints, respectively. Of the 68 TMJs with disc displacement, anterior disc displacement without reduction (ADDWR) was seen most frequently (47/68). CBCT imaging found 65 TMJs were characterized by the presence of osseous abnormalities and were significantly associated with disc deformity and ADDWR (P < 0.05). There was no statistically significant association between the presence of joint effusion and obscurity of TPA and TMJ osseous abnormalities.

CONCLUSIONS

TMD patients with confirmed ADDWR or disc deformity on MRI are at risk of having osseous abnormalities in the TMJ and further examination with CBCT is recommended.

Clinical significance of magnetization transfer contrast imaging for edematous changes in masticatory muscle

OBJECTIVE

To evaluate inflammatory changes in masticatory muscles by magnetization transfer contrast (MTC) imaging.

METHODS

Gradient-recalled echo (GRE) and MTC-GRE images of relaxed masticatory muscles in 28 healthy volunteers were obtained before and after exercise. At the same time, muscle stiffness and pain in the masseter muscles were also measured. Magnetization transfer ratios (MTRs) of the muscles were calculated from the GRE and MTC-GRE images. The MTRs of the masticatory muscles in 50 patients with temporomandibular disorder were compared with those in the volunteers.

RESULTS

Immediately after the exercise, the MTRs of the masseter muscles significantly decreased (P < 0.05), whereas muscle stiffness and pain increased in the healthy volunteers. In patients with masseter muscle pain, the MTRs of the masseter muscles were significantly lower than in the healthy volunteers (P < 0.05).

CONCLUSIONS

Magnetization transfer contrast imaging strongly reflects the masticatory muscle edematous changes, possibly leading to masseter muscle pain.

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.

Magnetic resonance signal intensity from retrodiscal tissue related to joint effusion status and disc displacement in elderly patients with temporomandibular joint disorders

Magnetic resonance imaging (MRI) on patients with temporomandibular joint disorders (TMD) has revealed that a decrease and/or increase in signal intensity from retrodiscal tissue, joint effusion (the excessive accumulation of joint fluid) and articular disc displacement are related to TMD. However, the effect of aging on these phenomena has yet to be clarified. This study was carried out to explore the relationship between changes in signal intensity from retrodiscal tissue, joint fluid status and pathological disc conditions in elderly patients with TMD. Twenty patients aged over 60 years were examined. They consisted of one man and 19 women, and ranged between 60 and 79 years in age (mean, 66.0 years). The relationships between decreased signal intensity on proton-density-weighted (PDW) images and increased signal intensity on T2-weighted (T2W) MR images from retrodiscal tissue, joint fluid status and state of articular disc were examined. Joint fluid status was classified into 5 levels by extent of high signal areas in upper and lower articular spaces on T2W images. Disc displacement status was evaluated by PDW images. The Wilcoxon test was applied for the statistical analysis. The group showing increased T2W signal intensities from the retrodiscal tissue consisted of 31 out of 40 joints (77.5%). This group showed a significant difference in comparison with the other groups in which no apparent joint fluid was shown (p<0.05). There were no statistically significant differences among other categories. The results suggest a negative relationship between joint fluid and increased signal intensity from retrodiscal tissue due to reflection of the inflammatory reaction in TM joints.

Osseous abnormalities related to the temporomandibular joint

With the arrival of arthrography, computed tomography, and magnetic resonance imaging, diagnostic imaging of the temporomandibular joint has improved tremendously over the last 20 years. In patients with temporomandibular joint pain and dysfunction, the main focus was on meniscal pathology. The purpose of this article is to discuss several osseous abnormalities and demonstrate their association with temporomandibular joint pain and dysfunction.

Association between high signal intensity in the posterior disc attachment seen on T2 weighted fat-suppressed images and temporomandibular joint pain

OBJECTIVES

We sought to determine whether high signal intensity in the posterior disc attachment (PDA) seen on T2 weighted fat-suppressed MRI is associated with temporomandibular joint (TMJ) pain and joint pathology.

