Disc Displacement With Reduction Research Articles

Temporomandibular joint disc displacement with reduction: a review of mechanisms and clinical presentation

Disc displacement with reduction (DDWR) is one of the most common intra-articular disorders of the temporomandibular joint (TMJ). Factors related to the etiology, progression and treatment of such condition is still a subject of discussion. This literature review aimed to address etiology, development, related factors, diagnosis, natural course, and treatment of DDWR. A non-systematic search was conducted within PubMed, Scopus, SciELO, Medline, LILACS and Science Direct using the Medical Subjective Headings (MeSH) terms “temporomandibular disorders”, “temporomandibular joint”, “disc displacement” and “disc displacement with reduction”. No time restriction was applied. Literature reviews, systematic reviews, meta-analysis and clinical trials were included. DDWR is usually asymptomatic and requires no treatment, since the TMJ structures adapt very well and painlessly to different disc positions. Yet, long-term studies have shown the favorable progression of this condition, with no pain and/or jaw locking occurring in most of the patients.

Swallowing changes related to chronic temporomandibular disorders.

To investigate whether chronic temporomandibular disorder (TMD) patients showed any changes in swallowing compared to a control group. Moreover, it was examined whether swallowing variables and a valid clinic measure of orofacial myofunctional status were associated. Twenty-three patients with chronic TMD, diagnosed with disc displacement with reduction (DDR) and pain, according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD), and 27 healthy volunteers (control group) were compared. Surface electromyography (EMG) of the temporalis, masseter, sternocleidomastoid, and suprahyoid muscles was performed during swallowing tasks of thin liquid (10 and 15mL) and spontaneous saliva. Data were normalized. Compared to the control group, TMD patients showed a prolonged duration of swallowing for liquid and saliva and required a longer time to reach the activity peak and half the integral. While the overall mean value of the relative peaks was similar for the groups, the suprahyoid peak was significantly lower in the TMD group during swallowing of liquid. Moreover, TMD patients recruited the jaw elevator muscles proportionally more than controls. The orofacial myofunctional status was moderately correlated with EMG parameters. Patients with chronic TMD showed temporal prolongation and changes in the relative activity of the muscles during the swallowing tasks. The present results contribute additional evidence regarding the reorganization of muscle activity in patients with chronic TMD.

Prevalence of internal derangements of temporomandibular joint in patients with cleft-lip/palate

Aim: The aim of this study was to estimate the prevalence of internal derangements (ID) of temporomandibular joint (TMJ) in patients with cleft-lip/palate. Also, to evaluate the correlation of diagnosis between Research Diagnostic Criteria for temporomandibular disorders (RDC/TMD) clinical examination and Magnetic resonance imaging (MRI). Methods: Twenty patients with cleft-lip/palate, were clinically evaluated by RDC/TMD and by MRI. The ID of TMJ evaluate were disc displacement with reduction (DDWR) and disc displacement without reduction (DDWOR). Results: The present study showed that 9 (45%) of the patients were diagnosed with ID of TMJ (8 [40%] patients with DDWR and 1 [5%] with DDWOR) and 11 (55%) present no disorders, by RDC/TMD. MRI examination revealed that 15 (75%) of the patients had ID of TMJ (13 [65%] patients with DDWR and 2 [10%] with DDWOR) and 5 (25%) present no disorders. The Kappa index between the clinical and imaging diagnosis was 0.01. Conclusion: In the present study, DDWR was diagnosed in 40-65% by the RDC/TMD and MRI, respectively; DDWOR was diagnosed in 5-10% by the RDC/TMD and MRI, respectively. The diagnostic correlation between the clinical examination based on RDC and on MRI was weak.

Myofascial trigger points in patients with temporomandibular joint disc displacement with reduction: a cross-sectional study.

