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Objectives: This study aimed to examine the relationship between computed tomography (CT) values of the condylar surface in the coronal plane, condylar morphology and the disc positions in the temporomandibular joint (TMJs) in patients with deformities before and after orthognathic surgery.  MATERIALS AND METHODS: The maximum CT values (pixel values) on the condylar surface, condylar thickness, condylar width, condylar angle, condylar height, and joint space were measured. TMJ disc position was classified into five types (anterior type, fully covered type, posterior type, anterior disc displacement with [AW] and without reduction [AWO]), using magnetic resonance imaging (MRI), before and 1 year after surgery. Statistical analysis was performed to assess differences between groups and between the pre- and postoperative values.  RESULTS: We enrolled 142 TMJs from 71 female patients diagnosed with jaw deformities. Disc position classification did not change after surgery in all TMJ. Significant differences were observed between anterior displacement (AW and AWO) and other types (fully covered type and posterior type) in the lateral CT value and condylar angle before and 1 year after surgery (P < 0.05).  CONCLUSIONS: This study demonstrated a strong relationship between condylar surface CT values in the coronal plane and condylar angle with TMJ disc position classification., Competing Interests: Declarations. Competing interests: The authors declare no competing interests. Ethics approval: This retrospective cohort study was performed in accordance with the Declaration of Helsinki and was approved by the Ethical Committee of the University of Yamanashi. Receipt number 1125, November/20/2013. Consent to participate: Informed consent was obtained from all individual participants included in the study. Consent to publish: The authors affirm that the human research participants provided informed consent for the publication of the images in Figures., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Few neuroimaging studies have investigated structural brain differences associated with variations in pain distribution., Objective: To explore structural differences of the brain in fibromyalgia (FM), temporomandibular disorder pain (TMD) and healthy pain-free controls (CON) using structural and diffusion MRI., Methods: A case-control exploratory study with three study groups with different pain distribution were recruited: FM (n = 16; mean age [standard deviation]: 44 [14] years), TMD (n = 17, 39 [14] years) and CON (n = 10, 37 [14] years). Participants were recruited at the University Dental Clinic in Malmö, Sweden. T1-weighted and diffusion MRIs were acquired, clinical and psychosocial measures were obtained. Main outcome measures were subcortical volume, cortical thickness, white matter microstructure and whole brain grey matter intensity., Results: Patients with FM had smaller volume in the right thalamus than patients with TMD (p = .020) and CON (p = .030). The right thalamus volume was negatively correlated to pain intensity (r = -0.37, p = .022) and pain-related disability (r = -0.45, p = .004). The FM group had lower cortical thickness in the right anterior prefrontal cortex than CON (p = .005). Cortical thickness in this area was negatively correlated to pain intensity (r [37] = - 0.48, p = .002)., Conclusions: This study suggests that thalamus grey matter alterations are associated with FM and TMD, and that anterior prefrontal cortex grey matter alterations are associated with FM but not TMD. Studies on chronic overlapping pain conditions are needed in relation to possible nociplastic pain mechanisms in the brain and central nervous system., (© 2024 The Author(s). Journal of Oral Rehabilitation published by John Wiley & Sons Ltd.)

Temporomandibular joint (TMJ) and infratemporal fossa (ITF) tumors, even though rare, present diagnostic complexities due to their nonspecific symptoms. Synovial sarcoma comprises 5-10% of adult soft-tissue sarcomas and is uncommon in the head and neck and exceptionally rare in the TMJ/ITF region. We presented a case of monophasic synovial sarcoma affecting the left TMJ/ITF in a 24-year-old man with severe preauricular pain who was misdiagnosed with temporomandibular disorder for 3 years. When in-depth evaluations uncovered a 40 mm tumor adjacent to the TMJ, extensive resection and immediate reconstruction were conducted, followed by postoperative radiotherapy and adjuvant chemotherapy. Magnetic resonance imaging photos of the early stage and after 3 years of tumor progression, initial signs and symptoms, and intraoperative images allowed tumor evolution assessment., (Copyright © 2024 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Objective: To assess the association between three-dimensional inclination of the osseous structures of temporomandibular joints (TMJ) and the risk of disc displacement (DD)., Methods: The 120 TMJs of 60 patients were evaluated. According to magnetic resonance images, disc position was classified as normal, anterior DD with reduction (ADDWR) and without reduction (ADDWoR) and as normal, medial DD (MDD), and lateral DD (LDD) on the sagittal and coronal views, respectively. Condyle and eminence inclinations were measured using cone beam computed tomography., Results: Smaller horizontal condylar inclination was associated with ADDWoR ( p < 0.05). Larger coronal condylar inclination was associated with ADDWR ( p < 0.05) and LDD ( p < 0.05). There was no association between sagittal eminence inclination and DD ( p < 0.05)., Conclusion: Medial condylar rotation in the axial view may be associated with ADDWoR. The condyle head horizontally inclined in the coronal view may be associated with ADDWR and LDD.

Objective: To investigate the highest opportunity skin puncture point and needle orientation according to facial asymmetry and classification., Methods: Computed tomography of 136 patients was analyzed. Horizontal and vertical angles and distances from the canthal-tragal line were investigated to determine the puncture point and needle's angle., Result: All patients' average points were 7.39 (±2.85) mm anterior to the tragus and 3.44 (±4.18) mm below the canthal-tragal line with an angle of 8.53 (±6.90)° anteriorly and 32.26 (±7.23)° superiorly. Regarding asymmetry, there was a statistical difference in horizontal angle, depth, and canthal-tragal distance between the deviated and non-deviated sides. Especially, vertical distances were 4.44 (±4.66) mm and 2.59 (±4.11) mm in the deviated and non-deviated sides, respectively ( p < 0.001)., Conclusion: In closed-mouth, the puncture point was closer to the tragus and lower than the conventional point. The point in the deviated side should be considered lower than the non-deviated side.

Objective: To verify temporomandibular disorders (TMDs) and cervical angles in a young and middle-aged population., Methods: Ninety participants were included, 45 of whom had TMDs. The participants were diagnosed according to the Research Diagnostic Criteria for TMDs. Lateral cervical radiographs were taken, and relevant cervical angles were measured. The general characteristics of the TMD group and control group were analyzed using chi-square analysis, and the relationship between cervical angles and TMDs was evaluated using the unpaired t -test., Results: The decrease in C2-C7 Cobb and increase in the posterior occipitocervical angle (POCA) were associated with the incidence of TMDs ( p < 0.0001)., Conclusion: This study revealed that the cervical angle was related to TMDs. People with a long-time habit of head bending posture had a decrease in C2-C7 Cobb and an increase in the POCA. This group of people was more likely to develop TMDs.

Temporomandibular joint (TMJ) arthrocentesis is a widely described and effective technique that promotes lysis and lavage of TMJ compartments, improving pain and mandibular range of motion. Mostly, this technique has been used to reach the upper TMJ compartment, besides effusion may be present also in lower compartment, that, in the absence of disc perforation, may also need to be assessed. Here, we propose an adaptation of arthrocentesis technique aiming to access both upper and lower compartments of the TMJ with a single needle puncture and guided by ultrasound real-time images. The technique was initially established in fresh cadavers and later replicated in 2 patients. Technique modification proved to be efficient and reproducible, reducing the number of perforations and, consequently, possible adverse events. The proposed technique can be applied to arthrocentesis and/or intra-articular injections through the combination of two previously validated techniques, to improve its safety and efficacy., (Copyright © 2024 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

In temporomandibular disorder (TMD), the effects of standard interventions such as using an occlusal splint and its impact on pain relief and pain catastrophizing are poorly understood. Earlier work pointed to a crucial role of insula activation with changes in pain relief by occlusal splint treatment. We performed a functional imaging study using specially developed splint systems to allow for a placebo-controlled longitudinal design. Using functional MRI we examined 20 TMD patients during repetitive occlusal movements at baseline and over the course of splint therapy and also collected self-reported pain catastrophizing. For balancing performance between baseline and after intervention we used occlusion force measures in an individualized fMRI-splint system. Splint therapy lasted for approximately 7 weeks with one group selected by randomization wearing a palatine placebo splint over the first 3 weeks (delayed start; 11 individuals). As expected, fMRI activation in areas involved in pain processing (insula, primary and secondary somatosensory cortex) decreased with intervention. At baseline a positive correlation between activation of the left anterior insula and pain catastrophizing was present. Both parameters decreased over intervention while associations were primarily observable for patients with rather mild TMD., (© 2024 The Author(s). Human Brain Mapping published by Wiley Periodicals LLC.)