METHODS

This study was based on 283 TMJs of 177 patients (31 males and 146 females, mean age 32.7 years) with TMJ disorders showing anterior disc displacement. MRI evaluation included assessment of signal intensity in the PDA and TMJ status (disc displacement with reduction, disc displacement without reduction and disc displacement with bone changes). Clinical criteria that were considered positive indicators of TMJ pain included the presence of pre-auricular pain during palpation, jaw function and assisted or unassisted mandibular opening. Association of signal intensity in the PDA with joint pain and TMJ status was analysed using chi2 test.

RESULTS

Joint pain was reported in 47 (77.0%) out of 61 joints with high signal intensity in the PDA and in 97 (43.7%) out of 222 joints with low signal intensity in the PDA (P<0.0001). High signal intensity in the PDA correlated closely with more advanced joint pathology. In joints with anterior disc displacement with bone changes, TMJ pain was more commonly reported in joints with high signal intensity in the PDA than with low signal intensity in the PDA (P<0.0001).

CONCLUSIONS

High signal intensity in the PDA on T2 weighted fat-suppressed MRI is associated with TMJ pain in TMJ disorders with anterior disc displacement with bone changes in the mandibular condyles.

Temporomandibular Joint Internal Derangement and Osteoarthrosis: Are Effusion and Bone Marrow Edema Prognostic Indicators for Arthrocentesis and Hydraulic Distention?

PURPOSE

Arthrocentesis and hydraulic distention of the temporomandibular joint (TMJ) has proven to be an effective modality in treating patients exhibiting clinical findings consistent with the diagnosis of disc displacement without reduction. The purpose of this study was to investigate whether the magnetic resonance imaging (MRI) variables of effusion and/or bone marrow edema may predict treatment outcomes of arthrocentesis and hydraulic distention of the TMJ.

PATIENTS AND METHODS

The study group comprised 37 consecutive patients with TMJ pain, who were assigned a unilateral clinical TMJ disorder of TMJ pain associated with an internal derangement (ID) type III (disc displacement without reduction) and a TMJ pain side-related MRI diagnosis of disc displacement without reduction associated with osteoarthrosis (OA). Bilateral sagittal and coronal MRI images were obtained immediately before the operation to establish the presence or absence of ID, OA, TMJ effusion, and bone marrow edema. Pain level and mandibular range of motion (ROM) were assessed preoperatively and compared with the respective 2-month follow-up findings. Outcome criteria for success were a ROM >or=35 mm and pain reduction >50%. A logistic regression analysis was used to compute the odds ratio for TMJ effusion and bone marrow edema for successful outcomes (n = 21) versus unsuccessful (n = 16) outcomes.

RESULTS

At the 2-month follow-up, clinical evaluation showed a significant reduction in TMJ pain during function (P = .000), a significant reduction in clinical diagnoses of TMJ disorders (P = .016), and a significant increase in ROM (P = .000). A significant increase in the risk of an unsuccessful outcome of ROM <35 mm and/or pain reduction >or=50% occurred with MRI findings of effusion (odds ratio 1:10.8 = 0.09; P = .007).

CONCLUSIONS

TMJ effusion may prove to be an important prognostic determinant of successful arthrocentesis. However, the data re-emphasize the concept that the prediction of a specific outcome is not a matter of simple linearity, in which the presence of 1 factor may equate with predictive ability, but rather is a function of a complex interaction among different biological variables.

The thickness of the roof of the glenoid fossa in the temporomandibular joint: relationship to the MRI findings

OBJECTIVES

The purpose of this study was to clarify the relationship between the thickness of the roof of the glenoid fossa (RGF) and magnetic resonance imaging (MRI) findings of temporomandibular joint (TMJ) disorders (TMDs).

METHODS

Eighty-seven patients with symptoms and indications of TMD in one or both TMJs were referred for MRI. Cone-beam CT (3DX) was used to measure the thickness of the RGF at its thinnest point. Linear measurements were made three times on the monitor by three separate investigators and the mean values obtained were used for the statistical analyses.

