Interdisciplinary Approach to the Temporomandibular Joint Osteoarthritis-Review of the Literature

A customized guide device for single needle arthrocentesis on temporomandibular joint

Objectives

: This study aims to evaluate the accuracy and effectiveness of temporomandibular joint (TMJ) arthrocentesis using the three-dimensional (3D)-printed TMJ injection guide in cases of hemarthrosis caused by condyle fractures.

Materials and Methods

: A retrospective chart review was conducted for patients treated with the customized TMJ arthrocentesis guide to address hemarthrosis. Inclusion criteria included adults older than 18 years with condylar fractures not indicated for open reduction and internal fixation. The guide was fabricated using computed tomography or cone-beam computed tomography scans and 3D printing to control the degree and depth of the needle through the guide to aspirate hemarthrosis.

Results

: Six joints from five patients (average age 52.4 years) were treated using the guide. Post-procedural magnetic resonance imaging confirmed complete resolution of hemarthrosis in all cases. A representative case demonstrated successful outcomes with normal healing and no complications at 8 months post-procedure.

Conclusion

: The customized TMJ injection guide, using ear-based reference points, significantly enhances the accuracy and safety of TMJ arthrocentesis. This innovation is expected to increase the accessibility and effectiveness of TMJ-related treatments for clinicians without specialized TMJ expertise.

Quality, reliability, and content on social media about temporomandibular joint disorders: A systematic review

OBJECTIVE

This systematic review aims to assess the quality, reliability, and content of TMD-related social media posts across multiple platforms.

METHODS

A comprehensive search of three databases were conducted. TMD related content on social media sites were considered eligible. The extracted data was narratively synthesized.

RESULTS

Out of 254 studies, seven were included. YouTube was the most commonly assessed social media platform (n=5). Information created by amateurs encourages greater interaction than that of experts or news outlets. A majority videos and threads cover treatment choices. However, there is a noticeable absence of discussion on complications and prevention methods. Health professionals' videos scored better in quality and reliability than -professionals' videos.

CONCLUSION

There is a need for creating evidence-based, accessible, and engaging content on TMD on social media and consideration of implementing rigorous information verification methods to ensure that high-quality, expert-validated content is prioritized in search results.

Does intra-articular injection of PRP help patients with temporomandibular joint osteoarthritis after joint puncture? a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

The aim of this study is to conduct a systematic review to evaluate whether intra-articular injection of platelet-rich plasma (PRP) after joint puncture can aid in the recovery of patients with temporomandibular joint osteoarthritis (TMJOA).

METHODS

We searched PubMed, Cochrane Library, Embase and Web of Science as of March 3, 2024. Retrieved a total of 392 articles. We included all published randomized controlled trials (RCTs). All RCTs, including studies on PRP injection after joint puncture in patients with TMJOA. The primary outcome was pain reduction, and the secondary outcome was the improvement of maximal mouth opening (MMO) and joint sounds. All outcome measures were analyzed by calculating the standardized mean differences (SMDs) and 95% confidence intervals (CIs).

RESULTS

A total of 392 articles were retrieved, and ultimately, 6 articles met the inclusion criteria. The study involved 199 TMJOA patients. The results indicated that compared to the control group, PRP injection after joint puncture showed significant improvements in alleviating pain (SMD =-0.99; 95% CI =-1.35 ~-0.63; P <0.00001, I2 = 59%) and MMO (SMD = 0.63; 95% CI = 0.30 ~ 0.95; P <0.0002, I2 = 54%) among TMJOA patients. However, there was no significant improvement observed in terms of joint sounds (SMD =-0.34; 95% CI = -0.71 ~ 0.02; P = 0.06, I2 = 0%) with the PRP.

CONCLUSIONS

Compared to joint puncture alone, the intra-articular injection of PRP after joint puncture was more effective in relieving pain. At 1-month and 6-month follow-ups, patients in the PRP group showed significant improvements in MMO compared to the control group. However, after 12 months of follow-up, limited evidence indicated significant improvements in MMO and joint sounds.

The effect of Rsk2 on TNFα-mediated bone loss in the TMJ and craniofacial skeleton

OBJECTIVES

This study aims to investigate the impact of the pro-osteoblastogenic ERK-activated ribosomal S6 kinase (Rsk2) on Tumor necrosis factor (TNF)α-induced bone loss in the craniofacial system, focusing on its role in rheumatoid arthritis (RA). The objective is to understand whether Rsk2, previously shown to have protective effects in long bones against TNFα-induced bone resorption, exhibits similar effects in the craniofacial region.

MATERIALS

, and Methods. The study compares mice with TNFα overexpression, Rsk2 knockout mice, and a combination of TNFα, and Rsk2 knockout mice using detailed micro-computed tomography coupled with landmark based morphometric analysis, and classical histology. The overall skull morphology, mandible shape, and the temporomandibular joint were examined. Additionally, histological sections were utilized to examine the synovial membrane.

RESULTS

Combining TNFα, and Rsk2 deficiency does not further alter overall skull shape compared to TNFα alone. TNFα overexpression shortens the mandibular ramus, exacerbated by Rsk2 absence. Micro-computed tomography (µCT) reveals significant temporomandibular joint damage from TNFα, independent of Rsk2. However, histological sections show increased synovial membrane thickness with TNFα, heightened in the absence of Rsk2.

CONCLUSIONS

Rsk2 mitigates TNFα-induced effects on mandibular ramus length in the craniofacial system but has limited impact on the temporomandibular joint, except for synovial membrane thickness. Overall, Rsk2 demonstrates a weaker preventive effect on TNFα-induced craniofacial bone loss compared to its established role in the appendicular skeleton.

CLINICAL RELEVANCE

This study highlights regional differences in Rsk2's protective mechanisms, emphasizing the need for further exploration of the underlying mechanisms for these disparities. Understanding these regional differences can be crucial for the development of targeted therapeutic interventions.

Advanced progress of adipose-derived stem cells-related biomaterials in maxillofacial regeneration

The tissue injury in maxillofacial region affects patients' physical function and specific mental health. This decade, utilizing regenerative medicine to achieve tissue regeneration has been proved a hopeful direction. Seed cells play a vital role in regeneration strategy. Among various kinds of stem cells that effectively to regenerate the soft and hard tissue of maxillofacial region, adipose-derived stem cells (ADSCs) have gained increasing interests of researchers due to their abundant sources, easy availability and multi-differentiation potentials in recent decades. Thus, this review focuses on the advances of ADSCs-based biomaterial in maxillofacial regeneration from the progress and strategies perspective. It is structured as introducing the properties of ADSCs, biomaterials (polymers, ceramics and metals) within ADSCs and the latest applications of ADSCs in maxillofacial regeneration, including temporomandibular joint (TMJ), bone, periodontal tissue, tooth, nerve as well as cosmetic field. In order to further facilitate ADSCs-based therapies as an emerging platform for regenerative medicine, this review also emphasized current challenges in translating ADSC-based therapies into clinical application and dissussed the strategies to solve these obstacles.

Loss of SCRG1 in chondrocytes inhibits osteoarthritis by promoting autophagy activity in the temporomandibular joint through inhibition of neurokine receptors

BACKGROUND

To investigate in vitro how scrapie responsive gene 1 (SCRG1) contributes to the development of temporomandibular joint osteoarthritis (TMJOA).

METHODS

Western blotting was used to identify protein expression. Proinflammatory cytokine levels were assessed by means of an enzyme-linked immunosorbent test. In order to find out whether chondrocytes expressed protein light chain 3B (LC3B), immunofluorescence was utilized.

RESULTS

In the TMJOA in vitro model, hydrogen peroxide (H2O2) treatment increased the expression of SCRG1, stimulated chondrocyte catabolism and inflammatory response, and blocked autophagy. In chondrocytes, SCRG1 silencing reduces the inflammatory response, catabolism, and autophagy inhibition brought on by H2O2. Concurrently, H2O2 induction triggers the nuclear factor (NF)-κB pathway and nerve growth factor receptor (NGFR). When SCRG1 is downregulated, NGFR expression is inhibited and the NF-κB pathway is blocked.

CONCLUSIONS

By inhibiting NGFR and blocking the NF-κB pathway, knocking down SCRG1 can prevent H2O2-induced inflammatory response, metabolic breakdown and autophagy inhibition in chondrocytes.

Temporomandibular Internal Derangements Denote Activity of Axial Spondyloarthritis

Objectives

The group of spondyloarthritis (SpA) disorders shares common clinical manifestations, including internal derangement (ID) of temporomandibular joint (TMJ). This study aimed to investigate SpA activity in patients with ID of TMJ.

