Temporomandibular disorders: a review of etiology, clinical management, and tissue engineering strategies

Temporomandibular Junction Disorders

Temporomandibular junction disorders (TMD) are a common problem for patients presenting to the primary care office. Symptoms may be acute or chronic. Patients may report a variety of complaints such as: painful clicking at the joint, difficulty opening the mouth or chewing, tenderness in the muscles around the joint, headaches, or tinnitus. Physical examination findings vary and may include palpable tenderness or spasm of the pterygoid muscles, palpable or audible clicking at the joint, wear and tear of tooth enamel, or dental malocclusion. Most TMDs respond well to conservative therapy, but some patients may benefit from more invasive treatments.

Quality and reliability evaluation of YouTube® exercises content for temporomandibular disorders

OBJECTIVES

YouTube is a popular source for health-related content, including exercises for temporomandibular disorders (TMD). This study aimed to evaluate the content and quality of YouTube videos on TMD exercises.

METHODS

A systematic search on YouTube using keywords related to TMD exercises and rehabilitation identified relevant videos. Two researchers independently assessed these videos. Content was evaluated using the Video Information and Quality Index (VIQI), reliability with modified DISCERN, and quality with the Global Quality Scale (GQS).

RESULTS

One hundred twenty one exercise videos were included in the study. Of these, 47 (38.3%) were helpful, and 89 (73.6%) were uploaded by healthcare professionals. Useful and misleading videos had similar metrics for views, likes, comments, and interaction (p > 0.05), but useful videos had longer durations and older upload dates (p < 0.05). Cohen's Kappa scores showed substantial agreement between raters (mDISCERN = 0.709, GQS = 0.753). The Intraclass Correlation Coefficient for VIQI was 0.907. Significant differences were found in mDISCERN, GQS, and VIQI scores based on the source and usefulness of videos (p < 0.05), with high correlations among the instruments (r = 0.740 to 0.909). The area under the curve for the instruments ranged from 0.785 to 0.876.

CONCLUSIONS

The majority of YouTube videos on TMD exercises were deemed useful, primarily uploaded by healthcare professionals, and contained reasonably safe, accurate, and quality information. Although this may seem like a positive outcome, unfortunately there was no explanation of TMD diagnoses in the videos. Therefore, it was unclear which types of TMD pathologies the videos were addressing.

Automated pediatric TMJ articular disk identification and displacement classification in MRI with machine learning

OBJECTIVE

To evaluate the performance of an automated two-step model interpreting pediatric temporomandibular joint (TMJ) magnetic resonance imaging (MRI) using artificial intelligence (AI). Using deep learning techniques, the model first automatically identifies the disk and the TMJ osseous structures, and then an automated algorithm classifies disk displacement.

MATERIALS AND METHODS

MRI images of the TMJ from 235 pediatric patients (470 joints) were reviewed. TMJ structures were segmented, and the disk position was classified as dislocated or not dislocated. The UNet++ model was trained on MRI images from 135 and tested on images from 100 patients. Disk displacement was then classified by an automated algorithm assessing the location of disk centroid and surfaces for bone landmarks.

RESULTS

The mean age was 14.6 ± 0.1 years (Female: 138/235, 58 %), with 104 of 470 disks (22 %) anteriorly dislocated. UNet++ performed well in segmenting the TMJ anatomical structures, with a Dice coefficient of 0.67 for the disk, 0.91 for the condyle, and a Hausdorff distance of 2.8 mm for the articular eminence. The classification algorithm showed disk displacement classification comparable to human experts, with an AUC of 0.89-0.92 for the distance between the disk center and the eminence-condyle line.

CONCLUSION

A two-step automated model can accurately identify TMJ osseous structures and classify disk dislocation in pediatric TMJ MRI. This tool could assist clinicians who are not MRI experts when assessing pediatric TMJ disorders.

CLINICAL SIGNIFICANCE

Automated software that assists in locating the articular disk and surrounding structures and classifies disk displacement would improve the TMJ-MRI interpretation and the assessment of TMJ disorders in children.

