Temporomandibular Joint Disorders and Orofacial Pain

Arthrocentesis for temporomandibular joint disorders: a network meta-analysis of randomised controlled trials

OBJECTIVE

Clinical studies have demonstrated the effectiveness of arthrocentesis in managing temporomandibular joint disorders (TMDs). However, there is a lack of consensus among these studies regarding the selection of injectables. Furthermore, an increasing number of drugs have been tested for TMDs in recent years, complicating the decision-making process for clinicians. This study conducted a network meta-analysis of randomized controlled trials (RCTs) to compare the clinical efficacy of different arthrocentesis treatment regimens.

METHODS

We conducted a comprehensive search of Embase, PubMed, Cochrane Library, and Web of Science to gather articles on RCTs pertaining to the management of TMDs using arthrocentesis. This search spanned from inception of these databases up to July 29, 2024. We then performed a network meta-analysis using Stata 17.0 software. The outcome indicators used were VAS scores and changes in unassisted maximum opening. To determine the efficacy of each regimen, we employed surface-under the cumulative ranking curve (SUCRA) ranking.

RESULT

Forty RCTs were included, encompassing 1904 temporomandibular joints (TMJs) cases. Treatment options encompass platelet-rich plasma (PRP), hyaluronic acid (HA), corticosteroids (CS), bone marrow concentrate (BMAC), injectable platelet-rich fibrin (i-PRF), concentrated growth factor (CGF), Tenoxicam (TX), microfragmented adipose tissue (FAT), and their combination regimens. The SUCRA ranking revealed that the most effective treatment options at 1-, 3-, and 6-months post-arthrocentesis were HA + PRP, i-PRF, and BMAC, respectively.

CONCLUSION

HA + PRP, i-PRF and BMAC may represent the optimal arthrocentesis agents for the management of TMDs symptoms and restoration of TMJ function in the short, medium, and long term, respectively.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/PROSPERO/ , identifier CRD42024563975.

Unveiling MRI-based structural phenotypes in temporomandibular joint osteoarthritis: implications for clinical practice and research

INTRODUCTION

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

OBJECTIVE

This article introduces the ROAMES-TMJ (Rapid OsteoArthritis MRI Eligibility Score for TMJ) to assess the structural eligibility of individuals for inclusion in TMJ OA clinical trials.

Reciprocal effects of scleroderma and temporomandibular dysfunction between patient cohorts

OBJECTIVE

To estimate the prevalence of temporomandibular dysfunction in scleroderma patients according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) and to correlate it with disease variables.

METHODS

Temporomandibular dysfunction was evaluated in 75 scleroderma patients and 74 healthy controls using DC/TMD. Gastrointestinal symptoms were evaluated through the University of California Los Angeles (UCLA) score in scleroderma patients.

RESULTS

There was no difference of prevalence in temporomandibular dysfunction [30 (40%) vs 30 (40.5%); p > 00.05] between scleroderma patients and healthy controls. Scleroderma patients had a significant reduction in all oral movements compared to healthy controls. Scleroderma patients with temporomandibular dysfunction had a statistically higher score in the UCLA distention/bloating item [1.75 (0.5-2.38) vs 0.75 (0.25-1.75); p < 0.05] than scleroderma patients without temporomandibular dysfunction.

DISCUSSION

Temporomandibular dysfunction prevalence between scleroderma patients and healthy controls is similar. In scleroderma patients, temporomandibular dysfunction reduces oral mobility and opening, which worsens distension/bloating.

Association between Clinical Manifestations in Temporomandibular Joint Disorders and Corresponding Radiographic Findings

Background: Temporomandibular disorders are common conditions characterized by discomfort within the temporomandibular joints, acoustic changes, and restricted mandibular movement. Accurate diagnosis and subsequent treatment rely heavily on clinical examination, but it is often necessary to add radiological examinations to the diagnostics. Magnetic Resonance Imaging (MRI) is the gold standard for visualizing the disc, while cone-beam computed tomography (CBCT) is primarily used for evaluating condylar morphology. Ultrasound (US) serves as a real-time imaging modality for soft tissues. The objective of the present study was to explore the association between clinical manifestations observed in patients with temporomandibular joint disorders and corresponding radiographic findings. Methods: A total of 63 adult patients (51 female and 12 male) with temporomandibular joint disorders were included in this cross-sectional study. Each patient underwent a clinical examination, followed by appropriate radiological examinations (MRI, CBCT, or US). The level of statistical significance was set at an alpha of 0.05. The Shapiro-Wilk test assessed the normality of numerical variables. The Wilcoxon rank sum test compared two independent groups with non-normally distributed data. Relationships between categorical variables were evaluated using the Pearson chi-square test or Fisher's exact test. The Kendall tau (τ) method analyzed the correlation between two binary variables. Results: The analysis included 63 patients with TMD, predominantly females (80.95%). Ages ranged from 18 to 74 years with a median of 39 years. In the CBCT study, we observed rarefied changes in the left bone structures in patients with bruxism (p = 0.010). MRI and ultrasound imaging revealed changes in patients with limited jaw opening: erosions in the right mandibular head on ultrasound (p = 0.008) and abnormal right bone structures on MRI (p = 0.009). In CBCT, asymmetry in the left joint space was correlated with a high incidence of right side muscle tension (p = 0.004). Additionally, both CBCT and ultrasound showed a correlation between muscle tension and erosion (p = 0.040 in ultrasound, p = 0.020 in CBCT). Acoustic changes, when compared with radiological imaging, were evident in all three studies, like temporomandibular joint pain or palpation. Conclusions: Our study compared three radiographic imaging methods with clinical examinations to assess their correlation with clinical symptoms. Each imaging technique provided unique insights depending on the specific symptoms presented. The observed correlations varied, highlighting the unique contributions of each modality to the diagnostic process. This underscores the importance of employing multiple diagnostic approaches for a thorough assessment of the temporomandibular joint. However, a limitation of our study is the small sample size and the uneven distribution of participants among the groups. Additionally, not all patients underwent every imaging modality.

Ultrasonographic characteristics of myogenous temporomandibular disorders: A scoping review

OBJECTIVE

To identify the available evidence on the ultrasonographic characteristics of masticatory muscles in subjects with myogenous TMD, as well as the potential use of ultrasonography as a diagnostic and treatment assessment outcomes tool.

METHOD

An electronic search of the PubMed, Web of Science and Scopus databases was performed using the following terms: 'ultrasonography', 'ultrasound', 'masseter', 'temporal', 'masticatory muscles', 'temporomandibular disorders', 'temporomandibular joint disorders'. Full-text articles were obtained from the records after applying the inclusion/exclusion criteria.

RESULTS

Thirteen articles were included for analysis: one comparative cross-sectional study, five case-control studies, six clinical trials and one randomised clinical trial. Main ultrasonographic characteristic assessed were local cross-sectional dimension and intramuscular ultrasonographic appearance. Retrieved studies reported the use ultrasonography for diagnosis or treatment assessment purposes showing heterogeneous results. For diagnosis purposes, the results of local cross-sectional dimension are not consistent; therefore, its diagnostic value for myogenous TMD diagnosis is weak. However, more homogeneous results were observed for intramuscular ultrasonographic appearance showing a higher prevalence of type-II pattern in myogenous TMD subjects than non-TMD subjects. On the other hand, for treatment assessment purposes, muscles were observed thinner after treatment compared to pre-treatment. Also, results of intramuscular ultrasonographic appearance show disappearance or reduction of anechoic areas, higher prevalence of type-II pattern and significant distinction of echogenic bands were observed after treating TMD subjects.

CONCLUSION

Ultrasonography cannot be considered as a diagnostic instrument, but maybe as a complementary tool for treatment assessment of myogenous TMD subjects, even though future research is required to confirm its utility.

Muscle oxygenation and pain in different types of temporomandibular disorders

OBJECTIVES

Studies exploring variations in peripheral muscle oxygenation and pressure pain thresholds (PPT) of masticatory muscles in individuals with Temporomandibular Disorders (TMDs) are limited. The purpose of this study was to compare variations in peripheral oxygenation of the masseter muscle; PPT of the masseter and temporal muscles and correlate peripheral muscle oxygenation and PPT of the masseter muscle in individuals with different types of TMDs.