Materials and Methods

We assessed 200 patients with neck pain using the Assessment of Spondyloarthritis International Society (ASAS) criteria. TMJ was examined using Diagnostic Criteria for Temporomandibular Disorders (DC/TMD protocol). Patients with SpA were divided into three groups: symptomatic ID of TMJ, asymptomatic ID of TMJ, or healthy TMJ (controls). Activity of SpA was evaluated using the Ankylosing Spondylitis Disease Activity Score (ASDAS), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Disease Activity Index in Psoriatic Arthritis (DAPSA), patients' self-estimated SpA activity, difficulties in performing daily activities, pain intensity (visual analogue scale) and laboratory parameters.

Results

Patients with symptomatic and asymptomatic ID showed statistically significantly increased ASDAS, anti-streptolysin titer, patients' self-estimated axial pain and activity of SpA, and decreased hematocrit than the control. Patients with symptomatic ID also had statistically significant earlier onset of SpA, along with increased BASDAI and DAPSA, total body pain, difficulties in performing daily activities, platelet count, and serum alpha-amylase but lower hemoglobin concentration than controls. Patients with asymptomatic ID had higher frequencies of exacerbated axial SpA and sacroiliac joint ankylosis compared to the control.

Conclusion

All patients with SpA and ID showed increased axial disease activity.

Fostamatinib alleviates temporomandibular joint osteoarthritis by maintaining cartilage homeostasis through MAPK/NF-κB and AKT/mTOR pathways

Temporomandibular joint osteoarthritis (TMJ OA) is a common degenerative disease characterized by cartilage degeneration. However, the therapeutic strategies aimed to maintain cartilage homeostasis remain unclear. Fostamatinib (Fos) is a potential clinical drug for rheumatoid arthritis (RA) and predicted as target drug for many inflammatory diseases. In this study we investigated the therapeutic effects of Fos for TMJ OA and underlying mechanisms. Interleukin-1β (IL-1β) was used to construct a condylar chondrocyte injury model in vitro and rat TMJ OA models were induced by unilateral anterior crossbite (UAC) in vivo. Subsequently, a series of experiments were performed to assess the therapeutic effects and potential mechanisms of Fos in TMJ OA. Herein, we verified that Fos improved IL-1β-induced decrease in chondrocyte viability and proliferation, as well as inhibited cell apoptosis. Additionally, Fos could alleviate IL-1β-induced inflammation, ECM degradation, and chondrocyte phenotype change through blocking MAPK/NF-κB pathways, as well as promote chondrocyte autophagy by regulating AKT/mTOR pathways. The therapeutic effects of Fos on TMJ OA were further validated through rat UAC model in vivo. Overall, Fos could maintaining cartilage homeostasis through regulating chondrocyte inflammation, ECM degradation, and abnormal cell biological behaviors (apoptosis and autophagy), which made it a promising small molecule drug for TMJ OA early intervention.

N-methyl-D-aspartate Receptor Subunits 2A and 2B Mediate Connexins and Pannexins in the Trigeminal Ganglion Involved in Orofacial Inflammatory Allodynia during Temporomandibular Joint Inflammation

Temporomandibular joint osteoarthritis (TMJOA) is a severe form of temporomandibular joint disorders (TMD), and orofacial inflammatory allodynia is one of its common symptoms which lacks effective treatment. N-methyl-D-aspartate receptor (NMDAR), particularly its subtypes GluN2A and GluN2B, along with gap junctions (GJs), are key players in the mediation of inflammatory pain. However, the precise regulatory mechanisms of GluN2A, GluN2B, and GJs in orofacial inflammatory allodynia during TMJ inflammation still remain unclear. Here, we established the TMJ inflammation model by injecting Complete Freund's adjuvant (CFA) into the TMJ and used Cre/loxp site-specific recombination system to conditionally knock out (CKO) GluN2A and GluN2B in the trigeminal ganglion (TG). Von-frey test results indicated that CFA-induced mechanical allodynia in the TMJ region was relieved in GluN2A and GluN2B deficient mice. In vivo, CFA significantly up-regulated the expression of GluN2A and GluN2B, Gjb1, Gjb2, Gjc2 and Panx3 in the TG, and GluN2A and GluN2B CKO played different roles in mediating the expression of Gjb1, Gjb2, Gjc2 and Panx3. In vitro, NMDA up-regulated the expression of Gjb1, Gjb2, Gjc2 and Panx3 in satellite glial cells (SGCs) as well as promoted the intercellular communication between SGCs, and GluN2A and GluN2B knocking down (KD) altered the expression and function differently. NMDAR regulated Gjb1 and Panx3 through ERK1/2 pathway, and mediated Gjb2 and Gjc2 through MAPK, PKA, and PKC intracellular signaling pathways. These findings shed light on the distinct functions of GluN2A and GluN2B in mediating peripheral sensitization induced by TMJ inflammation in the TG, offering potential therapeutic targets for managing orofacial inflammatory allodynia.

Controlled Release of Human Dental Pulp Stem Cell-Derived Exosomes from Hydrogels Attenuates Temporomandibular Joint Osteoarthritis

Temporomandibular joint osteoarthritis (TMJOA) is a painful inflammatory condition that limits mouth opening. Cell-derived exosomes, which have anti-inflammatory effects, are emerging as a treatment for TMJOA. Injection of dental pulp stem cells (DPSCs), which secrete exosomes, can moderate tissue damage in a rat model of TMJOA. However, injected exosomes are quickly cleared, necessitating repeated injections for therapeutic efficacy. Here, vinyl sulfone-modified hyaluronic acid (HA-VS) hydrogels, suitable for encapsulating exosomes are formulated. HA-VS hydrogels degrade in the presence of hyaluronidase and allow for the release of beads of similar size to exosomes over 3 to 6 days. In a rat model of TMJOA, injection of exosomes or exosomes within HA-VS hydrogels significantly attenuated damage-mediated subchondral bone loss as determined by micro-computed tomography, and reduced inflammatory and tissue damage scores as assessed by histology. Overall, DPSCs-derived exosomes attenuated joint damage, but treatment with exosomes within HA-VS hydrogels shows additional protective effects on subchondral bone maintenance and integrity. These findings confirm the protective effects of DPSCs-derived exosomes in moderating tissue damage in TMJOA and suggest that combining exosomes with HA hydrogels can further promote their therapeutic effects.

A clinical trial of ropivacaine in arthocentesis for TMD

INTRODUCTION

This study aims to compare the efficacy of ropivacaine and lidocaine in the treatment of temporomandibular joint (TMJ) disorders, with the goal of exploring a more effective treatment for TMJ disorders.

METHODS

Patients with Wilkes stage III and IV unilateral TMJ disorders were enrolled in the study. 0.5% ropivacaine was used for local anesthesia in group A, 2% lidocaine was used in group B. Sodium hyaluronate was injected after supra-articular lavage in both groups. The patients' general conditions, pain scores, and maximum opening before and after treatment were collected, the time of onset and maintenance of anesthesia, and the levels of inflammatory factors IL-1β and IL-6 in the joint lavage fluid were detected.

RESULTS

Study showed that the onset of anesthesia was faster and longer maintained in group A. The decrease in IL-1β was more pronounced in group A (16.08 ± 3.10) than in group B (18.03 ± 2.84), p < 0.05. At 2 months after treatment, the joint clicking rate was higher in group A (75%) compared to group B (35%), p < 0.05. At 3 months after treatment, the joint clicking rate was higher in group A (76.69%) compared to group B (40%) and the maximum mouth opening was greater in group A (45.00 ± 2.38) compared to group B (41.73 ± 4.18), p < 0.05. There were no statistically significant differences in VAS score and lateral excursion in group A compared with group B at 2 months and 3 months after treatment.

CONCLUSIONS

Compared with lidocaine, the application of ropivacaine combined with sodium hyaluronate supra-articular lavage for the treatment of temporomandibular joint disorder is more clinically effective.

CLINICAL TRIALS REGISTRATION NUMBER

ChiCTR2300075241 (30/08/2023).

Correlations of temporomandibular joint morphology and position using cone-beam computed tomography and dynamic functional analysis in orthodontic patients: A cross-sectional study

Objective

To correlate temporomandibular joint (TMJ) morphology and position with cone-beam computed tomography (CBCT) images, Joint Vibration Analysis (JVA), and Jaw Tracker (JT) to develop a radiation-free, dynamic method for screening and monitoring the TMJ in orthodontic patients.

Methods

A total of 236 orthodontic patients without symptoms of TMJ disorders who had undergone CBCT were selected for the JVA and JT tests in this cross-sectional study. TMJ position and morphology were measured using a three-dimensional analysis software. JT measurements involved six opening-closing cycles, and JVA measurements were performed using a metronome to guide the mouth opening-closing movements of the patients. The correlations among the three measuring devices were evaluated.