Objective The objective of this retrospective study was to evaluate the impact of myofascial trigger points (MTrPs) in patients with articular disc displacement with reduction (DDWR) and to identify which clinical variables are associated with the concomitant presence of DDWR and MTrPs.Material and Methods 130 patients were selected that sought treatment due to joint pain, with ages ≥18 years, of both genders, with DDWR confirmed by magnetic resonance imaging. The sample was divided into two groups: Group 1, patients with DDWR and MTrPs (N=101); and Group 2, patients with DDWR and no MTrPs (N=29). Information on gender, age, pain duration, pain scores, and maximal interincisal distance (MID) were collected. The logistic regression model was used and the odds ratios (OR) was calculated (p<0.05).Results Group 1 presented statistically significant higher mean pain scores (p=0.007), and smaller MID (p=0.0268) than Group 2. OR were significant for the pain scores (1.429), MID (0.937) and gender (women) (2.810).Conclusions Patients with DDWR and MTrPs had increased pain scores and a MID decrease compared to patients with DDWR and no MTrPs. The variables pain scores, MID, and gender (women) showed a significant association with the concomitant presence of DDWR and MTrPs.

Th1/Th17/Th22 immune response and their association with joint pain, imagenological bone loss, RANKL expression and osteoclast activity in temporomandibular joint osteoarthritis: A preliminary report.

It is well accepted that the presence of cytokines belonging to the Th1/Th17/Th22 axis of immuno-inflammatory response in the joint environment, such as IL-1β, IL-17 and IL-22, respectively, are associated with pathogenesis of several synovial joint degenerative disorders. During temporomandibular joint osteoarthritis (TMJ-OA), IL-1β and IL-17 have been implicated in the inflammation and resorption of sub-chondral bone; however, the role of Th22 response in the TMJ-OA pathophysiology has not been established. This study aimed to compare the expression of Th1/Th17/Th22-type cytokines, chemokines and chemokine receptors in synovial fluid samples obtained from TMJ-OA or disk displacement with reduction (DDWR) patients. In addition, it aimed to associate these levels with joint pain, imagenological signs of bone degeneration, RANKL production, osteoclastogenesis and osteoclast-induced bone resorption. Higher levels of IL-1β, IL-17 and IL-22 were expressed in TMJ-OA compared with DDWR subjects, and these increased levels significantly correlated with RANKL expression, joint pain and articular bone degeneration. Higher levels of CCR5, CCR6 and CCR7, as well as their respective ligands CCL5 and CCL20, responsible for recruitment of IL-1β, IL-17 and IL-22-producing cells, were over-expressed in TMJ-OA compared with DDWR subjects. Osteoclastogenesis and osteoclast-induced bone resorption were significantly greater in presence of synovial fluid from TMJ-OA compared with DDWR subjects. These data demonstrate that cytokines, CCLs and CCRs associated with the Th1/Th17/Th22 axis of immuno-inflammatory response are involved in TMJ-OA pathogenesis. These findings suggest that IL-22 is involved in the RANKL expression in TMJ-OA, which in turn induces differentiation of osteoclasts and subsequent resorption of sub-chondral bone.

Correlation between age, gender, and the number of diagnoses of temporomandibular disorders through magnetic resonance imaging: A retrospective observational study

ObjectiveThe aim of this study was to evaluate the correlation among age, gender and the number of temporomandibular disorder (TMD) findings.MethodsThe records from 228 patients with TMD were analyzed for the presence of these findings: morphological changes, disc displacement with reduction (DDWR) and without reduction (DDWOR), bone edema, effusion, and avascular necrosis. Statistical analyses were conducted using multinomial regression with a 5% significance level.ResultsDDWR was the most frequent finding. Group 1 was composed of 94 patients (41.22%), Group 2, of 67 patients (29.38%), and Group 3, of 67 patients (29.38%). Men were significantly less likely to belong to Group 3 than women (p = 0.5517). Older patients were slightly more likely to fall in Groups 2 and 3 than in Group 1.DiscussionWomen were shown to be more susceptible to developing a higher number of concomitant conditions than men, and the number of findings tended to increase with age.

Differences in signal intensities of temporomandibular joint (TMJ) effusion on fluid-attenuated inversion recovery (FLAIR) images.