MATERIALS AND METHODS

Cross-sectional study involving 116 participants classified into three groups: muscle group (MG, n = 32), joint group (JG, n = 30) and muscle-joint group (MJG, n = 54). Individuals aged 26.97 ± 6.93, 68.97% female, 31,03% males were included. All participants were evaluated using the Diagnostic Criteria for Temporomandibular Disorders, Near-infrared spectroscopy (NIRS) for peripheral muscle oxygenation and pressure algometer for PPT.

RESULTS

There was no difference in masseter muscle oxygenation among groups. In the masseter muscle, a weakly positive correlation was observed between PPT and variation in tissue saturation index in the MG (rho = 0.365) and JG (rho = 0.317). In addition, the MJG expressed lower PPT (p = 0.004) than JG, demonstrating that MJG had more pain in this muscle.

CONCLUSIONS

MJG have lower PPT in the masseter muscle. Although the PPT is dependent on the type of TMDs, the correlation between PPT and oxygenation is weak. All TMDs groups evaluated (MG, JG, MJG) showed hemodynamic similarities of the masseter muscle.

CLINICAL RELEVANCE

Understanding pain thresholds and the hemodynamic behavior of the masticatory muscles contributes to a more assertive physiotherapeutic assessment in TMDs, serving as a basis for careful and individualized interventions.

Significance of radiographic temporomandibular degenerative joint disease findings

The field of orthodontics has seen a recent increase in the number of patients over the age of 50 seeking treatment and also an increase in the use of cone beam technology. Similar to other joints in the body, the temporomandibular joint (TMJ) is associated with age-related degeneration. However, unlike other joints, degeneration of the TMJ is rarely symptomatic and when there is pain, it is usually self-limiting. In this article, we will review: a) the incidence and prevalence of TMJ degenerative diseases, b) similarities and differences of TMJ vs knee degenerative diseases, and c) current treatment recommendations for TMJ degenerative diseases. In the vast majority of people, radiographic evidence of TMJ degeneration is an incidental finding. Future longitudinal research is needed to follow the natural course of TMJ degenerative patients.

Tenosynovial giant cell tumor: case report and molecular investigation

Tenosynovial giant cell tumor is a benign neoplasm arising from the synovium of joints, including the temporomandibular joint (TMJ). Despite its benign nature, these tumors may exhibit aggressive behavior. A 57-year-old woman with a swollen, hardened area in the left TMJ was referred to the university´s clinic. The diagnosis of tenosynovial giant cell tumor was made based on the presence of hyperplastic synovial lining containing mononuclear and giant cells, hemorrhagic areas, hemosiderin deposits, and calcification foci in the biopsy. A low condylectomy was performed, and histopathologic analysis of the surgical piece upheld the diagnosis. Due to histopathologic resemblance with other giant cell-rich lesions (giant cell granuloma of the jaws, brown tumor of hyperparathyroidism, and non-ossifying fibroma) for which signature mutations are known, mutational analysis of KRAS, FGFR1, and TRPV4 genes was conducted. The results revealed wild-type sequences for all the mutations tested, thereby supporting the diagnosis of tenosynovial giant cell tumor.

Temporomandibular disorders: the most common diagnostic approaches

BACKGROUND

Temporomandibular disorders (TMDs) are a heterogeneous group of conditions involving the temporomandibular joint complex, and surrounding musculature and osseous components. They are a multifactorial disease that can be determined by organic, genetic aspects, oral parafunctional habits, and psychological stress. They have an annual incidence of more than 5% of the population and about 6% to 12% of the population is affected by symptoms. The diagnostic criteria (DC), introduced by Dworkin, is considered the standard system to diagnose this disease in a specific way. Imaging can support the diagnosis of TMD when history and physical examination findings are equivocal. The aim of the study was to evaluate instrumental examinations and therapies, clinicians prefer to use in different cases of TMDs.

METHODS

An anonymized survey, available in two languages (Italian and English), was given to 450 patients, 398 (120 males, 274 females and 4 who did not answer) of different private dental practices were considered, using Google Form (Google LLC, Mountain View, CA, USA) and used an electronic platform, from September 2021 to February 2022. There was no reminder sent to patients to let them feel free to answer.

RESULTS

We performed binary regression for oral bite prescription considering common symptoms and found that the most representative is jaw block (P=0.007, exponential value [EXP]=0.509), followed by TMJ noises (P=0.01, EXP=0.503) and feeling stressed (P=0.04, EXP=1.125) while headache and tinnitus resulted not significant.

CONCLUSIONS

The study highlighted that magnetic resonance imaging (MRI) is the most instrumental examination adopted by the clinicians and the oral splint(bite) is the therapy most widespread nowadays, even if TMDs are a multifactorial disease that is not, probably, only linked to an alteration of dental occlusion.

The challenge of ecological validity in temporomandibular disorders research

OBJECTIVE

To review the ecological validity of outcomes from current research involving temporomandibular disorders (TMDs), with an emphasis on chronic myofascial pain and the precocious development of degenerative disease of the temporomandibular joint (TMJ).

MATERIALS AND METHODS

Current approaches used to study TMDs in terms of neuromechanics, masticatory muscle behaviours, and the dynamics of the autonomic nervous system (ANS) were assessed for ecological validity in this review. In particular, the available literature was scrutinized regarding the effects of sampling, environmental and psychophysiological constraints and averaging data across biological rhythms.

RESULTS

Validated computer-assisted numerical modelling of the neuromechanics used biological objective functions to accurately predict muscle activation patterns for jaw-loading tasks that were individual-specific. With respect to masticatory muscle behaviour, current findings refute the premise that sustained bruxing and clenching at high jaw-loading magnitudes were associated with painful TMDs such as myofascial pain. Concerning the role of the ANS in TMDs, there remains the need for personalized assessments based on biorhythms, and where the detection of dysregulated physiologic oscillators may inform interventions to relieve pain and restore normal function.

CONCLUSIONS

Future human research which focuses on TMD myofascial pain or the precocious development and progression of TMJ degenerative joint disease requires experimental designs with ecological validity that capture objectively measured data which meaningfully reflect circadian and ultradian states.

Pain symptoms are associated with two-point discrimination threshold in patients with temporomandibular disorders

OBJECTIVE

This study aimed to explore the associations of orofacial two-point discrimination (2-PD) test result with pain symptoms and psychological factors in patients with Temporomandibular Disorders (TMDs).

METHODS

193 patients with TMDs were included in this study. Patients' demographics, pain intensity, and psychological status were recorded. The 2-PDs in the bilateral temporal, zygomatic, mandibular, and temporomandibular joint (TMJ) regions of the patients were measured. Statistical analyses were conducted to observe the associations between variables.

RESULTS

For Pain-related TMDs (PT) patients, Monthly Visual Analogue Scale (VAS-M) and Current Analogue Scale (VAS-C) were correlated with TMJ, zygomatic and temporal 2-PDs. Patients with PT tended to have higher TMJ 2-PDs[Right: β = 1.827 mm, 95%CI(0.107, 3.548), P = 0.038], zygomatic 2-PDs[Right: β = 1.696 mm, 95%CI(0.344, 3.048), P = 0.014], temporal 2-PDs[Left: β = 2.138 mm, 95%CI(0.127, 4.149), P = 0.037; Right: β = 1.893 mm, 95%CI(0.011, 3.775), P = 0.049]. Associations were also observed between VAS-C and TMJ 2-PDs[Left: β = 0.780, 95%CI(0.190, 1.370), P = 0.01; Right: β = 0.885, 95%CI(0.406, 1.364), P = 0.001], Zygomatic 2-PDs[Right: β = 0.555, 95%CI(0.172, 0.938), P = 0.005]; VAS-M and TMJ 2-PDs[Left: β = 0.812, 95%CI(0.313, 1.311), P = 0.002; Right: β = 0.567, 95%CI(0.152, 0.983), P = 0.008], zygomatic 2-PDs[Left: β = 0.405, 95%CI(0.075, 0.735), P = 0.016; Right: β = 0.545, 95%CI(0.221, 0.870), P = 0.001], and temporal 2-PDs [Left: β = 0.741, 95%CI(0.258, 1.224), P = 0.003; Right: β = 0.519, 95%CI(0.063, 0.975), P = 0.026].

CONCLUSION

TMJ, zygomatic, and temporal 2-PDs were significantly associated with PT and pain intensity. Age, gender and psychological factors were not associated with orofacial 2-PDs. PT patients exhibited weaker tactile acuity compared to Non-PT patients. Further discussion on the underlying mechanism is needed.