Results

Abnormalities in condylar surface morphology affected the mandibular range of motion. The cut-off value results show that when various measurement groups are within a certain range, abnormalities may be observed in morphology (area under the curve, 0.81; P < 0.001). A 300/< 300 Hz ratio ≥ 0.09 suggested abnormal morphology (P < 0.05). Correlations were observed among the maximum opening velocity, maximum vertical opening position, and joint spaces in the JT measurements. Correlations were also observed between the > 300/< 300 Hz ratio, median frequency, total integral, integral < 300 Hz, and peak frequency with joint spaces in the JVA measurements.

Conclusions

JT and JVA may serve as rapid, non-invasive, and radiation-free dynamic diagnostic tools for monitoring and screening TMJ abnormalities before and during orthodontic treatment.

Condylar Remodeling and Skeletal Changes Following Occlusal Splint and Manual Therapy: A Cone Beam Computed Tomography Study in Temporomandibular Disorders

Background: Temporomandibular disorders (TMD) may be associated with degenerative disease of temporomandibular joint (TMJ), such as condyle erosion and subchondral cysts. Occlusal splint and cranio-mandibular manual therapy, or combined therapy, is recommended as a conservative treatment to alleviate pain-related signs and symptoms in TMD. This study aimed to assess osseous condylar changes and skeletal changes following occlusal splint and cranio-mandibular manual therapy in TMD using cone beam computed tomography (CBCT). Methods: A retrospective cohort study included 24 patients diagnosed with TMD. Combined therapy was performed until pain-related signs and symptoms disappeared. CBCT scans were performed before and after therapy. Osseous structure of condyles and their subsequent modifications were analyzed on CBCT images: flattening, erosion, and subchondral cyst. Sella-Nasion-A point (SNA), Sella-Nasion-B point (SNB), A point-Nasion-B point (ANB), Sella-Articulare-Gonion (Condylar angle), and anterior and posterior facial height (AFH, PFH) were measured on CBCT-generated lateral cephalograms. A paired t-test, Wilcoxon rank-sum test, McNemar test, and Stuart-Maxwell test were used for the statistical analyses. Results: The treatment period with combined therapy was 7.42 ± 3.27 months, and 21 out of 33 TMJ presenting degenerative disease (63.6%) had significant complete remodeling (p < 0.05). Following therapy, SNB significantly decreased from 75.61 ±3.47° to 74.82 ± 3.41° (p = 0.02), ANB significantly increased from 4.05° (3.35-4.9°) to 4.8° (3.3-6.12°) (p < 0.001), AFH significantly increased from 112.85 mm (109.28-118.72) to 115.3 mm (112.58-118.88) (p < 0.001), PFH/AFH significantly decreased from 64.17 (61.39-66.1) to 63 (59.68-64.51) (p = 0.012), and condylar angle significantly increased from 140.84 ± 8.18° to 144.42 ± 8.87° (p = 0.007). Conclusion: Combined therapy promoted significant condylar remodeling in TMJ degenerative disease, along with skeletal changes (mandibular retrusion and increase in facial height). Therapeutic strategies should consider condylar remodeling in TMD. Skeletal and dental parameters should be evaluated prior to occlusal splint therapy.

Hyaluronic Acid-Based Microparticles with Lubrication and Anti-Inflammation for Alleviating Temporomandibular Joint Osteoarthritis

The pathogenesis of temporomandibular joint osteoarthritis (TMJOA) is closely associated with mechanical friction, which leads to the up-regulation of inflammatory mediators and the degradation of articular cartilage. Injectable drug-loaded microparticles have attracted widespread interest in intra-articular treatment of TMJOA by providing lubrication and facilitating localized drug delivery. Herein, a hyaluronic acid-based microparticle is developed with excellent lubrication properties, drug loading capacity, antioxidant activity, and anti-inflammatory effect for the treatment of TMJOA. The microparticles are facilely prepared by the self-assembly of 3-aminophenylboronic acid-modified hyaluronic acid (HP) through hydrophobic interaction in an aqueous solution, which can further encapsulate diol-containing drugs through dynamic boronate ester bonds. The resulting microparticles demonstrate excellent injectability, lubrication properties, radical scavenging efficiency, and antibacterial activity. Additionally, the drug-loaded microparticles exhibit a favorable cytoprotective effect on chondrocyte cells in vitro under an oxidative stress microenvironment. In vivo experiments validate that intra-articular injection of drug-loaded microparticles effectively alleviates osteoporosis-like damage, suppresses inflammatory response, and facilitates matrix regeneration in the treatment of TMJOA. The HP microparticles demonstrate excellent injectability and encapsulation capacity for diol-containing drugs, highlighting its potential as a versatile drug delivery vehicle in the intra-articular treatment of TMJOA.

Interprofessional care for temporomandibular joint disorders: the patient's perspective

The Indiana University School of Dentistry TMJ Institute is a multidisciplinary clinic designed to support the management of patients with challenging temporomandibular disorders. Professionals across dentistry, medicine, physical therapy, and social work collaborate to create a customised, interprofessional consensus to patient care. Compared with traditional, siloed healthcare models, are patients diagnosed with TMJ dysfunction satisfied with the quality of care received from an interprofessional approach? The objective of this study is to determine the level of patient satisfaction at the Institute using a 5-Point Likert scale patient questionnaire. A total of 93 questionnaires were distributed and 84 were collected. A total of 43% of patients travelled over 50 miles to be seen at the Institute. 'Strongly agree' was the most selected response for each prompt. The exception was whether patients preferred to meet with each clinician individually, to which 'strongly disagree' or 'disagree' was the most popular response, indicating that an interprofessional approach was preferred. The results and comments provided by patients revealed that most patients diagnosed with TMJ dysfunction were highly satisfied with the interprofessional approach used at the TMJ Institute. Our study suggests that positive patient satisfaction is an important factor in assessing the quality and efficacy of interprofessional, patient-centred clinic models.

17β-estradiol promotes the progression of temporomandibular joint osteoarthritis by regulating the FTO/IGF2BP1/m6A-NLRC5 axis

BACKGROUND

Temporomandibular joint osteoarthritis (TMJOA) is a degenerative cartilage disease. 17β-estradiol (E2) aggravates the pathological process of TMJOA; however, the mechanisms of its action have not been elucidated. Thus, we investigate the influence of E2 on the cellular biological behaviors of synoviocytes and the molecular mechanisms.

METHODS

Primary fibroblast-like synoviocytes (FLSs) isolated from rats were treated with TNF-α to establish cell model, and phenotypes were evaluated using cell counting kit-8, EdU, Tanswell, enzyme-linked immunosorbent assay, and quantitative real-time PCR (qPCR). The underlying mechanism of E2, FTO-mediated NLRC5 m6A methylation, was assessed using microarray, methylated RNA immunoprecipitation, qPCR, and western blot. Moreover, TMJOA-like rat model was established by intra-articular injection of monosodium iodoacetate (MIA), and bone morphology and pathology were assessed using micro-CT and H&E staining.

RESULTS

The results illustrated that E2 facilitated the proliferation, migration, invasion, and inflammation of TNF-α-treated FLSs. FTO expression was downregulated in TMJOA and was reduced by E2 in FLSs. Knockdown of FTO promoted m6A methylation of NLRC5 and enhanced NLRC5 stability by IGF2BP1 recognition. Moreover, E2 promoted TMJ pathology and condyle remodeling, and increased bone mineral density and trabecular bone volume fraction, which was rescued by NLRC5 knockdown.

CONCLUSION

E2 promoted the progression of TMJOA.

Correlation Between Radiological Changes of the Temporomandibular Joint and Upper Cervical Vertebrae in Degenerative Joint Disease: A Cone-Beam Computed Tomography-Based Analytical Study

Objectives This study was conducted to assess the radiological changes of the temporomandibular joint (TMJ) and cervical vertebrae individually and their correlation in degenerative joint disease (DJD) using a cone-beam computed tomography (CBCT)-based approach. Methodology The study employed a cross-sectional, analytical retrospective design, analyzing one-year data. CBCT scans of 60 patients (120 TMJs) were assessed for degenerative changes using standardized imaging parameters. Eligibility criteria included full field-of-view CBCT scans, excluding those with craniofacial anomalies or prior orthodontic treatment. Radiological assessments of TMJs and cervical vertebrae were conducted by experienced radiologists using the Anjos Pontual method and novel grading system (TMJ Spine Degenerative Severity Index). Results The study included 60 CBCT scans (120 joints), with 31.7% males and 68.3% females. Participants were predominantly aged 31-60 years (58.3%). DJD findings for the right TMJ showed grade 1 changes in 55.0% and grade 2 in 31.7%, while the left TMJ had 46.7% grade 1 and 35.0% grade 2 changes. A strong positive correlation (0.704) was found between bilateral TMJ and cervical vertebrae changes. Age correlated significantly with TMJ alterations but not with cervical vertebrae changes. Conclusion This study demonstrated that there exists a positive association between the radiological changes of TMJ and cervical vertebrae in DJD with age, which can be detected in mild stage of severity on CBCT and can be of use in clinical correlation and application of optimal interventions ensuring better prognosis.