Objective: To observe the dynamic changes of the temporomandibular joint (TMJ) disc in joint movement under different Angle's classification, providing reference for understanding joint functional movement and providing a basis for more accurate clinical imaging diagnosis. Methods: A total of 30 patients (13 males and 17 females) with temporomandibular disorders who were admitted to Beijing Friendship Hospital, Capital Medical University and General Hospital of the People's Liberation Army from January 2022 to April 2024 were enrolled. Thirty adults (13 males and 17 females) with different Angle's classification, with an average age of (34.4±8.5) years, were subjected to dynamic imaging of their TMJ from the closed position to the maximum opening position, and then to the closed position using MRI. The position and morphological changes of the articular discs were observed. Results: The results showed that volunteers with no displacement of the articular disc in class Ⅰ, Ⅱ, and Ⅲ relationships had different shapes of the articular disc during open and closed mouth movements. However, in the maximum opening position, the articular disc were all located directly below the maxillary nodules, and their shape is double concave. In terms of irreversible anterior displacement of the articular disc, in class Ⅰ Angle, the posterior zone of the disc contacts the anterior inclined plane of condyle from the maximum opening position back to the front of the closing position. In class Ⅱ, the posterior zone of the disc contacts the anterior inclined plane of condyle from the beginning of opening position to maximum opening position. In class Ⅲ, the posterior zone of the disc is always in contact with the anterior inclined plane of condyle throughout the entire movement process. And among them, the articular disc presents a forward displacement state at the closing position, its morphology undergoes folding phenomenon. When the openness is 2.5 cm, the articular disc moves up to a certain extent, and is closer to the anterior inclined plane of condyle, and its shape is also partially changed. When the openness is 4.3 cm, the shape of the articular disc, located between the anterior inclined plane of the joint node and the posterior inclined plane of the condyle, is typical double concave, which is sufficient to show that the articular disc is reversible when maximum opening position is reached. In terms of reversible anterior disc displacement, in class Ⅰ Angle, the posterior zone of the disc contact with the anterior inclined plane of condyle at the beginning of the opening position and the end of the closing position. In classⅡ Angle, the posterior zone of the articular disc is not in contact with the anterior inclined plane of condyle. In class Ⅲ Angle, the posterior zone of the articular disc contact with the anterior inclined plane of condyle at the end of the closing position. Conclusions: Multi level dynamic MR imaging data of the temporomandibular joint can dynamically observe the movement of the temporomandibular joint, intuitively and accurately display the position and shape of the articular disc during movement, and can serve as a useful supplement to static conventional MR imaging of the TMJ. The patient's TMJ needs to reach the maximum opening position in order to determine whether the joint disc displacement can be reversible or not.

BACKGROUND Anterior reduction disc displacement (ARDD) of the temporomandibular joint (TMJ) can present with pain and clicking of the jaw when chewing. This study aimed to evaluate the relationship between articular eminence cortication (AEC) and mandibular condyle cortication (MCC) in 81 patients with ARDD of the TMJ using cone beam computed tomography (CBCT) imaging. MATERIAL AND METHODS We examined images of 142 patients who applied to the outpatient clinic between 2022 and 2024 for various reasons and whose radiographic records included CBCT and MRI images. Sixty-one patients who did not meet the inclusion criteria were excluded from the study. MRI images of the remaining 81 patients were analyzed and evaluated for the presence of ARDD. Subsequently, all mandibular condylar processes and articular eminences included in the study were examined by CBCT and the degree of cortication was classified and noted. The relationship between MCC and AEC and ARDD was evaluated with the SPSS 23.0 program (SPSS, Chicago, IL, USA). RESULTS ARDD was observed in 46 (28.4%) of 162 condyles examined. Type 1 cortications were observed in 8 (17.4%), type 2 in 36 (78.3%), and type 3 in 2 (4.3%) of the condyles with disc displacement; 80.0% (8) of type 2 cortications were found in patients with ARDD (P<0.001), and 75.0% of type 3 cortication was observed in intact condyles (P<0.001). CONCLUSIONS This study shows that loss of AEC and MCC may be a significant factor in the diagnosis of ARDD, and decreased AEC and MCC may be a criterion for the diagnosis of ARDD.

The temporomandibular joint constitutes a synovial connection between the mandible and the skull base and plays a pivotal role in functions such as jaw movement, chewing, and verbal and emotional expression. Temporomandibular joint dysfunction is observed in about 30% of the population, with a higher prevalence in young to middle-aged women. Interestingly, a majority of individuals affected do not report pain, and only 5%-10% of symptomatic cases necessitate therapeutic intervention. The most common temporomandibular joint disorder manifests as pain in the masticatory muscles and is referred to as myofascial syndrome. However, articular disorders are also very common, usually due to disk displacement and degenerative or inflammatory arthropathies. Less frequently, the temporomandibular joint may be affected by a range of congenital and acquired conditions such as trauma and neoplasms. Imaging becomes necessary for the small percentage of patients who do not respond to conservative management or when there is uncertainty in the diagnosis. A comprehensive understanding of the normal imaging appearance of the temporomandibular joint as well as the wide range of potential pathologic conditions is essential for conducting an accurate radiologic assessment. Moreover, collaboration among multidisciplinary teams and the correlation of imaging findings with arthroscopic observations are crucial to advancing the diagnosis and treatment of temporomandibular joint dysfunction. © RSNA, 2024 Supplemental material is available for this article.

Fatigue of temporomandibular joint (TMJ) tissues reflects the effects of magnitude (energy density; ED) and frequency of loading (jaw muscle duty factor; DF). This observational study measured these variables and tested for differences in mechanobehavior scores (MBS = ED 2 × DF) and component variables in subjects with and without TMJ disc displacement (±D). In accordance with Institutional Review Board and STROBE guidelines, written informed consent was obtained, and examination and imaging protocols identified eligible adult subjects. Specifically, magnetic resonance imaging was used to assign subjects' TMJs to ±D groups. Subjects were trained to record in-field jaw muscle activities, from which DFs (percentage of recording time) were determined. EDs (mJ/mm 3 ) were estimated using modeled TMJ loads and in vivo dynamic stereometry. Multivariate analysis of variance, post hoc independent t tests, and K-means cluster analysis identified significant group differences ( P < 0.05). Of 242 individuals screened, 65 females (TMJs: 78 +D, 52 -D) and 53 males (TMJs: 39 +D, 67 -D) participated. Subjects produced 312 daytime and 319 nighttime recordings of average duration 6.0 ± 0.2 h and 7.6 ± 0.1 h, respectively, and 219 (114 right, 105 left) intact dynamic stereometry recordings. Average EDs were 2-fold and significantly larger in +D than -D TMJs ( P < 0.0001). DFs were on average 3-fold larger during the daytime versus nighttime for both masseter and temporalis muscles and 1.8- and 3.0-fold larger for the masseter versus temporalis muscle during the daytime and nighttime, respectively. Daytime masseter MBSs for +D TMJs in females were the largest overall at 621 ± 212 (mJ/mm 3 ) 2 % and 2- to 43-fold larger versus -D TMJs in both sexes during daytime and nighttime. Cluster analysis ( P < 0.0001) identified groups 2 and 3, which comprised 87% +D TMJs and had average MBSs 21-fold larger than group 1. The results show MBS as a potential biomarker to predict homeostasis versus progression or reversal of degenerative TMJ structural changes., Competing Interests: Declaration of Conflicting InterestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Objectives: This study aimed to propose a new method for the automatic diagnosis of anterior disc displacement of the temporomandibular joint (TMJ) using MRI and deep learning. By using a multistage approach, the factors affecting the final result can be easily identified and improved., Methods: This study introduces a multistage automatic diagnostic technique using deep learning. This process involves segmenting the target from MR images, extracting distance parameters, and classifying the diagnosis into 3 classes. MRI exams of 368 TMJs from 204 patients were evaluated for anterior disc displacement. In the first stage, 5 algorithms were used for the semantic segmentation of the disc and condyle. In the second stage, 54 distance parameters were extracted from the segments. In the third stage, a rule-based decision model was developed to link the parameters with the expert diagnosis results., Results: In the first stage, DeepLabV3+ showed the best result (95% Hausdorff distance, Dice coefficient, and sensitivity of 6.47 ± 7.22, 0.84 ± 0.07, and 0.84 ± 0.09, respectively). This study used the original MRI exams as input without preprocessing and showed high segmentation performance compared with that of previous studies. In the third stage, the combination of SegNet and a random forest model yielded an accuracy of 0.89 ± 0.06., Conclusions: An algorithm was developed to automatically diagnose TMJ-anterior disc displacement using MRI. Through a multistage approach, this algorithm facilitated the improvement of results and demonstrated high accuracy from more complex inputs. Furthermore, existing radiological knowledge was applied and validated., (© The Author(s) 2024. Published by Oxford University Press on behalf of the British Institute of Radiology and the International Association of Dentomaxillofacial Radiology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Objectives: Verify whether hypervigilance to pain (HP) and sleep quality (SQ) are confounding variables in the infrared thermography (IT) examination of the temporomandibular joint and temporal and masseter muscles., Methods: A cross-sectional and analytical study was conducted, collecting HP and SQ data from 80 participants without temporomandibular disorders (TMD), performing their IT and another 40 participants with TMD. For the selection of participants with and without TMD, the TMD Pain Screener questionnaire and axis I of the Diagnostic Criteria for Temporomandibular Disorders were applied. SQ was verified using the Pittsburgh Sleep Quality Index (PSQI) questionnaire. For the HP assessment the Pain Vigilance and Awareness Questionnaire (PVAQ) was applied. And the IT was performed through a FLIR infrared sensor camera, model T650 Infrared., Results: No significant correlations were found between SQ and the temperatures of the areas of interest (P > .05), and regarding HP, a statistically significant positive correlation was found with the dimensionless (ρ = 0.289) and non-dimensionless (ρ = 0.223) asymmetries of temporal muscle temperatures. In the temperature comparisons between the participants without TMD and the participants with TMD, significant differences were found (P < .05), also when the group without TMD was controlled according to both HP and SQ (P < .05), with higher temperatures found in the TMD group., Conclusions: HP and SQ can be considered confounding variables in IT examination of the temporomandibular region., (© The Author(s) 2024. Published by Oxford University Press on behalf of the British Institute of Radiology and the International Association of Dentomaxillofacial Radiology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Objective: The present study aimed to assess the consistencies and performances of deep learning (DL) models in the diagnosis of condylar osteoarthritis (OA) among patients with dentofacial deformities using panoramic temporomandibular joint (TMJ) projection images., Methods: A total of 68 TMJs with or without condylar OA in dentofacial deformity patients were tested to verify the consistencies and performances of DL models created using 252 TMJs with or without OA in TMJ disorder and dentofacial deformity patients; these models were used to diagnose OA on conventional panoramic (Con-Pa) images and open (Open-TMJ) and closed (Closed-TMJ) mouth TMJ projection images. The GoogLeNet and VGG-16 networks were used to create the DL models. For comparison, two dental residents with < 1 year of experience interpreting radiographs evaluated the same condyle data that had been used to test the DL models., Results: On Open-TMJ images, the DL models showed moderate to very good consistency, whereas the residents' demonstrated fair consistency on all images. The areas under the curve (AUCs) of both DL models on Con-Pa (0.84 for GoogLeNet and 0.75 for VGG-16) and Open-TMJ images (0.89 for both models) were significantly higher than the residents' AUCs (p < 0.01). The AUCs of the DL models on Open-TMJ images (0.89 for both models) were higher than the AUCs on Closed-TMJ images (0.72 for both models)., Conclusions: The DL models created in this study could help residents to interpret Con-Pa and Open-TMJ images in the diagnosis of condylar OA., (© 2024. The Author(s) under exclusive licence to Japanese Society for Oral and Maxillofacial Radiology.)

