Joint Disc Research Articles

Advances in 3D printing techniques for cartilage regeneration of temporomandibular joint disc and mandibular condyle.

Temporomandibular joint (TMJ) osteoarthritis causes fibrocartilage damage to the TMJ disc and mandibular condyle, resulting in local pain and functional impairment that further reduces patients' quality of life. Tissue engineering offers a potential treatment for fibrocartilage regeneration of the TMJ disc and mandibular condyle. However, the heterogeneous structure of TMJ fibrocartilage tissue poses significant challenges for the fabrication of biomimetic scaffolds. Over the past two decades, some researchers have attempted to adopt three-dimensional (3D) printing techniques to fabricate biomimetic scaffolds for TMJ fibrocartilage regeneration, but publications on such attempts are limited and rarely report satisfactory results, indicating an urgent need for further development. This review outlines several popular 3D printing techniques and the significant elements of tissue-engineered scaffolds: seed cells, scaffold materials, and bioactive factors. Current research progress on 3D-printed scaffolds for fibrocartilage regeneration of the TMJ disc and mandibular condyle is reviewed. The current challenges in TMJ tissue engineering are mentioned along with some emerging tissue-engineering strategies, such as machine learning, stimuli-responsive delivery systems, and extracellular vesicles, which are considered as potential approaches to improve the performance of 3D-printed scaffolds for TMJ fibrocartilage regeneration. This review is expected to inspire the further development of 3D printing techniques for TMJ fibrocartilage regeneration.

A Proposal for the Classification of Temporomandibular Joint Disc Deformity in Hemifacial Microsomia.

Hemifacial microsomia (HFM) is the second most common congenital craniofacial disease and has a wide spectrum of symptoms. The classic diagnostic criterion for hemifacial microsomia is the OMENS system, which was later refined to the OMENS+ system to include more anomalies. We analyzed the data of 103 HFM patients with magnetic resonance imaging (MRI) for temporomandibular joint (TMJ) discs. The TMJ disc classification was defined into four types: D0 for normal disc size and shape; D1 for disc malformation with adequate length to cover the (reconstructed) condyle; D2 for disc malformation with inadequate length to cover the (reconstructed) condyle; and D3 for no obvious presence of a disc. Additionally, this disc classification was positively correlated with the mandible classification (correlation coefficient: 0.614, p < 0.01), ear classification (correlation coefficient: 0.242, p < 0.05), soft tissue classification (correlation coefficient: 0.291, p < 0.01), and facial cleft classification (correlation coefficient: 0.320, p < 0.01). In this study, an OMENS+D diagnostic criterion is proposed, confirming the conjecture that the development of the mandibular ramus, ear, soft tissue, and TMJ disc, as homologous and adjacent tissues, is affected to a similar degree in HFM patients.

Comparison of Articular Eminence Steepness in Patients With Temporomandibular Joint Disc Disorders

Comparison of Articular Eminence Steepness in Patients With Temporomandibular Joint Disc Disorders

Estimation of the Lengths of Intact Rock Core Pieces and the Corresponding RQD considering the Influence of Joint Roughness

The lengths of intact rock core pieces (LIRCP) and the corresponding rock quality designation (RQD) are two essential indexes for grasping rock structure. However, joints are usually simplified to be perfect planes. Thus, the influence of joint roughness on the LIRCP and RQD is not fully considered. The joint roughness was described by the Hurst exponent (H) and the root-mean-square of the point heights on a joint (Rq) in the study. Theoretical formulas were derived and a new practical method of building non-planar joint disc models was proposed to reveal the influence of joint roughness and to estimate the LIRCP and RQD in the field. A 3D point cloud with the texture of a rock slope was acquired by photogrammetry to verify the practicability of the new method. Results showed that: a) the LIRCP obeyed a normal distribution, and the distribution form was mainly controlled by Rq rather than H when there was one equal spacing parallel joint set; b) Rq and H significantly affected the mean length and the number of intact rock core pieces and the value of RQD when joints were non-parallel; c) following the rise of Rq, the number of intact rock core pieces and the value of RQD trended to increase but the mean length of intact rock core pieces displayed a downtrend; however, the effect degree of Rq on the trend decreased as the rise of H; d) the new method of building non-planar joint disc models was applicable to estimate the LIRCP and RQD in engineering practices.

Mechanical overload induces TMJ disc degeneration via TRPV4 activation.