CLINICAL RELEVANCE

Orofacial tactile acuity of TMDs patients was associated with their pain symptoms, which researchers should take account into when performing 2-PD tests for TMDs patients. The 2-PD test can be considered as a potential tool along with the current procedures for the differentiations of PT and Non-PT.

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.

Machine learning-based medical imaging diagnosis in patients with temporomandibular disorders: a diagnostic test accuracy systematic review and meta-analysis

OBJECTIVES

Temporomandibular disorders (TMDs) are the second most common musculoskeletal condition which are challenging tasks for most clinicians. Recent research used machine learning (ML) algorithms to diagnose TMDs intelligently. This study aimed to systematically evaluate the quality of these studies and assess the diagnostic accuracy of existing models.

MATERIALS AND METHODS

Twelve databases (Europe PMC, Embase, etc.) and two registers were searched for published and unpublished studies using ML algorithms on medical images. Two reviewers extracted the characteristics of studies and assessed the methodological quality using the QUADAS-2 tool independently.

RESULTS

A total of 28 studies (29 reports) were included: one was at unclear risk of bias and the others were at high risk. Thus the certainty of evidence was quite low. These studies used many types of algorithms including 8 machine learning models (logistic regression, support vector machine, random forest, etc.) and 15 deep learning models (Resnet152, Yolo v5, Inception V3, etc.). The diagnostic accuracy of a few models was relatively satisfactory. The pooled sensitivity and specificity were 0.745 (0.660-0.814) and 0.770 (0.700-0.828) in random forest, 0.765 (0.686-0.829) and 0.766 (0.688-0.830) in XGBoost, and 0.781 (0.704-0.843) and 0.781 (0.704-0.843) in LightGBM.

CONCLUSIONS

Most studies had high risks of bias in Patient Selection and Index Test. Some algorithms are relatively satisfactory and might be promising in intelligent diagnosis. Overall, more high-quality studies and more types of algorithms should be conducted in the future.

CLINICAL RELEVANCE

We evaluated the diagnostic accuracy of the existing models and provided clinicians with much advice about the selection of algorithms. This study stated the promising orientation of future research, and we believe it will promote the intelligent diagnosis of TMDs.

Effectiveness of Rehabilitation for Disk Displacement of the Temporomandibular Joint-A Cross-Sectional Study

(1) Background: Dislocations of articular disk can occur as a result of parafunctions in the Temporo Mandibular Joint (TMJ), which limits the opening of the mandible and other movements. The aim of this study was to evaluate the effectiveness of rehabilitation in patients with disk displacement of the TMJ. A total of 327 subjects with Temporo Mandibular Disorders underwent stomathognatic physiotherapy. (2) Methods: Based on the results obtained by a manual functional analysis, 35 patients who were identified with articular disk locking (disk displacement without reduction) were included in the study. The study group (N = 35) was subjected to passive repositioning of the articular disk, reposition splints, and physiotherapy. The patient's TMJs were then examined before the therapy, immediately after the therapy, and during the follow-up visit 3-6 weeks after the therapy. The Diagnostic Criteria for the Most Common Intra-articular Temporomandibular Disorders was used to evaluate the effects of rehabilitation on the patients' range of motions and the Numeric Pain Rating Scale (NPRS). For the statistical analysis, Pearson's r correlation coefficient test and Wilcoxon signed-rank test were used. (3) Results: The results showed a significant improvement in the range of motion of the mandible movements. The level of improvement was dependent on the time from the incident until undergoing rehabilitation. (4) Conclusions: The stomatognathic physiotherapy applied increased the range of motion of the mandible and reduced pain levels to the expected range.

Adverse effect of botulinum toxin-A injections on mandibular bone: A systematic review and meta-analysis

INTRODUCTION

Botulinum toxin-A (BTX) is a potent neurotoxin that is emerging in the scope of dental practice for its ability to temporarily paralyse musculature and reduce hyperfunction. This may be desirable in diseases/disorders associated with hyperactive muscles such as the muscles of mastication, most implicated in painful temporomandibular disorders (TMDs). The use of BTX extends beyond its indications with off-label use in TMD's and other conditions, while potential adverse effects remain understudied. BTX is well-established hindlimb paralysis model in animals leading to significant bone loss with underlying mechanisms remaining unclear. The objective of this study is to systematically review the literature for articles investigating changes in mandibular bone following BTX injections and meta-analyse available data on reported bone outcomes.

METHODS

Comprehensive search of Medline, Embase and Web of Science retrieved 934 articles. Following the screening process, 36 articles in animals and humans were included for quantitative synthesis. Articles in human individuals (6) and three different animal species (14) presented mandibular bone outcomes that were included in the meta-analysis.

RESULTS

The masseter and temporalis muscles were frequently injected across all species. In humans, we observe a decrease of about 6% in cortical thickness of mandibular regions following BTX injection with no evident changes in either volume or density of bone structures. In animals, bone loss in the condylar region is significantly high in both cortical and trabecular compartments.

DISCUSSION

Our analysis supports the concept of BTX-induced bone-loss model in animal mandibles. Further, bone loss might be confined to the cortical compartments in humans. Most studies did not address the reality of repeated injections and excessive dosing, which occur due to the reversible action of BTX. More rigorous trials are needed to draw a full picture of potential long-term adverse effects on bone.

Skeletal facial asymmetry: reliability of manual and artificial intelligence-driven analysis

OBJECTIVES

To compare artificial intelligence (AI)-driven web-based platform and manual measurements for analysing facial asymmetry in craniofacial CT examinations.

METHODS

The study included 95 craniofacial CT scans from patients aged 18-30 years. The degree of asymmetry was measured based on AI platform-predefined anatomical landmarks: sella (S), condylion (Co), anterior nasal spine (ANS), and menton (Me). The concordance between the results of automatic asymmetry reports and manual linear 3D measurements was calculated. The asymmetry rate (AR) indicator was determined for both automatic and manual measurements, and the concordance between them was calculated. The repeatability of manual measurements in 20 randomly selected subjects was assessed. The concordance of measurements of quantitative variables was assessed with interclass correlation coefficient (ICC) according to the Shrout and Fleiss classification.

RESULTS

Erroneous AI tracings were found in 16.8% of cases, reducing the analysed cases to 79. The agreement between automatic and manual asymmetry measurements was very low (ICC < 0.3). A lack of agreement between AI and manual AR analysis (ICC type 3 = 0) was found. The repeatability of manual measurements and AR calculations showed excellent correlation (ICC type 2 > 0.947).

CONCLUSIONS

The results indicate that the rate of tracing errors and lack of agreement with manual AR analysis make it impossible to use the tested AI platform to assess the degree of facial asymmetry.

Do myofascial trigger points in masseter muscles affect the symptoms of disc displacement with reduction? A cross-sectional study

OBJECTIVE

The aim of this study was to demonstrate the effect of myofascial pain with referral from the trigger points in the masseter muscles on the clinical symptoms and functional limitations of the temporomandibular joint in participants with disc displacement with reduction.

METHODS

This prospective, cross-sectional study recruited participants aged 18-45 years with disc displacement with reduction with/without myofascial pain with referral in the masseter muscles based on the inclusion criteria. Maximum mouth opening and the presence of probable awake bruxism were assessed. The "Graded Chronic Pain Scale version 2.0" and "Jaw Function Limitation Scale-8" were used to evaluate Diagnostic Criteria for Temporomandibular Disorders Axis II. Pain levels were measured using the Visual Analog Scale.

RESULTS

A comparison between the disc displacement with reduction and disc displacement with reduction+myofascial pain with referral groups revealed statistically significant differences in Visual Analog Scale (p<0.001), the presence of awake bruxism (p=0.038), and Graded Chronic Pain Scale version 2.0 (p=0.010). However, no statistically significant difference was observed between the two groups concerning maximum mouth opening and Jaw Function Limitation Scale-8.

CONCLUSION

Participants with both disc displacement with reduction and myofascial pain with referral in the masseter muscle exhibited higher pain intensity, a higher prevalence of awake bruxism, and increased pain-related disability compared to those with disc displacement with reduction alone.