Background: Juvenile idiopathic arthritis (JIA) often affects the temporomandibular joint (TMJ) caused by an abnormal immune system that includes overactive inflammatory processes. Salivary biomarkers may be a powerful tool that can help establishing diagnosis, prognosis and monitor disease progress., Objective: The objective was to investigate biomarkers in parotid saliva and blood plasma in relation to temporomandibular joint (TMJ) magnetic resonance imaging (MRI) findings in patients with JIA and healthy individuals., Methods: Forty-five children aged 6 to 16 years with JIA and 16 healthy age- and sex-matched controls were included. Unstimulated parotid saliva samples and venous blood were collected. Biochemical analyses were performed for the cytokine biomarkers. The participants underwent MR imaging of the TMJs, where changes in the inflammatory and the damage domains were assessed., Results: In the JIA patients, lower concentrations of IL-6R and gp130 were found in parotid saliva than in plasma. Higher concentrations of IL-6 were found in parotid saliva than in plasma. IL-6, IL-6R and gp130 in parotid saliva explained the presence of bone marrow oedema and effusion in the JIA patients., Conclusions: This study suggests that the IL-6 family in parotid saliva is associated with TMJ bone marrow oedema and effusion in patients with JIA, suggesting that IL-6 has promising properties as a parotid saliva biomarker for TMJ inflammatory activity., (© 2024 The Author(s). Journal of Oral Rehabilitation published by John Wiley & Sons Ltd.)

Mandibular angle osteotomy with outer cortex grinding is an effective cosmetic procedure for correcting square faces. However, morphological changes in the mandible may also cause temporomandibular joint (TMJ) disorders. This retrospective study aimed to investigate the morphological stabilization of the TMJ and changes in masseter muscle thickness after mandibular angle osteotomy to evaluate the safety of the procedure. Data from patients who underwent mandibular angle osteotomy with outer cortex grinding between January 2016 and January 2019 were retrospectively reviewed. Preoperative and long-term follow-up (~1 y) computed tomography data were collected from these patients, and morphological changes in the TMJ and masseter muscle were analyzed. The results from the computed tomography data showed that the condylar length and condylar height were significantly reduced 1 year after the operation ( P < 0.05). In addition, the morphology of the TMJ was stable, and the distance between the mandibular condyle and the glenoid fossa did not change significantly. No significant difference was observed in masseter muscle thickness before and after the operation. After mandibular angle osteotomy with outer cortex grinding, the length and height of the mandibular condyle were functionally restored without any disorders of the TMJ. Moreover, the masseter muscle exhibited stable function. In conclusion, the procedure is safe for occlusal function and suitable for popularization., Competing Interests: The authors report no conflicts of interest., (Copyright © 2024 by Mutaz B. Habal, MD.)

Objective: To identify the available evidence on the ultrasonographic characteristics of masticatory muscles in subjects with myogenous TMD, as well as the potential use of ultrasonography as a diagnostic and treatment assessment outcomes tool., Method: An electronic search of the PubMed, Web of Science and Scopus databases was performed using the following terms: 'ultrasonography', 'ultrasound', 'masseter', 'temporal', 'masticatory muscles', 'temporomandibular disorders', 'temporomandibular joint disorders'. Full-text articles were obtained from the records after applying the inclusion/exclusion criteria., Results: Thirteen articles were included for analysis: one comparative cross-sectional study, five case-control studies, six clinical trials and one randomised clinical trial. Main ultrasonographic characteristic assessed were local cross-sectional dimension and intramuscular ultrasonographic appearance. Retrieved studies reported the use ultrasonography for diagnosis or treatment assessment purposes showing heterogeneous results. For diagnosis purposes, the results of local cross-sectional dimension are not consistent; therefore, its diagnostic value for myogenous TMD diagnosis is weak. However, more homogeneous results were observed for intramuscular ultrasonographic appearance showing a higher prevalence of type-II pattern in myogenous TMD subjects than non-TMD subjects. On the other hand, for treatment assessment purposes, muscles were observed thinner after treatment compared to pre-treatment. Also, results of intramuscular ultrasonographic appearance show disappearance or reduction of anechoic areas, higher prevalence of type-II pattern and significant distinction of echogenic bands were observed after treating TMD subjects., Conclusion: Ultrasonography cannot be considered as a diagnostic instrument, but maybe as a complementary tool for treatment assessment of myogenous TMD subjects, even though future research is required to confirm its utility., (© 2024 John Wiley & Sons Ltd.)