Joint effusion is demonstrated by high signal intensity in the upper and lower temporomandibular joint (TMJ) spaces on T2-weighted images. The fluid-attenuated inversion recovery (FLAIR) technique can be applied to analyze joint effusion in the TMJ. FLAIR signal intensity can be more sensitively influenced by the contents of joint effusion than T2-weighted signal intensity. The purpose of this study was to analyze the signal intensity of joint effusion on FLAIR images and to investigate the changes in joint effusion contents according to the status of TMJ disorders. A total of 48 joints (45 patients) with joint effusion were investigated by magnetic resonance (MR) imaging. Regions of interest were placed over the joint effusion and gray matter on FLAIR images. The joints were categorized as normal disk position (NL), disk displacement with reduction (DWR), disk displacement without reduction (DWOR), and osteoarthritis (OA). The signal intensity ratio of joint effusion was calculated using gray matter as the reference point. The Kruskal-Wallis test and Steel test were applied. A probability of less than 0.05 was considered statistically significant. The median signal intensity ratios of joint effusion differed significantly among the four joint categories (p = 0.02, Kruskal-Wallis test). The median signal intensity ratio of joint effusion in the OA category was significantly higher than that in the NL category (p = 0.04, Steel test). The present findings suggest that FLAIR images can demonstrate the changes in joint effusion contents according to the status of TMJ disorders.

Relationships between temporomandibular joint disk displacements and condylar volume

The aim of this study was to assess the relationship between mandibular condylar volume and disk displacement status in adult males and females. We evaluated 122 temporomandibular joints in 61 patients using magnetic resonance imaging (MRI) and computed tomography (CT). MRI data were used to assign disk status as normal disk position (NR), disk displacement with reduction (DDR), or disk displacement without reduction (DDNR). CT data were used to calculate total condylar volume and its components, cortical volume, and trabecular volume. The relationships among condylar volume, disk status, and gender were tested with 2-way analysis of variance. Condylar volumes significantly correlated with disk displacement, tending to decrease as displacement increased. There were significant differences in both total condylar volume and trabecular volume among the DD status (NR > DDR > DDNR), whereas cortical volume was significantly different only between NR/DDR and DDNR (NR/DDR > DDNR). The volume decreases associated with temporomandibular joint DD were found in both males and females, with greater decreases in men than in women as DD progressed. Condylar volumes are significantly associated with disk displacement status. Joints with nonreducing disks showed the smallest condylar volumes in both males and females.

Clinical Characteristics of Temporomandibular Disorders in Patients Admitted to a Dental School Clinic in Turkey

Objectives This study was undertaken to observe the frequency of different diagnostic groups for temporomandibular disorders (TMDs) in patients who sought treatment for TMD in an outpatient clinic of a dental school.Methods Files of patients who received a diagnosis of TMD in a period of 24 months were evaluated. Clinical and demographic data extracted from 213 patient files meeting the inclusion criteria were analyzed.Results According to the classification of RDC/TMD, 100 patients were diagnosed with myofascial pain and 113 patients were diagnosed with disc displacement. Myofascial pain was the most common diagnosis among women; disc displacement with reduction (DDwR) was the most common diagnosis in men. Self-reported bruxism was reported by 59% of the patients. The amount of maximal mouth opening showed a statistically significant difference among patients with different clinical diagnoses and also between males and females (P 0.05).Conclusion Demographic characteristics of patients with TMD presenting to a dental school clinic in Ankara, Turkey were similar to those reported in the literature. A thorough anamnesis can provide more detailed information about parafunctional activity and sociodemographic factors and enhance accurate diagnosis.

