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.     

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.     

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.     

Temporomandibular disorders: relationship between joint pain and effusion and nitric oxide concentration in the joint fluid.

OBJECTIVES: To evaluate the relationship between joint effusion, contrast enhancement of effusion, nitric oxide concentration in TMJ fluid and TM joint pain. METHODS: Nonenhanced T1- and T2-weighted and gadolinium-enhanced T1-weighted spin-echo sequences were performed in 77 patients with TMD. The nitric oxide concentration in TMJ fluid was analysed spectrophotometrically by the Griess reaction. RESULTS: Some or marked effusion was seen in five (9%) of the 56 asymptomatic joints and in 55 (56%) of the 98 symptomatic joints. The prevalence of contrast enhancement of joint effusion was significantly higher in the joint pain group than in the joint sound or asymptomatic joint groups (chi2 test, P<0.001). On postcontrast T1-weighted images, there was no evidence of synovial proliferation in patients with TMD. Anterior disk displacement without reduction was detected in 93% of the TMJs with marked effusion. The degree of joint pain correlated with raised nitric oxide concentration (Spearman's rank correlation, P<0.05). CONCLUSIONS: Painful joints are more likely to demonstrate contrast enhancement of joint effusion. Nitric oxide concentration in TMJ fluid is closely associated with inflammatory changes and painful TM joints.     

Temporomandibular joint disk displacement: comparison in asymptomatic volunteers and patients

PURPOSE: To compare the prevalence and type of temporomandibular joint (TMJ) disk displacement in asymptomatic volunteers with those in patients. MATERIALS AND METHODS: Bilateral oblique sagittal and oblique coronal intermediate-weighted magnetic resonance (MR) images of the TMJs in 58 patients with pain and dysfunction were analyzed and compared with corresponding MR images of 62 asymptomatic volunteers. RESULTS: Forty-five (78%) of 58 patients had disk displacement compared with 22 (35%) of 62 asymptomatic volunteers. Complete disk displacement was found in 46 (40%) of 115 joints in patients compared with three (2.4%) of 124 joints in asymptomatic volunteers, whereas partial disk displacement occurred in 26 (22.6%) and 27 (21.8%) joints, respectively. Two types of complete disk displacement, anterolateral and anterior, occurred frequently in patients, seldom in volunteers. Only minor differences were found between other types of disk displacement when prevalence in patients was compared with that of volunteers. The disk reduced to a normal position on open-mouth images in all joints in the volunteers compared with 76% of the joints in patients. CONCLUSION: TMJ disk displacement was less prevalent and was of a different type in asymptomatic volunteers compared with patients with pain and dysfunction.     

Radiographic assessment of asymmetry of the mandible.

PURPOSETo assess the relationship between mandibular asymmetry and disorders of the temporomandibular joint.METHODSWe used advanced imaging of the temporomandibular joint to distinguish different causes of mandibular asymmetry. MR imaging and arthrography were applied to the temporomandibular joints of 11 patients presenting with mandibular asymmetry.RESULTSCondyle hyperplasia was identified as the cause of the asymmetry in 5 patients. In the other 6 patients the mandibular condyle was normal on the long side, but the short side of the face demonstrated a small condyle head, short condyle neck associated with disk displacement, internal derangement, and degenerative joint disease of the temporomandibular joint.CONCLUSIONSThese observations suggest that both condyle hyperplasia on the long side of the mandible and disk displacement and degenerative joint disease of the temporomandibular joint on the short side can cause mandibular asymmetry. It was concluded that MR imaging or arthrography can be valuable for understanding the cause of mandibular asymmetry and be effective in treatment planning.     