Objective: The review involves the assessment of morphological variations in the temporomandibular joint (TMJ) and its associated structures in patients with temporomandibular disorder., Introduction: Temporomandibular disorders (TMD) are debilitating conditions that affect the TMJ complex, surrounding musculature and osseous components. Studies have reported that TMD result from morphological alterations in TMJ. These alterations can be efficiently studied using three-dimensional imaging. This review will summarise the morphological changes in TMJ and associated structures based on studies with three-dimensional imaging in patients with TMD., Inclusion Criteria: The systematic review will include studies with adult subjects with any one symptom of TMD and those studies that assessed TMJ morphology using three-dimensional imaging like CT, cone beam CT, MRI or arthrography., Methods: Systematic searches for relevant studies will be carried out in multiple databases. Sources will include MEDLINE, Scopus, Dentistry and Oral Sciences Source, Cochrane CENTRAL, CINAHL, Web of Science, ProQuest Dissertation and Thesis and Google Scholar. The databases will be searched from inception to November 2023. Analytical observational studies comprising retrospective and prospective cohort studies, case-control studies and analytical cross-sectional studies will be selected and critical appraisal will be performed. No restrictions will be imposed on the date and country of publication. Joanna Briggs Institute (JBI) guidelines for systematic effectiveness reviews will be followed for data appraisal, extraction and synthesis. The strength of evidence will be graded using the Grading of Recommendations, Assessment, Development and Evaluation method and the summary of findings will be created using GRADEpro software., Ethics and Dissemination: Ethical approval is not applicable for this study since this involves analysis of secondary data. Results will be disseminated through peer-reviewed publications and cnference presentations. A comprehensive summary of morphological alterations in TMJ is essential for assessing risk factors, accurate diagnosis, treatment planning and will collectively contribute to enhanced clinical care and overall patient well-being., Prospero Registration Number: The protocol is registered in PROSPERO: CRD42023448882., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Introduction: The relationship between posture and temporomandibular disease (TMD) is unclear. The aim of our study was to determine the influence of manual therapy (MT) on posture in TMD patients compared with healthy subjects., Material/method: After consideration of inclusion and exclusion criteria, 30 subjects were included. These were divided into two groups: group A comprised 15 healthy subjects and group B 15 patients with present proven TMD disease. Rasterstereographic images were taken at different times. Group A subjects were scanned twice within half a year and group B before initiation as well as after the first MT and after completion of the prescribed MT. The different posture variables were calculated using DIERS Formetric software., Results: To illustrate the differences between the two groups, 10 different postural variables were examined. Significant differences between the two groups were observed in pelvic tilt, surface rotation, and kyphotic apex. Pelvic tilt: mean = 7.581, p-value = 0.029; surface rotation: mean = 3.098, p = 0.049; and mean kyphotic apex = 11.538 and 11.946, respectively, with p-values of 0.037 and 0.029, respectively., Conclusion: MT leads to a change in posture in TMD patients. This could influence the course of TMD treatment., (© 2024. The Author(s).)

Background: Temporomandibular Disorders (TMD) is the dysfunction of group of muscles and bones in the joint area, the main symptoms of TMD are the pain of the chewing muscles and (or) the temporomandibular joints, mandibular movement disorders and joint noise. This study was designed to explore the therapeutic effects following Individual Musculoskeletally Stable (IMS) position stabilization splint therapy for TMD patients using Fricton index, cone beam computed tomography (CBCT) and surface-Electromyogram (sEMG)., Methods: In this study, we enrolled 31 TMD patients (ranging from 18 to 26 years old, including 7 males and 24 females), first Fricton index was used to evaluate the clinical curative effect of TMD with the treatment of IMS stabilization splint; then CBCT was used to observe the TMJ condylar position changes of TMD before and after the treatment of IMS stabilization splint; finally sEMG was used to observe the changes of electromyography of anterior temporalis (AT) and masseter muscles (MM) of TMD before and after the treatment of IMS stabilization splint., Results: The course of treatment was 6-8 months, with an average of 7.6 months. After the IMS stabilization splint treatment, TMD symptoms relieved, especially in pain, mandibular movement disorder, but still slightly inferior in the treatment of joint noise. And there was a statistically significant difference in the anterior and inner joint space, the condyle had the tendency of moving forward and outward. AT presented reduction significantly of EMG value at rest position after treatment., Conclusions: IMS stabilization splint is a therapeutic reversible treatment for TMD, especially for pain and mandibular movement disorder; it produces effects of forward and outward condylar movement and elimination of the masticatory muscles antagonism., (© 2024. The Author(s).)

Introduction: Osteoarthritis (OA) is a progressive degenerative disease characterized by the gradual degradation of cartilage, remodeling of subchondral bone, synovitis, and chronic pain. This condition impacts various large and small joints, including the temporomandibular joint (TMJ). However, addressing OA, particularly in impeding or reducing disease progression, is challenging due to its clinical and imaging heterogeneity. Authors are increasingly suggesting that this heterogeneity involves different phenotypes or subpopulations, discernible by variations in the disease's pathophysiology and structural manifestations. Even within the TMJ, these phenotypes may display distinct clinical features, laboratory parameters, biochemical markers, and imaging criteria. Recent research has proposed MRI as a reference standard for TMJ OA, highlighting its substantial agreement with histopathological changes. MRI-based phenotypes offer a promising avenue for understanding disease progression and treatment response, potentially providing valuable insights for prognosis and treatment planning., Objective: This article introduces the ROAMES-TMJ (Rapid OsteoArthritis MRI Eligibility Score for TMJ) to assess the structural eligibility of individuals for inclusion in TMJ OA clinical trials.

Temporomandibular Joint Magnetic Resonance Imaging (TMJ MRI) is crucial for diagnosing temporomandibular disorders (TMDs). This study advances the use of inductively coupled wireless coils to enhance imaging quality in TMJ MRI. After investigating multiple wireless resonator configurations, including a 1-loop design with a loop diameter of 9 cm, a 2-loop design with each loop having a diameter of 7 cm, and a 3-loop design with each loop having a diameter of 5 cm, our findings indicate that the 3-loop configuration achieves the optimal signal-to-noise ratio (SNR), surpassing other wireless arrays. Bilateral deployment of wireless coils further amplifies SNR, enabling superior visualization of TMJ structures, particularly with the 3-loop design. This cost-effective and comfortable solution, featuring a detunable design, eliminates the need for system parameter adjustments. The study indicates broad adaptability across MRI platforms, enhancing TMJ imaging for routine clinical diagnostics of TMDs., Competing Interests: Declaration of competing interest Haoqin Zhu is currently employed by Sino Canada Health Institute; Rangsong Li and Yuanyuan Chen are currently employed by Sino Canada Health Engineering Research Institute; the other authors report no disclosures., (Copyright © 2023. Published by Elsevier Inc.)

Objectives: The present study aimed to elucidate the pathogenesis of temporomandibular joint (TMJ) osteoarthritis (TMJ-OA) in a mouse model. We investigated morphological and histological changes in the head of mandible cartilage and early immunohistochemical (IHC) changes in transforming growth factor (TGF)-β, phosphorylated Smad-2/3 (p-Smad2/3), a TGF-β signaling molecule, and asporin., Methods: TMJ-OA was induced in a mouse model through unilateral partial discectomy. Micro-computed tomography (micro-CT) and safranin-O staining were performed to morphologically and histologically evaluate the degeneration of the head of mandible caused by TMJ-OA. IHC staining for TGF-β, p-Smad2/3, and asporin was performed to evaluate the changes in protein expression., Results: In the experimental group, three-dimensional (3D) morphometry revealed an enlarged head of mandible and safranin-O staining showed degeneration of cartilage tissue in the early stages of TMJ-OA compared to the control group. IHC staining revealed that TGF-β, p-Smad2/3, and asporin expression increased in the head of mandible cartilage before the degeneration of cartilage tissue, and subsequently decreased for a short period., Conclusion: The findings suggested a negative feedback relationship between the expression of asporin and the TGF-β/Smad transduction pathway, which may be involved in the degeneration of the head of mandible in the early stages of TMJ-OA. Asporin is a potential biomarker of the early stages of TMJ-OA, which ultimately leads to the irreversible degeneration of TMJ tissues., Competing Interests: Declaration of competing interest The authors declare no potential conflicts of interest with respect to the authorship or publication of this article., (Copyright © 2024 Japanese Association for Oral Biology. Published by Elsevier B.V. All rights reserved.)