Reorganization of muscle activity in patients with chronic temporomandibular disorders

ObjectiveTo investigate whether reorganization of muscle activity occurs in patients with chronic temporomandibular disorders (TMD) and, if so, how it is affected by symptomatology severity. MethodsSurface electromyography (sEMG) of masticatory muscles was made in 30 chronic TMD patients, diagnosed with disc displacement with reduction (DDR) and pain. Two 15-patient subgroups, with moderate (TMDmo) and severe (TMDse) signs and symptoms, were compared with a control group of 15 healthy subjects matched by age. The experimental tasks were: a 5s inter-arch maximum voluntary clench (MVC); right and left 15s unilateral gum chewing tests. Standardized sEMG indices characterizing masseter and temporalis muscles activity were calculated, and a comprehensive functional index (FI) was introduced to quantitatively summarize subjects’ overall performance. Mastication was also clinically evaluated. ResultsDuring MVC, TMDse patients had a significantly larger asymmetry of temporalis muscles contraction. Both TMD groups showed reduced coordination between masseter and temporalis muscles’ maximal contraction, and their muscular activity distribution shifted significantly from masseter to temporalis muscles. During chewing, TMDse patients recruited the balancing side muscles proportionally more than controls, specifically the masseter muscle. When comparing right and left side chewing, the muscles’ recruitment pattern resulted less symmetric in TMD patients, especially in TMDse. Overall, the functional index of both TMDmo and TMDse patients was significantly lower than that obtained by controls. ConclusionsChronic TMD patients, specifically those with severe symptomatology, showed a reorganized activity, mainly resulting in worse functional performances.

Three-dimensional analysis of jaw kinematic alterations in patients with chronic TMD - disc displacement with reduction.

The study investigated whether chronic TMD patients with disc displacement with reduction (DDR), performing non-assisted maximum jaw movements, presented any changes in their mandibular kinematics with respect to an age-matched control group. Moreover, it was examined whether jaw kinematics and a valid clinic measure of oro-facial functional status have significant associations. Maximum mouth opening, mandible protrusion and bilateral laterotrusions were performed by 20 patients (18 women, 2 men; age, 18-34 years) and 20 healthy controls (17 women, 3 men; age, 20-31 years). The three-dimensional coordinates of their mandibular interincisor and condylar reference points were recorded by means of an optoelectronic motion analyser and were used to quantitatively assess their range of motion, velocity, symmetry and synchrony. Three functional indices (opening-closing, mandibular rototranslation, laterotrusion - right and left - and protrusion) were devised to summarise subject's overall performance, and their correlation with the outcome of a clinical protocol, the oro-facial myofunctional evaluation with scores (OMES), was investigated. TMD patients were able to reach maximum excursions of jaw movements comparable to healthy subjects' performances. However, their opening and closing mandibular movements were characterised by remarkable asynchrony of condylar translation. They had also reduced jaw closing velocity and asymmetric laterotrusions. The functional indices proved to well summarise the global condition of jaw kinematics, highlighting the presence of alterations in TMD-DDR patients, and were linearly correlated with the oro-facial functional status. The jaw kinematic alterations seem to reflect both oro-facial motor behaviour adaptation and a DDR-related articular impairment.

Is Hyaluronic Acid Injection Effective for the Treatment of Temporomandibular Joint Disc Displacement With Reduction?

Hyaluronic acid (HA) injections and occlusal splints have been suggested in the treatment of temporomandibular joint (TMJ) derangements, but no sufficient data are available from controlled clinical trials comparing HA injection with another treatment modality. This study compared the effectiveness of a single HA injection, a double HA injection, and splint therapy for the treatment of TMJ disc displacement with reduction (DDR). A prospective clinical trial was designed. The study sample included patients with TMJ DDR. The primary predictor variable was treatment method. Patients were divided into 4 groups: control, single HA injection, double HA injection, and stabilization splint therapy. Patients were randomly assigned to 1 of 3 treatment groups. The control group was self-selected. The primary outcome variable was pain at rest and during mastication. The secondary outcome variables were TMJ noise, quality of life, and level of jaw movements. Clinical symptoms and jaw movements were evaluated at baseline and at 6-month follow-up. Descriptive, comparative, correlation, and multivariate analyses were conducted. The sample included 51 patients (66 TMJs) 18 to 48years old. All treatment groups showed significant improvement compared with baseline values for pain, TMJ noise, quality of life, and maximum mouth opening (MMO) at 6-month follow-up (P < .05). However, the 2 HA injection groups indicated superior improvement for pain, MMO, and quality of life compared with the stabilization splint group (P < .05). The results of this study showed that HA injection and stabilization splinting are acceptably successful treatment modalities to alleviate the clinical signs and symptoms of TMJ DDR.