Bruxism repercussions in muscular activation: Ultrasound differences in abdominal wall between women with and without bruxism. A cross-sectional study

INTRODUCTION

Bruxism, often triggered by stress, induces temporomandibular alterations, increasing muscle activity and affecting dental occlusion. Prevalence of musculoskeletal conditions related to stress is higher in women, with craneo-cervical affectation being frequently reported. Moreover, some authors explore the relationship between temporomandibular disorders and postural alteration, affecting the trunk complex. This study aims to evaluate differences in abdominal muscle morphology between women with and without bruxism in Spain, and, secondarily, the effects of voluntary teeth grinding in abdominal muscle activation.

METHODOLOGY

An observational analytical cross-sectional study was conducted with 44 Spanish women (diagnosed with bruxism = 22, non-bruxism = 22). To ensure and corroborate the absence of bruxism from the control group, the Clinical Based Assesment questionnaire was used. Ultrasound measures of Transverse Abdominal, External Oblique and Internal oblique were recorded during rest and voluntary grinding.

RESULTS

Grinding was associated with changes in abdominal muscle thickness in both groups, with statistically significant higher thickness values for all studied muscles. Moreover, the Bruxism group showed statistically significant higher values for all muscles in grinding conditions compared to the Non-Bruxism group. Significant differences in left transverse abdominal thickness were found between groups in resting condition. Further analysis using linear regression indicated that both Bruxism (t = -2.03, p = 0.049) and BMI (t = 3.13, p = 0.003) were significantly associated with muscle thickness, with BMI acting as a confounding factor. Age was not a significant predictor (p = 0.506), suggesting its limited role in this context.

CONCLUSION

The results of this study support the existence of an association between bruxism and the abdominal wall muscles structure and activation. This emphasizes the importance of considering bruxism in the evaluation of abdominal muscle function.

Association between estrogen receptors polymorphisms and temporomandibular joint disorders: A systematic review

OBJECTIVES

This systematic review aimed to investigate the association between genetic polymorphisms in estrogen receptor alpha (ERα) and beta (ERβ) and the presence and severity of temporomandibular disorders (TMDs).

MATERIALS AND METHODS

A comprehensive search was conducted in PubMed, Scopus and Web of Science on October 19, 2024, without language or time restrictions. Studies were included if they were cross-sectional, case-control, or cohort designs and reported data on ER-polymorphisms and TMDs, diagnosed using validated criteria. Two independent reviewers screened the results to identify eligible studies. Data were extracted and synthesized narratively due to high heterogeneity across included studies, with a subgroup analysis performed to evaluate the influence of sex. The risk of bias was assessed using the Joanna Briggs Institute's critical appraisal tools.

RESULTS

The search identified 277 articles, of which 8 studies met the inclusion criteria. Seven were case-control and two cross-sectional studies. The most commonly investigated ER polymorphisms were ESR1 (Pvu II and Xba I) and ESR2 (rs1676303). Some studies identified associations between specific polymorphisms and TMD-related pain or joint conditions, although results varied across different populations and subtypes of TMDs.

CONCLUSIONS

The findings suggest potential associations between specific ERα and ERβ polymorphisms and TMD risk, particularly in women. However, inconsistencies across studies underscore the need for prospective and larger studies to confirm these genetic links and clarify their clinical significance.

SYSTEMATIC REVIEW REGISTRATION

CRD42024581266.

Diagnostic accuracy of ultrasonography compared with magnetic resonance imaging in diagnosing disc displacement of the temporomandibular joint: A systematic review and meta-analysis

STATEMENT OF PROBLEM

Diagnosing temporomandibular disorders without an adjunctive chairside diagnostic tool has made the management of temporomandibular disorders challenging and subjective. The use of magnetic resonance imaging, considered the standard imaging modality, is hindered because of high cost, a long learning curve, availability, and a longer examination time.

PURPOSE

The purpose of this systematic review and meta-analysis was to determine whether ultrasonography could be a chairside tool to help clinicians diagnose disc displacement in temporomandibular disorders.

MATERIAL AND METHODS

An electronic search was conducted of the PubMed (including MEDLINE) and Cochrane Central database and the Google Scholar search engine for articles published from January 2000 to July 2020. Studies were chosen based on the inclusion criteria, which included the diagnostic technique's sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) with respect to imaging the displacement of the articular disc. The quality assessment of diagnostic accuracy studies (QUADAS- 2) tool was applied to assess the risk of bias for the included studies. The Meta-Disc 1.4 and RevMan 5.3 software program were used to conduct the meta-analysis.