RESULTS

The joints were categorised as normal (70 joints), anterior disc displacement with reduction (ADWR; 53 joints) or anterior disc displacement without reduction (ADWOR; 51 joints). The joint disorders were also categorised into the following subgroups: with osteoarthritis (OA) (21 joints), without OA (153 joints), with disc deformation (33 joints), without disc deformation (141 joints), with joint effusion (JE) (61 joints) and without JE (113 joints). The average minimum thickness of the RGF was 0.85 mm for normal joints, 0.90 mm with ADWR, 0.93 mm with ADWOR, 0.99 mm with OA, 0.87 mm without OA, 0.87 mm with disc deformation and 0.89 mm without disc deformation. There was no significant difference between these figures. There was a significant difference in the thickness of the RGF with (0.97 mm) and without (0.84 mm) JE.

CONCLUSIONS

These results suggest that RGF thickness is influenced by JE, but is unaffected by disc position and configuration.

Magnetic resonance imaging characteristics of temporomandibular joint pain during opening and biting in patients with disc displacement

OBJECTIVE

The purpose of this study was to evaluate the magnetic resonance (MR) imaging characteristic of temporomandibular joint (TMJ) pain during opening and biting in patients with disk displacement.

STUDY DESIGN

MR images of 1252 TMJs in 640 patients with disk displacement were studied retrospectively. The relationship between TMJ pain and age, sex, and MR imaging findings, such as disk displacement with or without reduction, TMJ fluid, and osteoarthrosis, was analyzed using logistic regression analysis.

RESULTS

The resultant data showed a significant relationship between TMJ pain during maximum jaw opening and disk displacement without reduction (OR = 2.36). The resultant data also showed a significant relationship between TMJ pain during maximum biting and TMJ fluid (OR = 1.85).

CONCLUSION

The results suggest that TMJ pain during opening and biting is related to disk displacement without reduction and TMJ fluid on MR images.

Magnetic resonance imaging findings of internal derangement, osteoarthrosis, effusion, and bone marrow edema before and after performance of arthrocentesis and hydraulic distension of the temporomandibular joint

OBJECTIVES

To investigate whether temporomandibular joint (TMJ) internal derangement type III and capsulitis/synovitis are related to magnetic resonance imaging (MRI) diagnoses of internal derangement, osteoarthrosis (OA), effusion, and/or bone marrow edema (BME), and whether arthrocentesis is associated with changes in diagnoses of internal derangement, OA, effusion, and/or BME.

STUDY DESIGN

The study comprised 28 patients with a clinical unilateral TMJ disorder of internal derangement type III and capsulitis/synovitis. Bilateral MRI was immediately performed preoperatively and at a 2-month follow-up.

RESULTS

There was a significant relationship between TMJ internal derangement type III and capsulitis/synovitis and TMJ internal derangement (P = .000), effusion (P = .036), and BME (P = .002). MRI showed a significant decrease in diagnoses of TMJ BME ((P = .018).

CONCLUSIONS

MRI variables of internal derangement, effusion, and BME were related to TMJ internal derangement type III and capsulitis/synovitis; however, arthrocentesis was only associated with a significant change in diagnoses of TMJ BME.

Parameters for Diffusion Weighted Magnetic Resonance Imaging for Temporomandibular Joint

The purpose of this study was to determine optimum diffusion parameters for diffusion weighted imaging (DWI) techniques, including echo planer imaging (EPI), single-shot fast spin echo (SSFSE), and steady-state free precession (SSFP) in Magnetic Resonance Imaging (MRI) of the Temporomandibular Joint (TMJ). A polyethylene tube with distilled water was individually positioned at the external acoustic meatus foramen in each of three volunteers with normal healthy TMJs. Images were obtained using three types of DWI at differing diffusion parameters, b-factors, and diffusion moment. Signal intensity and imaging ability for various anatomical structures, including the distilled water, were evaluated from each image. The details of the anatomical structures of the TMJ were unidentifiable in the images produced with EPI and SSFSE, but were identifiable on the SSFP images. A diffusion moment value from 100 mT/m(*)msec to 150 mT/m(*)msec for SSFP, in particular, restrained the signal intensity of the water, thereby protecting the comparably high image quality of the TMJ structure. In conclusion, only SSFP is capable of allowing interpretation of emerging pathologic conditions in the TMJ region, when used with a diffusion moment set at between from approximately 100 mT/m(*)msec to 150 mT/m(*)msec.