Changes in the temporomandibular joint space after functional treatment of disk displacement with reduction.

This study aimed to evaluate the changes of temporomandibularjoint (TMJ) space in the treatment of disk displacement with reduction (DDWR) for class II cases. Forty-two adolescent patients with unilateral DDWR, who were successfully treated by functional appliance, were selected in this study. Magnetic resonance imaging scans were used before treatment (T1), at the start of treatment (T2), and after functional treatment (T3). Compared with the normal joint, the change of joint space index was calculated. The anterior, posterior, and superior joint spaces were analyzed on the largest sagittal plane among T1, T2, and T3. Student's t-test was used for statistical analysis. The mean treatment period was 10 months (6-16 mo). Functional appliance was effective in eliminating pain and clicking. During the phase of T1, the value of the joint space index of DDWR was significantly higher than that of the control (P < 0.05). There was a significant decrease in the anterior space and an increase in the postsuperior space at T2 (P < 0.01), and then the contrary changes occurred at T3. However, there was a significant increase in the postsuperior space and no significant decrease in the anterior space when T1 and T3 were compared. This study indicates that the TMJ space is well distributed after disk repositioning with functional treatment of DDWR. It is also suggested that the adaptive remodeling in TMJ occurs via functional treatment.

Management of painful temporomandibular joint clicking with different intraoral devices and counseling: a controlled study

Objective The benefit of the use of some intraoral devices in arthrogenous temporomandibular disorders (TMD) patients is still unknown. This study assessed the effectiveness of the partial use of intraoral devices and counseling in the management of patients with disc displacement with reduction (DDWR) and arthralgia.Materials and Methods A total of 60 DDWR and arthralgia patients were randomly divided into three groups: group I (n=20) wore anterior repositioning occlusal splints (ARS); group II (n=20) wore the Nociceptive Trigeminal Inhibition Clenching Suppression System devices (NTI-tss); and group III (n=20) only received counseling for behavioral changes and self-care (the control group). The first two groups also received counseling. Follow-ups were performed after 2 weeks, 6 weeks and 3 months. In these sessions, patients were evaluated by means of a visual analogue scale, pressure pain threshold (PPT) of the temporomandibular joint (TMJ), maximum range of motion and TMJ sounds. Possible adverse effects were also recorded, such as discomfort while using the device and occlusal changes. The results were analyzed with ANOVA, Tukey’s and Fisher Exact Test, with a significance level of 5%.Results Groups I and II showed improvement in pain intensity at the first follow-up. This progress was recorded only after 3 months in Group III. Group II showed an increased in joint sounds frequency. The PPT values, mandibular range of motion and the number of occlusal contacts did not change significantly.Conclusion The simultaneous use of intraoral devices (partial time) plus behavioral modifications seems to produce a more rapid pain improvement in patients with painful DDWR. The use of NTI-tss could increase TMJ sounds. Although intraoral devices with additional counseling should be considered for the management of painful DDWR, dentists should be aware of the possible side effects of the intraoral device’s design.

The effects of TMJ symptoms on skeletal morphology in orthodontic patients with TMJ disc displacement

Objective. The aim of this study was to investigate the effects of temporomandibular joint (TMJ) symptoms on skeletal morphologies of orthodontic patients with TMJ disc displacement (DD). Materials and methods. The sample consisted of 197 women seeking orthodontic treatment. The subjects were divided into two groups according to the presence of TMJ symptoms: the presence and absence of TMJ symptoms. Each group was sub-divided into three groups based on magnetic resonance images of bilateral TMJs: bilateral normal disc position (BN), bilateral disc displacement with reduction (DDR) and bilateral disc displacement without reduction (DDNR). Seventeen variables from lateral cephalograms were analyzed by two-way analysis of variance to identify differences in skeletal morphologies with respect to TMJ symptoms and TMJ DD status. Results. Patients with TMJ DD were more likely to have short ramus height, short mandibular body length and backward positioning of the ramus and mandible. These skeletal morphologies became more severe as TMJ DD progressed to DDNR. However, the skeletal morphologies associated with TMJ DD were not significantly different between symptomatic and asymptomatic patients. As a result, patients with TMJ DD had backward positioning and clockwise rotation compared to those with bilateral normal TMJs, irrespective of the presence of TMJ symptom. Conclusions. This study suggests that TMJ DD is associated with altered skeletal morphology, but TMJ symptoms do not significantly influence the relationships between TMJ DD and skeletal morphology.