The temporomandibular joint (TMJ) disc cushions intraarticular stress during mandibular movements. While mechanical overloading is related to cartilage degeneration, the pathogenesis of TMJ disc degeneration is unclear. Here, we determined the regulatory role of mechanoinductive transient receptor potential vanilloid 4 (TRPV4) in mechanical overload-induced TMJ disc degeneration. We explored the effect of mechanical overload on the TMJ discs in a rat occlusal interference model in vivo, and by applying sustained compressive force in vitro. TRPV4 inhibition was delivered by small interfering RNA or GSK2193874; TRPV4 activation was delivered by GSK1016790A. The protective effect of TRPV4 inhibition was validated in the rat occlusal interference model. Occlusal interference induced TMJ disc degeneration with enhanced extracellular matrix degradation in vivo and mechanical overload promoted inflammatory responses in the TMJ disc cells via Ca2+ influx with significantly upregulated TRPV4. TRPV4 inhibition reversed mechanical overload-induced inflammatory responses; TRPV4 activation simulated mechanical overload-induced inflammatory responses. Moreover, TRPV4 inhibition alleviated TMJ disc degeneration in the rat occlusal interference model. Our findings suggest TRPV4 plays a pivotal role in the pathogenesis of mechanical overload-induced TMJ disc degeneration and may be a promising target for the treatment of degenerative changes of the TMJ disc.

Photogrammetry-Based 3D Textured Point Cloud Models Building and Rock Structure Estimation

Trace lines on the outcrop of a rock mass are usually the primary data source for the estimation of rock structure. It is important to obtain the data of trace lines precisely. Photogrammetry is well suited to finish this task. However, this is mainly conducted by commercial software, and not every researcher has easy access to the method of digital photogrammetry. This study aims to provide researchers with a low-cost method of building a photogrammetry-based textured 3D point cloud model (FMBPM) and display the applicability of the method to estimating the rock structure of rock masses. In the FMBPM, a digital single-lens reflex camera with a prime lens and a total station are the necessary hardware employed to capture images and measure the coordinates of feature points. A coordinate transformation means of converting model coordinates to physical coordinates was introduced. A program for calculating a joint orientation based on the coordinates of inflection points on the trace line of the joint was developed. A section of a rock slope was selected as a case to show the procedures and the practicability of the FMBPM. The textured 3D point cloud model of the rock slope was successfully built, and the rock structure of the rock slope was analyzed using the joint disk model generated based on the trace lines extracted from the point cloud model. The results show that: (1) the precision of the point coordinates of the textured 3D point cloud model could achieve 3.96 mm, taking the data of the total station as the reference; (2) the rock structure of the slope is good, according to the value of the rock quality designation; (3) the new method is applicable in engineering practices.

Therapeutic effects of kartogenin on temporomandibular joint injury by activating the TGF-β/SMAD pathway in rats.

Patients with temporomandibular dysfunction (TMD) usually suffer from pathology or malpositioning of the temporomandibular joint (TMJ) disk, leading to the degenerative lesion of condyles. Kartogenin can promote the repair of damaged cartilage. This study aimed to explore whether intra-articular injection of kartogenin could alleviate the TMJ injury induced by type II collagenase. We measured the head withdrawal threshold and found that kartogenin alleviated the pain around TMD induced by type II collagenase. We observed the morphology of the condylar surface and found that kartogenin protected the integration of the condylar surface. We analyzed the density of the subchondral bone and found that kartogenin minimized the damage of TMJ injury to the subchondral bone. We next explored the histological changes and found that kartogenin increased the thickness of the proliferative layer and more collagen formation in the superficial layer. Then, to further ensure whether kartogenin promotes cell proliferation in the condyle, we performed immunohistochemistry of proliferating cell nuclear antigen (PCNA). The ratio of PCNA-positive cells was significantly increased in the kartogenin group. Next, immunofluorescence of TGF-β1 and SMAD3 was performed to reveal that kartogenin activated the TGF-β/SMAD pathway in the proliferative layer. In conclusion, kartogenin may have a therapeutic effect on TMJ injury by promoting cell proliferation in cartilage and subchondral bone. Kartogenin may be promising as an intra-articular injection agent to treat TMD.