Circadian rhythm disruption upregulating Per1 in mandibular condylar chondrocytes mediating temporomandibular joint osteoarthritis via GSK3β/β-CATENIN pathway

BACKGROUND

Temporomandibular joint osteoarthritis (TMJOA) has a high incidence rate, but its pathogenesis remains unclear. Circadian rhythm is an important oscillation in the human body and influences various biological activities. However, it is still unclear whether circadian rhythm affects the onset and development of TMJOA.

METHODS

We disrupted the normal rhythm of rats and examined the expression of core clock genes in the mandibular condylar cartilage of the jaw and histological changes in condyles. After isolating rat mandibular condylar chondrocytes, we upregulated or downregulated the clock gene Per1, examined the expression of cartilage matrix-degrading enzymes, tested the activation of the GSK3β/β-CATENIN pathway and verified it using agonists and inhibitors. Finally, after downregulating the expression of Per1 in the mandibular condylar cartilage of rats with jet lag, we examined the expression of cartilage matrix-degrading enzymes and histological changes in condyles.

RESULTS

Jet lag led to TMJOA-like lesions in the rat mandibular condyles, and the expression of the clock gene Per1 and cartilage matrix-degrading enzymes increased in the condylar cartilage of rats. When Per1 was downregulated or upregulated in mandibular condylar chondrocytes, the GSK3β/β-CATENIN pathway was inhibited or activated, and the expression of cartilage matrix-degrading enzymes decreased or increased, which can be rescued by activator and inhibitor of the GSK3β/β-CATENIN pathway. Moreover, after down-regulation of Per1 in mandibular condylar cartilage in vivo, significant alleviation of cartilage degradation, cartilage loss, subchondral bone loss induced by jet lag, and inhibition of the GSK3β/β-CATENIN signaling pathway were observed. Circadian rhythm disruption can lead to TMJOA. The clock gene Per1 can promote the occurrence of TMJOA by activating the GSK3β/β-CATENIN pathway and promoting the expression of cartilage matrix-degrading enzymes. The clock gene Per1 is a target for the prevention and treatment of TMJOA.

Image preprocessing with contrast-limited adaptive histogram equalization improves the segmentation performance of deep learning for the articular disk of the temporomandibular joint on magnetic resonance images

OBJECTIVES

The objective was to evaluate the robustness of deep learning (DL)-based encoder-decoder convolutional neural networks (ED-CNNs) for segmenting temporomandibular joint (TMJ) articular disks using data sets acquired from 2 different 3.0-T magnetic resonance imaging (MRI) scanners using original images and images subjected to contrast-limited adaptive histogram equalization (CLAHE).

STUDY DESIGN

In total, 536 MR images from 49 individuals were examined. An expert orthodontist identified and manually segmented the disks in all images, which were then reviewed by another expert orthodontist and 2 expert oral and maxillofacial radiologists. These images were used to evaluate a DL-based semantic segmentation approach using an ED-CNN. Original and preprocessed CLAHE images were used to train and validate the models whose performances were compared.

RESULTS

Original and CLAHE images acquired on 1 scanner had pixel values that were significantly darker and with lower contrast. The values of 3 metrics-the Dice similarity coefficient, sensitivity, and positive predictive value-were low when the original MR images were used for model training and validation. However, these metrics significantly improved when images were preprocessed with CLAHE.

CONCLUSIONS

The robustness of the ED-CNN model trained on a dataset obtained from a single device is low but can be improved with CLAHE preprocessing. The proposed system provides promising results for a DL-based, fully automated segmentation method for TMJ articular disks on MRI.

Applications of hydrogels in tissue-engineered repairing of temporomandibular joint diseases

Epidemiological studies reveal that symptoms of temporomandibular joint disorders (TMDs) occur in 60-70% of adults. The inflammatory damage caused by TMDs can easily lead to defects in the articular disc, condylar cartilage, subchondral bone and muscle of the temporomandibular joint (TMJ) and cause pain. Despite the availability of various methods for treating TMDs, few existing treatment schemes can achieve permanent recovery. This necessity drives the search for new approaches. Hydrogels, polymers with high water content, have found widespread use in tissue engineering and regeneration due to their excellent biocompatibility and mechanical properties, which resemble those of human tissues. In the context of TMD therapy, numerous experiments have demonstrated that hydrogels show favorable effects in aspects such as articular disc repair, cartilage regeneration, muscle repair, pain relief, and drug delivery. This review aims to summarize the application of hydrogels in the therapy of TMDs based on recent research findings. It also highlights deficiencies in current hydrogel research related to TMD therapy and outlines the broad potential of hydrogel applications in treating TMJ diseases in the future.

Challenges in Optimizing Nanoplatforms Used for Local and Systemic Delivery in the Oral Cavity

In this study, we focused on innovative approaches to improve drug administration in oral pathology, especially by transmucosal and transdermal pathways. These improvements refer to the type of microneedles used (proposing needles in the saw), to the use of certain enhancers such as essential oils (which, besides the amplifier action, also have intrinsic actions on oral health), to associations of active substances with synergistic action, as well as the use of copolymeric membranes, cemented directly on the tooth. We also propose a review of the principles of release at the level of the oral mucosa and of the main release systems used in oral pathology. Controlled failure systems applicable in oral pathology include the following: fast dissolving films, mucoadhesive tablets, hydrogels, intraoral mucoadhesive films, composite wafers, and smart drugs. The novelty elements brought by this paper refer to the possibilities of optimizing the localized drug delivery system in osteoarthritis of the temporomandibular joint, neuropathic pain, oral cancer, periodontitis, and pericoronitis, as well as in maintaining oral health. We would like to mention the possibility of incorporating natural products into the controlled failure systems used in oral pathology, paying special attention to essential oils.

TRIM52 knockdown inhibits proliferation, inflammatory responses and oxidative stress in IL-1β-induced synovial fibroblasts to alleviate temporomandibular joint osteoarthritis

To explore the mechanism of tripartite motif 52 (TRIM52) in the progression of temporomandibular joint osteoarthritis (TMJOA). Gene and protein expression were tested by quantitative real-time polymerase chain reaction and western blot, respectively. The levels of pro-inflammatory cytokines and oxidative stress factors were evaluated using enzyme-linked immunosorbent assay and biochemical kit, respectively. Cell counting kit-8 and 5-ethynyl-2'-deoxyuridine assays were carried out to assess cell proliferation. Immunofluorescence was used to detect the expression of CD68 and Vimentin in primary synovial fibroblasts (SFs). Haematoxylin and eosin staining and Safranin O/Fast green were used to evaluate the pathological damage of synovial and cartilage tissue in rats. TRIM52 was upregulated in the synovial tissue and SFs in patients with TMJOA. Interleukin (IL)-1β treatment upregulated TRIM52 expression in TMJOA SFs and normal SF (NSF), promoting cell proliferation, inflammatory response and oxidative stress in NSF, SFs. Silence of TRIM52 relieved the cell proliferation, inflammatory response and oxidative stress induced by IL-1β in SFs, while overexpression of TRIM52 enhanced IL-1β induction. Meanwhile, IL-1β induction activated toll-like receptor 4 (TLR4)/nuclear factor (NF)-κB pathway, which was augmented by upregulation of TRIM52 in NSF, and was attenuated by TRIM52 knockdown in SFs. Besides, pyrrolidinedithiocarbamic acid ameliorated IL-1β-induced proliferation and inflammatory response by inhibiting TLR4/NF-κB signalling. Meanwhile, TRIM52 knockdown inhibited cell proliferation, oxidative stress and inflammatory response in IL-1β-induced SFs through downregulation of TLR4. TRIM52 promoted cell proliferation, inflammatory response, and oxidative stress in IL-1β-induced SFs. The above functions were mediated by the activation of TLR4/NF- κB signal pathway.

Ginsenoside Rg1/ADSCs supplemented with hyaluronic acid as the matrix improves rabbit temporomandibular joint osteoarthrosis

OBJECTIVE

To investigate whether and how ginsenoside Rg1/ADSCs supplemented with hyaluronic acid as the matrix can improve rabbit temporomandibular joint osteoarthrosis.

