MRI Of Temporomandibular Joint Research Articles

Is there a superiority between arthrocentesis and stabilizing occlusal splint for the treatment of anterior disc displacement with reduction and intermittent block and anterior disc displacement without reduction in TMJ? Randomized clinical trial

Anterior displacement of the temporomandibular joint (TMJ) disc is a disorder in which the articular disc is dislocated from its correct position relative to the mandibular condyle and mandibular fossa. Traditionally, the initial treatment of disc displacements involves various conservative measures, including the use of a stabilizing interocclusal splint. However, in cases where there is associated limited mouth opening, as in the case of anterior disc displacement with reduction and intermittent block (ADDwRIB), and anterior disc displacement without reduction (ADDw/oR), arthrocentesis has been suggested as another modality of initial treatment due to its faster effect in preventing disease progression to a more advanced stage, as well as reducing the chances of pain chronification and central sensitization. This study aimed to analyze whether there is a preponderance in efficacy between treatments with a stabilizing interocclusal splint or arthrocentesis in these patients. A randomized, prospective, longitudinal clinical trial was conducted. The sample was obtained by convenience, between June 2021 and January 2023. Twenty-four patients with diagnoses of ADDwRIB and ADDw/oR were included. The diagnosis and clinical evaluations followed the DC/TMD criteria, and TMJ MRI was performed. Patients were randomly allocated to 2 treatment groups. Group 1 (n = 13): stabilizing interocclusal splint. Group 2 (n = 11): arthrocentesis. Patients were evaluated after 1, 2, 3, and 6 months for clinical parameters of pain, functionality, and psychosocial status. Both treatments were effective in reducing pain levels, with no statistically significant differences. Group 1 showed significantly greater mouth-opening levels compared to Group 2 (P = .041). Both groups showed significant improvements in various parameters evaluated throughout the study, indicating they are equally effective in pain control and most functional and quality of life parameters. However, the stabilizing interocclusal splint treatment was superior in restoring mouth opening.

A detunable wireless resonator insert for high-resolution TMJ MRI at 1.5 T

MRI is essential for evaluating and diagnosing various conditions affecting the temporomandibular joint (TMJ) and surrounding structures, as it provides highly detailed images that enable healthcare professionals to assess the joints and surroundings in great detail. While commercial MRI scanners typically come equipped with basic receive coils, such as the head receive array, RF coils tailored for specialized applications like TMJ MRI must be obtained separately. Consequently, TMJ MRI scans are often conducted using the head receive array, yet this configuration proves suboptimal due to the lack of specialized coils. In this study, we introduce a simple, low-cost, and easy-to-reproduce wireless resonator insert to enhance the quality of TMJ MRI at 1.5 T. The wireless resonator shows a significant improvement in signal-to-noise ratio (SNR) and noticeably better imaging quality than the head array alone configuration in both phantom and in vivo images.

Evaluation of Effects of Bimaxillary Anchored Fixed Functional Appliance on Temporomandibular Joint and Maxillomandibular Complex in Late Adolescents: An MRI Study

Objective To evaluate and assess changes in temporomandibular joint (TMJ), dental, skeletal and soft tissue changes following bimaxillary anchored fixed functional appliance (FFA) treatment of skeletal Class II malocclusion using Magnetic Resonance Imaging. Methods The prospective single-arm clinical trial included 15 patients (8 males, 7 females; mean age 15.71 + 1.81years) with Class II Division 1 malocclusion treated with bimaxillary anchored Forsus FRD. Four miniplates were placed bilaterally in maxilla and mandible. Then Forsus FRD L pin module was attached to miniplates without levelling of the arches. Pre-treatment (T1) and post-functional (T2) lateral cephalograms and MRI of TMJ were recorded. A total of 7 parameters were used to assess TMJ in all the 3 planes using MRI. Student’s t-test was carried out to compare pre- and post-treatment-induced changes. Results The mandible significantly moved forward (SNB, 3.71 + 0.91°; SND, 3.21 + 1.25°; Pg-OLp, 2.61 + 0.66 mm, p < 0.001) and there was distalizing effect on maxilla (SNA, –0.79 + 0.89°; A-OLp, –0.57 + 0.47mm, <0.001). Mean overjet correction of 4.43mm was achieved, of which 71.8% were skeletal changes. 65% of skeletal changes contributed to molar relationship correction. The forward positioning of mandible seems to be because of condylar and glenoid fossa remodelling, with condyle moving in anterior position within glenoid fossa (3.28 + 2.29) and articular disc moved posteriorly relative to condylar head (2.27 + 1.62°). Conclusion Significant skeletal changes and TMJ remodelling were observed with bimaxillary anchored FFA in correcting skeletal Class II malocclusion.

