Temporomandibular Disc Research Articles

Conservative versus Invasive Approaches in Temporomandibular Disc Displacement: A Systematic Review of Randomized Controlled Clinical Trials.

Temporomandibular disorders (TMDs) frequently cause orofacial pain and dysfunction, with treatment options spanning from conservative therapies to invasive surgical procedures. The aim of this systematic review was to analyze and compare the efficacy and safety profiles of conservative, minimally invasive interventions and surgical procedures in patients diagnosed with TMDs and disc displacement. Following PRISMA recommendations, PubMed, Scopus, and Web of Science databases were searched for randomized clinical trials (RCT). Data were synthesized in a table and evaluated through the Cochrane risk of bias 2 (RoB 2) tool. Thirty-eight RCTs, most with moderate RoB, were selected. Conservative approaches, including physical therapy and occlusal devices, led to an improvement in symptoms and function. Pharmacological treatments demonstrated effectiveness in reducing pain and improving function; however, they can have undesirable side effects. Minimally invasive and invasive treatments also demonstrated efficacy, although most trials did not show their superiority to conservative treatments. The primary approach to TMDs should be a conservative, multimodal treatment plan tailored to patient complaints and characteristics. Treatment goals should focus on symptom control and functional recovery. Surgical treatment should be reserved for cases with a precise diagnosis and a clear etiology.

The biomechanical effects of bimaxillary osteotomies to the patients with mandibular retraction under incisal clenching.

The purpose of this study is to investigate the biomechanical effect of bimaxillary osteotomies on patients with mandibular retraction. Mandibular retraction, as a typical maxillofacial deformity, and has great adverse effects on TMJ. Bimaxillary osteotomies are widely used to correct symptoms of mandibular retraction. It is necessary to understand the effect of surgery on temporomandibular disc (TMJ). Five patients with mandibular retraction and 10 asymptomatic subjects were involved in this study. Finite element models of preoperative, postoperative and control group were constructed based on the CT data. Nine sets of concentrated forces were used to simulate the muscle effect and contact method was used to simulate the interaction within the TMJs and dentitions. The results showed that bimaxillary osteotomies could effectively improve the maxillofacial morphology and alleviate the overload in TMJ. The facial asymmetry and right chewing side preference could cause imbalanced stress distributions in the TMJs and interfere the surgical treatment.

Finite element analysis of stabilization splint pressure distribution in a patient with disc displacement without reduction: A preliminary study.

This study was performed to investigate the pattern of condylar pressure distribution in the discs of a patient diagnosed with disc displacement without reduction. This research consisted of a pre- and post-test observational clinical study. A patient diagnosed with disc displacement without reduction underwent treatment with an occlusal splint for 3 months. Finite element analysis employed a 3-dimensional model constructed from magnetic resonance images of the patient, taken both before the application of the splint and 3 months after its use. The post-test model demonstrated a decrease in condylar pressure on the disc, with measurements dropping to 72 MPa from the pre-test level of 143 MPa. In the pre-test, the pressure distribution pattern was concentrated on the lateral posterior border, whereas in the post-test, it shifted toward the intermediate zone of the disc. Utilization of a stabilization splint for 3 months resulted in decreased pressure and a marked change in the pressure distribution pattern on the temporomandibular disc.

Assessing the Efficacy of Anterior Repositioning Splints in the Management of Temporomandibular Disc Displacement: A Systematic Review and Meta-Analysis.

Disc displacement (DD) occurs when the cushioning disc of the temporomandibular joint (TMJ), situated between the jawbone and the skull, is out of position. The condition can be of two kinds: disc displacement with reduction (ddwr) and disc displacement without reduction (ddwor). The present systematic review was undertaken to assess the efficacy of anterior repositioning splints (ARS) for ddwr and ddwor. Three online databases were searched for relevant studies using MeSH keywords and Boolean operators. Initial searches of the databases extracted 552 records. Twelve studies equally representing ARS with ddwr and ddwor were selected. No clear difference could be assessed regarding ARS usage in both conditions. The outcome assessed was the improvement in TMJ symptoms. The results suggested that both ddwr and ddwor were effective in improving temporomandibular joint (TMJ) symptoms in patients who received ARS therapy. Efficacy levels ranged from 71-83% and 50-95% for ARS in ddwr and ddwor, respectively; odds ratio (OR) values ranging from 0.30 and 0.36 were obtained for ARS in both therapies, respectively, indicating similar performance levels. Both ddwr and ddwor respond well to the use of ARS; however, more clinical trials are needed to ascertain and validate the role of ARS as a treatment modality in this regard.