Effects of osseous structure based on three-dimensional reconstructive imaging evaluation in the assessment of temporomandibular joint disc position

This pilot morphological study aimed to investigate the association between anterior disc displacement (ADD) and the status of the mandibular condyle and articular fossa. Thirty-four patients were divided into a normal articular disc position group and an ADD with and without reduction group. Images reconstructed were used to determine multiple group comparisons of these three different types of disc position, and the diagnostic efficacy for the morphological parameters with significant group difference was analyzed to assess. The condylar volume (CV), condylar superficial area (CSA), superior joint space (SJS), and medial joint space (MJS) all exhibited obvious changes (P < 0.05). Additionally, they all had a reliable diagnostic accuracy in differentiating between normal disc position and ADD with an AUC value from 0.723 to 0.858. Among them, the CV, SJS, and MJS (P < 0.05) had a significantly positive impact on the groups by analysis of multivariate logistic ordinal regression model. The CV, CSA, SJS, and MJS are significantly associated with different disc displacement types. The condyle in ADD exhibited altered dimensions. These could be promising biometric markers for assessing ADD. The morphological changes of mandibular condyle and glenoid fossa were significantly influenced by the status of disc displacement, and condyles with disc displacement had three-dimensionally altered condylar dimensions, irrespective of age and sex.

Decellularized-disc based allograft and xenograft prosthesis for the long-term precise reconstruction of temporomandibular joint disc.

Currently, no effective disc reconstruction treatment strategy is clinically available for temporomandibular joint (TMJ) disc-related diseases. To address this, we developed a prosthesis construct with laser-drilled decellularized natural disc reinforced by polycaprolactone, which mimics the natural morphology, and structural, biomechanical and biological property of the TMJ disc. The construct demonstrated good biocompatibility, safety and immunological tolerance both in vitro, and in a rat subcutaneous model. During 6 months implantation in an allogeneic rabbit TMJ disc reconstruction model, the disc prosthesis maintained its integrity, collagen fiber-orientation, mechanical property, joint structural stability and prevented articular cartilage and bone from damage. Furthermore, the "upgraded" disc prosthesis obtained from decellularized porcine disc was implanted into a goat TMJ disc reconstruction model. The xenograft prosthesis, with strength and viscoelasticity similar to a natural TMJ disc, was able to restore the structure and function of TMJ up to 20 weeks. These results demonstrate the translational feasibility of an allogeneic or xenogeneic decellularized disc prosthesis for treatment of advanced TMJ disc-related diseases. STATEMENT OF SIGNIFICANCE: This study makes a significant contribution to TMJ disc disease treatment both in theory and in clinics, because: (1) it provided an innovative approach to prepare an artificial TMJ disc with decent mechanical properties and long-term condyle-protecting effect; (2) it specified an advanced decellularized method for fibrocartilage decellularization and xenograft application; (3) it developed a facile and reproducible TMJ disc reconstruction model not only for middle size animal but also for large animal study; (4) the comprehensive and unreported biomechanical tests on the natural TMJ discs would act as a valuable reference for further research in the field of artificial TMJ disc materials or TMJ disc tissue engineering; (5) it suggested a potential treatment for patients with severe TMJ diseases that were commonly met but difficult to treat in clinics.

Analysis of the Curative Effect of Temporomandibular Joint Disc Release and Fixation Combined with Chitosan Injection in the Treatment of Temporomandibular Joint Osteoarthrosis

Temporomandibular joint osteoarthritis (TMJ-OA) is common in clinic. The purpose of this study was to evaluate the efficacy of disc release, fixation and chitosan injection in the treatment of TMJ-OA. From March 2021 to March 2022, 32 patients who underwent the unilateral reduction and fixation of temporomandibular joint disc release were retrospectively studied. All patients were diagnosed with TMJ-OA and were treated with chitosan injection. This group of patients was analyzed by the visual analog scale (VAS) for pain and improvement of maximum comfortable mouth opening before treatment and 6 months after treatment. A paired t-test was used to evaluate the treatment effect, and p < 0.05 indicated that the difference was statistically significant. All 32 patients were successfully treated by surgery and chitosan injection in the second week after operation. The duration of disease in this group ranged from 1 to 10 months, with an average of 5.7 months. After 6 months of follow up, 30 patients were satisfied with the treatment and two were unsatisfied. The difference in the treatment effect was found to be statistically significant (p < 0.05). Temporomandibular joint disc release and fixation combined with chitosan injection is effective in the treatment of TMJ-OA.