Role of Ultrasound Evaluation of Temporomandibular Joint in Juvenile Idiopathic Arthritis: A Systematic Review.

Background: Juvenile idiopathic arthritis (JIA) is childhood’s most frequent chronic rheumatic disease. JIA is a broad term that includes all arthritides starting before 16 years, lasting at least six weeks, and of unknown cause. The temporomandibular joint (TMJ) could be involved in JIA both at onset and during the disease course. The presence of TMJ synovitis might severely impair dentofacial maturation in pediatric patients. The ultrasound (US) application to detect early signs of TMJ synovitis in children with JIA has provided contradictory results. We sought to assess the current role of TMJ US in JIA through a systematic literature review. Methods: The systematic review was conducted according to the recommendations of the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA). Results: The literature search found 345 records. After duplicates removal, 253 records were screened, 20 full-text articles were reviewed to assess their eligibility, and 7 of them were included in the qualitative analysis. Joint effusion was the most recorded parameter, followed by bony condylar abnormalities. Compared to contrast enhancement MRI, the capability to detect signs of active synovitis of TMJ by US is low, especially at the early stages. Conclusion: Understanding how US may help diagnose and manage children with JIA is advisable for several reasons. MRI cannot be frequently repeated, may need sedation, and is expensive. The constant technical improvement of US will undoubtedly allow for better evaluation of what, in the past, was not clear or not even captured by sonography. So far, the role of US in the assessment of TMJ involvement in JIA is indubitably secondary to the MRI. Even so, we think that a baseline MRI of TMJ and the repetition of the sonography over time might both help the interpretation of US images and intercept significative changes.

Evaluation of lateral pterygoid muscle in patients with temporomandibular joint anterior disk displacement using T1-weighted Dixon sequence: a retrospective study

BackgroundPathological alterations of lateral pterygoid muscle (LPM) are implicated in temporomandibular joint anterior disk displacement (ADD). However, quantification of the fatty infiltration of LPM and its correlation with ADD have rarely been reported. The aim of this study was to evaluate the fatty infiltration, morphological features and texture features of LPM in patients with ADD using T1-weighted Dixon sequence.MethodsThis retrospective study included patients who underwent temporomandibular joint MRI with T1-weighted Dixon sequence between December 2018 and August 2020. The temporomandibular joints of the included patients were divided into three groups according to the position of disk: Normal position disk (NP) group, Anterior disk displacement with reduction (ADDWR) group and Anterior disk displacement without reduction (ADDWOR) group. Fat fraction, morphological features (Length; Width; Thickness), and texture features (Angular second moment; Contrast; Correlation; Inverse different moment; Entropy) extracted from in-phase image of LPM were evaluated. One-way ANOVA, Welch’s ANOVA, Kruskal–Wallis test, Spearman and Pearson correlation analysis were performed. Intra-class correlation coefficient was used to evaluate the reproducibility.ResultsA total of 53 patients with 106 temporomandibular joints were evaluated. Anterior disk displacement without reduction group showed higher fat fraction than normal position disk group (P = 0.024). Length of LPM was negatively correlated with fat fraction (r = -0.22, P = 0.026). Angular second moment (ρ = -0.32, P < 0.001), correlation (ρ = -0.28, P = 0.003) and inverse different moment (ρ = -0.27, P = 0.005) were negatively correlated with fat fraction, while positive correlation was found between entropy and fat fraction (ρ = 0.31, P = 0.001). The intra-class correlation coefficients for all values were ranged from 0.80 to 0.97.ConclusionsPatients with ADDWOR present more fatty infiltration in the LPM compared to NP or ADDWR patients. Fatty infiltration of LPM was associated with more atrophic and higher intramuscular heterogeneity in patients with ADD. Fat fraction of LPM quantitatively and noninvasively evaluated by Dixon sequence may has utility as an imaging-based marker of the structural severity of ADD disease process, which could be clinical helpful for the early diagnose of ADD and predication of disease progression.