The aim of this paper was to determine the optimal needle depth for temporomandibular joint (TMJ) arthrocentesis using magnetic resonance imaging (MRI), with the aim of improving procedural safety and efficacy in clinical practice. A retrospective analysis of 264 TMJ MRIs from 132 patients at Istanbul Medipol Mega University Hospital was conducted. T2-weighted MRI sequences were utilised to measure distances from skin to joint capsules at varying needle entry points, applying the double puncture technique. The study adhered to ethical standards with appropriate approvals. The analysis revealed significant gender-related variations in needle depths (females showing shorter distances than males, p < 0.05). No significant gender differences were found in condylar angles. An inverse correlation between age and condylar angle suggested age-related anatomical changes. Crucially, a 20 mm needle depth was identified as safer and more effective than the previously recommended 25 mm. This study underscores the necessity of revising needle depth to 20 mm in TMJ arthrocentesis. These findings hold significant implications for improving procedural safety and catering to demographic variations., (Copyright © 2024 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Purpose: Intraoral vertico-sagittal ramus osteotomy (IVSRO) was first reported by Choung in 1992 as a surgical procedure to decrease postoperative condylar dislocation. In 2017, Iwanaga et al. developed modified L-shaped IVSRO (mIVSRO) to reduce postoperative nerve dysfunction and achieved favorable outcomes. This study aimed to clarify the effect of mIVSRO on changes in temporomandibular joint (TMJ) symptoms and three-dimensional condylar position., Methods: We conducted a retrospective study of thirty sides in fifteen Japanese adults diagnosed with jaw deformities who underwent mIVSRO and sagittal split ramus osteotomy (SSRO). TMJ symptoms were assessed chronologically, and the condylar long axis and the condylar position were analyzed two- and three-dimensionally using axial cephalograms and cone-beam computed tomography., Results: Postoperative TMJ symptoms improved by 90% (9/10 sides) in the mIVSRO group and by 50% (7/14 sides) in the SSRO group. The mIVSRO group exhibited outward rotation of the condylar long axis, while the SSRO group exhibited inward rotation. Moreover, mIVSRO induced residual anteromedial-inferior deviation of the condyle. The inclination angle of the condylar process was not significantly different between the two procedures pre- and postoperatively., Conclusion: These results clearly demonstrated the effect of mIVSRO on symptomatic TMJ. Residual changes in the position of the condyle following mIVSRO may not affect jaw function., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Mandibular malpositioning may result in an abnormal concentration of stresses within the temporomandibular joint (TMJ) in adult rats, which may further lead to a series of pathological changes, such as articular cartilage wear, subchondral bone sclerosis and osteophyte formation. However, the pathological and adaptive changes in condylar cartilage caused by different stress distributions are still controversial., Objective: The aim of this study was to observe the effect of sagittal changes in mandibular position on condylar cartilage by changing the occlusal vertical dimension (OVD) in adult rats., Methods: Fifteen-week-old female rats were divided into three groups: control (CON), increased OVD (iOVD) and loss of occlusion (LO) groups. An occlusal plate and tooth extraction were used to establish the animal model. TMJ samples of the experimental and CON groups were observed and investigated by bone morphological, histomorphological and immunohistochemical staining analyses at 3 days, 1 week, 2 weeks, 4 weeks and 8 weeks. Weight curves were plotted., Results: Micro-computed tomography showed that, compared with the CON group, cartilage destruction followed by repair occurred in both experimental groups, which was similar to the trend observed in haematoxylin-eosin staining. All experimental results for the iOVD group showed an approximately similar time trend. Compared with the iOVD group, the toluidine blue and immunohistochemical staining results in the LO group showed no obvious change trend over time., Conclusion: Compared with occlusal loss, an increase in OVD caused faster and more severe damage to condylar cartilage, and subchondral bone repair occurred later., (© 2024 John Wiley & Sons Ltd.)

The authors aim to present an updated protocol for mandibular reconstruction in nongrowing patients with Pruzansky/Kaban type IIb/III congenital craniofacial microsomia with customized temporomandibular joint (TMJ) prosthesis to reduce facial nerve (FN) damage and improve surgical accuracy. This is illustrated (using 3 cases) and is based on preoperative mapping of the FN using MRI for better virtual surgical planning of custom-made TMJ prosthesis. Intraoperative FN mapping and monitoring, as well as verification of the final result with intraoperative cone-beam computed tomography (CBCT) and 3D-reconstructed images is also achieved. All 3 patients presented mild transient postoperative facial palsy due to surgical soft tissue stretching which resolved within 2 months of surgery. All patients presented proper occlusion and mouth opening without pain, with an average incisal opening of 38.8 mm (range 35.5-42 mm) at two months of follow-up. Moreover, superposition of intraoperative and preoperative 3D reconstruction images ensured surgical accuracy and avoided the need for a potential reintervention. In conclusion, the proposed surgical protocol for mandibular reconstruction with customized alloplastic TMJ prosthesis in nongrowing patients with type IIb/III Pruzansky-Kaban congenital mandibular hypoplasia may reduce FN morbidity, improve surgical accuracy and final outcomes., (Copyright © 2024. Published by Elsevier Ltd.)

Objectives: This study aimed to verify the accuracy of clinical protocols for the diagnosis of disc displacement (DD) compared with MRI, considering examiners' calibration., Methods: PubMed, Cochrane (Central), Scopus, Web of Science, LILACS, Embase, Science Direct, Google Scholar, and DANS EASY Archive databases were searched. Two reviewers independently screened and selected the studies. A meta-analysis was conducted using the R Statistical software. Results are shown using sensitivity and specificity, and 95% confidence intervals., Results: Of the 20 studies included in the systematic review, only three were classified as low risk of bias. Seventeen studies were included in the meta-analysis. Compared to MRI, clinical protocols showed overall sensitivity and specificity of 0.75 (0.63-0.83) and 0.73 (0.59-0.84) for DD diagnosis, respectively. For DD with reduction, sensitivity was 0.64 (0.48-0.77) and specificity was 0.72 (0.48-0.87). For DD without reduction, sensitivity was 0.58 (0.39-0.74) and specificity 0.93 (0.83-0.97). Only 8 studies reported examiner calibration when performing clinical and/or MRI evaluation; nevertheless, calibration showed a tendency to improve the diagnosis of DD., Conclusion: The sensitivity and specificity of clinical protocols in the diagnosis of DD are slightly below the recommended values, as well as the studies lack calibration of clinical and MRI examiners. Examiner calibration seems to improve the diagnosis of DD., (© The Author(s) 2024. Published by Oxford University Press on behalf of the British Institute of Radiology and the International Association of Dentomaxillofacial Radiology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: The authors retrospectively studied the relationship between the morphology and position of the articular disc in magnetic resonance imaging (MRI) and the morphology and position of the condyle in cone beam computed tomography (CBCT), with the purpose for providing reference for clinical diagnosis and treatment of temporomandibular disorders (TMD)., Methods: Patients with both CBCT and MRI imaging data were studied retrospectively, excluding TMJ tumour, fracture, severe condylar morphological abnormalities, non-intercuspal position, and poor quality images. A total of 744 temporomandibular joints (TMJs) from 372 patients were included, with the mean age of 25.94±11.04Y (75 males and 297 females). T2-weighted image (T2WI) of MRI imagings were used to evaluate disc morphology and disc displacement, while CBCT was obtained to evaluate the condylar bone and sagittal condylar position. Data were analysed by Pearson Chi square test and Spearman correlation coefficient., Results: THE DISTRIBUTION OF 744 TMJS IS AS FOLLOWS: 1) DISC MORPHOLOGY: contracture (37.1 %) > biconcave (32.9 %) > irregular (18.5 %) > lengthened (11.4 %); 2) disc position: ADDWoR (48.3 %) > NA (26.9 %) > ADDWR (21.6 %) > PDDWR (2.8 %) > PDDWoR (0.4 %); 3) condylar position: concentric (43.7 %) > posterior (37.6 %) > anterior (18.7 %); 4) condylar bone: normal (63.4 %)> abnormal (36.6 %). There were significant differences in the distribution of disc morphology and disc position between the sex (P < 0.05). There were significant differences in the distribution of disc position and condylar morphology amongst the age groups (P < 0.05). There were significant differences in the distribution of disc position, condylar position and condylar morphology amongst disc morphology (P < 0.05), and there were positive correlation between disc position(r = 0.703, P = 0.000), the score of condyle (r = 0.478, P = 0.000) and disc morphology respectively. There were significant differences in the distribution of disc position and condylar position amongst condylar morphology (P < 0.05). There was a positive correlation between disc position and condyle morphology (r = 0.413, P = 0.000), and a negative correlation between condyle position and condyle morphology (r=-0.152, P = 0.000). There were significant differences in the distribution of disc position amongst condylar position (P < 0.05), but there was no linear correlation (P = 0.159)., Conclusions: The mutual distribution of disc morphology, disc position, condylar morphology and condylar position was statistically significant. Disc displacement did not necessarily lead to condylar bone changes, but 92.7 % TMJs with condylar bone abnormalities had disc displacement., Trial Registration: This study was retrospectively registered on 28/03/2022 and endorsed by the Ethics committee (LCYJ2022014)., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Objective: TMD is a multifaceted condition with various contributing factors, but the actual impact of the lateral pterygoid plate on the development of TMD remains uncertain. This research aims to investigate the relationship between anatomical variations of the lateral pterygoid plate (LPP), including its angle and proximity to the condyle, and the prevalence of temporomandibular disorders (TMD), to improve diagnostic accuracy and therapeutic approaches for TMD., Materials & Methods: A retrospective analysis was conducted on 189 Cone Beam Computed Tomography (CBCT) images of individuals aged 18 to 45. Inclusion criteria were based on definitive diagnoses of degenerative joint disease, excluding individuals with orthodontic treatments, injuries, or craniofacial disorders.Participants were divided into TMD and control groups using standardized DC/TMD protocols for assessment. A radiologist, blinded to the patient's clinical status, then analyzed the CBCT images. LPP dimensions, angles, and condyle distances were measured using OnDemand 3D Imaging Software., Results: The study found a statistically significant higher average LPP length in females compared to males (right LPP p < 0,001, left LPP p = 0,004), with no significant differences in LPP-condyle distances and angles between genders. Comparing the TMD and control groups revealed a positive correlation between lateral plate angles and TMJ disorders (p = 0,044), suggesting a potential biomechanical linkage., Conclusion: Conclusively, the study challenges the assumption that LPP anatomical variations significantly impact TMD while underscoring a potential link between LPP angle and TMD. The novel insight into the potential role of the LPP angle in TMD provides a new direction for research and clinical practice, emphasizing the importance of considering subtle anatomical differences in the management of TMD., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Background: Adolescents with temporomandibular joint (TMJ) anterior disk displacement (ADD) frequently develop dentofacial deformities. It is unknown whether adjunctive arthroscopic diskopexy compared with orthodontic treatment alone increases condylar growth and then improves dentofacial deformity. This study aimed to determine whether arthroscopic diskopexy before functional appliance (joint-occlusal treatment) or single functional appliance (occlusal treatment) increases condylar growth and improves dentofacial deformity among adolescents with TMJ ADD., Methods: A multicenter, randomized, parallel, controlled trial was conducted in 3 centers in China. Adolescents diagnosed with TMJ ADD and dentofacial deformity were enrolled. Eligible participants were randomly assigned to a joint-occlusal group or occlusal group at a ratio of 2:1. Magnetic resonance imaging scans and cephalometric radiographs were evaluated at baseline, at 8 months, and at 14 months. The primary outcome was changes in condylar height from 14 months to baseline. Secondary outcomes were changes in skeletal position., Results: A total of 240 patients (14.65 ± 1.88 years of age) were randomized (joint-occlusal group, 160; occlusal group, 80). The overall difference in condylar height between groups was 3.65 mm (95% CI, 3.10 to 4.19 mm; P < 0.001). The between-group differences in condylar height on the left and right sides were 3.60 mm (95% CI, 2.92 to 4.28 mm; P < 0.001) and 3.69 mm (95% CI, 3.06 to 4.32 mm; P < 0.001), respectively. Significant between-group differences were noted in skeletal position (all P < 0.001)., Conclusion: Joint-occlusal treatment can promote condylar growth and improve dentofacial deformity in adolescents after 14 months when compared with single occlusal treatment., Clinical Question/level of Evidence: Therapeutic, I., (Copyright © 2023 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of the American Society of Plastic Surgeons.)