A single-cell transcriptional atlas reveals resident progenitor cell niche functions in TMJ disc development and injury

The biological characteristics of the temporomandibular joint disc involve complex cellular network in cell identity and extracellular matrix composition to modulate jaw function. The lack of a detailed characterization of the network severely limits the development of targeted therapies for temporomandibular joint-related diseases. Here we profiled single-cell transcriptomes of disc cells from mice at different postnatal stages, finding that the fibroblast population could be divided into chondrogenic and non-chondrogenic clusters. We also find that the resident mural cell population is the source of disc progenitors, characterized by ubiquitously active expression of the NOTCH3 and THY1 pathways. Lineage tracing reveals that Myh11+ mural cells coordinate angiogenesis during disc injury but lost their progenitor characteristics and ultimately become Sfrp2+ non-chondrogenic fibroblasts instead of Chad+ chondrogenic fibroblasts. Overall, we reveal multiple insights into the coordinated development of disc cells and are the first to describe the resident mural cell progenitor during disc injury.

Automatic temporomandibular disc displacement diagnosis via deep learning

Temporomandibular joint (TMJ) disc displacement is a common condition that required magnetic resonance imaging (MRI) for diagnosis. However, it has occasionally been challenging for doctors to make a firm diagnosis based on TMJ MRI due to imaging concerns and the significant requirement for clinical competence. As a result, a Multimodal Stepped Attention Net (MSANet) was built in this study, and a deep learning network was used to train the assisted diagnosis AI model (TMJ MRI-Net).A total of 600 patients were recruited, including 1200 lateral joint MRI sequences, which are made up of eight consecutive images for each lateral joint. 11 sides of cases with poor image quality were excluded. MSANet combining multimodal technology and attention mechanism was proposed and designed for this study, which mainly included Area Detection Module and Feature Network.The whole experiment was designed according to stard standard. There is statistically significant difference between the least square mean of diagnosis time for the physicians (from TMJ, Orthodontics and General Dentistry) with AI (TMJ MRI-Net) assistance group (16.15, 95% CI:10.88–21.41) and the physician only group (21.01, 95%CI: 15.74–26.28). The AUC, sensitivity and specificity of patients whether is disc displacement and patients whether the disc displacement is with/without reduction for the physicians' diagnoses were all statistically improved by the assistance of AI. In addition, AUC and specificity were improved for three different specialties with the AI assistance. Meanwhile, AI can help to save reading time for physicians from all three departments, and the increment was statistically significant.To conclude, the AI-assisted strategy significantly improved the diagnostic accuracy of physicians (especially in General Dentistry) on anterior disc displacement in TMJ MRI and improve diagnostic efficiency.

Biomimetic construction of a lubricious hydrogel with robust mechanics via polymer chains interpenetration and entanglement for TMJ disc replacement

Developing a temporomandibular joint (TMJ) disc substitute with reliable long-term functional support has faced a huge challenge in replicating the unique microarchitecture, biomechanics and lubrication of the natural tissue. Herein, a novel biomimetic hydrogel consisting of graphene oxide nanosheets modified anionic polyurethane (nGO-APU) and polyvinyl alcohol (PVA) was successfully fabricated through combined freeze-thawing and annealing treatment. Of which, the annealed PVA (a-PVA) with entanglement network acted as the main frame to provide mechanical support, while the interpenetrated nGO-APU chains endowed the function for water retention and lubrication, thus resisting the compressive loads and fulfilling a durable energy absorbing and cushion. The resultant nGO-APU/a-PVA hydrogel achieved better lubrication effect through the synergistic effect of fluid film and boundary lubrication, exhibiting a low friction coefficient of about 0.06, close to the natural TMJ disc. After implantation into rabbit TMJ for up to 24 weeks, the nGO-APU/a-PVA hydrogel kept the structural stability to offer effective protection against wearing of the cartilage, meanwhile ameliorating the worsening of osteoarthritis. The finite element analysis (FEA) further proved that the resultant hydrogel could effectively disperse the applied stress and dissipate energy under practical loading conditions. This strategy based on a biomimetic hydrogel with enhanced mechanical stability and lubrication performance shows clinical promise for TMJ disc replacement.

Suprafoveal condylar arthroplasty in unilateral disc displacement without reduction – A retrospective study