Imaging signs of temporomandibular joint osteoarthritis in an urban population of 65-year-olds: A cone beam computed tomography study

BACKGROUND

Symptoms of osteoarthritis (OA) in the temporomandibular joint (TMJ) may vary and possible causes should be further explored, such as prevalence and characteristics of imaging features.

OBJECTIVES

Investigate prevalence, gender differences and characteristics of imaging signs of TMJ-OA by cone beam computed tomography (CBCT) in a population-based sample of 65-year-old Oslo citizens.

MATERIALS AND METHODS

159 (86 women, 73 men) individuals randomly recruited from a cohort of 460 Oslo citizens were examined with CBCT. The TMJs were categorised as with imaging signs of OA, no OA or indeterminate for OA.

RESULTS

CBCT signs of TMJ-OA were found in 35% of the 159 participants: 47% of the women and 22% of the men. CBCT signs of TMJ-OA were unilateral in two-thirds of the TMJs and characterised by articular surface flattening and condylar osteophytes. In almost all joints with bone erosive findings, bone productive findings were also found. Participants with and without CBCT signs of TMJ-OA showed no significant difference in TMD pain screener. Fourteen of the 159 participants (9%) had pain-related TMD and 12 (8%) had been in contact with health care services due to TMD.

CONCLUSIONS

CBCT signs of TMJ-OA was common in this study group of 65-year-old Oslo citizens, found in every second woman and every fifth man. Articular surface flattening and bone productive changes, in particular condylar osteophytes, were the most frequent imaging features. Despite the high frequency of CBCT signs of TMJ-OA, few of the participants had pain-related TMD.

An artificial intelligence model for the radiographic diagnosis of osteoarthritis of the temporomandibular joint

The interpretation of the signs of Temporomandibular joint (TMJ) osteoarthritis on cone-beam computed tomography (CBCT) is highly subjective that hinders the diagnostic process. The objectives of this study were to develop and test the performance of an artificial intelligence (AI) model for the diagnosis of TMJ osteoarthritis from CBCT. A total of 2737 CBCT images from 943 patients were used for the training and validation of the AI model. The model was based on a single convolutional network while object detection was achieved using a single regression model. Two experienced evaluators performed a Diagnostic Criteria for Temporomandibular Disorders (DC/TMD)-based assessment to generate a separate model-testing set of 350 images in which the concluded diagnosis was considered the golden reference. The diagnostic performance of the model was then compared to an experienced oral radiologist. The AI diagnosis showed statistically higher agreement with the golden reference compared to the radiologist. Cohen's kappa showed statistically significant differences in the agreement between the AI and the radiologist with the golden reference for the diagnosis of all signs collectively (P = 0.0079) and for subcortical cysts (P = 0.0214). AI is expected to eliminate the subjectivity associated with the human interpretation and expedite the diagnostic process of TMJ osteoarthritis.

A Comparative Study of Condylar Bone Pathology in Patients with and without Temporomandibular Joint Disorders Using Orthopantomography

This study aimed to compare condylar bony pathology in patients with and without temporomandibular joint disorder (TMD) using orthopantomography at Ajman University dental clinics between 2017 and 2021. Patient data from the Ajman University archives were collected after obtaining ethical approval. OPG (orthopantomogram) views were evaluated for potential TMJ pathology. Three independent observers underwent calibration and image analysis, with their agreement level calculated using Kappa statistics (score 0.781). Condylar changes were coded from 0 to 6. Statistical tests such as the Mann-Whitney Test, Kruskal-Wallis test, Spearman's correlation, and logistic regression analysis were used to analyze the data. The inter-examiner reliability for OPG was 0.903, and intra-examiner reliability was 0.908. The most common condylar bony changes observed in OPG views were flattening and osteophyte. Female participants had a higher prevalence of all bony changes. Temporomandibular Disorder (TMD) can manifest with symptomatic and detectable bony changes in OPG views. The prevalence of temporomandibular disorder appeared similar between genders, but differences were observed regarding the number of teeth lost, with unilateral tooth loss being more common. Interestingly, bruxism did not seem to significantly impact of temporomandibular disorder patients.

A Comprehensive Review of Artificial Intelligence Based Algorithms Regarding Temporomandibular Joint Related Diseases

Today, with rapid advances in technology, computer-based studies and Artificial Intelligence (AI) approaches are finding their place in every field, especially in the medical sector, where they attract great attention. The Temporomandibular Joint (TMJ) stands as the most intricate joint within the human body, and diseases related to this joint are quite common. In this paper, we reviewed studies that utilize AI-based algorithms and computer-aided programs for investigating TMJ and TMJ-related diseases. We conducted a literature search on Google Scholar, Web of Science, and PubMed without any time constraints and exclusively selected English articles. Moreover, we examined the references to papers directly related to the topic matter. As a consequence of the survey, a total of 66 articles within the defined scope were assessed. These selected papers were distributed across various areas, with 11 focusing on segmentation, 3 on Juvenile Idiopathic Arthritis (JIA), 10 on TMJ Osteoarthritis (OA), 21 on Temporomandibular Joint Disorders (TMD), 6 on decision support systems, 10 reviews, and 5 on sound studies. The observed trend indicates a growing interest in artificial intelligence algorithms, suggesting that the number of studies in this field will likely continue to expand in the future.

Examination for the Factors Involving to Joint Effusion in Patients with Temporomandibular Disorders Using Magnetic Resonance Imaging

BACKGROUND

This study investigated the factors involving joint effusion in patients with temporomandibular disorders.

METHODS

The magnetic resonance images of 131 temporomandibular joints (TMJs) of patients with temporomandibular disorders were evaluated. Gender, age, disease classification, duration of manifestation, muscle pain, TMJ pain, jaw opening disturbance, disc displacement with and without reduction, deformation of the articular disc, deformation of bone, and joint effusion were investigated. Differences in the appearance of symptoms and observations were evaluated using cross-tabulation. The differences in the amounts of synovial fluid in joint effusion vs. duration of manifestation were analyzed using the Kruskal-Wallis test. Multiple logistic regression analysis was performed to analyze the factors contributing to joint effusion.

RESULTS

Manifestation duration was significantly longer when joint effusion was not recognized (p < 0.05). Arthralgia and deformation of the articular disc were related to a high risk of joint effusion (p < 0.05).

CONCLUSIONS

The results of this study suggest that joint effusion recognized in magnetic resonance imaging was easily observed when the manifestation duration was short, and arthralgia and deformation of the articular disc were related to a higher risk of joint effusion.

Myofascial Temporomandibular Disorders at a Turning Point: Pragmatic or Evidence-Based Management?

Unvalidated theories have been proposed for the etiopathogenesis of masticatory myofascial temporomandibular disorders (mTMD). Modalities such as cone-beam computed tomography/computed tomography and MRI contributes little to the diagnosis of mTMD. Diagnosing mTMD is based on the recognition of "familiar pain" presentation in the masticatory myofascial tissue. This assessment tool contributes little our understanding of the underlying disease process. Thus, management of mTMD is empirical and arbitrary. Exploring emerging technologies to identify biomarkers and objectively assess myofascial tissue physiology in disease and health may be key in moving the diagnosis of mTMD from the pragmatic paradigm to an evidence-based paradigm.

Pathogenesis and Differential Diagnosis of Temporomandibular Joint Disorders

Temporomandibular disorders (TMDs) are an umbrella term including disorders of the temporomandibular joint and muscles of the masticatory system. They are the most common nonodontogenic cause of pain in the orofacial region. A clear understanding of various conditions, underlying mechanisms, clinical presentation, and examination skills is required to effectively diagnose and manage these patients.

Knowledge and awareness of physical therapy role in evaluating and treating temporomandibular disorders among physical therapists in Saudi Arabia

Background

Practitioners, including physical therapists, are not proficiently trained to evaluate and treat individuals with temporomandibular disorders. The purpose of this study is to evaluate the knowledge and awareness of examining and treating temporomandibular disorders among physical therapists in Saudi Arabia.

Methods

An online questionnaire was distributed to physical therapists on different social media platforms. The survey covered demographics characteristics and knowledge of examining and treating temporomandibular disorders. Descriptive statistics were used for data analysis.