MRI histogram texture analysis of lateral pterygoid muscle in patients with temporomandibular disorders

Objective: To evaluate the functional changes of lateral pterygoid muscle (LPM) in the patients with temporomandibular disorders (TMD) using histogram texture analysis. Methods: A total of 28 TMD patients, including 15 males and 13 females, aged (26.2±12.1) years (15-62 years), were enrolled in the outpatient clinic of Department of Radiology, Hainan Hospital of Chinese PLA General Hospital from May 2016 to April 2020. At the same time, 13 volunteers with normal temporomandibular joint [6 males and 7 females, aged (23.5±3.3) years (20-30) years] were recruited. All participants were performed with temporomandibular joint MRI scan, and the subjects were classified into 3 groups according to the disc displacement: TMD with disc without displacement (TMD-DwoD), TMD with disc displacement without reduction (TMD-DDwoR) and NC with disc displacement without reduction (NC-DwoD) for each temporomandibular joint. The area, signal intensity, coefficient of variation (CV) of mean signal intensity and histogram texture of the superior belly of LPM (SBLPM) and inferior belly of LPM (IBLPM) were measured using regions of interests. Results: The area of SILPM presented significantly smaller in TMD-DwoD [(67.36±30.23) mm2] compared with that in NC-DwoD [(91.42±45.01) mm2] (P<0.05) and in TMD-DDwoR group [(72.27±37.53) mm2] (P>0.05). The mean signal intensity of SBLPM was identified significantly higher in TMD-DwoD (304.20±29.90) and TMD-DDwoR (315.06±40.20) compared with that in NC-DwoD (269.79±25.54) (P<0.05). The CV of mean signal intensity of SBLPM presented significantly higher in TMD-DwoD (8.89±2.60) compared with that in NC-DwoD (6.76±1.82) and TMD-DDwoR (7.63±1.62) (P<0.05). The skew and kurtosis showed no significantly differences among three groups for SBLPM (P>0.05). The mean signal intensity and CV for IBLPM presented significantly higher in TMD-DwoD (286.69±23.48 and 9.96±2.24, respectively) and TMD-DDwoR (275.98±30.55 and 10.25±1.96, respectively) compared with that in NC-DwoD (243.56±17.04 and 8.49±1.94, respectively) (P<0.05). The skewness showed significantly lower in TMD-DwoD (0.90±0.94) and TMD-DDwoR (0.73±0.97) compared with that in NC-DwoD (1.40±1.03) (P<0.05). The area and kurtosis for IBLPM showed no significant differences among three groups (P>0.05). Conclusions: The MR histogram texture analysis could primarily be considered as a tool to evaluate the LPM function in TMD patients.

Selection and application of coils in temporomandibular joint MRI

Objective:To compare and evaluate the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) values between a 15-channel phased array head coil and 6-channel dS Flex M surface coil in the MRI of temporomandibular joint.Methods:300 patients were randomly assigned to two groups: 150 patients were examined by using a 15-channel phased array head coil and the other 150 patients were scanned by using a 6-channel dS Flex M surface coil. All of the data were set in the same 6 regions of interest including the temporal lobe, condyle neck, lateral pterygoid muscle, parotid gland, the adipose area and an area of the background noise）. SNR and CNR values were measured respectively.Results:The numerical variation law of SNR and CNR values measured in regionsof interest of each group was similar, although different coils were used. There were statistically significant differences of SNR values in all of the oblique sagittal (OSag) proton density-weighted imaging, the part of OSag T 2 weighted image (T 2WI) except for SNR4 and SNR5. and oblique coronal (OCor) T 2WI sequence except for SNR2. On the contrary, SNR4 and SNR5 values in the OCor T 2WI and SNR5 values in OSag T 2WI sequences by using the surface coil were higher than those by using the head coil. There were no statistically significant intergroup differences of CNR values in OSag proton density-weighted imaging sequence except CNR1 and in OSag T 2WI sequence except CNR5. But, statistically significant differences of all the values in the OCor T 2WI sequence except for CNR1 were observed.Conclusion:Both the phased array head coil and dS Flex M surface coil can be used for temporomandibular joint MRI.