The aim of this study was to evaluate the efficacy of suprafoveal condylar arthroplasty (SFCA) in the management of patients with unilateral temporomandibular joint (TMJ) disc displacement without reduction (DDWoR). A retrospective study comprising patients who underwent unilateral SFCA for clinically and radiologically confirmed unilateral DDWoR from 2008 to 2020 was conducted. Patients older than 18 years at the time of diagnosis with a minimum of 6 months of unsuccessful non-surgical and minimally invasive management (including diet and life style modification, physiotherapy, appliance therapy, pharmacotherapy, arthrocentesis and arthroscopic lysis and lavage) before undergoing surgery with a minimum of 1 year follow-up post-surgery were included in the study. Patients with other articular and extra-articular causes of restricted mouth opening, prior history of mandibular surgery and/or trauma, growth abnormalities, systemic, metabolic, infective, neoplastic conditions affecting TMJ, including gross occlusal disharmony, untreated existing para-functional habits and bilateral DDWoR, were excluded from the study. Patients were assessed in terms pain on a visual analog scale (VAS), interincisal mouth opening (MO) and subjective assessment of mandibular range of movements including deviation of mouth opening, protrusion and ability for contralateral laterotrusion. 23 patients (10 males and 13 female) were included in the study, with a mean age of 35.09 years and mean follow up period of 37.7 months (range = 12–58; SD = 15.3). The mean pain scores on the VAS reduced from 6.35 preoperatively to 1.13 postoperatively and were found to be statistically significant (p < 0.0001). The improvement of the mean pre-operative mouth opening of 21.83 mm to a mean post-operative mouth opening of 42.09 mm was also found to be statistically significant (p < 0.0001). The subjective improvement in protrusive (p = 0.0003), laterotrusive (p = 0.0005) and opening movements (p = 0.0001) after 1 year were also found to be statistically significant. No patient developed any significant changes in occlusion post-operatively. Four of 23 (17.3%) patients developed transient neuromotor deficit of the temporal branch of the facial nerve. Within the limitations of the study, it seems that SFCA (without addressing the disc) might be an alternative to less invasive treatment approaches, if the latter turned out not to be successful.

Changes in strain energy density in the temporomandibular joint disk after sagittal split ramus osteotomy using acomputed tomography-based finite element model.

We evaluated the changes in the strain energy density (SED) in the temporomandibular joint (TMJ) disk after sagittal split ramus osteotomy (SSRO) at three time points. Afinite element model (FEM) based on real patient-based computed tomography (CT) data was used to examine the effect of SSRO on the TMJ. Measurements of the condylar position and angulation in CT images and FEM analyses were performed for 17patients scheduled to undergo SSROs at the following time points: before surgery, immediately after surgery, and 1year after surgery. SED on the entire disk was calculated at each of the three time points using FEM. Furthermore, the relationship between individual SED values and the corresponding condylar position was also evaluated. No significant change was observed in the condylar position at the three time points. The FEM analysis showed that SED was the highest and lowest immediately after and 1year after surgery, respectively. Apossible SED distribution imbalance between the left and right joints was improved 1year after SSRO. Concerning the effect of fossa morphometry and condylar position, wide and deep glenoid fossae and amore posterior condylar position tended to show lower SED. SED in the articular disk temporarily increased after surgery and significantly decreased 1year after surgery compared with that before surgery. SSRO generally improved the imbalance between the left and right joints. Thus, SSRO, which improves maxillofacial morphology, may also improve components of temporomandibular disorders.

Efficacy of stabilisation splint and low-level laser therapy for patients with chronic closed lock from non-reducible displacedtemporo-mandibular joint discs: A parallel randomised clinical trial.

Stabilisation splint therapy (SST) and low-level laser therapy (LLLT) are effective-invasive treatment for temporo-mandibular disorder (TMD) patients. However, the specific efficacy of each therapy in patients with chronic closed lock (CCL) from temporo-mandibular joints (TMJ) disc displacement without reduction (DDwoR) remains unknown. The aim of this study was to assess and compare the efficacy of SST and LLLT alone or in combination in patients with CCL from TMJ DDwoR. This parallel randomised clinical trial included 42 patients who were diagnosed with CCL from TMJ DDwoR. Patients were allocated equally and randomly into three treatment groups: group I received combined SST and LLLT, group II received LLLT and group III received SST. Maximum mouth opening (MMO), visual analogue scale (VAS), muscle and joint palpation scores and time required to achieve normal state were evaluated at baseline, 1, 2, 4 weeks, 3 and 6months after the intervention. Data were collected and analysed using SPSS software. Regarding MMO and VAS, a statistically significant improvement was found between group I versus group II and versus group III at all evaluation times. Regarding muscle and joint palpation scores, a statistically significant difference was found between group I versus group III, while non-significant difference was found between group I and group II. A statistically significant faster improvement was found in group I versus group III and versus group II. All treatment modalities can be effective in management of CCL from a TMJ DDwoR cases, but the combined SST and LLLT group seems to provide the best and quickest improvement. NCT05548894.