Results

A total of 143 participants with a mean of age of 30 (± 6.6) years participated in this study. The majority of participants (n = 109; 76.2%) did not take educational courses on temporomandibular disorders; more than half (n = 84; 58.7%) had never evaluated or treated individuals with temporomandibular disorders. Most physical therapists were aware that they could treat individuals with temporomandibular disorders (n = 121, 84.6%). The most common evaluation methods were temporomandibular joint palpation, jaw movement during opening and closing, and palpation of the masticatory muscles (n = 56, 95%); (n = 49, 83%); (n = 48, 81%), respectively. The common methods used for treatment were therapeutic exercise strengthening, manual therapy, and patient education (n = 49; 83%; n = 46; 78%; n = 33; 56%), respectively. Thirty-one participants (53%) referred patients to other practitioners.

Conclusion

This preliminary study indicates there is a fair level of knowledge, low confidence, low education, and low clinical experience for physical therapists in the evaluation and treatment of temporomandibular disorders in Saudi Arabia. More attention is needed on physical therapy education programs and post-graduate education courses on temporomandibular disorders.

What is the image appearance of juvenile idiopathic arthritis in MRI, CT, and CBCT of TMJ? A systematic review

OBJECTIVE

We performed a systematic review to investigate the appearance of imaging signs on magnetic resonance imaging (MRI), cone-beam computed tomography (CBCT), and conventional computed tomography (CT) scans of the temporomandibular joints (TMJs) of patients with juvenile idiopathic arthritis (JIA).

MATERIALS AND METHODS

We performed electronic searches of the PubMed, Embase, Web of Science, Scopus, Lilacs, and the Cochrane Library databases to identify studies investigating JIA and its related imaging findings. Inclusion criteria were as follows: original article studies based on humans and systematic reviews, studies enrolling patients under 18 years of age with a diagnostic of JIA, the use of International League of Associations for Rheumatology (ILAR) criteria and one type of medical imaging (MRI, CBCT, or CT), and papers published in the English language.

RESULTS

A total of six studies met the inclusion criteria, four involving MRI and two involving CBCT. Additionally, all six studies analyzed the imaging findings of pathological TMJ affected by JIA. The results showed that synovial membrane enhancement, condylar erosions, and condylar flattening were the most prevalent imaging findings in JIA.

CONCLUSION

MRI examinations are more specific for detecting anomalies in the TMJ than CBCT and CT. Additionally, these results must be correlated with clinical signs to verify the correct diagnosis.

CLINICAL RELEVANCE

This study identified the most prevalent imaging signs of JIA to provide an early and correct diagnosis of the disease.

Cross-sectional and longitudinal assessment of subchondral cysts in temporomandibular joints: Clinical and MRI study with a mean follow-up of 66 months

PURPOSE

This observational study aimed to elucidate the pathophysiology of subchondral cysts (SC) in the temporomandibular joint (TMJ) and examine the results of conservative therapy administered to patients with SCs in the TMJ.

METHODS

The study included 41 patients with SCs, extracted from 684 consecutive patients who underwent magnetic resonance imaging (MRI). The anatomical features of SCs and positional abnormalities of the articular disc were initially evaluated using MRI. A second MRI examination was performed for 28/41 patients at 40-107 months (mean, 66 months) after the first MRI. The joint space, anteroposterior width of the condylar head (WiC), articular eminence angle (AEA), and visual analog scale of jaw pain (VAS) were assessed alongside the MRI examinations.

RESULTS

Most SCs were present in the anterosuperior and central condyle. Disc displacement was observed in 100% of 42 TMJs with SCs. Of the 29 joints in 28 patients, SCs in 19 joints resolved with time, whereas SCs in 10 joints persisted. A significant increase in the WiC and a significant decrease in AEA and VAS scores were observed on the second MRI scan.

CONCLUSIONS

SCs tended to form in the anterosuperior and central parts of the condyle, where mechanical loading was likely to be applied. SCs are strongly associated with articular disc displacement. Two-thirds of SCs resolved over time, accompanied by resorption and osteophytic deformation of the condyle. SC might not be an indicator for the start of surgical treatment, and nonsurgical treatment could improve the clinical symptoms of patients with SCs.

Current Trends in the Management of Temporomandibular Joint Dysfunction: A Review

The temporomandibular joint (TMJ) is a synovial bi-condylar joint with 3 degrees of freedom. One-third of the adult population reportedly suffers from temporomandibular joint dysfunction (TMD). Females are more commonly affected than males. Almost 50% of TMD patients do not require any intervention, and the symptoms are self-limiting within one year after the onset; however, 75-80% of adults suffering from TMD require medical intervention and it takes up to three years for the complete remission of the symptoms. The clinical features of TMD are clenching, clicking, and locking of the jaw, and occlusion due to faulty posture. Based on the diagnostic criteria for temporomandibular disorder (DC/TMD) criteria proposed in the year 2014, the classification of TMD is done based on axis I and axis II diagnoses. This review aims to provide an overview of TMD and examine available treatment strategies for TMD. Various conservative treatment methods have been proven to be effective, including self-care strategies, dental treatment strategies, pharmacological treatment, physical therapy modalities, manual mobilization, electrotherapy and dry needling, relaxation techniques, intra-articular injections, cognitive behavioral therapy, and surgical corrections.

A Randomized Controlled Trial Evaluating the Levels of the Biomarkers hs-CRP, IL-6, and IL-8 in Patients with Temporomandibular Disorder Treated with LLLT, Traditional Conservative Treatment, and a Combination of Both

Temporomandibular disorders (TMDs) are a type of idiopathic orofacial pain. Inflammation, particularly elevated circulating levels of high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), and interleukin-8 (IL-8), has been linked to pain symptoms. The purpose of this study was to compare hs-CRP, IL-6, and IL-8 biomarkers and pain intensity with different treatment strategies (LLLT, standard conservative treatment, and combination) for TMD patients. Methods: A total of 32 participants were randomly included in the study and divided into three groups (Group I, Group II, and Group III) referred from the Dental Clinic, School of Dental Science, HUSM. Patients received LLLT (Groups II and III) in five sessions for the duration of 10 days. Patients in Groups I and III received standard conservative TMD treatment (diet and stress counseling, jaw exercises, physical therapy, which was a hot towel application) by the principal investigator. All blood samples for biomarkers were performed before starting treatments and directly after finishing the treatment protocols, where all results were recorded. Results: The result showed a significant difference in the mean IL-8 (p = 0.001) between the three intervention groups (LLLT, standard treatment, and combined treatment). IL-6 showed an increase in the mean of IL-6 levels from baseline to post-treatment with a better mean in the LLLT treatment group without any significant differences. Additionally, there were no significant mean differences found between the groups and in the group for the hs-CRP biomarker. Conclusions: A statistically non-significant difference was found in hs-CRP and IL-6 before and after LLLT, conservative, and combined treatment strategies of TMD. A statistically significant difference was observed in the mean levels of IL-8 between the LLLT intervention group and the combined treatment group. Although there was no statistically significant correlation between pain intensity and biomarkers, a statistically significant difference was found in pain intensity before and after LLLT, conservative, and combined treatment strategies. TMJ degeneration could be exacerbated by elevated IL-8 levels. Thus, this can be an important biomarker to mark or identify the painful condition of TMJ.

Temporomandibular disorder in construction workers associated with ANKK1 and DRD2 genes

The study aimed to explore the influence of genetic polymorphisms in ANKK1 and DRD2 on the signs and symptoms of temporomandibular disorder (TMD) in construction workers. This cross-sectional study included only male subjects. All construction workers were healthy and over 18 years age. Illiterate workers and functionally illiterate workers were excluded. The diagnosis of TMD was established according to the Research Diagnostic Criteria for TMD (RDC/TMD). Genomic DNA was used to evaluate the genetic polymorphisms ANKK1 (rs1800497) and DRD2 (rs6275; rs6276) using Real-Time PCR. Chi-square or Fisher exact tests were used to evaluate genotypes and allele distribution among the studied phenotypes. The established alpha of this study was 5%. The sample included a total of 115 patients. The age of the patients ranged from 19 to 70 years (mean age 38.2; standard deviation 11.7). Chronic pain (87.7%), disc displacement (38.2%), and joint inflammation (26.9%) were the most frequently observed signs and symptoms. The genetic polymorphism rs6276 in DRD2 was associated with chronic pain (p=0.033). In conclusion, our study suggests that genetic polymorphisms in DRD2 and ANKK1 may influence TMD signs and symptoms in a group of male construction workers.