Observational study investigating the relationship between maxillomandibular characteristics and temporomandibular disc conditions in female patients with a skeletal class III pattern.

The objective of this study was to analyze the relationship between maxillomandibular characteristics and the severity of temporomandibular disc displacement in female patients with a skeletal class III (SKIII) pattern. Fifty-seven samples were included in the study. The evaluation of articular disc conditions was conducted using magnetic resonance imaging, while 25 cephalometric variables from lateral and postero-anterior (P-A) cephalograms were measured to determine their maxillomandibular characteristics. The samples were categorized into three groups based on the articular disc conditions: (1) normal disc position (NDP), (2) disc displacement with reduction (DDwR), and (3) disc displacement without reduction (DDwoR). The relationship between the maxillomandibular characteristics and disc conditions was examined through both basic statistical analysis and multivariate analysis using principal component analysis (PCA). The Kruskal-Wallis and Dunn-Bonferroni tests revealed a significant difference between the groups in terms of the deviation of mandibular characteristics observed on the P-A cephalogram. The DDwoR group exhibited significantly larger menton deviation, ramal height asymmetry index, and total mandibular length asymmetry index compared to the NDP and DDwR groups. Moreover, the PCA successfully extracted all cephalometric variables into eight principal components. Among them, only the principal component related to mandibular asymmetry was able to differentiate the SKIII samples with DDwoR from the other groups. The findings of this study highlight a significant relationship between mandibular asymmetry and the severity of disc displacement, particularly DDwoR, in female patients with a SKIII pattern.

TMJ disc repositioning associated with orthognathic surgery for the treatment of severe retrognathism

Introduction: Orthognathic surgery associated with temporomandibular disc reposition is a modality of surgical treatment for dentofacial deformities associated with temporomandibular disorders that has been shown to be a stable and predictable alternative for such situations. However, there is still no consensus in the literature regarding the treatment modality in these cases. Several studies have been developed looking for more stable and predictable results in favor of the best patient treatment. Case Report: Patient with a class II facial pattern and temporomandibular dysfunction, submitted to bilateral repositioning of the articular disc and orthognathic surgery with counterclockwise rotation of the maxillomandibular complex, with improvement of the symptoms and of the functionality of the stomatognathic system, and satisfaction with facial aesthetics. Conclusion: Although there are controversies about the surgical repositioning of chronic articular disc displacements in retrognathism, this treatment modality has demonstrated long-term stability and reduction or resolution of joint symptoms.

Effects of Occlusal Plane Inclination on the Temporomandibular Joint Stress Distribution: A Three-Dimensional Finite Element Analysis.

Background Sudden changes in masticatory loads and occlusal conditions contribute to temporomandibular disorders. Clockwise (CW) or counterclockwise (CCW) rotation of the occlusal plane is one of the factors that alter the direction of the occlusal forces transmitted to the temporomandibular joint structures. Finite element analysis was used to identify possible regions of high stress in the temporomandibular joint. Materials and Methods A computer-aided design model of a symmetrical edentulous maxillomandibular bony complex with a temporomandibular joint was manually generated using Rhinoceros 4.0 freeform modeling software. Three-dimensional discrete mesh generation was performed using VRMesh Studio. The reference occlusal plane angle was accepted as 8° in the sagittal plane, and by modifying 4° in the CW and CCW directions, CW and CCW models were obtained, respectively. The present study aimed to evaluate the changes in stress distribution in the condylar cartilage and temporomandibular disc using the von Mises and maximum-minimum principal stress evaluations of three different occlusal plane inclinations. The null hypothesis of this three-dimensional finite element analysis was that “occlusal plane inclination does not change the stress distribution on the temporomandibular joint structures.” Results The compressive stress on the condyle increased with CW rotation of the occlusal plane. The von Mises equivalent stress of the temporomandibular disc shifted to the medial, posterior, and superior directions after CW and CCW rotations of the occlusal plane. The CW rotation of the occlusal plane increased the von Mises equivalent.