METHOD

Isolate and culture adipose stem cells, measure the activity of differentiated chondrocytes by MTT assay and expression of type II collagen in these cells by immunohistochemistry, in order to evaluate the effect of ginsenoside Rg1 on adipose stem cell proliferation and differentiation into chondrocytes.32 New Zealand white rabbits were randomly divided into four groups: blank group, model group, control group and experimental group, 8 in each group. Osteoarthritis model was established by intra-articular injection of papain. Two weeks after successful model building, medication was given for the rabbits in control group and experimental group. 0.6 mL ginsenoside Rg1/ ADSCs suspension was injected into superior joint space for the rabbits in control group, once a week; 0.6 mL ginsenoside Rg1/ ADSCs complex was injected for the rabbits in experimental group, once a week.

RESULTS

Ginsenoside Rg1 can promote ADSCs-derived chondrocytes' activity and expression of type II collagen. Scanning electron microscopy histology images showed cartilage lesions of the experimental group was significantly improved in comparison with control group.

CONCLUSION

Ginsenoside Rg1 can promote ADSCs differentiate into chondrocytes, and Ginsenoside Rg1/ADSCs supplemented with hyaluronic acid as the matrix can significantly improve rabbit temporomandibular joint osteoarthrosis.

Alleviation of temporomandibular joint osteoarthritis by targeting RIPK1-mediated inflammatory signalling

Temporomandibular joint osteoarthritis (TMJOA), prevalent in adolescents and the elderly, has serious physical and psychological consequences. TMJOA is a degenerative disease of the cartilage and bone, mostly driven by inflammation, and synoviocytes are the first and most important inflammatory factor releasers. Receptor-interacting serine/threonine-protein kinase (RIPK1) promotes inflammatory response and cell death during an array of illnesses. This research aimed to explore the impacts of RIPK1 inhibitor therapy in TMJOA and the mechanism of RIPK1 in inducing inflammation during TMJOA. Herein, inhibition of RIPK1 suppressed the elevated levels of inflammatory factors, nuclear factor kappa B (NF-κB), along with markers of apoptosis and necroptosis after tumour necrosis factor (TNF)-α/cycloheximide (CHX) treatment in synoviocytes. Moreover, inflammation models were constructed in vivo through complete Freund's adjuvant (CFA) induction and disc perforation, and the findings supported that RIPK1 inhibition protected TMJ articular cartilage against progressive degradation. RIPK1 regulates NF-κB activation via cellular inhibitor of apoptosis proteins (cIAP), apoptosis via caspase-8, and necroptosis via RIPK3/mixed lineage kinase domain-like (MLKL) in synoviocytes, which in turn facilitates TMJOA inflammation progression.

Equine Models of Temporomandibular Joint Osteoarthritis: A Review of Feasibility, Biomarkers, and Molecular Signaling

Osteoarthritis (OA) of the temporomandibular joint (TMJ) occurs spontaneously in humans and various animal species, including horses. In humans, obtaining tissue samples is challenging and clinical symptoms appear late in the disease progression. Therefore, genetically modified, induced, and naturally occurring animal models play a crucial role in understanding the pathogenesis and evaluating potential therapeutic interventions for TMJ OA. Among the naturally occurring models, the equine TMJ OA model is characterized by slow, age-related progression, a wide range of clinical examinations, and imaging modalities that can be performed on horses, as well as easy tissue and synovial fluid collection. The morphological and functional similarities of TMJ structures in both species make the equine model of TMJ OA an excellent opportunity to track disease progression and response to treatment. However, much work remains to be carried out to determine the utility of human TMJ OA biomarkers in horses. Among the main TMJ OA biomarkers, IL-1, IL-6, TGF-β, TNF-α, and PGE2 have been recently investigated in the equine model. However, the majority of biomarkers for cartilage degradation, chondrocyte hypertrophy, angiogenesis, and TMJ overload-as well as any of the main signaling pathways-have not been studied so far. Therefore, it would be advisable to focus further research on equine specimens, considering both mediators and signaling.

AI in Orthodontics: Revolutionizing Diagnostics and Treatment Planning-A Comprehensive Review

The advent of artificial intelligence (AI) in medicine has transformed various medical specialties, including orthodontics. AI has shown promising results in enhancing the accuracy of diagnoses, treatment planning, and predicting treatment outcomes. Its usage in orthodontic practices worldwide has increased with the availability of various AI applications and tools. This review explores the principles of AI, its applications in orthodontics, and its implementation in clinical practice. A comprehensive literature review was conducted, focusing on AI applications in dental diagnostics, cephalometric evaluation, skeletal age determination, temporomandibular joint (TMJ) evaluation, decision making, and patient telemonitoring. Due to study heterogeneity, no meta-analysis was possible. AI has demonstrated high efficacy in all these areas, but variations in performance and the need for manual supervision suggest caution in clinical settings. The complexity and unpredictability of AI algorithms call for cautious implementation and regular manual validation. Continuous AI learning, proper governance, and addressing privacy and ethical concerns are crucial for successful integration into orthodontic practice.

Age and Gender-related Morphometric Assessment and Degenerative Changes of Temporomandibular Joint in Symptomatic Subjects and Controls using Cone Beam Computed Tomography (CBCT): A Comparative Analysis

BACKGROUND

The temporomandibular joint diseases have been associated with various predisposing factors. Joint spaces, articular eminence height and inclination, and the shapes of the condylar and glenoid fossa have all been shown to vary in temporomandibular joint diseases (TMD) patients. Advanced imaging techniques like cone beam computed tomography (CBCT) have been employed to estimate these parameters.

AIMS AND OBJECTIVES

The aim of the current study was to investigate the condylar morphology, condylar and glenoid fossa shapes, and assessment of joint spaces, such as anterior, posterior, superior, lateral, and medial spaces, through CBCT slices in coronal and sagittal planes and compare them between the control group and TMD group.

MATERIALS AND METHODS

A cross-sectional study was planned where 80 joints in 40 patients were assessed for the above parameters; group I consisted of healthy patients, and group II included those with temporomandibular joint diseases (TMDs). The articular eminence height and inclination were assessed on the midsagittal section. The condylar changes and shapes of the glenoid fossa and condyles, as well as the joint spaces, were assessed on the selected coronal and sagittal sections.

RESULTS

The condylar fossa had a triangular shape in the TMJ group and an oval shape in the control group. The results were highly significant (P = 0.000**). A highly significant difference in morphological parameters, such as AJS, PJS, SJS, MJS, LJS, articular eminence height, and inclination, was found between the two groups (P = 0.000**). The association of morphological parameters, such as AJS, PJS, SJS, MJS, LJS, and articular eminence height and inclination were compared with condylar and glenoid fossa shapes, where the association of superior joint space and articular eminence inclination was observed. A highly significant difference was noted between the two groups with regard to all the parameters with P=0.00*.

CONCLUSION

The articular eminence inclination, as well as the superior joint space, were found to be associated with the glenoid and condyle fossa shapes in the TMJ group. These observations would, therefore, help in the early diagnosis of temporomandibular joint diseases.

Clock gene Per1 regulates rat temporomandibular osteoarthritis through NF-κB pathway: an in vitro and in vivo study

PURPOSE

Temporomandibular joint osteoarthritis (TMJOA) is a common disease that negatively affects the life quality of human beings. Circadian rhythm acts an important role in life activities. However, whether the clock genes are rhythmic expressed in mandibular condylar chondrocytes, or the clock genes have an effect on the progression of TMJOA remains unknown. In this study, we aim to explore expression of clock genes and regulatory mechanism of TMJOA in rat mandibular condylar chondrocytes.

METHODS

After synchronized by dexamethasone, the expression of core clock genes Per1, Per2, Clock, Cry1, Cry2 and Bmal1 and cartilage matrix degrading factor gene Mmp13 were analyzed in mandibular condylar chondrocytes every 4 h with RT-qPCR. The mandibular condylar chondrocytes were stimulated with IL-1β, and expression of Per1, Mmp13, P65 and p-P65 was assessed by RT-qPCR and Western blot. Sh-Per1 lentivirus was used to assess the effect of clock gene Per1 in IL-1β-induced chondrocytes, and expression of Mmp13, P65 and p-P65 was measured. After establishing a rat TMJOA model using unilateral anterior crossbite (UAC), micro-CT, H & E, Alcian Blue & Nuclear Fast Red and Safranin O & Fast Green, cartilage thickness was utilized to assess the damage of cartilage and subchondral bone. Immunohistochemistry of PER1, MMP13 and P65 was performed in condylar sections.

RESULTS

All core clock genes and Mmp13 were rhythmically expressed. And Mmp13 expression curve was closed in phase and amplitude with Per1. After stimulation with IL-1β, the expression of MMP13, PER1 and P65 and ratio of p-P65/P65 increased in condylar chondrocytes. After Per1 was down-regulated in condylar chondrocytes, the expression of MMP13 and P65 and ratio of p-P65/P65 decreased. Compared with the condyles of Sham group, the bony parameters of UAC group were significantly worse. The thickness of cartilage in UAC group significantly reduced. The modified Mankin scores and the expression of PER1, MMP13 and P65 in cartilage of UAC group significantly increased compared with Sham group.