Imaging of the Temporomandibular Joint

Temporomandibular disorder (TMD) is a common musculoskeletal condition that causes pain and disability for patients and imposes a high financial burden on the healthcare system. The most common cause of TMD is internal derangement, mainly secondary to articular disc displacement. Multiple other pathologies such as inflammatory arthritis, infection, and neoplasm can mimic internal derangement. MRI is the modality of choice for evaluation of the TMJ. Radiologists need to be familiar with the normal anatomy and function of the TMJ and MR imaging of the internal derangement and other less common pathologies of the TMJ.

Invasive surgical procedures for the management of internal derangement of the temporomandibular joint: a systematic review and meta-analysis regarding the effects on pain and jaw mobility

OBJECTIVES

This systematic review compared minimally and invasive surgical procedures to manage arthrogenous temporomandibular joint (TMJ).

MATERIALS AND METHODS

The review included clinical trials assessing surgical procedures of arthrogenous temporomandibular disorder (TMD) management by carrying out comparisons within the same surgical procedure (pre- and post-treatment) as well as between different surgical procedures. Meta-analyses were conducted only for similar comparison reporting the same outcome measures, visual analog scale (VAS) values to evaluate pain and maximum incisal opening (MIO) values.

RESULTS

Of the 1,015 studies identified by the search strategy, 26 were selected for full-text reading, and 19 were included in the review. Of these, 16 studies were included in the meta-analysis and 3 in the qualitative analysis. The VAS scores showed significantly lower values after discectomies (p < 0.001) and discoplasties (p < 0.001) in the within-group comparison. Moreover, significantly lower VAS scores and higher MIO values were observed after discectomy compared to arthroscopy, eminectomy, and discoplasty (p < 0.05).

CONCLUSION

The findings of this systematic review suggest that although significantly lower VAS scores and higher MIO values were observed after discectomy, the currently available scientific evidence is unclear, and the use of invasive surgical procedures should be implemented as an efficient first-line treatment option for arthrogenous TMD management.

CLINICAL SIGNIFICANCE

VAS and MIO outcomes could be insufficient to describe the success or failure of open surgical procedures like discectomy and discoplasty.

Needle orientation for temporomandibular joint arthrocentesis in Koreans

OBJECTIVE

To investigate the highest opportunity skin puncture point and needle orientation according to facial asymmetry and classification.

METHODS

Computed tomography of 136 patients was analyzed. Horizontal and vertical angles and distances from the canthal-tragal line were investigated to determine the puncture point and needle's angle.

RESULT

All patients' average points were 7.39 (±2.85) mm anterior to the tragus and 3.44 (±4.18) mm below the canthal-tragal line with an angle of 8.53 (±6.90)° anteriorly and 32.26 (±7.23)° superiorly. Regarding asymmetry, there was a statistical difference in horizontal angle, depth, and canthal-tragal distance between the deviated and non-deviated sides. Especially, vertical distances were 4.44 (±4.66) mm and 2.59 (±4.11) mm in the deviated and non-deviated sides, respectively (p < 0.001).

CONCLUSION

In closed-mouth, the puncture point was closer to the tragus and lower than the conventional point. The point in the deviated side should be considered lower than the non-deviated side.

Comparison of intraarticular injection of platelet-rich plasma following arthrocentesis, with sodium hyaluronate and conventional arthrocentesis for management of internal derangement of temporomandibular joint

Aim:

The aim of the study is to compare the efficacy of platelet-rich plasma (PRP) for the management of internal derangement of temporomandibular joint (TMJ).

Settings and Design:

Thirty-three patients were selected from the pool of patients visiting the department of oral and maxillofacial surgery. Simple randomization was done.

Subjects and Methods:

Patients with anterior disc displacement without reduction (DDWOR) were indicated for arthrocentesis. Group A patients are treated with PRP, Group B patients with sodium hyaluronate following arthrocentesis, and Group C patients were treated with arthrocentesis alone. Postoperative pain and maximal incisal opening are the primary outcomes evaluated.

Statistical Analysis Used:

The collected data were analyzed with IBM. SPSS statistics software 23.0 version and the one-way ANOVA with Tukey's post hoc test were used.

Results:

The mean age is 33 years, with female predominance. The statistical significant differences (P < 0.05) in pain and MIO between the 3 groups at the end of 3^rdweek, 4^thweek, and 3^rd month postoperatively are seen in PRP group comparative to other groups.

Conclusions:

Our study has concluded that the intraarticular injection of PRP is an effective management for anterior DDWOR of TMJ than intraarticular injection of sodium hyaluronate and arthrocentesis in, reducing the pain and improving the interincisal distance in patients with DDWOR, thus providing a rapid recovery and improved quality of life.

Orthodontic management of anterior disc displacement without reduction

This article presents a novel idea for managing patients with anterior disc displacement without reduction that often develops in susceptible patients during routine orthodontic treatment. The patient was a 24-year-old male who presented with class I right molar and canine relationship and class III left molar and canine relationship on a class I skeletal base, complaining of bimaxillary crowding. The case was treated with fixed orthodontic appliance with maxillary expansion and unilateral mandibular extraction to eliminate the mandibular crowding. Due to a life crisis, the patient developed anterior disc displacement on the right joint. A maxillary occlusal splint was fabricated to reduce the symptoms and attempt to recapture the disc; however, this attempt failed. An attempt was then made to recapture the disc using occlusal pivots and elastics. The disc was eventually recaptured, and the patient resumed normal jaw function and mouth opening. This case report aims to demonstrate a new way to achieve stable occlusion in a patient who sustained disc displacement.

VALUE OF ULTRASONOGRAPHY METHOD IN THE DIAGNOSIS OF TEMPOROMANDIBULAR DISORDERS AND PATIENT MANAGEMENT MONITORING. CASE REPORT

Value of ultrasonography method in the diagnosis of temporomandibular disorders and patient management monitoring is underestimated. Application of ultrasonography in the diagnosis of patients with temporomandibular disorders in many countries is limited. The main advantage and feature of the method is the ability to conduct examination in dynamics (during the function). Its safety and availability allow applying the method often and at different stages of diagnosis and treatment. So, ultrasonography fully satisfies the needs of primary diagnosing. MRI remains the recognized «gold standard» for the diagnosis of temporomandibular disorders. A case report which is presented, demonstrates the relevance and scope of diagnostic information obtained by ultrasonography, and their verification and clarification with the use of magnetic resonance imaging. Upon comparing the results of USG and MRI described in the clinical case report, we can conclude that ultrasound is quite sensitive and specific in diagnosing anterior disc displacement and blocked movement of the head of the mandible.

Elder Mice Exhibit More Severe Degeneration and Milder Regeneration in Temporomandibular Joints Subjected to Bilateral Anterior Crossbite

Temporomandibular joints (TMJs) have a biomechanical relationship with dental occlusion. Aberrant occlusion initiates degenerative remodeling responses in TMJ condyles. Aging is a promoting factor of osteoarthritis (OA) development. The aim of this study was to assess the effect of aging on degenerative remodeling in TMJ condyles in response to occlusal biomechanical stimulation caused by the installation of aberrant prostheses and observe rehabilitation after their removal. The experiments involved 84 female C57BL/6J mice (42 at 6 weeks old and 42 at 28 weeks old). A bilateral anterior crossbite (BAC) model was developed, and the TMJs were sampled at 3, 7, and 11 weeks. BAC was removed at 7 weeks in a subset of mice, which accepted BAC treatment at 6 week of age, and maintained for another 4 weeks after BAC removal. TMJ changes were assessed with micro-CT, histomorphology, immunohistochemistry (IHC), and immunofluorescence staining assays. The results showed that BAC induced typical OA-like TMJ lesions that were more severe in the elder groups as evaluated by the acellular zones, clustered chondrocytes, fissures between cartilage and subchondral bone, reductions in matrix amount and the cartilage thickness as revealed by histomorphological measurements, and subchondral bone loss as detected on micro-CT images. IHC indicated significant increases in cleaved caspase-3-expressing cells and decreases in ki67-positive cells in the BAC groups. There were obvious age-dependent changes in the numbers of superficial zone cells and CD90-expressing cells. Supportively, cleaved caspase-3-expressing cells obviously increased, while ki67-expressing cells significantly decreased with aging. In the elder BAC groups, the superficial zone cells such as CD90-expressing cells were greatly reduced. At 11 weeks, the superficial zone cells were almost non-existent, and there were clear serrated injuries on the cartilage surface. BAC removal attenuated the degenerative changes in the condylar cartilage and subchondral bone. Notably, the rescue effect was more pronounced in the younger animals. Our findings demonstrate the impacts of aging on both TMJ degenerative changes in response to BAC and regenerative changes following BAC removal. The reduced number of chondro-progenitor cells in aged TMJ cartilage provides an explanation for this age-related decline in TMJ rehabilitative behaviors.