Additive Manufacturing of TMJ Device used in Temporomandibular Joint MRI Scan by using 3D Printer

Additive Manufacturing of TMJ Device used in Temporomandibular Joint MRI Scan by using 3D Printer

Qualitative and semi-quantitative assessment of temporomandibular joint MRI protocols for juvenile idiopathic arthritis at 1.5 and 3.0 T

ObjectiveTemporomandibular joints (TMJs) frequently develop silent inflammatory and osteochondral changes in children with juvenile idiopathic arthritis. Data-driven recommendations for TMJ imaging protocol are needed to reduce measurement error and scanning time. This study compares the impact of different protocols, imaging coils, and magnet strength on the reliability of image assessment and the subjective quality of images. Materials and methodsThree groups of bilateral TMJ MR studies were retrospectively collected from two institutions, including 24 1.5T and 19 3.0T studies using dedicated TMJ surface coils, and 23 1.5T studies with head coil. Post-contrast sequences were re-compiled from the full protocol to create minimum protocol studies for the three groups. Two radiologists and two non-radiologists first scored the three minimum protocol images according to pre-specified definitions, then scored the full protocol images. Minimum-to-full protocol agreement, inter-reader agreement, and subjective item visibility scores were assessed. ResultsWith dedicated TMJ dual surface coils, minimum-vs-full protocol agreement was moderate to good (0.5–0.8 intraclass correlation coefficients or kappa) for most items, and was not influenced by the magnet strength. Inter-reader reliability was more significantly influenced by the imaging coil and reader’s training background than by protocol length or magnet strength differences. Sagittal and coronal planes weighted on PD, T2 Fat Suppressed and T1 Fat Suppressed -postcontrast adequately visualized all the different features, whereas the axial plane was more limited to visualizing synovium. ConclusionInter-reader reliability and qualitative measure of image quality improved more consistently with the coil offering the higher resolution, rather than increased magnet strength.

Physiological effects of anterior repositioning splint on temporomandibular joint disc displacement: a quantitative analysis.

Anterior repositioning splints (ARS) are used primarily for the management of temporomandibular joint (TMJ) anterior disc displacement with reduction (ADDwR). However, the exact physiological effects of ARS are still unclear. This study investigated the short and long-term effects of ARS on disc and condyle angles/positions by metric analysis. Twenty-two subjects diagnosed with ADDwR were recruited. Maxillary full-coverage ARS were fabricated, and MRI of TMJs was obtained before splint treatment, immediate post-insertion and 6 months after splint treatment. Disc-condyle relationship was determined by disc-condyle angle measurement. Disc and condyle positions were described as X-Y coordinates with the summit of glenoid fossa as the origin of the coordinates. Thirty-two TMJs were classified as ADDwR and 12 were normal. Upon ARS insertion, all TMJs with ADDwR got normal disc-condyle relationships. The condyles moved significantly forward and downward, while the discs moved significantly backward and upward. MRI at 6 months after treatment (without ARS insertion) indicated that only 40·6% (13/32) of the joints were maintained in the normal disc-condyle relationship. The majority of condyles returned to their pre-treatment positions, while the discs generally moved anteriorly again. The use of ARS resulted in forward and downward condyle movement, and a concurrent backward movement of the disc resulting in ideal spatial disc-condyle relationship. The stability of this relationship, however, could not be maintained in the majority of TMJs upon ARS removal. Findings explain the good short-term clinical outcomes with ARS and their relatively lower efficacy in the long term.