Objective: To evaluate radiological characteristics of the temporomandibular joint., Methods: Retrospective study of images of 20-80 year-old patients. Two independent clinicians analyzed the images, and a radiological score was obtained, considering sclerosis, osteophites, cysts, and erosion., Results: Seventy eight percent of the joints belonged to females. The main complaints were pain and headache (54.5%) and reduced motion (21.2%). The most common diagnoses were disc dislocation with reduction (35.9%), myofascial pain (20.7%), and osteoarthritis (15.2%). The majority of the joints (96.5%) showed degeneration, with an average radiological score of 3.86 ± 1.47 (0-8). Non-parametric tests showed that females had significantly higher radiological scores (p = 0.014), and TMD-joint patients had higher scores than TMD-muscle patients (p = 0.013). No statistically significant association between radiological scores and chief complaint., Conclusion: There were differences among the radiological findings between genders and joint/ muscle TMD, as well as across diagnoses, as expected.

Objective: To investigate the morphological and positional temporomandibular joint (TMJ) characteristics of different temporomandibular disorders (TMDs)., Methods: One hundred forty-three TMD patients were divided into three groups: Group 1: Myalgia (M), Group 2: Disc displacement with reduction (DDWR), and Group 3: Disc displacement without reduction (DDWOR). Three-dimensional positional and dimensional parameters of the TMJ, including mandibular fossa, condyle, and TMJ spaces were evaluated using cone beam computed tomography (CBCT). The significance level was p < 0.05., Results: Mandibular condyles were significantly positioned in more vertical, posterior, and medial directions, with the reduced condylar width in the DD groups ( p < 0.001). Anterior joint space was significantly higher in the DDWR group than the myalgia group; the superior joint spaces were more reduced in DD groups than the myalgia group., Conclusion: Patients diagnosed with disc displacement showed significantly different condylar positions and joint spaces compared to the myalgia group in a skeletally comparable sample.

Objective: To study the correlation between condylar morphology and clinical manifestations in patients with degenerative joint disease (DJD) of the temporomandibular joint (TMJ)., Methods: A total of 175 joints of 131 patients with DJD were included. Data on patients' basic information and symptoms were collected and analyzed. Condylar morphology was evaluated using cone beam computed tomography (CBCT). The correlation between the condylar morphology and clinical manifestations was analyzed., Results: The prevalence of joint noises, clicks, and crepitus was 93/175 (53%), 73/175 (42%), and 20/175 (11%), respectively. Condylar anteroposterior diameter and condylar height were correlated with pain. There was a correlation between the shape of the condyle in the sagittal plane and joint noise., Conclusion: Condylar morphology and clinical features of DJD were correlated to some extent.

Objective: To three-dimensionally evaluate the position and morphology of the TMJ in skeletal Class I with variable degrees of overbite and overjet in comparison with normal peers., Methods: Pretreatment CBCT scans of 126 adults were retrieved. Based on the severity of overjet and overbite, the sample was divided into three main groups and six subgroups (18 patients each): the first group with a normal overbite and variable overjet degree and the second group with normal overjet and variable overbite degree. These six subgroups were compared with a third control group of normal overjet and overbite., Results: There were significant differences in vertical condylar position, vertical and anteroposterior condylar inclinations, condylar height, and significant posterior condylar positioning in severe deep overbite, compared with the control group., Conclusion: There were significant changes in the TMJ components in severe deep overbite cases. Therefore, sever deep overbite could be considered a predisposing factor for temporomandibular disorders.

Objective: To evaluate the inter-examiner reliability of the Chinese version of the Axis I diagnoses of the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) and to compare the consistency between clinical diagnoses and magnetic resonance imaging (MRI)., Methods: Sixty-seven individuals were evaluated by three TMD specialists, and 49 underwent MRI examination. Cohen's Kappa coefficient (κ) was used to evaluate the inter-examiner reliability and the consistency between clinical diagnoses and MRI manifestations., Results: Diagnostic agreement was good to excellent for pain and disc displacement with or without reduction (κ = 0.659-1.000). Agreement between clinical diagnoses and MRI findings was fair to good (κ = 0.400)., Conclusion: Inter-examiner diagnostic reliability using the Chinese version of the DC/TMD Axis I instruments was excellent, especially for arthrogenic TMDs.

Purpose: This study aimed to compare the effects of two different mandibular advancement devices on the upper airway volume, polysomnographic parameters, and sleepiness scale scores in patients with obstructive sleep apnea and Temporomandibular disorders (TMD)., Materials and Methods: Monoblock and twinblock mandibular advancement devices were applied to patients with obstructive sleep apnea syndrome for 3 months separated by a wash-out period of 2 weeks. Research Diagnostic Criteria for TMD (RDC/TMD), Polysomnographic parameters and cone-beam computed tomography findings were recorded before and after the use of the mandibular advancement devices. A three-dimensional analysis of the airway was then performed., Results: The use of the monoblock device significantly increased the upper airway volume compared with the use of the twinblock device (p = 0.032). The polysomnographic parameters similarly improved with the use of the twin-block and monoblock devices. The significant reduction in TMD symptoms was observed., Conclusion: The use of the monoblock device increased the retropalatal airway volume. This volume increase may be attributed to the fact that the design of the monoblock device allows less mandibular movement than does that of the twinblock device. Indicates the potential benefits of MAD S treatment in alleviating TMD-related issues., Clinical Significance: Monoblock MADs have improved effects on respiratory parameters and upper airway dimensions in patients with OSA and mild to moderate TMD., (© 2024. The Author(s).)