The study by Manfredini et al. used the Myotronics K6 device contrary to the device's published indications for use

The study by Manfredini et al. used the Myotronics K6 device contrary to the device's published indications for use

The prevalence of temporomandibular disorders in patients with late whiplash syndrome who experience orofacial pain: A case-control series study

Background The authors conducted a study to compare the frequency of specific temporomandibular disorder (TMD) diagnoses in patients who had late whiplash syndrome (LWS) with that in a control group. Methods The authors recruited 65 patients who had orofacial pain and a previous diagnosis of LWS and 65 age- and sex-matched control patients who had chronic orofacial pain without a history of whiplash injury (WI) for a case-control series study. All patients completed a questionnaire pertaining to the Research Diagnostic Criteria for Temporomandibular Disorders and underwent a clinical examination. Results The authors compared the frequency of TMD diagnoses in case patients with that in control patients by using a χ2 test; they set the α level a priori at .05. The number of patients diagnosed with myofascial pain (MP) and disk displacement with reduction (DDWR) was significantly higher in the case group than in the control group (P = .002 and P = .001, respectively). Conclusions The results of this study show a higher frequency of MP and DDWR in patients with LWS than in patients with chronic orofacial pain and no history of WI. Practical Implications Clinicians should be knowledgeable about the correlation between WI and TMD so they can inform and treat patients accurately.

Magnetic resonance imaging-verified temporomandibular joint disk displacement in relation to sagittal and vertical jaw deformities

This retrospective study was designed to analyze the relationships between temporomandibular joint (TMJ) disk displacement and skeletal deformities in orthodontic patients. Subjects consisted of 460 adult patients. Before treatment, lateral cephalograms and TMJ magnetic resonance imaging (MRI) were recorded. Subjects were divided into six groups based on TMJ MRI according to increasing severity of TMJ disk displacement, in the following order: bilateral normal TMJs, unilateral disk displacement with reduction (DDR) and contralateral normal, bilateral DDR, unilateral disk displacement without reduction (DDNR) and contralateral normal, unilateral DDR and contralateral DDNR, and bilateral DDNR. Subjects were subdivided sagittally into skeletal Class I, II, and III deformities based on the ANB (point A, nasion, point B) angle and subdivided vertically into hypodivergent, normodivergent, and hyperdivergent deformities based on the facial height ratio. Linear trends between severity of TMJ disk displacement and sagittal or vertical deformities were analyzed by Cochran–Mantel–Haenszel test. The severity of TMJ disk displacement increased as the sagittal skeletal classification changed from skeletal Class III to skeletal Class II and the vertical skeletal classification changed from hypodivergent to hyperdivergent. There were no significant differences in the linear trend of TMJ disk displacement severity between the sexes according to the skeletal deformities. This study suggests that subjects with skeletal Class II and/or hyperdivergent deformities have a high possibility of severe TMJ disk displacement, regardless of sex.