CONCLUSION

Core clock genes and Mmp13 are rhythmic expressed in rat mandibular condylar chondrocytes. PER1 can regulate the expression of MMP13 through NF-κB pathway in IL-1β-induced mandibular condylar chondrocytes.

A Patient with Moderate-to-Severe Temporomandibular Joint Degenerative Joint Disease and Unilateral Joint Pain Presents for Oral Medicine Consult

A patient presents with severe one-sided temporomandibular joint (TMJ) pain. Workup reveals a diagnosis of TMJ degenerative joint disease, articular disc disorder with reduction, and myofascial pain of the muscles of mastication. The patient's goals were to remain noninvasive in treatment. Conservative recommendations such as physical therapy, analgesics, and current occlusal appliance wear were recommended.

Temporomandibular joint osteoarthritis: A review of animal models induced by surgical interventions

OBJECTIVES

The pathological mechanism of temporomandibular joint osteoarthritis (TMJOA) is still unclear. Animal models induced by surgical interventions are one of the most ideal tools to imitate human pathological conditions. This review aims to define the similarities and differences of different surgical animal models.

METHODS

Articles of TMJOA surgical animal models were collected including anterior disc displacement, disc perforation, and discectomy. We analyzed their experiments strategies based on comparing preoperative selection, intraoperative methodology, and postoperative manifestations.

RESULTS

No matter which surgical intervention is selected, abnormal stress forces the whole joint to remodel its structure so that it could adapt to functional requirements, resulting in TMJOA eventually. However, anterior disc displacement needs more than 16 weeks to obtain typical manifestations, where the methodology is complicated. The course of perforation and discectomy is around 12-16 weeks, but they could cause excessive damage to the TMJ structure.

CONCLUSIONS

All surgical interventions can cause TMJOA, but the extent of pathology varies from each other. This review will assist future experiments to better understand the pathogenesis of TMJOA and choose the most appropriate model.

Kartogenin potentially protects temporomandibular joints from collagenase-induced osteoarthritis via core binding factor β and runt-related transcription factor 1 binding - A rat model study

Background/purpose

Temporomandibular joint (TMJ) osteoarthritis (TMJOA) is a chronic disease with progressive destruction of articular cartilage. This study aimed to explore the therapeutic effects of kartogenin on TMJOA via promoting the binding of core binding factor β (CBFβ) and runt-related transcription factor 1 (RUNX1).

Materials and methods

Type II collagenase was injected into 35 8-week-old male Sprague Dawley rat TMJs to establish the TMJOA model. Kartogenin, or the CBFβ-RUNX1 complex inhibitor (Ro5-3335), was also delivered via intra-articular injection. Subchondral bone was analyzed by MicroCT. The hematoxylin-eosin, Safranin O, and toluidine blue O staining were used to observe histopathology. Immunohistochemical staining of proliferating cell nuclear antigen (PCNA), caspase-3 (CASP3), interleukin-1β (IL-1β), and collagen II (COL2) was performed.

Results

TMJOA was established in rats by intra-articular injection of type II collagenase. The condylar cartilage and subchondral bone were damaged, with decreased PCNA and COL2 and increased CASP3 and IL-1 (P < .001). Compared with the OA group, kartogenin alleviated the destruction of cartilage and subchondral bone, rescued the expression of PCNA and COL2, and decreased the expression of CASP3 and IL-1β (P < .01). Ro5-3335 did not aggravate the pathology of TMJOA but neutralized the therapeutic effects of kartogenin on TMJOA.

Conclusion

Kartogenin has a potential therapeutic effect on TMJOA via promoting the CBFβ-RUNX1 binding.

Multiple roles of ALK3 in osteoarthritis

Osteoarthritis (OA) is a chronic degenerative joint disease characterized by progressive cartilage degradation, synovial membrane inflammation, osteophyte formation, and subchondral bone sclerosis. Pathological changes in cartilage and subchondral bone are the main processes in OA. In recent decades, many studies have demonstrated that activin-like kinase 3 (ALK3), a bone morphogenetic protein receptor, is essential for cartilage formation, osteogenesis, and postnatal skeletal development. Although the role of bone morphogenetic protein (BMP) signalling in articular cartilage and bone has been extensively studied, many new discoveries have been made in recent years around ALK3 targets in articular cartilage, subchondral bone, and the interaction between the two, broadening the original knowledge of the relationship between ALK3 and OA. In this review, we focus on the roles of ALK3 in OA, including cartilage and subchondral bone and related cells. It may be helpful to seek more efficient drugs or treatments for OA based on ALK3 signalling in future.

State of the Art in Temporomandibular Joint Arthrocentesis-A Systematic Review

Temporomandibular joint disorders are a heterogenic group of clinical conditions, which impair physiological functioning of the masticatory system. Arthrocentesis of the temporomandibular joint has become a widely approved method for non-invasive treatment, bridging the gap between conservative and surgical approaches. Regardless of technique, treatment is based upon joint lavage and lysis of the inflammatory fibrous tissue adhesions, which, in turn, improves joint mobility and reduces pain and closed lock. Recently, approaches for intra-articular injections have been proposed as adjuvant or replacement therapy. The aim of this study was to assess the most efficient technique of arthrocentesis. A systematic search based on PRISMA guidelines, including a computer search with specific keywords, a reference list search and a manual search, was performed. Relevant articles were selected after three search rounds for final review. The studies pulled for the analysis presented information about the relevant predictors, including the technique of arthrocentesis (single- or two-needle method), fluid used for lavage (Ringer lactate or saline), volume of the fluid, application of the injectable, number of interventions, pain (VAS) and mouth opening scores (MMO) and follow-up. All cohorts showed improvement in mouth opening, but significant pain reduction was observed only in cohorts treated either by arthrocentesis alone or arthrocentesis followed by intra-articular injectables. Intra-articular injectables used alone failed to reduce pain post-operatively when compared to other cohorts. We concluded that both double-needle and single-puncture arthrocentesis techniques are equally efficient. Application of the adjuvant injectable did not improve the outcomes of arthrocentesis performed alone. The volume of the fluid used for joint lavage and its chemical composition were not significant in clinical outcomes. However, due to the lack of homogeneity in the study settings, a meta-analysis could not be applied and a systematic review was conducted. We still, however, state that there is a knowledge gap in the current literature regarding the use of injectables alone, as well as a longitudinal follow-up, which provides information about treatment efficiency. More high-quality and randomized controlled trials are required to shed light on this subject.

Near-Infrared Light-Activated Mesoporous Polydopamine for Temporomandibular Joint Osteoarthritis Combined Photothermal-Chemo Therapy

The treatments generally employed for temporomandibular joint osteoarthritis (TMJOA) involve physical therapy and chemotherapy, etc., whose therapeutic efficacies are impaired by the side effects and suboptimal stimulus responsiveness. Although the intra-articular drug delivery system (DDS) has shown effectiveness in addressing osteoarthritis, there is currently little reported research regarding the use of stimuli-responsive DDS in managing TMJOA. Herein, we prepared a novel near-infrared (NIR) light-sensitive DDS (DS-TD/MPDA) by using mesoporous polydopamine nanospheres (MPDA) as NIR responders and drug carriers; diclofenac sodium (DS) as the anti-inflammatory medication; and 1-tetradecanol (TD) with a phase-inversion temperature of 39 °C as the drug administrator. Upon exposure to 808 nm NIR laser, DS-TD/MPDA could raise the temperature up to the melting point of TD through photothermal conversion, and intelligently trigger DS release. The resultant nanospheres exhibited an excellent photothermal effect and effectively controlled the release of DS through laser irradiation to accommodate the multifunctional therapeutic effect. More importantly, the biological evaluation of DS-TD/MPDA for TMJOA treatment was also performed for the first time. The experiments' results demonstrated that DS-TD/MPDA displayed a good biocompatibility in vitro and in vivo during metabolism. After injection into the TMJ of rats afflicted with TMJOA induced by unilateral anterior crossbite for 14 days, DS-TD/MPDA could alleviate the deterioration of TMJ cartilage, thus ameliorating osteoarthritis. Therefore, DS-TD/MPDA could be a promising candidate for photothermal-chemotherapy for TMJOA.