TMJ disorders and pain: assessment by contrast-enhanced MRI

Though magnetic resonance (MRI) is a widely accepted standard for the assessment of patients with temporomandibular joint (TMJ) disorders, efforts to correlate symptoms to MRI findings have often given controversial results. Aim of this study was to investigate the correlation between TMJ pain and findings of contrast-enhanced MRI. Thirty-eight consecutive patients with TMJ dysfunction syndrome (study group) were examined with MRI. Protocol included T2 turbo spin-echo sequence, T1 spin-echo sequence, and T2 gradient-echo (acquired with closed jaw, at intermediate and maximal opening). Post-contrast phase was obtained through a fat sat 3D T1 gradient-echo sequence (VIBE). Post-contrast findings in the study group were matched with those obtained in a control group of 33 patients submitted to MRI of the paranasal sinuses. Statistically significant difference was found between condylar medullary bone enhancement in painful TMJ, in painless TMJ and control group. In addition the average thickness of joint soft tissue enhancement in painful TMJ was superior to painless TMJ (p<0.0001) and to control group. On multivariate logistic regression analysis, the odds ratio that a painful TMJ showed disk displacement, osteoarthrosis, effusion and JST enhancement were 3.05, 3.18, 1.2 and 11.36, respectively. Though not histologically proven, TMJ enhancement could reflect the presence of inflammation in painful joints. Furthermore, the administration of contrast could be of help for the assessment of patients with orofacial pain, particularly when clinical exploration is insufficient to ascribe the pain to TMJ.     

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.     

Rheumatic and nonrheumatic disease in the temporomandibular joint: gadolinium-enhanced MR imaging.

Magnetic resonance (MR) imaging of 36 temporomandibular joints (TMJs) in 27 patients and six healthy volunteers was performed before and after injection of gadopentetate dimeglumine. Twelve asymptomatic joints were used as controls, 12 TMJs had symptomatic internal derangement, and 12 TMJs had rheumatic inflammatory disease. A small or moderate joint effusion was seen in one asymptomatic joint, four joints with internal derangement, and one joint with rheumatic involvement; in all of these, contrast enhancement of the effusion was observed. A large effusion in one rheumatic joint was enhanced only after delayed imaging. In healthy controls and patients with internal derangement, no or only minimal enhancement of intraarticular tissues was seen. Eleven of the 12 rheumatic TMJs showed moderate or intense soft-tissue enhancement along the disk and articular surfaces (ie, in areas normally devoid of synovial membrane). The one rheumatic joint without enhancement had bony ankylosis and no remaining soft tissue within the joint space. Gadolinium-enhanced MR imaging of the TMJ may effectively depict the proliferating synovium of rheumatic inflammatory joint disease.     

Disk displacement of the temporomandibular joint: sonography versus MR imaging

OBJECTIVE: The purpose of this study was to determine the value of dynamic sonography in the evaluation of internal derangements of a temporomandibular joint (TMJ) during maximal mandibular range of motion. SUBJECTS AND METHODS: Maximal mandibular range of motion was performed during high-resolution sonography of the TMJ in 64 consecutive patients (128 joints; nine males and 55 females; age range, 17-65 years; mean age, 35 years 6 months), all of whom subsequently underwent MR imaging. MR imaging confirmed disk displacement with reduction in 27 joints and disk displacement without reduction in 60 joints of the 128 examined. The high-resolution sonography and MR imaging findings for these 27 and 60 TMJs, respectively, were analyzed. RESULTS: Dynamic high-resolution sonography performed during the maximal range of motion helped to detect 81 instances (93%) of internal derangement, 22 instances (82%) of disk displacement with reduction, and 50 instances (83%) of disk displacement without reduction. There was one false-positive finding for internal derangement. The accuracy of prospective interpretation of high-resolution sonograms of internal derangement, disk displacement with reduction, and disk displacement without reduction was 95%, 92%, and 90%, respectively. CONCLUSION: When real-time images are interpreted by expert radiologists, dynamic sonography performed during maximal mandibular range of motion may provide valuable information about disk displacement of the TMJ.     