MRI IN DIAGNOSIS OF CRANIOMANDIBULAR DYSFUNCTIONS

Visualization of the temporomandibular joint (TMJ) is constantly evolving with the improvement of technology. Magnetic resonance imaging is commonly used to evaluate the TMJ due to the high contrast resolution and the ability to obtain dynamic images to demonstrate the functional capability of the joint. Aim - to determine the functional changes after TMJ splint therapy conducted at various stages of intra-articular disorders. Data and methods. We conducted a survey, clinical examination and MRI of TMJ of 37 patients with temporomandibular disorders (TMD). Two groups of patients were formed according to the received MR picture of TMJ. Results. The study highlighted that regression of pain in TMJ and masticatory muscles, and normalization of functional parameters after splint rehabilitation occur more often in the first group of patients, who have disorders of the articular disc of the TMJ. Conclusion. In both groups of patients we noted positive dynamics of functional parameters of TMJ, reduction of pain in TMJ and masticatory muscles. Though 36,8% of the second group of patients, who have bone remodeling of TMJ condyles, didn’t show dynamics of functional parameters. Consequently, the use of splint in one third of patients with temporomandibular joint condyles destruction is effective for TMJ and muscular pain reduction.

Comparison of a 32-channel head coil and a 2-channel surface coil for MR imaging of the temporomandibular joint at 3.0 T

To quantitatively and qualitatively compare MRI of the temporomandibular joint (TMJ) using a standard TMJ surface coil and a head coil at 3.0 T. 22 asymptomatic volunteers were MR imaged using a 2-channel surface coil (standard TMJ coil) and a 32-channel head coil at 3.0 T (Philips Ingenia; Philips Healthcare, Netherlands). Imaging protocol consisted of an oblique sagittal proton density weighted turbo spin echo sequence (repetition time/echo time, 2700/26 ms). For quantitative assessment, a spherical phantom was imaged using the same sequence including a noise scan and a B1+ scan. Signal-to-noise ratio (SNR) maps and B1+ maps were calculated on a voxelwise basis. For qualitative evaluation, all volunteers underwent MRI of both TMJs with the jaw in the closed position. Two independent blinded readers assessed accuracy of TMJ anatomical representation and overall image quality on a 5-point scale. Quantitative and qualitative measurements were compared between coils using t-tests and Wilcoxon signed-rank test, respectively. Quantitative analysis showed similar B1+ and significantly higher SNR for the head coil than the TMJ surface coil. Qualitative analysis showed significantly better visibility and delineation of clinically relevant anatomical structures of the TMJ, including the articular disc, bilaminar zone and lateral pterygoid muscle. Furthermore, better overall image quality was observed for the head coil than for the TMJ surface coil. A 32-channel head coil is preferable to a standard 2-channel TMJ surface coil when imaging the TMJ at 3.0 T, because it yields higher SNR, thus increasing accuracy of the anatomical representation of the TMJ.

Ehlers Danlos syndrome in an edentulous patient with temporomandibular joint dislocation

Background: Ehlers Danlos syndrome (EDS) is heterogeneous genetic syndrome involving connective tissue. It is characterized by clinical signs of skin hyper-extensibility, delayed wound healing with atrophic scarring, joint hypermobility, easy bruising and generalized connective tissue fragility. Oral cavity is not immune to these systemic effects. Case Presentation: A 40 year old Indian male patient reported to the Department of Oral Medicine and Radiology with chief complaint of clicking in front of ear and difficulty in closing the mouth properly as his jaw seems to get stuck sometimes. The problem started about two years back when patient underwent full mouth extraction due to mobility in all teeth. On general examination certain anomalous features were observed which included hyper-extensibility of fingers of the hands and cigarette paper scars on legs and foot. The patient was completely edentulous and could touch tip of tongue to the tip of nose. Panoramic and temporomandibular joint (TMJ) limitation views were taken and MRI of TMJ was advised. Based on history and clinical features; we came to diagnosis of TMJ dislocation and Ehlers Danlos syndrome. Patient was advised to avoid wide opening of the mouth. Since the medical condition of the patient was capricious for implants prosthesis, the patient was advised to use relined complete denture. Conclusion: Ehlers Danlos syndrome is a rare genetic disorder of connective tissue. Oral manifestation and dental consideration for such cases should be well evaluated and managed appropriately.