RESULTS

Seventeen articles were included in this systematic review, and a meta-analysis of 14 articles was done after applying the inclusion and exclusion criteria. None of the included articles were considered to have applicability concerns; however, 2 articles had a high risk of bias. The sensitivities and specificities for the different selected studies vary substantially from 21% to 95% with a good pooled sensitivity estimate of 71% while the specificities varied from 15% to 96% with a good pooled specificity estimate of 76%.

CONCLUSIONS

This systematic review and meta-analysis suggested that ultrasonography may have clinically acceptable diagnostic accuracy in diagnosing disc displacement of the temporomandibular joint, allowing the treatment of patients with temporomandibular disorders with greater assurance and success. Additional training in the operation and interpretation of ultrasonography is required to reduce the learning curve and make the use of ultrasonography relevant, straightforward, and routine in dentistry to supplement clinical examination and diagnosis in patients with suspected disc displacement of the temporomandibular joint. The evidence acquired needs to be standardized, and further research is required to provide stronger evidence.

Extraction of 3D trajectories of mandibular condyles from 2D real-time MRI

OBJECTIVE

Computing the trajectories of mandibular condyles directly from MRI could provide a comprehensive examination, providing both anatomical and kinematic details. This study aimed to investigate the feasibility of extracting 3D condylar trajectories from 2D real-time MRI.

MATERIALS AND METHODS

Twenty healthy subjects underwent real-time MRI while performing jaw opening and closing movements. One axial and two sagittal slices were segmented using a U-Net-based algorithm. After motion compensation, the centers of mass of the resulting masks were projected onto the coordinate system based on anatomical markers and temporally adjusted. The quality of the computed trajectories was evaluated using metrics designed to estimate movement reproducibility, head motion, and slice placement symmetry.

RESULTS

The segmentation of the axial slices demonstrated good-to-excellent quality; however, the segmentation of the sagittal slices required some fine-tuning. On average, the intercuspal position shifted by 0.6 mm after an opening-closing cycle. The difference in the superior-inferior coordinate of the condyles in the intercuspal position was 1.5 mm on average. Some subjects demonstrated a significant discrepancy between the axial and the sagittal trajectories.

DISCUSSION

Real-time MRI enables the extraction of condylar trajectories for evaluating some clinically relevant parameters. However, attention is required during patient installation and image acquisition.

Relationship Between Estrogen and Idiopathic Mandibular Condylar Resorption: A Systematic Literature Review

Background and Objectives: Pain in the TMJ is the second most common in the orofacial region. The objective of this systematic review was to assess whether a decrease in estrogen levels increases the risk of idiopathic condylar resorption by reviewing relevant literature and evidence. Material and Methods: This systematic review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A comprehensive search was performed in the PubMed (Medline), Science Direct (Elsevier), and Web of Science electronic databases. Results: The initial database search identified a total number of 453 studies. After applying the selection criteria, 36 articles were selected for a full-text analysis, and nine studies involving 1105 patients were included in the systematic review. According to the Newcastle-Ottawa Scale (NOS), two of the included articles were graded as being of "Moderate" quality and one was of "Fair" quality. After evaluating the rest of the articles according to the AXIS tool for cross-sectional studies, we generally found that the reliability is moderate. The results show that the decrease in estrogen promotes the occurrence of inflammation in the temporomandibular joint, and some sources mention that it increases the occurrence of idiopathic joint resorption, but we did not establish a complete correlation between the level of estrogen and idiopathic joint resorption. Conclusions: This systematic review indicates that there is no evidence suggesting that fluctuations in estrogen levels contribute to idiopathic mandibular condylar resorption, but reduced estrogen levels can be associated with chronic pain in the temporomandibular joint.

Development of a 3D cephalometric index to grade severity of dentofacial deformity in patients with juvenile idiopathic arthritis

This investigation aimed to develop a radiographic 3D cephalometric index to grade severity of dentofacial deformity in patients with juvenile idiopathic arthritis (JIA), and to perform a validation against expert evaluations. Data were collected from a population-based Nordic JIA cohort of 240 patients that received a cone-beam computed tomography (CBCT) scan approximately 17 years after onset of JIA. The cohort was randomized into two groups: A baseline group for establishing the index (n = 210) and a test group (n = 30). The standardized index generation process led to the inclusion of six radiographic outcome measures, each representing different facets of dentofacial deformities. Specific severity scores were established for three domains; dentofacial asymmetry (0-8), vertical deviation (0-8), and sagittal deviation (0-8). An overall dentofacial deformity index score was computed by aggregating the scores from the six variables, with the total score ranging from 0 to 24. The validity of the index was assessed by comparing the index score with expert evaluations. Based on the generated index, 10 patients exhibited severe deformities. Reliable agreement between data-generated index scores and expert assessments was found. A 3D radiographic dentofacial deformity index was generated and tested. This index can support an objective assessment of the severity of dentofacial deformities related to JIA in a clinical setting and future research.