Design and Implement Strategy of Wireless Bite Force Device

Abnormal bite force is an important risk factor for oral and maxillofacial disorders, which is a critical dilemma that dentists face every day without effective solutions. Therefore, it is of great clinical significance to develop a wireless bite force measurement device and explore quantitative measurement methods to help find effective strategies for improving occlusal diseases. This study designed the open window carrier of a bite force detection device through 3D printing technology, and then the stress sensors were integrated and embedded into a hollow structure. The sensor system mainly consisted of a pressure signal acquisition module, a main control module, and a server terminal. A machine learning algorithm will be leveraged for bite force data processing and parameter configuration in the future. This study implemented a sensor prototype system from scratch to fully evaluate each component of the intelligent device. The experimental results showed reasonable parameter metrics for the device carrier and demonstrated the feasibility of the proposed scheme for bite force measurement. An intelligent and wireless bite force device with a stress sensor system is a promising approach to occlusal disease diagnosis and treatment.

Diagnostic accuracy of fused CBCT images in the evaluation of temporomandibular joint condylar bone resorption

OBJECTIVES

To evaluate the diagnostic accuracy of fused CBCT images for patients with condylar bone resorption of temporomandibular joint (TMJ) osteoarthrosis.

MATERIALS AND METHODS

Forty-two TMJs from twenty-one patients were included. Bone resorption of condyles evaluated by three experts was used as the reference standard. Three oral and maxillofacial radiology residents evaluated the resorption of condyles with a five-point scale for the four sets of images (two consecutive CBCT images without fusion, fused 2D cross-sectional images, fused 3D images, and combining fused 2D cross-sectional images and fused 3D images) randomly and independently. Each set of images was evaluated at least 1 week apart, and a second evaluation was performed 4 weeks later. Intraclass correlation coefficients were calculated to assess the intra- and inter-observer agreement. The areas under the ROC curves (AUCs) were compared among the four image sets using the Z test.

RESULTS

Twenty-four TMJs were determined as condylar bone resorption, and eighteen were determined as no obvious change. The average AUC values from the three observers for the three fused image sets (0.94, 0.93, 0.93) were significantly higher than the image set without fusion (p < 0.01). The intra- and inter-observer agreement on the three fused image sets (0.70-0.89, 0.91-0.92) was higher than the image set without fusion (0.37-0.63, 0.75).

CONCLUSIONS

Fused CBCT images of TMJ osteoarthrosis patients can intuitively display the condylar bone resorption and significantly improve the diagnostic accuracy.

CLINICAL RELEVANCE

Fused CBCT images can help clinicians intuitively observe bone changes of the condyle in TMJ osteoarthrosis patients.

Vitamin D3 Metabolism and Its Role in Temporomandibular Joint Osteoarthritis and Autoimmune Thyroid Diseases

The aim of this review was to present the metabolism of vitamin D3, as well as to discuss the role of vitamin D3 in bone metabolism, temporomandibular joint osteoarthritis (TMJ OA), and autoimmune thyroid diseases (AITD) on the basis of the literature. Vitamin D3 plays a significant role in human health, as it affects the calcium-phosphate balance and regulates the bone metabolism. Calcitriol impresses the pleiotropic effect on human biology and metabolism. Its modulative function upon the immune system is based on the reduction of Th1 cell activity and increased immunotolerance. Vitamin D3 deficiency may lead to an imbalance in the relationship between Th1/Th17 and Th2, Th17/Th reg, and is considered by some authors as one of the possible backgrounds of autoimmune thyroid diseases (AITD), e.g., Hashimoto's thyroiditis or Graves' disease. Moreover, vitamin D3, through its direct and indirect influence on bones and joints, may also play an important role in the development and progression of degenerative joint diseases, including temporomandibular joint osteoarthritis. Further randomized, double blind studies are needed to unequivocally confirm the relationship between vitamin D3 and abovementioned diseases and to answer the question concerning whether vitamin D3 supplementation may be used in the prevention and/or treatment of either AITD or OA diseases.

Chemokine Regulation in Temporomandibular Joint Disease: A Comprehensive Review

Temporomandibular joint disorders (TMDs) are conditions that affect the muscles of mastication and joints that connect the mandible to the base of the skull. Although TMJ disorders are associated with symptoms, the causes are not well proven. Chemokines play an important role in the pathogenesis of TMJ disease by promoting chemotaxis inflammatory cells to destroy the joint synovium, cartilage, subchondral bone, and other structures. Therefore, enhancing our understanding of chemokines is critical for developing appropriate treatment of TMJ. In this review, we discuss chemokines including MCP-1, MIP-1α, MIP-3a, RANTES, IL-8, SDF-1, and fractalkine that are known to be involved in TMJ diseases. In addition, we present novel findings that CCL2 is involved in β-catenin-mediated TMJ osteoarthritis (OA) and potential molecular targets for the development of effective therapies. The effects of common inflammatory factors, IL-1β and TNF-α, on chemotaxis are also described. In conclusion, this review aims to provide a theoretical basis for future chemokine-targeted therapies for TMJ OA.

Effects of an Interdisciplinary Approach in the Management of Temporomandibular Disorders: A Scoping Review

Temporomandibular disorders (TMD) is an umbrella term that encompasses many musculoskeletal problems that include the masticatory muscles, the temporomandibular joint, and other associated structures. TMD can be divided into two large groups: those that affect the musculature and those that affect the joint. The treatment of TMD requires the combined skills of physiotherapists and dentists, as well as sometimes psychologists and other medical specialists. This study aims to examine the effectiveness of the interdisciplinary approach using physiotherapy and dental techniques on pain in patients with temporomandibular disorders (TMDs). This is a Scoping Review of studies investigating the effects of combined therapy on patients with TMD. PRISMA guidelines were followed during this review's design, search, and reporting stages. The search was carried out in the MEDLINE, CINHAL, and EMBASE databases. A total of 1031 studies were detected and analyzed by performing the proposed searches in the detailed databases. After removing duplicates and analyzing the titles and abstracts of the remaining articles, six studies were ultimately selected for this review. All the included studies showed a positive effect on pain decreasing after a combined intervention. The interdisciplinary approach characterized by the combination of manual therapy and splint or electrotherapy can positively influence the perceived symptoms; positively decrease pain; and reduce disability, occlusal impairments, and perception of change.

Therapeutic effect of alendronate in an experimental temporomandibular joint osteoarthritis

BACKGROUND

Temporomandibular joint osteoarthritis is a common degenerative joint disease. This disease negatively affects the daily life, speech and chewing functions of patients.

OBJECTIVE

This study aimed to evaluate the effects of intra-articular injection of alendronate to osteoarthritis, which has a protective effect on bone and cartilage tissue and helps reduce inflammation in temporomandibular joint osteoarthritis.

METHODS

A total of 24 Wistar albino rats were used in the study. Rats were divided into four groups: study, saline, control and sham. In both saline and control groups, monosodium iodoacetate was injected intra-articularly to induce osteoarthritis. Alendronate was administered intra-articularly to the study group weekly for 4 weeks. In the saline group, saline was administered by intra-articular injection. At the end of the 12th week, all groups were sacrificed. Mandibular condyle tissues were examined histopathologically.

RESULTS

According to the results, osteoarthritic changes in the control group were higher than those in the study group (p < .05). No significant reduction in osteoarthritic changes was observed in the saline group (p > .05). Significant osteoarthritis findings were observed in all groups compared with the sham group (p < .05).

CONCLUSION

Intra-articular injection of alendronate was found to have positive results on TMJ osteoarthritis. In addition, it was seen that alendronate has effects on reducing cartilage tissue degeneration and loss of matrix proteins.

Temporomandibular Joint Osteoarthritis: Pathogenic Mechanisms Involving the Cartilage and Subchondral Bone, and Potential Therapeutic Strategies for Joint Regeneration

The temporomandibular joint (TMJ) is a specialized synovial joint that is crucial for the movement and function of the jaw. TMJ osteoarthritis (TMJ OA) is the result of disc dislocation, trauma, functional overburden, and developmental anomalies. TMJ OA affects all joint structures, including the articular cartilage, synovium, subchondral bone, capsule, ligaments, periarticular muscles, and sensory nerves that innervate the tissues. The present review aimed to illustrate the main pathomechanisms involving cartilage and bone changes in TMJ OA and some therapeutic options that have shown potential restorative properties regarding these joint structures in vivo. Chondrocyte loss, extracellular matrix (ECM) degradation, and subchondral bone remodeling are important factors in TMJ OA. The subchondral bone actively participates in TMJ OA through an abnormal bone remodeling initially characterized by a loss of bone mass, followed by reparative mechanisms that lead to stiffness and thickening of the condylar osteochondral interface. In recent years, such therapies as intraarticular platelet-rich plasma (PRP), hyaluronic acid (HA), and mesenchymal stem cell-based treatment (MSCs) have shown promising results with respect to the regeneration of joint structures or the protection against further damage in TMJ OA. Nevertheless, PRP and MSCs are more frequently associated with cartilage and/or bone repair than HA. According to recent findings, the latter could enhance the restorative potential of other therapies (PRP, MSCs) when used in combination, rather than repair TMJ structures by itself. TMJ OA is a complex disease in which degenerative changes in the cartilage and bone develop through intricate mechanisms. The regenerative potential of such therapies as PRP, MSCs, and HA regarding the cartilage and subchondral bone (alone or in various combinations) in TMJ OA remains a matter of further research, with studies sometimes obtaining discrepant results.