Locking-free Appliance(LA)를 이용한 개구운동치료 : 예비실험

Introduction: 모든 정복성 관절원판변위가 비정복성 관절원판변위로 진행되는 것은 아니지만 심각한 포착이나 걸림을 동반하는 정복성 관절원판변위는 비정복성 관절원판변위로 진행하게 된다. 이번 연구에서는 Locking-free Appliance(LA)를 이용한 개구운동치료의 효과를 살펴보고자 한다. Patients and Method: 후향적으로, 2010년 1월부터 2011년 12월까지 전북대학교병원 치과진료처 구강내과에서 LA를 이용한 개구운동치료를 받은 37명의 환자를 대상으로 분석을 시행하였다. 환자는 LA를 착용한 상태에서 하루 30번의 개구운동을 할 것을 교육받았다. Results: 치료를 받은 환자들 중 비정복성 관절원판변위로 악화된 환자는 없었다. 37명 중 16명의 환자들은 과두걸림 없이 개구가 가능해졌다. Mann-whitney test와 fisher's test, Chi-square test를 이용하여 분석 시, 과두걸림이 해소된 환자와 그렇지 않은 환자간의 나이, 성별, 통증유무, 과두걸림 호소 기간, 통증의 정도(VAS score)에는 통계학적으로 유의한 차이가 없었다. Conclusion: 이번 연구에서, LA를 이용한 개구운동치료 후 일부 환자는 과두걸림 없이 개구가 가능해졌고, 일부 환자는 과두걸림이 해소되지 않았으나, 비정복성 관절원판변위로 악화된 경우는 없었다. 이 치료는 기존의 전통적인 치료방법에 비해 환자의 교합장치 착용 시간이 짧고, 비용이 저렴하며, 환자의 불편함을 최소화 할 수 있다는 장점이 있다. 따라서, LA를 이용한 개구운동치료는 과두걸림을 해소하거나, 비정복성 관절원판변위로의 악화를 예방하는데 새로운 치료방법이 될 것으로 기대된다. Objective: All patients who have the disc displacement with reduction (DDwR) are always not progressive but some of them with significant catching or locking progress to disc displacement without reduction (DDw/oR). In this study, we suggest opening exercise therapy using Locking-free Appliance (LA) to be helpful to prevent progressive derangement. Methods: Retrospectively, a total 37 patients who received exercise treatment using LA was analyzed from January 2010 to December 2011. Patients had been instructed in proper exercise technique to practise for opening and closing of mouth wearing the appliance 30 times a day in locking-free position. Results: None of the patients took a turn for worse to DDw/oR (37 patients). The 16 patients (43.2%, locking-free group) of them could open their mouth without intermittent condylar locking. Measurement of data was analyzed using and Mann-Whitney test. There was no statistically significant difference for age, gender, presence of palpational pain, locking period, VAS quantitative pain score between locking-free group and locking group. Conclusions: In this study, some patients could open their mouth without intermittent locking and did not take a turn for worse to DDw/oR after opening exercise therapy with LA. Furthermore, LA had advantages which were short wearing time, low costs and minimizing patients' uncomfortable compared to conventional treatment method. This therapy can be more appropriate new treatment to prevent progress to DDw/oR.

MRI Findings in Patients with TMJ Click

Introduction: It has been shown that joint click, an initial and common finding in internal derangement (ID), respond to neither conservative treatment nor surgical intervention. This raises the question as to whether it must be treated in the absence of other pertinent signs and symptoms, so the aim of this study was to investigate and compare the MRI findings of TMJ in both normal subjects and patients with click, in order to determine the importance of click in predicting TMJ pathological changes. Methods: A total of 26 patients with clinical symptoms of disk displacement with reduction (DDwR) according to RDC/TMD were compared to 14 normal subjects in terms of their MRI findings, including disk displacement, effusion, condylar osteoarthritic changes and disk deformities. Results: Out of 80 joints in total (52 affected joints in 26 patients and 28 joints in control group), 48 were shown with normal disk position in MRI whereas 28 (35%) and 4 (5%) were categorised as DDwR and (disk displacement without reduction) DDwoR, respectively. Statistically significant correlations were established between the following pairs of variables in order: Click and disk displacement, effusion and disk displacement, disk displacement and effusion with disk deformity. Conclusion: The correlation between the presence of click and disk displacement, disk deformity and effusion emphasizes the importance of MRI for an accurate diagnosis and development of an appropriate treatment plan in these cases and shows that clinical examination is not sufficient for these purposes.