Temporomandibular Disk Dislocation Impacts the Stomatognathic System: Comparative Study Based on Biexponential Quantitative T2 Maps.

In this study, we aimed to assess the potential impact of temporomandibular disk displacement on anatomical structures of the stomatognathic system using biexponential T2 magnetic resonance imaging (MRI) maps. Fifty separate MRI scans of the temporomandibular joints (TMJ) of 25 patients were acquired with eight echo times. Biexponential T2 maps were created by weighted reconstruction based on Powell’s conjugate direction method and divided into two groups: the TMJ without (32 images) and with (18 images) disk displacement. The disk, retrodiscal tissue, condylar bone marrow, masseter muscle, lateral and medial pterygoid muscles and dental pulp of the first and second molars were manually segmented twice. The intrarater reliability was assessed. The averages and standard deviations of the T2 times and fractions of each segmented region for each group were calculated and analysed with multiple Student’s t-tests. Significant differences between groups were observed in the retrodiscal tissue, medial pterygoid muscle and bone marrow. The pulp short T2 component showed a trend toward statistical significance. The segmentation reliability was excellent (93.6%). The relationship between disk displacement and quantitative MRI features of stomatognathic structures can be useful in the combined treatment of articular disk displacement, pterygoid muscle tension and occlusive reconstruction.

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.

Is condyle morphology a factor for anterior temporomandibular disc displacement?

To investigate morphological features of the mandibular condyle and its association with anterior temporomandibular disc displacement on sagittal oblique MRI plane. One hundred and twenty patients with temporomandibular MRI examination were retrospectively involved in the study. Patients aged less than 18 years and those with severe osteoarthritis, posterior disk displacement, tumor, abscess, history of a rheumatic disease, facial trauma, and motion artifacts on images were excluded. Three radiologists evaluated all images in consensus. Temporomandibular disc locations were classified as normal, anteriorly displaced with reduction (ADr), and anteriorly displaced without reduction (ADwr) on sagittal oblique T1-weighted images. Condylar shapes were classified as flat, rounded, and angled, and condyle anteroposterior width (c-APW) was measured on these images in closed-mouth position. Ninety six discs were in normal position (40%), 70 discs were ADr (29%), and 74 discs were ADwr (31%). Eighty-four condyles were flat (35%), 100 condyles were rounded (42%), and 56 condyles were angled (23%). Mean c-APW was 7 mm in normal joints, 5.9 mm in ADr, and 5.8 mm in ADwr joints, and it was smaller in joints with anterior disc displacement (p < 0.001). In normal joints, flat and rounded type condylar shape was more common and almost equally prevalent (44% and 43%); however, rounded type was more common among ADr (%47) and angled type was more common among ADwr joints (36%) (p = 0.008). Patients with anterior disc displacement were significantly younger from normal cases and anterior disc displacement was more common among female sex. Mandibular condyle shape alterations and condyle size on sagittal oblique MRI plane are associated with anterior disc displacement. Angled shape was more common among ADwr joints. Joints with anterior disc displacement had smaller c-APW than normal joints.

Dextrose prolotherapy versus BOTOX injection for the management of TMJ disc displacement with reduction

Background: Temporomandibular disc displacement is a widely faced clinical condition and the management options are vast with varying difficulty and success rates. This study aims to evaluate the use of Botulinum Toxin injection and dextrose prolotherapy for such cases. Methods: 20 joints were included in this study divided into 2 groups; Group 1 receiving 25% 3mL Dextrose injection (with local anesthetic and saline solution) into the retrodiscal region while group 2 received 35 U Botulinum Toxin – Type A injection in the lateral pterygoid muscle. Pain (according to the visual analogue scale), clicking and maximal interincisal opening were assessed preoperatively and at 4 months followup. Results: The results showed no statistically significant differences between the 2 groups. The click disappeared in 7/10 joints in group 1 and 9/10 in group 2. The maximal interincisal opening was regained and slightly increased in all participants of the study. All patients reported better pain scores at the end of the followup period. Conclusions: Within the limitations of this study, we conclude that both treatment options tested are considered acceptable in the management of TMJ anterior disc displacement with reduction. Moreover, the results do not allow recommending one over the other as no statistically significant differences were found.