Diagnosis and Treatment of Myogenous Temporomandibular Disorders: A Clinical Update

Myogenous temporomandibular disorders (M-TMDs) are the most common chronic orofacial pain, affecting the masticatory muscles and, thus, jaw movement. While a concise diagnosis is crucial to formulate a rational treatment plan, the similarities in clinical presentations that M-TMDs share with other neuromuscular disorders affecting the temporomandibular joint (TMJ) could easily confuse physicians. In addition to the basics, such as thorough history taking and meticulous clinical examinations, different imaging techniques are useful adjuncts to facilitate the diagnostic process. This review presents an overview of the current understanding on a variety of diagnostic and treatment modalities for M-TMD patients. It is essential to highlight that there is not a single treatment for all, and the benefits of multidisciplinary strategies have been noted for the effective management of myogenous TMD pain. Treatment modalities ranging from conservative to minimally invasive options are discussed in this review.

Association between Sleep Disorders and Sleep Quality in Patients with Temporomandibular Joint Osteoarthritis: A Systematic Review

Background: Osteoarthritis (OA) is a leading cause of disability, the most common form of chronic disease in the temporomandibular joint (TMJ), and the most severe disease type of temporomandibular disorders (TMD). The etiology of TMD is multifactorial, considering parafunctional habits, sleep bruxism, or sleep disturbance as common factors. Insomnia and apnea are the two most frequent forms of sleep disorders in TMD patients. Due to this, the objective of this systematic review was to highlight whether there is currently scientific evidence in the literature describing that patients with temporomandibular joint osteoarthritis (TMJ-OA) are associated with increased sleep disorders or impaired sleep quality. Methods: This systematic review was completed in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) statement and was registered with PROSPERO prior to completion of the main search. Original observational studies that analyze the association of sleep disorders and sleep quality in patients with TMJ-OA were included in the present review. Results: 770 studies were screened by abstract and title according to inclusion and exclusion criteria, and finally, 7 articles were included in the qualitative synthesis and a total of 772 patients diagnosed with TMJ-OA. Conclusions: There is insufficient evidence to indicate that patients with TMJ OA are associated with increased sleep disorders or poorer sleep quality.

Position of the Hyoid Bone and Dimension of Nasopharynx and Oropharynx after Occlusal Splint Therapy and Physiotherapy in Patients Diagnosed with Temporomandibular Disorders

Background: The aim of the study was to assess the position of the hyoid bone, as well as the width of the nasopharynx and oropharynx after occlusal splint therapy combined with physiotherapy in patients diagnosed with temporomandibular disorders (TMD). Methods: This was a clinical trial study. The study group consisted of 40 patients diagnosed with TMD, who were qualified for the treatment combining physiotherapy and occlusal splint therapy. Hyoid bone position as well as the width of the nasopharynx and oropharynx were assessed in lateral cephalograms taken before and after the end of the treatment. There were 15 generally healthy participants included into the control group, who had taken lateral cephalograms twice within the period of 1 to 2 years and did not receive any occlusal treatment in the meantime. Results: The position of the hyoid bone was significantly lowered and the dimension of the lower part of the oropharynx was significantly decreased after the end of the long-term occlusal splint therapy combined with physiotherapy in patients diagnosed with TMD. Conclusions: Long-term occlusal splint therapy combined with physiotherapy affected the position of the hyoid bone and the dimension of the lower part of the oropharynx.

The use of platelet-rich plasma in management of musculoskeletal pain: a narrative review

Musculoskeletal pain is the most common pain reported by patients. Platelet-rich plasma (PRP) is widely used to treat musculoskeletal pain. However, the efficacy of PRP to treat this pain remains controversial. This review highlights the application of PRP in the treatment of musculoskeletal pain. PRP treatment appears to reduce pain and improve function in patients with musculoskeletal pain. However, there are limitations to the currently published studies. These limitations include the PRP preparation methods, type of activators, types of pathology to be treated, methods and times of administration, and association of PRP with other treatments.

Identification of Biomarkers Associated with Diagnosis of Osteoarthritis Patients Based on Bioinformatics and Machine Learning

Osteoarthritis (OA) is thought to be the most prevalent chronic joint disease. The incidence of OA is rising because of the ageing population and the epidemic of obesity. This research was designed for the identification of novel diagnostic biomarkers for OA and analyzing the possible association between critical genes and infiltrated immune cells. 10 OA samples from patients with spinal OA and 10 normal samples were collected. GSE55235 and GSE55457 datasets including human OA and normal samples were downloaded from the GEO datasets. Differentially expressed genes (DEGs) were identified between 20 OA and 20 controls. SVM-RFE analysis and LASSO regression model were carried out to screen possible markers. The compositional patterns of the 22 types of immune cell fraction in OA were determined by the use of CIBERSORT. The expression level of the biomarkers in OA was examined by the use of RT-PCR. In this study, an overall 44 DEGs were identified: 18 genes were remarkably upregulated and 26 genes were distinctly downregulated. KEGG pathway analyses revealed that pathways were significantly enriched including IL-17 signal path, rheumatoid arthritis, TNF signal path, and lipid and atherosclerosis. Based on the results of machine learning, we identified APOLD1 and EPYC as critical diagnostic genes in OA, which were further confirmed using ROC assays. Immune cell infiltration analysis revealed that APOLD1 was correlated with mastocytes stimulated, NK cells resting, T cells CD4 memory resting, DCs stimulated, T cells gamma delta, macrophages M0, NK cells stimulated, and mastocytes resting. Moreover, we found that EPYC was correlated with mastocytes stimulated, NK cells resting, T cells CD4 memory resting, DCs stimulated, T cells gamma delta, macrophages M0, NK cells stimulated, and mastocytes resting. Overall, our findings might provide some novel clue for the exploration of novel markers for OA diagnosis. The critical genes and their associations with immune infiltration may offer new insight into understanding OA developments.

Temporomandibular Joint Disk Displacements in Class II Malocclusion and Cervical Spine Alterations: Systematic Review and Report of a Hypodivergent Case with MRI Bone and Soft Tissue Changes

(1) Background: This study aimed to perform a literature review related to disk displacement (DD) in class II malocclusion or cervical vertebrae position alterations and to report a hypodivergent case with cervical pain and right anterolateral DD with reduction, left anterolateral DD with reduction, and left joint effusion. (2) Methods: A structured electronic search was conducted between March 2022 and April 2022, without time limits, following PRISMA guidelines, in the following databases: PubMed, Scopus, Embase and Cochrane; the terms “disc displacement”, “disk displacement”, “temporomandibular joint”, “class II malocclusion” and “cervical vertebrae” are searched. (3) Results: the following thirteen publications are included in this review: two prospective studies and eleven cross-sectional studies; for evaluating disk position, eight included publications used magnetic resonance imaging (MRI), whilst six studies used lateral cephalogram to determine craniofacial morphology and relationships between the cranial base, vertical skeletal pattern, maxilla and mandible. (4) Conclusions: although the literature still shows contradictory opinions, a relationship between temporomandibular disorders and cervical posture has been shown in the presented case as well as in the literature review.

Craniovertebral and Craniomandibular Changes in Patients with Temporomandibular Joint Disorders after Physiotherapy Combined with Occlusal Splint Therapy: A Prospective Case Control Study

Background and Objectives: The aim of the study was to assess the craniovertebral and craniomandibular changes in patients diagnosed with temporomandibular joint disorders (TMD) after physiotherapy combined with occlusal splint therapy. Materials and Methods: There were forty patients (32 females, 80%), diagnosed with TMD, included into the study group. After the initial series of physiotherapy, patients received maxillary occlusal splints to be worn day and night. Participants continued physiotherapy simultaneously with occlusal splint therapy for 6 months. Lateral cephalograms taken in natural head position before and after the end of the therapy were used for measurements. The control group consisted of 15 healthy participants (12 females, 80%), who had taken lateral cephalograms twice, and did not receive any type of occlusal treatment nor physiotherapy in the meantime. Results: Occlusal splint therapy and physiotherapy combined together significantly affected: the vertical position of the mandible (significant increase, p < 0.0001), the sagittal position of mandible (significant decrease, p = 0.0065), as well as the width of the functional space between C1 and C2 (significant decrease, p = 0.0042). Moreover, the cervical lordosis was restored after the end of the treatment (p < 0.0001). Conclusions: Cooperation of physiotherapists with dental practitioners is necessary in the treatment of patients with TMD, including temporomandibular joint osteoarthritis.