Modified minimally invasive surgery in reconstructing the temporomandibular joint disk by transplantation of the temporalis myofascial flap

ObjectiveThe transplantation of temporalis myofascial flap (TMF) is an indispensable method to treat severe temporomandibular joint disorders with disk failure. How to select the indication and the ways of transplantation is still a challenging topic for achieving the ideal effect. We reported the new methods and follow-up results of the patients treated with pedicled TMF transplantation.MethodsRetrospective case series was performed at Temporomandibular Joint Specialist Clinic, the First Affiliated Hospital of Xinjiang Medical University, from December 2014 to August 2022. 39 patients (50 sides) included anterior disk displacement without reduction and disk perforation who underwent discectomy and immediate reconstruction with pedicled TMF. The initial and postoperative maximum mouth opening (MMO), and pain visual analogue scale (VAS) were compared via paired t-test and Wilcoxon signed-rank sum test, respectively.ResultsThe average of follow-up time was 30.07 months. The reconstructed temporomandibular joints basically achieved stable occlusion, good function, and satisfactory effect. The patients displayed a remarkable reduction of VAS score of pain, and improvement of the MMO compared with that before operation (P < 0.001). MR scanning revealed the grafts in joint space showed band-shaped soft tissue density of medium signal and had the clear edges, without interruption and fragment.ConclusionReconstruction of the temporomandibular joint disk by transplantation of the TMF applying modified minimally invasive surgery was a feasible method, which could improve the function of joints and prevent adhesion, without obvious complications in donor region.

Clinical Evaluation of Platelet Rich Growth Factors (PRGFS) in Treatment of Temporomandibular Joint Disc Displacement—Study Report

Objective: The aim of the study was to evaluate the effect of platelet rich growth factors (PRGFs) in treatment of temporomandibular joint disc displacement. Materials and Methods: The study subjects included 8 females having bilateral anterior disc displacement with reduction and 1 female having bilateral anterior disc displacement without reduction with the age range between 20 - 35 years. The process of obtaining PRGFs was carried out following the Anitua Technique. Results: Clinical parameters of Interincisal distance, Lateral excursion of mandible using digital caliper in millimeters and Visual Analogue Scale (VAS 0/10) for pain intensity score were used. All of these parameters were running through the intervals of two, four, and eight weeks till the end of the follow-up period at twenty-six weeks (six months). The participated patients showed the clinical improvement in the different clinical statuses such as interincisal distance; lateral excursion of mandible and Pain Score. Conclusion: the study reported early efficacy of PRGFs after the arthrocentesis of the joint in treatment of TMJ disc displacement, and according to our results, the injection of PRGFs could be a possible alternative treatment for patients who did not respond to standard treatment.

To review the research progress of temporomandibu-lar joint disc displacement in patients with malocclusion

With the continuous improvement of living standards, people pay more and more attention to facial appearance and oral health. Dentists found that patients with malocclusion had temporomandibular disorders (TMJ), in which disc displacement was the most common. Because it affects the growth and reconstruction of condyle, which affects joint function, facial appearance, growth and development, etc. This article summarizes the etiology, imaging examination, manifestations and related treatment of articular disc displacement, in order to provide clinical guidance for the treatment of Anterior Disc Displacement patients, improve clinicians' understanding of the disease, and reduce the occurrence of Anterior Disc Displacement or relieve the symptoms of Anterior Disc Displacement.

Efficacy of Occlusal Splints and Low-Level Laser Therapy on the Mandibular Range of Motion in Subjects with Temporomandibular Joint Disc Displacement with Reduction.

The study was carried out to evaluate the efficacy of four conservative therapeutic modalities on the mandibular range of motion (MRM) in subjects with anterior disc displacement with reduction (ADDwR) of the temporomandibular joint (TMJ). One hundred patients (64 women and 36 men) were selected, and randomly distributed into four groups. Group I: Subjects receiving behavioral therapy (BT). Group II: Subjects receiving low-level laser therapy (LLLT). Group III: Subjects receiving maxillary anterior repositioning splint (MARS). Group IV: Subjects receiving stabilization splint (SS). The MRM was evaluated for each patient before treatment and after 6 months. Paired t test and one-way analysis of variance (ANOVA) tests were used for statistical analysis followed by a post hoc Tukey test (P ≤ 0.05). All groups showed significant improvement in MRM after 6 months of treatment (P ≤ 0.05) except for BT. There was a significant improvement for SS and MARS on the different movements of MRM, more than for LLLT and BT (P ≤ 0.05). The MARS and the SS are effective in increasing the MRM for patients with ADDwR.