Role of Magnetic Resonance Imaging in the Clinical Diagnosis of the Temporomandibular Joint

Temporomandibular joint (TMJ) abnormalities cannot be reliably assessed by a clinical examination. Magnetic resonance imaging (MRI) may depict joint abnormalities not seen with any other imaging method and thus is the best method to make a diagnostic assessment of the TMJ status. In patients with temporomandibular joint disorder (TMD) referred for diagnostic imaging the predominant TMJ finding is internal derangement related to disc displacement. This finding is significantly more frequent than in asymptomatic volunteers, and occurs in up to 80% of patients consecutively referred for TMJ imaging. Moreover, certain types of disc displacement seem to occur almost exclusively in TMD patients, namely complete disc displacements that do not reduce on mouth opening. Other intra-articular abnormalities may additionally be associated with the disc displacement, predominantly joint effusion (which means more fluid than seen in any asymptomatic volunteer) and mandibular condyle marrow abnormalities (which are not seen in volunteers). These conditions seem to be closely related. Nearly 15% of TMD patients consecutively referred for TMJ MRI will have joint effusion, of whom about 30% will show bone marrow abnormalities. In a surgically selected material of joints with histologically documented bone marrow abnormalities nearly 40% showed joint effusion. Disc displacement is mostly bilateral, but joint effusion seems to be unilateral or with a lesser amount of fluid in the contralateral joint. Abnormal bone marrow is also mostly unilateral. Many patients have unilateral pain or more pain on one side. In a regression analysis the self-reported in-patient TMJ pain side difference was positively dependent on TMJ effusion and condyle marrow abnormalities, but negatively dependent on cortical bone abnormalities. Of the joints with effusion only one fourth showed osteoarthritis. Thus, there seems to be a subgroup of TMD patients showing more severe intra-articular pathology than disc displacement alone, and mostly without osteoarthritis. It should, however, be emphasized that patients with TMJ effusion and/or abnormal bone marrow in the mandibular condyle seem to constitute only a minor portion (less than one fourth) of consecutive TMD patients referred for diagnostic TMJ imaging. The majority of patients have internal derangement related to disc displacement, but without accompanying joint abnormalities. In patients with rheumatoid arthritis and other arthritides TMJ involvement may mimick the more common TMDs. Using MRI it is possible, in most cases, to distinguish these patients from those without synovial proliferation.

The relationship of bone marrow edema pattern in the mandibular condyle with joint pain in patients with temporomandibular joint disorders: longitudinal study with MR imaging

The purpose of this study was to investigate the course of bone marrow edema pattern (decreased signal intensity on T1- or proton-density-weighted images and increased signal intensity on T2-weighted fat-suppressed images) in the mandibular condyle after improvement in clinical symptoms, and to clarify its relationship with temporomandibular joint (TMJ) pain. This study was based on 14 joints of 11 patients (all female, mean age 37.5 years) with TMJ disorders showing condylar bone marrow edema pattern on initial magnetic resonance (MR) images. All joints were re-evaluated clinically and using MR images after relief of joint pain following arthrocentesis combined with non-surgical treatment. The time interval between the initial and follow-up MR images ranged from 14 to 27 months (mean 17 months). Of the 14 joints, 4 joints (28.6%) showed a normal bone marrow signal, whereas 10 joints (71.4%) showed persistent bone marrow edema pattern on follow-up MR images (P = 0.125). Therefore, the reduction in TMJ pain did not correlate with resolution of bone marrow edema pattern in most joints. The results of this study suggest that the bone marrow edema pattern in the mandibular condyle does not always contribute to the occurrence of joint pain in patients with TMJ disorders.

Temporomandibular joint internal derangement: relationship between joint pain and MR grading of effusion and total protein concentration in the joint fluid

OBJECTIVES

The objective of this study was to determine whether there is any association between the protein concentration in the synovial fluid and (i) the amount of articular hydrops, as graded in magnetic resonance (MR) images, and (ii) joint pain in temporomandibular joints (TMJs) with and without displacement of the disc.