Background: This study aimed to investigate the range of angles and depths necessary for effective entry into the TMJ using CBCT images, focusing on classical Holmlund Hellsing points and a two-needle approach., Methods: A retrospective cohort of CBCT images from January 2020 to November 2023 was analysed using 3D analysis to determine the variance in the required angles and depths., Results: The average age of the 68 participants included in the study was 29.5 ± 11.1, 58.8% of the participants were female and 41.2% were male. The anterior needle measurements showed a relatively low standard deviation(SD) in depth(SD:3.6) with a low variance coefficient(12.5%), whereas the axial and coronal angles exhibited greater variability(SD:9.1 and 7.6, respectively). For the posterior needles, moderate SDs in depth(SD:3.5) and greater variabilities in axial and coronal angles(SD:9.6 and 5.3, respectively) were observed. A weak negative correlation was observed between the axial angle of the posterior needle and age(p: 0.028, Pearson r: -0.29) Anterior needle depth (p:0.037) and posterior needle axial angle(p:0.014) were greater in males than females. The anterior needle depth in patients with temporamandibular disease was greater than in those without(p:0,03)., Conclusion: There were significant differences in the angle measurements for both anterior and posterior needles, but lower variance in depth. The depths and angles of the needles did not correlate with age., (© 2024. The Author(s).)

Background and Objectives: This research was aimed at constructing a complete automated temporomandibular joint disc position identification system that could assist with magnetic resonance imaging disc displacement diagnosis on oblique sagittal and oblique coronal images. Materials and Methods: The study included fifty subjects with magnetic resonance imaging scans of the temporomandibular joint. Oblique sagittal and coronal sections of the magnetic resonance imaging scans were analyzed. Investigations were performed on the right and left coronal images with a closed mouth, as well as right and left sagittal images with closed and open mouths. Three hundred sagittal and coronal images were employed to train the artificial intelligence algorithm. Results: The accuracy ratio of the completely computerized articular disc identification method was 81%. Conclusions: An automated and accurate evaluation of temporomandibular joint disc position was developed by using both oblique sagittal and oblique coronal magnetic resonance imaging images.

Obstructive sleep apnea (OSA) is closely associated with the development and chronicity of temporomandibular disorder (TMD). Given the intricate pathophysiology of both OSA and TMD, comprehensive diagnostic approaches are crucial. This study aimed to develop an automatic prediction model utilizing multimodal data to diagnose OSA among TMD patients. We collected a range of multimodal data, including clinical characteristics, portable polysomnography, X-ray, and MRI data, from 55 TMD patients who reported sleep problems. This data was then analyzed using advanced machine learning techniques. Three-dimensional VGG16 and logistic regression models were used to identify significant predictors. Approximately 53% (29 out of 55) of TMD patients had OSA. Performance accuracy was evaluated using logistic regression, multilayer perceptron, and area under the curve (AUC) scores. OSA prediction accuracy in TMD patients was 80.00-91.43%. When MRI data were added to the algorithm, the AUC score increased to 1.00, indicating excellent capability. Only the obstructive apnea index was statistically significant in predicting OSA in TMD patients, with a threshold of 4.25 events/h. The learned features of the convolutional neural network were visualized as a heatmap using a gradient-weighted class activation mapping algorithm, revealing that it focuses on differential anatomical parameters depending on the absence or presence of OSA. In OSA-positive cases, the nasopharynx, oropharynx, uvula, larynx, epiglottis, and brain region were recognized, whereas in OSA-negative cases, the tongue, nose, nasal turbinate, and hyoid bone were recognized. Prediction accuracy and heat map analyses support the plausibility and usefulness of this artificial intelligence-based OSA diagnosis and prediction model in TMD patients, providing a deeper understanding of regions distinguishing between OSA and non-OSA., (© 2024. The Author(s).)

Temporomandibular joint disorders are prevalent causes of orofacial discomfort. Diagnosis predominantly relies on assessing the configuration and positions of temporomandibular joint components in magnetic resonance images. The complex anatomy of the temporomandibular joint, coupled with the variability in magnetic resonance image quality, often hinders an accurate diagnosis. To surmount this challenge, we developed deep learning models tailored to the automatic segmentation of temporomandibular joint components, including the temporal bone, disc, and condyle. These models underwent rigorous training and validation utilizing a dataset of 3693 magnetic resonance images from 542 patients. Upon evaluation, our ensemble model, which combines five individual models, yielded average Dice similarity coefficients of 0.867, 0.733, 0.904, and 0.952 for the temporal bone, disc, condyle, and background class during internal testing. In the external validation, the average Dice similarity coefficients values for the temporal bone, disc, condyle, and background were 0.720, 0.604, 0.800, and 0.869, respectively. When applied in a clinical setting, these artificial intelligence-augmented tools enhanced the diagnostic accuracy of physicians, especially when discerning between temporomandibular joint anterior disc displacement and osteoarthritis. In essence, automated temporomandibular joint segmentation by our deep learning approach, stands as a promising aid in refining temporomandibular joint disorders diagnosis and treatment strategies., (© 2024. The Author(s).)

Objective: To assess the influence of unilateral open disc repositioning surgery (ODRS) of the temporomandibular joint (TMJ) on the internal derangement (ID) of the contralateral joint., Methods: Patients with bilateral ID of TMJ who underwent unilateral ODRS were enrolled and followed-up for one year. They were divided into two groups based on the contralateral disease: the anterior disc displacement with reduction (ADDWR) and without reduction (ADDWoR). Postoperative evaluation included clinical and MRI evaluation. Indices measured were unilateral intermaxillary distance (UID), visual analogue scale (VAS), disc length (DL), condylar height (CH), and disc-condyle angle (DCA). Paired t tests were used to compare the clinical and MRI indices between different time points., Results: Ninety-six patients were enrolled, including 47 in the ADDWR group and 49 in the ADDWoR group. One-year post-surgery, ODRS led to significant increases in MMO, DL, and CH, and decrease in VAS and DCA on the operated side (P < 0.05). In ADDWR group, UID, DL, and CH increased significantly, and VAS decreased (P < 0.05), with no significant change in DCA (P > 0.05). In ADDWoR group, clinical and MRI variables worsened slightly, except for UID, which remained unchanged (P > 0.05)., Conclusions: ODRS is a promising method for correcting TMJ ID and may improve condition of ADDWR and decrease progress of ADDWoR at the contralateral joint. Preoperative bilateral TMJ evaluation is essential for better outcomes., Clinical Relevance: ODRS can effectively treat TMJ ID and produce adaptive changes in the contralateral ID, for which continuous monitoring of the contralateral joint is essential., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

This study investigated the usefulness of deep learning-based automatic detection of temporomandibular joint (TMJ) effusion using magnetic resonance imaging (MRI) in patients with temporomandibular disorder and whether the diagnostic accuracy of the model improved when patients' clinical information was provided in addition to MRI images. The sagittal MR images of 2948 TMJs were collected from 1017 women and 457 men (mean age 37.19 ± 18.64 years). The TMJ effusion diagnostic performances of three convolutional neural networks (scratch, fine-tuning, and freeze schemes) were compared with those of human experts based on areas under the curve (AUCs) and diagnosis accuracies. The fine-tuning model with proton density (PD) images showed acceptable prediction performance (AUC = 0.7895), and the from-scratch (0.6193) and freeze (0.6149) models showed lower performances (p < 0.05). The fine-tuning model had excellent specificity compared to the human experts (87.25% vs. 58.17%). However, the human experts were superior in sensitivity (80.00% vs. 57.43%) (all p < 0.001). In gradient-weighted class activation mapping (Grad-CAM) visualizations, the fine-tuning scheme focused more on effusion than on other structures of the TMJ, and the sparsity was higher than that of the from-scratch scheme (82.40% vs. 49.83%, p < 0.05). The Grad-CAM visualizations agreed with the model learned through important features in the TMJ area, particularly around the articular disc. Two fine-tuning models on PD and T2-weighted images showed that the diagnostic performance did not improve compared with using PD alone (p < 0.05). Diverse AUCs were observed across each group when the patients were divided according to age (0.7083-0.8375) and sex (male:0.7576, female:0.7083). The prediction accuracy of the ensemble model was higher than that of the human experts when all the data were used (74.21% vs. 67.71%, p < 0.05). A deep neural network (DNN) was developed to process multimodal data, including MRI and patient clinical data. Analysis of four age groups with the DNN model showed that the 41-60 age group had the best performance (AUC = 0.8258). The fine-tuning model and DNN were optimal for judging TMJ effusion and may be used to prevent true negative cases and aid in human diagnostic performance. Assistive automated diagnostic methods have the potential to increase clinicians' diagnostic accuracy., (© 2024. The Author(s).)