颞下颌关节紊乱综合征的MRI诊断价值

目的 探讨ＭＲＩ诊断颞下颌关节紊乱综合征（ｔｅｍｐｏｒｏｍａｎｄｉｂｕｌａｒ ｊｏｉｎｔ ｄｅｒｅｎｇｍｅｎｔ ｓｙｎｄｒｏｍｅ,ＴＭＪＤｓ）的价值。材料与方法 回顾性分析３７例（７４侧）ＴＭＪＤｓ患者ＭＲＩ表现。７４侧均采用超导磁共振成像系统扫描。５０侧附加模拟动态扫描;关节腔造影３３侧,关节腔镜检查１９侧,手术１４侧,病理切片４侧,结果 （１）４４侧有症状关节中,３８侧关节盘病变,其中最多见为     

Temporomandibular joint: MR assessment of rotational and sideways disk displacements

The accuracy of coronal and sagittal magnetic resonance (MR) imaging was examined in the assessment of rotational and sideways displacements of the temporomandibular joint (TMJ) disk. Rotational disk displacement implies a combination of anterior and medial or lateral displacements, whereas sideways displacement implies pure medial or lateral displacement without an anterior component. Multiple 3-mm-thick coronal and sagittal MR images were obtained of 18 fresh TMJ autopsy specimens and compared with the observations in corresponding coronal cryosections. MR imaging correctly delineated the mediolateral position of the disk in 15 joints (83%) and incorrectly delineated it in three joints (17%). Osseous anatomy was correctly assessed in 17 joints (94%). On cryosections, six joints (33%) showed medial disk displacement and two joints (11%) showed lateral displacement. In five of these eight joints the medial or lateral displacement occurred in conjunction with an anterior displacement, that is, rotational displacement. Clinical MR imaging in 37 patients (61 joints with coronal images) showed medial or lateral disk displacement in 16 joints (26%). This study suggests that rotational and sideways displacements of the TMJ disk are an important aspect of internal derangement. The multiplanar capabilities of MR are suitable for an assessment of these abnormalities.     

Facial skeleton remodeling due to temporomandibular joint degeneration: an imaging study of 100 patients

One hundred patients with recently acquired, externally visible mandibular deformity and no history of previous extraarticular mandible fracture were selected for retrospective analysis. All had been investigated clinically and with radiography, tomography, and high-field surface-coil MR imaging to determine the presence or absence and extent of temporomandibular joint degeneration. Temporomandibular joint degeneration was found in either one or both joints of each patient studied. Chin deviation was always toward the smaller mandibular condyle or more diseased joint, and many patients either complained of or exhibited malocclusion, often manifested by unstable or fluctuating occlusion disturbances. Three radiologically distinct forms of degenerative vs adaptive osteocartilaginous processes--(1) osteoarthritis, (2) avascular necrosis, and (3) regressive remodeling--involving the mandibular condyle and temporal bone were identified in joints most often exhibiting meniscus derangement. Osteoarthritis and avascular necrosis of the mandibular condyle and temporal bone were generally associated with pain, mechanical joint symptoms, and occlusion disturbances. Regressive remodeling was less frequently associated with occlusion disturbances, despite remodeling of the facial skeleton, and appears to result from regional osteoporosis. Forty patients (52 joints) underwent open arthroplasty procedures, including either meniscectomy or microsurgical meniscus repair, at which time major radiologic diagnoses were confirmed. Surgical and pathologic findings included meniscus displacement, disk degeneration, synovitis, joint effusion, articular cartilage erosion, cartilage healing/fibrosis, cartilage hypertrophy, osseous sclerosis, osteophyte formation, osteochondritis dissecans, localized or extensive avascular necrosis, and decreased mandibular condyle mass and vertical dimension. We conclude that temporomandibular joint degeneration is the principal cause of both acquired facial skeleton remodeling and unstable occlusion in patients with intact dentition and without previous mandible fracture.     

Facial skeleton remodeling due to temporomandibular joint degeneration: an imaging study of 100 patients