PATIENTS AND METHODS

This study involved 16 joints in 16 patients referred to our clinic with the complaint of pain and limited mouth opening. The control group consisted of 15 joints in 15 patients with unilaterally normal disc and condyle relationship and no pain while the opposite side had a non-painful joint with disc displacement without reduction (DDwoR). The subjects and controls were different individuals and only a single joint was used for each. Pain and dysfunction were evaluated by visual analogue scale. Bilateral proton density and T2 weighted images of the TMJs of the 31 subjects were analysed for fluid and condyle bony changes as well as disc position. The amount of fluid, identified as an area of high signal intensity in the region of the upper and lower joint spaces, was characterized as none, minimal, moderate or marked. Arthrocentesis was performed both for synovial fluid analysis of total protein concentration and the treatment of the joints with DDwoR. Total protein concentration was measured by using protein dye binding on spectrophotometry.

RESULTS

All patients experienced a significant (P<0.01) increase in maximal mouth opening immediately post-arthrocentesis. In the study group, the disc was displaced most frequently in an anteriormedial direction (75%) and deformation of disc form was seen in 13 joints. Condylar bony changes were seen in 27% of joints in the control group and in 81% of joints in the study group. A statistically significant association was found between joints with disc displacement, disc form and condylar bony changes (P<0.05). In the control group, only one joint, which had an osteophyte, showed joint effusion (JE) with moderate fluid. In the study group, only four joints had no fluid (25%). JE was found in 10 (63%) joints with disc displacement on anteromedial direction, in 10 (63%) joints with disc deformation and in 10 (63%) joints with osteophytes and erosion. Mean total protein concentration was 16.87+/-7.9 (range 7.4-34.1 mg dl-1) in control joints, 55.08+/-35.16 (range 21.5-153.9 mg dl-1) in study joints. There were significant differences in the mean total protein concentration between the control and study groups (P<0.01). Significant positive correlation was found between the total protein concentration and JE (r=0.65, P<0.01). No significant correlation was found between the level of pain and dysfunction and JE and total protein concentration in either control or study groups (P>0.05).

CONCLUSION

Pain in the TMJ was not related to MR findings of effusion in internal derangement and synovial fluid aspirate findings of total protein concentration. However, total protein concentration was related to the amount of JE in DDwoR joints and painful joints were more likely to demonstrate the JE.

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.

T2-weighted MRI for the assessment of joint effusion: comparative study of conventional spin-echo and fast spin-echo sequences

OBJECTIVE

This study aimed to evaluate the usefulness of suitable conventional spin-echo (CSE) and fast spin-echo (FSE) T2-weighted imaging parameters for the assessment of joint effusion in a phantom study and in a comparative study of CSE and FSE using clinical cases.

STUDY DESIGN

In the phantom study, the signal ratios of water and oil signal fields were determined and studied comparatively. The shape and size of signals were evaluated separately. In the study of joint effusion images, 318 joints were evaluated. CSE T2-weighted imaging and FSE T2-weighted imaging were carried out, and a comparative assessment was performed.

RESULTS

In both CSE and FSE imaging, the ratios of mean MRI signal values showed divergence as TR/TE values increased. The evaluation of joint effusion with FSE TR/TE 8000/120 msec was significantly better than that in all other groups (P <.01).

CONCLUSION

The use of FSE requires investigation of TR/TE values. When a 0.5 T static field strength MRI apparatus is employed, TR/TE 8000/120 msec is recommended.

Temporomandibular internal derangement: correlation of MRI findings with clinical symptoms of pain and joint sounds in patients with bruxing behaviour

OBJECTIVES

The aim of this study was to correlate magnetic resonance imaging (MRI) findings of effusion, disc displacement, condylar bony changes and disc form with clinical findings of pain and sounds in patients with bruxing and non-bruxing behaviour.

METHODS

Disc displacement was confirmed by MRI in 102 joints from 64 patients (total of 128 joints) with bruxing behaviour who were referred for clinically diagnosed internal derangements of the temporomandibular joint (TMJ). Sixty joints with internal derangement from 30 patients without bruxing behaviour served as a control group. The clinical inclusion criteria were pain in the pre-auricular area and muscles of mastication, limitation or deviation in mandibular range of motion, and TMJ sounds. Signs of bruxism were diagnosed clinically and were obtained from the patient's history given on their first visit. Pain was evaluated using a visual analogue scale.