Assessment of anterior positioning splint in conjunction with lateral pterygoid BTX injection to treat TMJ disc displacement with reduction \u2014 a preliminary report

ObjectiveTreatment of temporomandibular disc displacement with reduction is controversial. This study assesses the use of an anterior positioning splint with botulinum toxin in the lateral pterygoid muscle (BTX) for such cases.MethodsTwelve joints were included; groups I and II received BTX injection while group II also received an anterior positioning splint. Pain scores and clicking status were recorded at regular intervals then a postoperative MRI was done after 4 months.ResultsClinical improvement was noted in both groups. Mean pain scores dropped significantly and clicks in the twelve joints disappeared in 83% of group I and 33% of group II. MRIs showed significant disc position improvement with the higher mean change (1.33 ± 0.76) in group I.Group I showed better improvement of discal position and only one joint regained a click. Patients of group II reported discomfort from the splint which may have caused psychological distress and so worst pain scores.ConclusionsGroup I showed slightly better results but the cost of BTX injections and the complications of the splint should be kept in mind and the decision of treatment selection made according to each condition.

Clinical Effects of the Combination of Rhytidectomy and Temporomandibular Joint Disc Repositioning Surgery.

This study aims to investigate the clinical effects of the combination of rhytidectomy and temporomandibular joint (TMJ) disc repositioning surgery in internal derangement (ID) stage IV-V and facial aging patients. Eighteen facial aging with bilateral ID IV-V patients were enrolled in this study. All of them had undergone temporomandibular disc repositioning surgery and rhytidectomy by the same surgeon (Yao Min Zhu). Pre-/post-surgical clinical manifestations, facial photography, radiographic data were recorded and analyzed, as well as doctor, patient, third-party evaluation of postsurgical facial appearance satisfaction. The average age of 18 female patients was 52.9. The average of presurgical visual analog pain scale score was 5.94, ranged from 4 to 8. After 6 months, the average of postsurgical visual analog pain scale score was 0.28, ranged from 0 to 1 ( P > 0.05). The average maximal mouth opening of presurgical and postsurgical was 2.19 and 3.29 cm, ranged from 1.2 to 2.8 cm and 3.0 to 3.5 cm, respectively ( P < 0.05). Postoperative magnetic resonance imaging showed the location of the bilateral TMJ discs directly above the mandibular condyle. The satisfaction rate of doctors, patients and third-party with facial appearance was 95% to 98%, 96% to 99% and 96% to 99%, respectively, with an average of 95.72%, 98.11%, and 97.50%. For patients with bilateral ID IV-V and facial aging, the combination of disc repositioning surgery and rhytidectomy is a very feasible procedure to treat TMJ disorders and improve patients' facial appearance and satisfaction.

Quantitative assessment of temporomandibular disc and masseter muscle with shear wave elastography.

To assess the normal stiffness values of temporomandibular joint disc (TMJ) and masseter muscle by shear wave elastography (SWE) in a healthy adult population. This may be helpful in diagnosing and understanding the mechanism of temporomandibular disorders (TMD). This prospective study evaluated a total of 160 healthy adult volunteers (77 males, 83 females). The stiffness values of anterior, intermediate and posterior parts of the TMJ disc and masseter muscle were measured. Study cohort was classified into four groups based on age. Additionally, we investigated the changes in mean shear wave elasticity (kPa) and shear wave velocity(m/s) values of disc parts and masseter muscle in closed and open mouth positions, and the correlation of these SWE values with age and gender. Mean stiffness values of the disc were 37.02 ± 23.75kPa and 3.28 ± 1.09m/s in the anterior part, 30.47 ± 18.89kPa and 2.97 ± 1.04m/s in the intermediate part, 22.61 ± 13.97kPa and 2.55 ± 0.88m/s in the posterior part. Stiffness values showed significant decrease in the posterior part compared to the rest of the disc both in males and females. No significant differences in mean stiffness values of masseter muscle related to mouth position, age or gender. This study provides the normative quantitative elasticity values of disc and masseter muscle which could be a reference point for upcoming studies. Disc elasticity values are higher in women than men. Maybe this is one of the reason why TMD is more common in women. TMJ disc stiffness was significantly lower in the posterior part. SWE is a useful imaging method that can be used with routine ultrasonography in evaluation of the TMJ disc and masticatory muscles .