Background: In recent years, obstructive sleep apnea (OSA) has been increasingly recognized as a significant health concern. No previous studies assessed the effect of recommended treatment modalities of patients with OSA on the temporomandibular joint (TMJ). The current study aimed to evaluate the effect of different treatment modalities of OSA, such as continuous positive airway pressure (CPAP), mandibular advancement device (MAD), and oral myofunctional therapy (OMT) on subjective symptoms, clinical, and radiographic signs of temporomandibular disorders., Patients & Methods: This hospital-based prospective randomized controlled clinical trial study was approved by the institutional review board and formal patient consent, 39 OSA patients, ranging in age from 19 to 56 after confirmation with full night Polysomnography (PSG) with healthy TMJ confirmed clinically and radiographically with magnetic resonance imaging (MRI) were randomly allocated into three treatment groups. Group 1: 13 patients were managed with CPAP after titration, group 2: 13 patients were managed with digitally fabricated MAD, and group 3: 13 patients were managed with OMT. The following parameters were evaluated before and 3 months after the intervention. Pain using a visual analogue scale (VAS), maximum inter-incisal opening (MIO), lateral movements, and clicking sound of TMJ. MRI was done before and 3 months after the intervention., Results: Out of the 83 patients enrolled, 39 patients completed the treatment. There were no statistically significant differences in lateral jaw movements or clicking, and no significant difference in MRI findings between the three studied groups before and after the intervention. The OMT group showed a statistically significant difference in pain (p = 0.001), and MIO (p = 0.043) where patients experienced mild pain and slight limitation in mouth opening after 3 months of follow-up in comparison to MAD and CPAP groups., Conclusion: CPAP and MAD are better for preserving the health of TMJ in the treatment of OSA patients. While OMT showed mild pain and slight limitation of MIO (that is still within the normal range of mouth opening) compared to CPAP and MAD., Trial Registration: The study was listed on www., Clinicaltrials: gov with registration number (NCT05510882) on 22/08/2022., (© 2024. The Author(s).)

Objective: Temporomandibular disorders (TMD) affect the temporomandibular joint and associated structures. Despite its prevalence and impact on quality of life, the underlying mechanisms of TMD remain unclear. Magnetic resonance imaging studies suggest brain abnormalities in patients with TMD. However, these lines of evidence are essentially observational and cannot infer a causal relationship. This study employs Mendelian randomisation (MR) to probe causal relationships between TMD and brain changes., Methods: Genome-wide association study (GWAS) summary statistics for TMD were collected, along with brain imaging-derived phenotypes (IDPs). Instrumental variables were selected from the GWAS summary statistics and used in bidirectional 2-sample MR analyses. The inverse-variance weighted analysis was chosen as the primary method. In addition, false discovery rate (FDR) correction of P value was used., Results: Eleven IDPs related to brain imaging alterations showed significant causal associations with TMD (P-FDR < .05), validated through sensitivity analysis. In forward MR, the mean thickness of left caudal middle frontal gyrus (OR, 0.76; 95% CI, 0.67-0.87; P-FDR = 1.15  ×  10 -2 ) and the volume of right superior frontal gyrus (OR, 1.24; 95% CI, 1.10-1.39; P-FDR = 2.26  ×  10 -2 ) exerted significant causal effects on TMD. In the reverse MR analysis, TMD exerted a significant causal effect on 9 IDPs, including the mean thickness of the left medial orbitofrontal cortex (β = -0.10; 95% CI, -0.13 to -0.08; P-FDR = 2.06 × 10 -11 ), the volume of the left magnocellular nucleus (β = -0.15; 95% CI, -0.22 to -0.09; P-FDR = 3.26 × 10 -4 ), the mean intensity of the right inferior-lateral ventricle (β = -0.09; 95% CI, -0.14 to -0.04; P-FDR = 2.23 × 10 -2 ), the volume of grey matter in the anterior division of the left superior temporal gyrus (β = 0.09; 95% CI,  0.04-0.14; P-FDR = 1.69 × 10 -2 ), and so forth., Conclusions: This study provides genetic evidence supporting the bidirectional causal associations between TMD and brain IDPs, shedding light on potential neurobiological mechanisms underlying TMD development and its relationship with brain structure., Competing Interests: Conflict of interest None disclosed., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Objectives: To describe the clinical and radiographic oro-dental characteristics of patients with pycnodysostosis (PDO)., Materials & Methods: A short interview and clinical examination of seven patients with PDO were performed as well as assessment of the temporomandibular joints and masticatory muscles using the diagnostic criteria for temporomandibular disorders, DC-TMD form. A full set of records were taken including photos and intraoral scan. Finally, existing cone beam computed tomography (CBCT) images and radiographs were also studied., Results: All patients presented with bimaxillary micrognathia, five had a convex profile, and two had a straight profile. In addition, posterior open bite, Angle Class III molar relation with accompanying anterior crossbite and a grooved median palate were common findings. No patient showed symptoms of temporomandibular disorder (TMD) apart from some clicking. Finally, the main radiographic findings were the obtuse mandibular angle, the frontal bossing, the elongation of the coronoid/condylar process and the presence of hypercementosis with obliterated pulp chambers., Conclusion: The examined patients with PDO were characterized by dental crowding, malocclusion (anterior crossbite, posterior open bite), hypercementosis, obliterated pulp chambers and deviations in mandibular morphology. In conclusion, patients with PDO have a specific need for dental and orthodontic monitoring with focus on crowding and posterior open bite. The patients will benefit from a long-term orthodontic plan including extractions., (© 2024 The Authors. Orthodontics & Craniofacial Research published by John Wiley & Sons Ltd.)

Objectives: This randomized clinical trial study aims to compare ultrasound-guided versus non-guided Dextrose 10% injections in patients suffering from internal derangement in the temporomandibular joint (TMJ)., Material and Methods: The study population included 22 patients and 43 TMJs suffering from unilateral or bilateral TMJ painful clicking, magnetic resonance imaging (MRI) proved disc displacement with reduction (DDWR), refractory to or failed conservative treatment. The patients were divided randomly into two groups (non-guided and ultrasound (US)-guided groups). The procedure involved injection of 2 mL solution of a mixture of 0.75 mL 0.9% normal saline solution, 0.3 mL 2% lidocaine and 0.75 mL dextrose 10% using a 25G needle in the joint and 1 mL intramuscular injection to the masseter muscle at the most tender point. The Visual Analogue Score (VAS) was used to compare joint pain intensity over four different periods, beginning with pre-injection, 1-, 2-, and 6-months postinjection., Results: Twenty-two patients 5 males (n = 5/22, 22.7%) and 17 females (n = 17/22, 77.2%) were included in this study. The mean age was 27.3 ± 7.4 years (30.2 ± 7.0) for the non-guided group and 24.3 ± 6.9 for the US-guided group. The dextrose injection reduced intensity over time in both groups with statistically significant improvement (P value <.05) at 2 and 6 months in both groups. There was no statistically significant difference in VAS assessment between both groups., Conclusion: Intra-articular injection of dextrose 10% for patients with painful clicking and DDWR resulted in reduced pain intensity in both US-guided and non-guided groups with significant symptomatic improvement over time in both groups. US guidance allowed accurate anatomical localization and safe procedure with a single joint puncture., (© 2024 American Institute of Ultrasound in Medicine.)

In children with juvenile idiopathic arthritis (JIA), the temporomandibular joint (TMJ) can be involved. To prevent TMJ damage due to inflammation, early recognition is important, for which contrast-enhanced magnetic resonance imaging (MRI) is the gold standard. In this study, the interobserver reliability and construct validity of the Juvenile Idiopathic Arthritis Magnetic Resonance Scoring System for Temporomandibular Joints (JAMRIS-TMJ) was assessed. Two radiologists independently examined 38 MRIs using the JAMRIS-TMJ scoring system. Inter-observer reliability was assessed by Cohen's (weighted) kappa (κ), 95% confidence intervals (CIs) and absolute agreement (%). Construct validity was assessed by correlation between the JAMRIS-TMJ items and TMJ involvement, active maximum interincisal mouth opening (AMIO), and anterior maximum voluntary bite force (AMVBF). The interobserver reliability for the JAMRIS-TMJ items varied from poor to good (κ = 0.18-0.61). Joint enhancement had the highest reliability (κ = 0.61). Correlations were found between TMJ involvement, AMIO, and the JAMRIS-TMJ items, although variation between radiologists and TMJ side existed. No correlation was found between AMVBF and the JAMRIS-TMJ items for both radiologists. The strongest correlations were found between most of the JAMRIS-TMJ items and AMIO. Our findings support the utility of AMIO as a clinical measure of TMJ status in children with JIA., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)