Hyaluronan injection versus oral glucosamine and diclofenac in the treatment of temporomandibular joint osteoarthritis

OBJECTIVES

This study was aimed to compare the effects of 4 biweekly hyaluronan (HA) injection with glucosamine and diclofenac oral administration on TMJ OA patients.

MATERIALS AND METHODS

This retrospective cohort study included TMJ OA patients who had the treatment of 4 biweekly HA injection (group HA) or oral glucosamine hydrochloride for 3 months and diclofenac sodium for 2 weeks (group G/D), and had complete data at first-visit, 3 months, 6 months, and 12 months. Clinical signs and symptoms were scored by anamnestic dysfunction index (Ai) and clinical dysfunction index (Di), and condylar bone changes were evaluated by CBCT scoring system.

RESULTS

We included 22 patients in group HA and 20 patients in group G/D. After HA injection, Ai was decreased from 4.3 to 1.6(CI [- 4.0, - 1.4]) at 3-month follow-up, which was smaller than that in group G/D significantly. Di in group HA was declined significantly from 8.1 at first-visit to 3.6 at 3-month follow-up, while Di in group G/D scarcely changed until at 6- and 12-month follow-up. Neither HA injection nor oral glucosamine/diclofenac showed positive effect on the bone of TMJs during follow-ups with statistical significance.

CONCLUSIONS

HA injection alleviated signs and symptoms of TMJ OA rapidly and presented superior clinical effects over oral glucosamine with diclofenac. However, both treatments did not limit the bone destruction of TMJs significantly.

CLINICAL RELEVANCE

This cohort study provides knowledge on the symptom relief and bone changes of TMJ OA patients when treated with HA injection or glucosamine and diclofenac oral administration.

High pretreatment systemic immune-inflammation index values are associated with diminished short-term success after temporomandibular joint arthrocentesis procedure

Background

The systemic immune-inflammation index (SII) has been demonstrated to be a valid biomarker of a patient's immunological and inflammatory state, with the ability to accurately predict outcomes in a variety of disease conditions. In the absence of comparable studies, we intended to examine the relevance of pretreatment SII in predicting the success rates of temporomandibular joint arthrocentesis (TMJA) at 1-week, 1-month, and 6-month periods, defined as maximum mouth opening (MMO) > 35 mm and VAS ≤ 3.

Methods

A sum of 136 patients with disc displacement without reduction (DDwo-red) who underwent TMJA was included. For each patient, pre-TMJA SII was calculated as; SII = Platelets × neutrophils/lymphocytes. Additionally, baseline MMO and VAS measurements were recorded for each patient. The success criteria of TMJA included MMO > 35 mm and VAS ≤ 3. The optimal pre-TMJA SII cutoff that predicts TMJA success was determined using receiver operating characteristic (ROC) curve analysis. The primary endpoint was the link between the pre-treatment SII and TMJA success (simultaneous achievement of MMO > 35 mm and VAS ≤ 3).

Results

The median pre-TMJA jaw locking duration, maximum mouth opening (MMO), and visual analog score (VAS) were 7 days, 24 mm, and 8, respectively. The overall TMJA success rates were determined as 80.1%, 91.9%, and 69.1% at 1-week, 1-month, and 6-months, respectively. The results of ROC curve analysis exhibited the optimal SII cutoff at 526 (AUC: 67.4%; sensitivity: 66.7%; specificity: 64.2%) that grouped the patients into two subgroups: Group 1: SII ≤ 526 (N = 81) and SII > 526 (N = 55), respectively. Spearman correlation analysis revealed a strong inverse relationship between the pretreatment SII values and the success of TMJA 1-week (r_s: − 0.83; P = 0.008) and 1-month, (r_s: − 0.89; P = 0.03). Comparative analyses displayed that TMJA success rates at 1-week (87.7% vs. 69.1%; P = 0.008) and 1-month (96.2% vs. 80%; P = 0.03) were significantly higher in the SII ≤ 526 than SII > 526 group, respectively, while the 6-month results favored the SII ≤ 526 group with a trend approaching significance (P = 0.084).

Conclusion

The current study's findings suggested the SII as a unique independent prognostic biomarker that accurately predicts treatment outcomes for up to 6 months.

Trial registration The results of this research were retrospectively registered.

Factors influencing the articular eminence of the temporomandibular joint (Review)

The temporomandibular joint (TMJ), the most complex and evolved joint in humans, presents two articular surfaces: the condyle of the mandible and the articular eminence (AE) of the temporal bone. AE is the anterior root of the zygomatic process of the temporal bone and has an anterior and a posterior slope, the latter being also known as the articular surface. AE is utterly important in the biomechanics of the TMJ, as the mandibular condyle slides along the posterior slope of the AE while the mandible moves. The aim of this review was to assess significant factors influencing the inclination of the AE, especially modifications caused by aging, biological sex or edentulism. Studies have reported variations in the angles of the slopes of the AE between medieval and recent human dry skulls, as well as between subjects of different racial origin. Recent articles have emphasized the significant role that tooth loss has on the flattening of the AE. Although some papers have described biological sex or age as factors which could be associated with differences in AE angulations, edentulism seems to be a significant factor impacting on the inclination of the AE.

The Effectiveness of Physical Therapy in Patients with Generalized Joint Hypermobility and Concurrent Temporomandibular Disorders-A Cross-Sectional Study

Temporomandibular disorders (TMD) consist of a group of symptoms such as: pain of temporomandibular joints, masticatory muscles or surrounding tissues, dysfunctions of TMJs’ mobility, and crepitation. The Hypermobility Joint Syndrome (HJS) manifests in the flaccidity of joint structures, an increase in the range of joint motion, and occurs more often in the young and women. The aim of this study was to present the occurrence of HJS among patients with myogenic TMD and disc displacement with reduction. The secondary goal was to assess the effectiveness of physiotherapy directed to TMD with coexisting HJS. The study involved 322 patients with symptoms of TMD. HJS was diagnosed using the Beighton Scale, which confirmed its occurrence in 26 cases. 79 subjects (7 males and 72 females; mean age, 33.9 ± 10.4 years) were selected and divided into two groups: HJS + TMD (n = 26; 2 males and 24 females; mean age, 27.1 ± 9.4 years) and TMD (n = 53; 5 males and 48 females; mean age, 37.4 ± 9.2 years). These patients completed 3-week physiotherapy management. Before and after physiotherapy, the myofascial pain severity on Numeric Pain Rating Scale, linear measurement of maximum mouth opening, and opening pattern, were assessed. To demonstrate differences between the results, the level of significance for statistical analysis was set at α = 0.05. A statistically significant improvement was obtained in decreasing myofascial pain in both groups. Coordination of mandibular movements was achieved in both groups. Generalized joint hypermobility occurred among patients with TMD. Physiotherapy directed to TMD was effective in reducing myofascial pain and restoring TMJ’s coordination also in patients with HJS.

Systematic review of studies on drug-delivery systems for management of temporomandibular-joint osteoarthritis

INTRODUCTION

Temporomandibular-joint osteoarthritis (TMJOA) management is a major challenge. Minimally invasive therapies (based mainly on injections) have been developed to increase local efficacy and limit adverse systemic effects. However, the requirement for repeat injections due to a short duration of action and expensive healthcare costs have pushed researchers to develop, via tissue engineering, drug-delivery systems (DDSs). In this literature systematic review, we aim to provide an overview of studies that tested DDSs on a TMJOA model.

MATERIAL AND METHODS

We searched on PubMed for articles published from November 1965 to March 2021 on DDSs using a TMJOA model. We highlighted the different DDSs and the active molecule employed. Route of drug administration, model type, test duration, and efficacy duration were assessed. To evaluate the quality of each study, a protocol bias was tested using QUADAS-2™.