One hundred patients with recently acquired, externally visible mandibular deformity and no history of previous extraarticular mandible fracture were selected for retrospective analysis. All had been investigated clinically and with radiography, tomography, and high-field surface-coil MR imaging to determine the presence or absence and extent of temporomandibular joint degeneration. Temporomandibular joint degeneration was found in either one or both joints of each patient studied. Chin deviation was always toward the smaller mandibular condyle or more diseased joint, and many patients either complained of or exhibited malocclusion, often manifested by unstable or fluctuating occlusion disturbances. Three radiologically distinct forms of degenerative vs adaptive osteocartilaginous processes--(1) osteoarthritis, (2) avascular necrosis, and (3) regressive remodeling--involving the mandibular condyle and temporal bone were identified in joints most often exhibiting meniscus derangement. Osteoarthritis and avascular necrosis of the mandibular condyle and temporal bone were generally associated with pain, mechanical joint symptoms, and occlusion disturbances. Regressive remodeling was less frequently associated with occlusion disturbances, despite remodeling of the facial skeleton, and appears to result from regional osteoporosis. Forty patients (52 joints) underwent open arthroplasty procedures, including either meniscectomy or microsurgical meniscus repair, at which time major radiologic diagnoses were confirmed. Surgical and pathologic findings included meniscus displacement, disk degeneration, synovitis, joint effusion, articular cartilage erosion, cartilage healing/fibrosis, cartilage hypertrophy, osseous sclerosis, osteophyte formation, osteochondritis dissecans, localized or extensive avascular necrosis, and decreased mandibular condyle mass and vertical dimension. We conclude that temporomandibular joint degeneration is the principal cause of both acquired facial skeleton remodeling and unstable occlusion in patients with intact dentition and without previous mandible fracture.     

Utility of frequency-selective fat saturation T2-weighted MR images for the detection of joint effusion in the temporomandibular joint

OBJECTIVES: To evaluate joint effusion in the temporomandibular joint (TMJ) using frequency-selective fat saturation (FS) T2-weighted images and assess this technique. To investigate whether bone marrow abnormalities and magnetic resonance imaging (MRI) findings of internal derangement may be linked to joint effusion in the TMJ in patients with pain. METHODS: TMJ effusion was sought on FS T2-weighted images and conventional T2-weighted images in 400 joints from 200 patients with TMJ-related pain. Self-reported pain records were obtained from patients immediately before MRI and images assessed by the amount of TMJ fluid graded bilaterally using reference films by two radiologists. Other parameters recorded included disk displacement categories and condyle marrow abnormalities. The association between the recorded parameters and TMJ effusion judged by FS-sequences or conventional sequences was analysed using chi-square and Kappa tests. RESULTS: The detection rate of TMJ effusion by FS-sequences was significantly greater than by conventional methods, and the results showed a significant relationship between MRI interpretation of TMJ effusion using FS-sequences or conventional methods and the presence of pain. The correlation between TMJ effusion on FS-sequences and pain was significantly stronger than the conventional method. Kappa test indicated good agreement between pain and MRI TMJ effusion by FS-sequences (kappa = 0.66), but not by conventional sequences (kappa = 0.56). The other parameters showed a similar trend for TMJ-related pain. CONCLUSIONS: FS T2-weighted imaging is useful for detection of TMJ effusion, without known causes and confirms the importance of TMJ effusion as an indicator in patients with TMJ-related pain, bone abnormalities, and disk displacement.     

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 χ² 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.     

MR imaging of temporomandibular joint abnormalities associated with cervical hyperextension/hyperflexion (whiplash) injuries.

Patients often have temporomandibular joint (TMJ) dysfunction-related symptoms after cervical hyperextension/hyperflexion injuries ("whiplash") caused by rear-end motor-vehicle collisions. To determine abnormalities of the TMJ associated with these injuries, 33 consecutive symptomatic patients (66 joints) with no direct trauma to the jaw, mouth, head, or face due to the accident and no prior history of TMJ dysfunction underwent magnetic resonance (MR) imaging, and the images were retrospectively analyzed. Overall, 29 (88%) patients had some type of TMJ abnormality related to whiplash injury. Displacement of the disk was seen in 37 (56%) of the TMJs as follows: 21 (32%) had anterior displacement with reduction, nine (14%) had anterior displacement without reduction, six (9%) had lateral or medial displacement, and one (2%) had posterior displacement. On T2-weighted images, 43 (65%) TMJs had abnormal joint fluid or edema, predominantly affecting the joint capsule and/or lateral pterygoid muscles. The finding that many of the patients had joint fluid and/or soft-tissue edema indicates that T2-weighted images are especially useful for assessment of patients with a history of whiplash injury.     