Relative risk of positional and dynamic temporomandibular disc abnormality for osteoarthritis-magnetic resonance imaging study.

Dynamic articular disc abnormality (wR, with reduction; woR, without reduction) is well known as the risk factor for temporomandibular joint osteoarthritis (TMJOA). However, there are few speculations on the potential risk of positional disc abnormalities for TMJOA. The purpose of this study was to investigate the relative risk of positional abnormality and dynamic abnormality of the temporomandibular disc for OA after the three-dimensional interpretation of all the sagittal and coronal planes of magnetic resonance (MR) data in a large dataset of consecutive subjects. Experimental samples consisted of images of 1356 TMJs of patients. A diagnosis of disc state was established in each TMJ utilising a 1.5T MR imaging scanner. A binary logistic regression analysis was performed to identify the significant associations between the outcome (dependent variable: the presence of OA) and the predictors (covariates: age, sex, dynamic disc state [the presence of woR], and 5 categories of the positional disc state [NA, no abnormality; SW, sideways; pADD, partial anterior; cADD, complete anterior; PDD, posterior]). Based on the result of the binary logistic regression analysis, the presence of woR showed an odds ratio of 14.1 (P<.05). In addition, compared with the joints NA, those with SW and cADD showed odds ratios of 5.62 and 10.88, respectively (P<.05). Despite the limitations of the study, in the positional disc abnormalities, sideways disc displacement and complete anterior disc displacement could be associated with the occurrence of TMJOA. All the coronal and sagittal MR images should be evaluated to assess intra-articular joint disorders accurately.

Short-Term Morphological Changes in Asymptomatic Perimandibular Muscles after Dry Needling Assessed with Rehabilitative Ultrasound Imaging: A Proof-of-Concept Study.

Facial anatomical structures are not easily accessible to manual palpation. The aim of our study is to objectively assess temporomandibular joint and perimandibular muscles dimensions by means of sonographic measurements before and after dry needling (DN) in asymptomatic subjects. Seventeen subjects participated in this before-after study with a within-subject control. After random allocation, one side of the face was used for the intervention and the contralateral as control. DN was performed on the temporal, masseter, and sternocleidomastoid muscles. Each subject was examined bilaterally before, immediately after, and one month after the intervention through Rehabilitative Ultrasound Imaging (RUSI) of the temporomandibular articular disc and the three target muscles. Maximum mouth opening was measured at baseline and at one month. After a single DN session, articular disc thickness significantly decreased; muscles’ thicknesses (except for temporal thickness) significantly decreased immediately and at follow-up on the treated side; no significant changes resulted for the control side. The maximum mouth opening increased from 4.77 mm to 4.86 mm. RUSI may be useful to assess the dimensions and thickness of the temporomandibular disc and muscles before and after an intervention. DN influences muscle morphology, and it has a positive influence on mouth opening in the short term.

Relative impact of masticatory muscle pain, dynamic temporomandibular disc abnormality, and osteoarthritis on clinical symptoms of patients with temporomandibular disorders

Relative impact of masticatory muscle pain, dynamic temporomandibular disc abnormality, and osteoarthritis on clinical symptoms of patients with temporomandibular disorders

Magnetic resonance imaging texture analysis of unilateral lateral pterygoid myospasm in patients with temporomandibular joint disorders: A pilot study