RESULTS

Of the 10 studies that were full text-screened, four used a poly(lactic-co-glycolic acid)-based delivery system. The other DDSs employed chitosan-based hydrogels, microneedles patches, nanostructured lipid carriers, or poloxamer micelles. Hyaluronic acid, nonsteroidal anti-inflammatory drugs, and analgesics were used as active molecules in five studies. The main way to administer DDSs was intra-articular injection and the most used model was the rat.

DISCUSSION

Various DDSs and active molecules have been studied on a TMJOA model that could aid TMJOA management. Further works using longer test durations are necessary to validate these advances.

Automated cortical thickness measurement of the mandibular condyle head on CBCT images using a deep learning method

This study proposes a deep learning model for cortical bone segmentation in the mandibular condyle head using cone-beam computed tomography (CBCT) and an automated method for measuring cortical thickness with a color display based on the segmentation results. In total, 12,800 CBCT images from 25 normal subjects, manually labeled by an oral radiologist, served as the gold-standard. The segmentation model combined a modified U-Net and a convolutional neural network for target region classification. Model performance was evaluated using intersection over union (IoU) and the Hausdorff distance in comparison with the gold standard. The second automated model measured the cortical thickness based on a three-dimensional (3D) model rendered from the segmentation results and presented a color visualization of the measurements. The IoU and Hausdorff distance showed high accuracy (0.870 and 0.928 for marrow bone and 0.734 and 1.247 for cortical bone, respectively). A visual comparison of the 3D color maps showed a similar trend to the gold standard. This algorithm for automatic segmentation of the mandibular condyle head and visualization of the measured cortical thickness as a 3D-rendered model with a color map may contribute to the automated quantification of bone thickness changes of the temporomandibular joint complex on CBCT.

Biological Treatments for Temporomandibular Joint Disc Disorders: Strategies in Tissue Engineering

The temporomandibular joint (TMJ) is an important structure for the masticatory system and the pathologies associated with it affect a large part of the population and impair people's lifestyle. It comprises an articular disc, that presents low regeneration capacities and the existing clinical options for repairing it are not effective. This way, it is imperative to achieve a permanent solution to guarantee a good quality of life for people who suffer from these pathologies. Complete knowledge of the unique characteristics of the disc will make it easier to achieve a successful tissue engineering (TE) construct. Thus, the search for an effective, safe and lasting solution has already started, including materials that replace the disc, is currently growing. The search for a solution based on TE approaches, which involve regenerating the disc. The present work revises the TMJ disc characteristics and its associated diseases. The different materials used for a total disc replacement are presented, highlighting the TE area. A special focus on future trends in the field and part of the solution for the TMJ problems described in this review will involve the development of a promising engineered disc approach through the use of decellularized extracellular matrices.

Physical therapist guided active intervention of chronic temporomandibular disorder presenting as ear pain: A case report

This case report describes the successful physical therapy management of a 40-year-old female who presented with left ear pain referred from the temporomandibular joint. Diagnosis was primarily based on clinical examination findings and ruling out of red flags. Guidance was given on active self-care approaches consisting of pain neuroscience education designed with individualized pain curriculum, exercise therapy, manual therapy, and breathing exercises for a period of  sixweeks. Clinically meaningful improvements were obtained in the outcome measures of Numeric Pain Rating Scale (NPRS), Patient-Specific Functional Scale (PSFS), and Global Rating of Change (GROC) scale and progress in Pain-Self Efficacy Questionnaire (PSEQ) and Tampa Scale for Kinesiophobia (TSK) scores. Positive changes were achieved with functional activities (chewing, eating, yawing, brushing teeth and physical intimacy), and the patient was pain-free on discharge, which was maintained at a six-month follow-up.

Effect of botulinum toxin on quality of life of patients with chronic myofascial pain

Aim: This prospective controlled clinical study aimed to evaluate the effect of botulinum toxin Type A (BTX-A) on pain control and quality of life (QoL) in patients with chronic myofascial pain. Materials & methods: Patients with chronic myofascial pain were randomly divided into two groups (n = 20): counseling and self-care and Michigan-type occlusal splint (MOS) (CG-control group) or BTX-A injection (BTX-AG). The pain was evaluated with visual analogue scale and QoL with the oral health impact profile-14 (OHIP-14) questionnaire. Results: In both groups, the pain was reduced, and QoL improved after 30 days. The results of social disability and handicap were better for patients treated with counseling and self-care and MOS. Conclusion: Minimally invasive strategies and BTX-A application improved QoL and alleviated myofascial pain.

Determining the optimal magnetic resonance imaging sequences for the efficient diagnosis of temporomandibular joint disorders

Background

To compare and analyze nine MRI sequences of the TMJ and determine the optimum sequence for the rapid diagnosis of TMDs so as to develop new clinical guidelines.

Methods

Twenty young volunteers (a total of 40 joints) aged 22-26 years were recruited. Three basic sequences, T₁-weighted imaging (T₁WI), T₂-weighted imaging (T₂WI), and proton density-weighted imaging (PDWI), together with three positions, oblique sagittal (OSag) with closed mouth, oblique coronal (OCor) with closed mouth, and OSag with opened mouth, were selected in combination for testing. In the OCor position, four regions of interest (ROIs), the condyle (C), the disc (D), the disc outside (DO), and fat (F), were analyzed. For the OSag with closed mouth position and the OSag with opened mouth position sequences, the four ROIs were the condyle (C), the disc (D), the disc ahead (DA), and the disc rear (DR). The signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and signal intensity ratio (SIR) were calculated and analyzed using independent sample t-tests and one-way analysis of variance. Two senior radiologists scored the images of the nine MRI sequences subjectively and selected three optimal sequences. Using the three selected sequences, 1479 patients with anterior disc displacement with reduction (ADDwR) or anterior disk displacement without reduction (ADDwoR) were evaluated by comparing the preoperative TMJ MRI with the outcomes of the maxillofacial arthroscopy or open surgery.

Results

The T₁WI sequence showed the highest SNR while the T₂WI group had the lowest SNR. The ROIs of the T₂WI group had the highest CNR and SIR values in the OCor and OSag sequences. In the OCor sequence, the value for the SIR F/DO group was higher than the SIR C/D and SIR C/DO values. Using subjective analysis to evaluate the quality of the scans, the highest total scores were obtained for the OSag T₂WI with opened mouth and OSag PDWI with closed mouth sequences. From the objective and subjective analysis, the three optimal sequences selected were OSag PDWI, OCor T₂WI with closed mouth, and OSag T₂WI with opened mouth. In patients with anterior disc displacement, the comparisons of the surgery and the selected MRI sequences indicated that the total diagnostic accuracy of the MRI was 96.3% (1,425/1,479 cases). For patients with ADDwoR, the diagnostic accuracy was 98.5% (1,372/1,393 cases), and for those with ADDwR it was 61.6% (53/86 cases). There were significant differences between the ADDwoR and ADDwR groups (χ²=312.92, P<0.01).

Conclusions

The three optimal MRI sequences for the rapid and efficient diagnosis of TMD were determined to be OSag PDWI, OCor T₂WI with closed mouth, and OSag T₂WI with opened mouth.

Orally Administered NSAIDs-General Characteristics and Usage in the Treatment of Temporomandibular Joint Osteoarthritis-A Narrative Review

Background: Temporomandibular joint osteoarthritis (TMJ OA) is a degenerative joint disease. The aim of this review was to present the general characteristics of orally administered nonsteroidal anti-inflammatory drugs (NSAIDs) and to present the efficacy of NSAIDs in the treatment of TMJ OA. Methods: PubMed database was analyzed with the keywords: "(temporomandibular joint) AND ((disorders) OR (osteoarthritis) AND (treatment)) AND (nonsteroidal anti-inflammatory drug)". After screening of 180 results, 6 studies have been included in this narrative review. Results and Conclusions: Nonsteroidal anti-inflammatory drugs are one of the most commonly used drugs for alleviation of pain localized in the orofacial area. The majority of articles predominantly examined and described diclofenac sodium in the treatment of pain in the course of TMJ OA. Because of the limited number of randomized studies evaluating the efficacy of NSAIDs in the treatment of TMJ OA, as well as high heterogeneity of published researches, it seems impossible to draw up unequivocal recommendations for the usage of NSAIDs in the treatment of TMJ OA. However, it is highly recommended to use the lowest effective dose of NSAIDs for the shortest possible time. Moreover, in patients with increased risk of gastrointestinal complications, supplementary gastroprotective agents should be prescribed.