Incidental findings on MRI of the temporomandibular joint

The aim of this study was to determine the prevalence of incidental findings in MRI of the temporomandibular joint (TMJ). MRI reports of 730 patients were assessed. The reports were analysed by one consultant and one clinical lecturer in dental and maxillofacial radiology. The prevalence of intracranial and extracranial incidental findings was recorded and categorized. There were 53 (7.3%) incidental findings, of which 11 (1.5%) were intracranial and 42 (5.7%) were extracranial (divided into paranasal sinuses, mastoid air cells, muscle hypertrophy, lymphadenopathy and salivary glands). A total number of eight intracranial findings needed further dedicated imaging and/or specialist clinical opinion. Only one tumour (a meningioma) was found and required surgical intervention. Incidental findings on TMJ MRI are rare but not unheard of. The clinical relevance of incidental findings can be significant, and it is therefore important to ensure that the full data set of images is inspected, including any scout slices. A close working relationship between the areas of dental and maxillofacial radiology and neuroradiology is essential in expediting a second opinion relating to intracranial findings. All incidental findings should be communicated to referring clinicians in a timely manner, based on their urgency and clinical significance.

Magnetic resonance imaging of temporomandibular joint dysfunction-correlation with clinical symptoms, age, and gender

To determine whether the morphological (magnetic resonance imaging) MRI manifestations correlate with the signs and symptoms of temporomandibular joint (TMJ) dysfunction according to gender and age of the patients. One hundred and forty-four subjects with TMJ dysfunction underwent a MRI of both TMJ to establish the presence of disk displacement, osteoarthritis, and effusion. Chi-square test and logistic regression analysis were preformed. For the comparison of mean values between samples, we used T-test. A significant relationship between symptoms and morphological manifestations was found. In the group without reduction there were significant increases in the risk of experiencing symptoms (P = .002). Significant correlation between age and osteoarthritis (P = .001) and age and effusion (P = .022) was found. There was no correlation between gender and morphological manifestations. MRI morphological manifestations of the TMJ correlate with the presence of symptoms, therefore MRI has a crucial role in the diagnosis of TMJ dysfunction.

Risk factors for the poor clinical outcome of visually guided temporomandibular joint irrigation in patients with chronic closed lock

Objective This study aimed to explore the risk factors of poor clinical outcome of visually guided irrigation (VGIR) in patients with chronic closed lock (CCL) of the temporomandibular joint (TMJ). Materials and methods Sixty-one patients with unilateral CCL who underwent a VGIR were enrolled in this study. At the 3-month follow-up after VGIR, the 61 patients were divided into either the good outcome (g-) group ( n = 37) or poor outcome (p-) group ( n = 24), according to the clinical success criteria. Age, gender, duration of symptoms, preoperative painless range of mandibular motion (P-ROM), preoperative TMJ pain, muscle symptoms, MRI findings (the severity of bony change, disc deformity and joint effusion), and arthroscopic findings (the severity of osteoarthritic change, synovial lesion and fibrous adhesion) were selected as the candidates of prognostic factors for VGIR. Each factor was compared between the two groups. Moreover, multiple logistic regression analysis was performed. Result The preoperative P-ROM of the p-group was significantly lower than that of the g-group. The severity of osteoarthritic change in the p-group was significantly greater than that of the g-group. Regarding the MRI findings, there were no significant differences between the two groups. The multivariate adjusted odds ratio showed that only a decreased preoperative P-ROM was significantly predictive for a poor clinical outcome of VGIR. Conclusion A pronounced decrease of preoperative P-ROM would be a significant risk factor for a poor clinical outcome of TMJ irrigation in patients with CCL.

Correlation between disc displacements and locations of disc perforation in the temporomandibular joint

The aim of this study was to investigate the correlation between disc displacement types and locations of disc perforation in the temporomandibular joint (TMJ). 157 patients (162 joints) with disc perforation observed through arthroscopy were included in this study. The types of disc displacement were analysed by TMJ MRI before operation. The locations of disc perforation under arthroscopy were recorded. The correlation between types of disc displacement and locations of disc perforation was analysed by Fisher's exact test. Medial disc perforation was observed in 55.6% of patients with anterolateral displacement without reduction, but was observed in only 3.7% of patients with pure anterior displacement, and was not observed in patients with anteromedial displacement without reduction. There was a statistically significant difference between these groups in the incidence of medial disc perforation. There is a correlation between different disc displacements and locations of disc perforation. The incidence of medial disc perforation in patients with anterolateral displacement was significantly higher. The types of disc displacement may have direct influence over the locations of disc perforation.