RESULTS

Of the 102 joints in the study group with disc displacement, 53 (52%) showed disc displacement with reduction and 49 (48%) showed disc displacement without reduction. In the control group, 16 joints were classified as normal. Of the remaining 44 joints, 27 (61%) had disc displacement with reduction and 17 (39%) had unilateral disc displacement without reduction. Condylar bony changes were seen in 55% of the reducing joints in the study group and in 38% of the reducing joints in the control group, compared with 86% of the non-reducing joints in the study group and 24% of the non-reducing joints in the control group. There was a strong correlation between age and degenerative change in the study group. In the reducing joints, there was a significant difference in the prevalence of condylar bony changes between the study and control groups (P<0.01). In non-reducing joints, 30% of painful joints in the study group and 59% of those in the control group showed a strong signal in the joint space on T(2) weighted imaging. Statistically significant differences between the study and control groups were also found for disc form and the prevalence of effusion and disc displacement. Joint sounds were important in unilaterally affected joints in the study group. A statistically significant correlation was found between joint sounds and reducing joints (P<0.05).

CONCLUSION

It was demonstrated that a higher prevalence of condylar bony changes occurred in reducing joints in patients with bruxing behaviour.

Common abnormalities in temporomandibular joint imaging

Magnetic resonance imaging has evolved as a prime diagnostic method for soft-tissue abnormalities of the temporomandibular joint. The most common temporomandibular joint abnormalities are internal derangement and osteoarthritis, but there are many other reasons for pain and dysfunction that are often overlooked. The purpose of this paper is to illustrate several of these more unusual and less well-recognized causes for temporomandibular joint pain and dysfunction. For example, internal derangement is often seen in asymptomatic individuals. Another purpose is to illustrate the difference in magnetic resonance imaging of asymptomatic and symptomatic internal derangement.

Magnetic Resonance Imaging of Synovial Proliferation in Temporomandibular Disorders with Pain

OBJECTIVE

The objective of this study was to assess the clinical significance of synovial proliferation in patients with painful temporomandibular disorders based on magnetic resonance imaging findings.

METHODS

The current study was conducted in 100 joints of 100 patients with unilateral painful temporomandibular disorders. One hundred joints on the contralateral side of patients with unilateral disease were used as nonpain group. Areas in the articular space that showed a low signal intensity on T1-weighted imaging, a high signal intensity on T2-weighted imaging, and high signal intensity on gadolinium-enhanced fat-suppressed T1-weighted imaging were judged to be regions of synovial proliferation.

RESULTS

Synovial proliferation alone was observed in 8.0% of the pain group, but in none of the nonpain group. Synovial proliferation + effusion was observed in 33.0% of the pain group and in 7.0% of the nonpain group. Effusion alone was observed in 7.0% of the pain group and in 3.0% of the nonpain group. The mean visual analog scale value of pain was in the order of synovial proliferation alone > synovial proliferation + effusion > effusion alone. The incidence rates of anterior displacement of the disk were 100% for synovial proliferation alone, 93.9% for synovial proliferation + effusion, 57.1% for effusion alone, and 57.7% for "without synovial proliferation/effusion."

CONCLUSIONS

Strong correlations were observed between synovial proliferation, pain, and disk displacement. It is considered that evaluating effusion alone provides only limited information on the disease state in painful temporomandibular disorders. Thus, it is essential to include enhanced T1-weighted imaging as a means to judge the disease state as well as to assess disease progression.

Usefulness of proton density and T2-weighted vs. T1-weighted MRI in diagnoses of TMJ disk status

The aim of this study was to test the hypothesis that proton density and T2-weighted magnetic resonance (MR) images are more useful than T1-weighted MR images in the diagnoses of disk displacement, disk reduction, and disk shape. The subject group consisted of 92 patients referred for bilateral MRI imaging because of diagnosed signs of temporomandibular disorders (TMD). In the experimental group (52 patients), both T2-weighted and proton density images were made. In the control group (40 patients), only T1-weighted images were taken. The images were evaluated by two oral radiologists relative to their usefulness as a diagnostic aid and rated as either good or fair in each diagnostic category. The percentages of ratings that were good were higher (p < 0.01) for T2-weighted and proton density images than for T1-weighted images in all three types of diagnoses (Fisher's Exact test). In conclusion, T2-weighted and proton density-weighted images were found to be more useful than T1-weighted images in the diagnoses of disk status.