Relationship between increased horizontal condylar angle and resorption of the posterosuperior region of the lateral pole of the mandibular condyle in temporomandibular joint internal derangement

OBJECTIVES: The purpose of this study was to analyse the relationship between horizontal condylar angle, temporomandibular joint (TMJ) disk displacement and resorption of the lateral pole of the mandibular condyle (RLC). METHODS: The study comprised 162 TMJs (81 patients). Disk displacement was assessed and the horizontal angle of the condyle was measured on axial MR images. RLC was assessed on oblique frontal projection plain radiographs. RESULTS: The horizontal angle was increased in joints with disk displacement without reduction (one-factor ANOVA and Scheffe's f-test, P<0.05). The angle was greater in joints with RLC than in the joints without RLC (Student's t-test, P<0.05). CONCLUSIONS: Results suggest that the horizontal condylar angle is increased in joints with disk displacement without reduction. A possible relationship exists between RLC and increased horizontal condylar angle.     

MR imaging of the juvenile temporomandibular joint: preliminary report.

Thirty-two children were evaluated by means of medical history and physical examination for signs and symptoms of internal derangement (ID) of the temporomandibular joint (TMJ) and mandibular dysfunction. These children also underwent magnetic resonance (MR) imaging of the TMJs. The study was double blind. At clinical examination, 19 patients (59%) had at least one positive finding of ID of the TMJ and/or mandibular dysfunction. MR images of the TMJ obtained in 60 of the 64 TMJs demonstrated 57 normal joints (95%) and three abnormal joints (5%). Two of these three joints had a mild anterior-lateral disk displacement, and one joint had an anterior dislocated disk. There were no false-positive MR examinations. MR imaging failed to depict abnormalities in 16 patients who had positive findings at history and/or physical examination. Although MR imaging may fail to depict ID of the TMJ in some patients, clinical techniques commonly used in population surveys probably overstate the prevalence of ID of the TMJ in children.     

The diagnosis of temporomandibular joint disease: two-compartment arthrography and MR

The reliability and accuracy of two-compartment temporomandibular joint (TMJ) arthrography was compared with MR imaging on the basis of an analysis of surgical findings obtained from joints that had been studied preoperatively with arthrography or MR or, in some cases, both procedures. Seven hundred forty-three consecutive TMJ arthrograms were successfully obtained in a total of 443 patients by using a single 27-gauge needle and a two-compartment technique in each joint. There was a 100% correlation with surgical findings in 218 radiologically abnormal joints operated on within 90 days of arthrography with respect to the presence or degree of meniscus displacement and normal or abnormal disk morphology and function. In 604 patients 1052 TMJs were studied with high-field-strength surface-coil MR. Surgical findings were available for correlation in 170 of the joints studied. Forty-three joints were studied with both two-compartment arthrography and MR. Eight operated joints had been imaged successfully with both two-compartment arthrography and MR. Both methods of evaluation provided highly reliable and accurate information regarding meniscus position and shape. Arthrography was superior to MR in detecting capsular adhesions and the presence or absence of perforation of the disk or meniscus attachments. Simple meniscectomy (with or without insertion of a temporary Silastic TMJ implant) was the most frequently performed surgical procedure in the series, followed by meniscus repositioning procedures. Joint effusions, failed TMJ implants, and avascular necrosis were demonstrated best with MR. Soft-tissue lesions, including intrinsic degeneration of the meniscus, anomalous muscle development, muscle atrophy, tendinitis, and injuries such as contusions and hematomas, were demonstrated only with MR. Partial-flip-angle GRASS (gradient-recalled acquisition in the steady state) techniques permit both fast scanning and study of functional joint dynamic. Joint fluid may appear as high signal intensity on GRASS images because of T2*-weighting. We recommend MR as the procedure of choice for diagnosis of uncomplicated internal derangements of the TMJ. Two-compartment arthrography with videofluoroscopy is an important ancillary procedure that should be performed whenever capsular adhesions or perforations are suspected and not demonstrated with MR and whenever MR is inconclusive.