Evaluation of the reproducibility in the interpretation of magnetic resonance images of the temporomandibular joint

The aim was to determine the intra- and interexaminer reproducibility in the interpretation of MRI of the temporomandibular joint among independent observers, with respect to six specific articular characteristics, and to discover which of these had greater and lesser agreement. 30 magnetic resonance examinations of temporomandibular joints of adults were independently interpreted by 9 experienced and trained observers at 2 different times. Observers were divided into three groups according to their specialties: surgeon dentists specialized in temporomandibular dysfunction and orofacial pain, surgeon dentists specialized in radiology and medical doctors specialized in radiology. The reproducibility analysis was carried out using Cohen's kappa coefficient. The interexaminer reproducibility ranged from slight to fair. The intraexaminer reproducibility ranged from slight to no agreement. In the interexaminer evaluation, anterior disc displacement without reduction presented greater agreement, whereas change in condylar head shape showed the poorest agreement. In the intraexaminer evaluation, anterior disc displacement without reduction presented slight agreement, whereas, for the other characteristics, no agreement was observed. Examiners do not demonstrate reproducibility in the interpretation of MRI of temporomandibular joints. Therefore, more efforts are necessary with respect to understanding the changes that may be detected in these images in terms of diagnosis and appropriate treatment approaches.

Poster 252: Preliminary Study of Temporomandibular Joint MRI and CT View After Intraoral Modified Condylotomy for the Treatment of an Anterior Disc Dislocation of the TMJ

The aim of this study was to evaluate the changes in the disc and condyle shape through a review of MRI and CT findings after an intraoral modified condylotomy (no formation of a butt joint, none or less stripping of the medial pterygoid muscle under 3mm) for treating a painful disc dislocation of the TMJ (Wiles Stage II and III). Thirteen sides in 7 consecutive patients with a painful anterior disc dislocation, who were operated on by a single surgeon at the Armed forces Capital Hospital in South Korea, were examined. Preoperatively, 6 patients complained of severe popping bilaterally or unilaterally. All the patients suffered from frequent pain, joint tenderness, intermittent locking, and masticatory muscle pain. A decision was made to perform this procedure after at least 6 months of conservative treatment (behavior, medication, splint therapy, and arthrocentesis). The positions of disc and condyle were inspected 3 times (pre op, post 1 week to 1 month, post 3 month to 6 month) with MRI. From the magnetic resonance imaging view, 11 sides had ADD with a reduction before surgery. In addition, the changes of condylar position and remodeling of the condylar surface were examined. n/a The symptoms of the TMJ showed significant improvement (by VAS) with the disappearance of the popping and intermittent locking. The MRI view showed that all discs had been reduced by the reciprocal movement of the condyle and disc. On the 3D CT view, the deposition of new bone at condylar surface was confirmed in 5 patients. However, one patient with ADD without a reduction (clinically no sounds with mouth opening limitation under 20mm) underwent surgery twice. He showed the relief of his TMJ symptoms but complained of an anterior open bite. The anterior open bite still remained even after the second operation. IVRO is useful of the treatment of TMJ disorder in selective case with severe popping refractory to conservative treatment.

Longitudinal MRI follow-up of non-reducible posterior disc displacement accompanied by bone marrow oedema in the mandibular condyle

Serial MRI was used to examine the long-term course of posterior disc displacement (PDD) after non-surgical treatment. Serial MRI was performed on a 63-year-old woman with PDD accompanied by bone marrow oedema (BME) in the mandibular condyle. The patient had joint pain of the right temporomandibular joint (TMJ) and posterior open bite immediately after manual reduction of TMJ dislocation. Initial MRI of the right TMJ showed non-reducible PDD and subchondral BME. The patient underwent non-surgical treatment, and symptoms improved. The first follow-up MRI after 5 months showed non-reducible PDD, expansion of BME and erosion of the mandibular condyle. 1 year and 8 months after the initial examination the patient was asymptomatic, and a second follow-up MRI showed resolution of both BME and erosion, despite the persistence of non-reducible PDD. The MRI findings suggest that BME in the mandibular condyle complicating PDD is a reversible change, and may contribute to joint pain. This case report complements previous observations of the longitudinal course of PDD after non-surgical treatment.