Background and Purpose: Lots of clinical observations have found that there is a close relationship between the pathological changes of lateral pterygoid muscle (LPM) and temporomandibular disc displacement. On medical images, unfortunately, these occult dysfunctions of LPM could scarcely be detected by naked eyes. As the presence of intrinsic properties of the human body, textural feature is capable to effectively discover the subtle functional changes of involved tissues. This study aimed to evaluate the lateral pterygoid myospasm in patients with temporomandibular joint disorders (TMD) applying magnetic resonance imaging (MRI) texture analysis. Patients and Methods: From December 2019 to October 2020, totally nine patients suffered from unilateral spasm of LPM (which is a subtype of TMD) were evaluated by MRI, who were consecutively recruited from Xinjiang Medical University Affiliated First Hospital. Gray-level co-occurrence matrix method was used to analyze the textural features of MRI T2-weighted images with the maximum area of LPM scanned at axial (closed-mouth) plane. Independent samples t-test was performed to compare the relevant parameters of bilateral LPMs (healthy- and affected-side of one individual self-controlled trial). Results: There were no statistically significant values between the two sides of angular second moment, inversed differential moment, and entropy (P &gt; 0.05). The contrast of the healthy-side (267.983 ± 45.952) was significantly higher than that of the affected-side (210.003 ± 29.613) (P &lt; 0.05); and the autocorrelation of the healthy-side (4.536 ± 0.819) was significantly lower than that of the affected-side (6.563 ± 1.653) (P &lt; 0.05). Conclusion: The texture contrast and autocorrelation have certain clinical meanings of diagnosis since they could identify the altered status of LPM, and could be considered as the efficient imaging biomarkers to assess LPM changes in patients with TMD.

Diagnostic value of dynamic magnetic resonance imaging of temporomandibular joint dysfunction

BackgroundTo estimate the diagnostic value of dynamic magnetic resonance imaging (MRI) for the assessment of the temporomandibular joint (TMJ) compared to standard static MRI sequences in patients with TMJ dysfunction (TMD). Methods and materialsThis retrospective study included 71 patients with clinical diagnose of TMD. We acquired 5 static T1- and T2-weighted sequences in parasagittal and paracoronal views and one dynamic sequence (trueFISP) in parasagittal view for each TMJ. Image analysis included evaluation of morphology and function of intra-articular structures and rating of the dynamic images as more, equally, or less informative compared to static MRI sequences. ResultsMean age was 35.0 ± 14.7 years and 50/71 (70.4%) were female. 127/142 (89.4%) TMJs were of diagnostic quality. 42/127 (33.1%) TMJs showed no disc displacement (DD), 56 (44.1%) had DD with disc reduction (DDwR), and 29 (22.8%) had DD without disc reduction (DDwoR). In 38/127 (29.9%) TMJs, dynamic images were rated “more informative”, in 84/127 (66.2%) “equally informative”, and in 5/127 (3.9%) “less informative” compared to solely static images. Overall, 27/71 (38.0%) patients benefited from additional dynamic sequences compared to solely static images. Dynamic images were “more informative” in TMJs with DDwR (23/56 [41.1%], p < 0.001) and in TMJs with DDwoR (13/29 [44.8%], p = 0.007), while it had no beneficial value for TMJ without DD. For evaluation of joint effusion, static T2-weighted images were rated better in 102/127 (80.3%) TMJs compared to dynamic images (<0.001). ConclusionDynamic MRI sequences are beneficial for the evaluation of morphology and function of the TMJ compared to static sequences, especially in patients with temporomandibular disc displacement.

Relationship between menton deviation and temporomandibular disc displacement in adult patients

ABSTRACT Purpose: This study investigated the relationships among characteristics of maxillomandibular asymmetry in patients with menton deviation and temporomandibular joint (TMJ) disc conditions, including normal disc position (NDP), anterior disc displacement with reduction (ADDwR), rotational disc displacement with reduction (RDDwR), and anterior and/or rotational disc displacement without reduction (DDwoR). Materials and methods: Eighty-six patients with menton deviation (62 female patients and 24 male patients) were included. The TMJ magnetic resonance images were categorized into four groups: bilateral-NDP (n = 15), ADDwR (n = 13), RDDwR (n = 19) and DDwoR (n = 39). The characteristics of menton deviation and maxillomandibular asymmetry were determined using posteroanterior and lateral cephalograms. Differences in cephalometric variables among the groups were statistically analysed. Results: Patients with menton deviation under Skeletal Class I, and Skeletal Class II relationship showed a higher rate of DDwoR on lateral cephalograms. Significant differences were detected among groups on posteroanterior cephalograms with respect to the cant of the frontal mandibular plane and menton deviation. These two variables were significantly greater in the DDwoR group than in the bilateral-NDP group. Conclusion: The anteroposterior jaw relatioship and mandibular deviation may be associated with the severity of TMJ disc displacement.