TMJ Replacement in Degenerative Disease: A Systematic Review

Objectives: This study aims to describe and analyze the indications and clinical results of total TMJ replacement in participants with degenerative and/or inflammatory joint diseases, defining patient and intervention conditions. Methods: A systematic review was conducted according to the Cochrane Handbook for Systematic Reviews of Intervention and reported according to the PRISMA Items update. The search strategy was from 1997 to July 2024 in Pubmed, Embase, Scopus, and Web of Science. A search for gray literature was conducted in the databases Google Scholar and Open Access Theses and Dissertations (OATD), and there were no limitations on the language or study design. We incorporated studies involving human patients over 15 years of age with degenerative and/or inflammatory joint conditions who underwent joint prosthesis replacement, either concurrently or separately from orthognathic surgery, as an initial intervention or after prosthesis installation. Participants with a postoperative follow-up of 12 months or longer were included. A risk of bias analysis was performed for non-randomized studies using the ROBINS-I tool, and GRADE profiler (GRADEpro) software was used to assess the quality of evidence and synthesize the data. Results: All the selected studies performed postoperative follow-up with quantitative and qualitative parameters; 10 performed a follow-up of 2 to 5 years. The indication for joint prosthesis replacement due to system failure was only 4.07%. Concerning diagnoses, 579 presented degenerative and/or inflammatory joint diseases, with osteoarthritis being the most frequent, followed by osteoarthrosis, juvenile idiopathic arthritis, and rheumatoid arthritis. The maximum mouth opening of the participants with TMJ disease presented an average of 24.32 ± 5.8 mm with a range of 18 to 36.4 mm. Of the 579 participants, the studies mention that they presented a soft to liquid diet and pain associated with decreased mandibular functionality. Conclusions: A total of 76.18% of the participants presented a range of moderate to severe pain associated with a decrease in functionality and, after joint replacement, all participants mentioned a decrease in pain or absence of pain, a change in diet by incorporating solid foods, and an increase in opening with an average of 40.74 ± 3.1 mm. Total joint replacement shows favorable long-term results. It is not possible to identify the best time to perform joint replacement surgery, considering the time since diagnosis of the disease, the time since the start of non-surgical treatment, or the number of previous surgeries.

Effect of dry needling, ischemic compression and cross-taping of the masseter in patients with orofacial myofascial pain: a randomized comparative study

Background and objective

Temporomandibular disorders, of multifactorial etiology, refer to a series of pathologies that affect the temporomandibular joint and the associated musculature of the orofacial region and are the result of alterations in the physiological relationships of the stomatognathic system, responsible for functions such as chewing, phonation and swallowing. They produce, among other symptoms, mainly pain, which affects the quality of life of the patients who suffer from them. To alleviate the discomfort of neuromuscular pathology in the orofacial region, various therapeutic strategies are employed, ranging from non-invasive to more invasive methods. The aim of the study was to compare the efficacy of three therapeutic methods (dry needling, ischemic compression and cross-taping) in reducing or relieving masseter pain in individuals with orofacial myofascial pain.

Materials and methods

A multicenter randomized comparative clinical trial was conducted in 60 subjects over 18 years of age, divided into three groups: dry needling, ischemic compression and cross-taping. Pain intensity was assessed, randomly, by a single blinded evaluator, according to the Numerical Pain Rating Scale in the pre-treatment period, immediately after, 1-2 weeks and one month later.

Results

Immediately after applying the therapies, there was a greater decrease in pain intensity in dry needling, followed by ischemic compression and a smaller decrease in the cross-taping technique (p < 0.0001; p = 0.0001; p = 0.0014, respectively). After 1-2 weeks, there was a noticeable increase in the dry needling technique, however, there was a decrease in pain in the cross-taping technique. After 1 month of application, both dry needling and ischemic compression showed a slight reduction in pain intensity, in contrast to the cross-taping group, which showed an increase in pain intensity.