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.

Magnetic Resonance Evidence of Joint Fluid with Temporomandibular Joint Disorders

OBJECTIVES

The relationship between temporomandibular joint (TMJ) effusion and TMJ disorders is controversial. The frequency of TMJ effusion has varied as shown in previous studies. Furthermore, though some authors have suggested a correlation between TMJ effusion and pain, others question the relationship. In order to clarify the relationship, it is necessary to quantify the degree of effusion and thoroughly investigate its relationship to other factors. The purpose of this study was to analyze the amount of TMJ fluid present in joints with TMJ disorders and to see how TMJ effusion is related to TMJ status and pain.

METHODS

We studied 577 joints in 293 patients referred to us for magnetic resonance imaging. The joints were divided into painful and nonpainful categories and also classified according to Westesson's criteria for the status of the TMJ. The grading system of Larheim et al was used for categorizing the amount of fluid. Statistical methods were used for analyzing the relationship between TMJ fluid and TMJ status and pain.

RESULTS

TMJs with disk displacement without reduction showed the largest amount of fluid while TMJs with normal superior disk position showed the least fluid (Kruskal-Wallis test, P<0.001; Scheffe test, P<0.001). There was a significant difference in the amount of the fluid between painful and nonpainful joints in the group of disk displacement without reduction (Wilcoxon rank sum test, P<0.001). No significant differences were found between other groups.

CONCLUSIONS

Joint effusion is likely to appear in painful TMJs with disk displacement without reduction. Joint effusion may be an abnormal entity just suited to joints with disk displacement without reduction.

Temporomandibular joint: MR imaging

Diagnostic imaging of TMJ has improved remarkably in the last 20 years. Various abnormalities related patient symptoms. Further studies using the latest imaging techniques will allow a better understanding of the sources of joint pain and the discrepancy between imaging findings and patient symptoms. For clinical practice, appropriate clinical examinations are needed to determine exactly which imaging findings are significant.

Magnetic resonance imaging predictors of temporomandibular joint pain

BACKGROUND

The authors conducted a study to evaluate whether temporomandibular joint, or TMJ, disorder subgroups are related to magnetic resonance imaging, or MRI, diagnoses of TMJ internal derangement, or ID; osteoarthrosis, or OA; effusion; and bone marrow edema.

METHODS

The TMJ disorder group was composed of 118 subjects with TMJ pain who were assigned a clinical unilateral single diagnosis of a specific TMJ disorder. The control group consisted of 46 subjects who did not have TMJ pain. Sagittal and coronal magnetic resonance images were obtained to establish the prevalence of ID, OA, effusion and bone marrow edema. The authors used a multiple logistic regression analysis to compute the odds ratios, or OR, for MRI features for control subjects versus four groups of subjects who had TMJ pain: ID type I (n = 35), ID type III (n = 39), capsulitis/synovitis (n = 26) and degenerative joint disease, or DJD, (n = 18).

RESULTS

MRI diagnoses that did not contribute to the risk of TMJ pain included disk displacement, or DD, with reduction and effusion. Significant increases in the risk of experiencing TMJ pain occurred selectively with DD without reduction (OR = 10.2:1; P = .007) and bone marrow edema (OR = 15.6:1, P = .003) for the ID type III group and with DD without reduction (OR = 11.7:1, P = .054) for the DJD group. Subjects in the group with ID type I were less likely to be associated with an MRI finding of OA than were control subjects (OR = 1:5.6).

CONCLUSIONS

While the contribution of MRI variables to the TMJ pain subgroups was not zero, most of the variation in each TMJ pain population was not explained by MRI parameters. Thus, MRI diagnoses may not be considered the unique or dominant factor in defining TMJ disorder populations.

CLINICAL IMPLICATIONS

Therapy for subjects with TMJ based on the evaluation of concomitant morphological abnormalities, whether prophylactically or as treatment for TMJ disorders, may be unwarranted.