Conclusions

Dry needling and ischemic compression were more effective than cross-taping for immediate reduction of orofacial myofascial pain. Further short- and long-term research is needed to confirm these findings.

Clinical Trial Registration

clinicaltrials.gov, identifier (NCT0660604).

Panoramic Radiographic Analysis of Age- and Sex-related Variations in Upper Mandibular Morphology: Focus on the Condyle, Sigmoid Notch, and Coronoid Process

BACKGROUND/AIM

This study aimed to investigate age- and sex-related morphological variations of the mandibular condyle, sigmoid notch, and coronoid process in a mid-sized German population using panoramic radiographs.

PATIENTS AND METHODS

A total of 150 participants (89 males, 61 females) aged between 18 and 80 years were included. Participants were divided by age and sex. Panoramic radiographs were obtained, and the right and left condylar processes, sigmoid notches, and coronoid processes were evaluated for shape variations.

RESULTS

Age-related differences were found in the mandibular condyles, with younger individuals exhibiting round-shaped condyles more frequently, while older participants showed a higher prevalence of flat-shaped condyles (p<0.001). Sex-related differences included females displaying more diamond-shaped condyles (p=0.033) and triangular-shaped coronoid processes (p=0.004), whereas males exhibited more round condylar processes.

CONCLUSION

This study highlights significant age- and sex-related morphological variations in the mandibular condyles, sigmoid notches, and coronoid processes. These findings have important clinical implications for the diagnosis and treatment of temporomandibular joint disorders and maxillofacial surgery. Understanding these variations can improve diagnostic accuracy and surgical outcomes in patient-specific care.

Malocclusion Associated With Temporomandibular Joint Anterior Disc Displacement and Condylar Resorption in Adolescents: A Cross-Sectional Study

BACKGROUND

Anterior disc displacement (ADD) is the most common type of temporomandibular joint (TMJ) internal derangement and may lead to condylar resorption (CR) during the adolescence period, but the specific malocclusion associated with ADD and CR remains unclear.

OBJECTIVE

This study aimed to investigate the malocclusion associated with TMJ ADD and CR in adolescents.

METHODS

This cross-sectional study included a clinical examination of adolescent patients aged 11-19 years. Magnetic resonance imaging (MRI) was used to diagnose both TMJ ADD and CR. Occlusal measurements were obtained and analysed using 3D scanning models.

RESULTS

A total of 242 adolescent patients (53 males and 189 females) underwent TMJ MRI examination and dental occlusion scanning. The prevalence of anterior disc displacement without reduction (ADDwoR) was higher in females than that in males (OR > 1, p < 0.05). Deep overbite and posterior scissor bite were significantly associated with anterior disc displacement with reduction (ADDwR), while Angle Class II malocclusion, anterior open bite and posterior scissor bite were significantly associated with ADDwoR (OR > 1, p < 0.05). Adolescents with excessive overjet and anterior open bite were at a higher risk of CR (OR > 1, p < 0.05), whereas those with deep overbite and individual crossbite had a lower risk of CR (OR < 1, p < 0.05).

CONCLUSION

Our study offers valuable insights into the association between deep overbite, posterior scissor bite, Angle Class II malocclusion, anterior open bite, excessive overjet and the ADD and CR in adolescents. Orthodontic treatment for adolescent patients should prioritise the health of the TMJ, particularly for these types of malocclusion.

Comparative Evaluation of Temporomandibular Disorders and Dental Wear in Video Game Players

Background/Objectives: The increasing prevalence of video gaming has raised concerns about its potential impact on musculoskeletal health, particularly temporomandibular disorders (TMDs). This study aims to compare TMD symptoms, mandibular function, and dental wear between gamers and non-gamers among university students. Methods: An observational study included 108 students aged 20 to 23 years, divided into gamers (n = 48) and non-gamers (n = 60). Participants completed questionnaires assessing TMD symptoms, gaming habits, and screen time. Clinical examinations measured mandibular movements, palpation-induced pain, and dental wear using the Smith and Knight Tooth Wear Index. Statistical analyses included independent t-tests, chi-square tests, Pearson's correlations, and logistic regression. Seven comprehensive tables present the findings with p-values. Results: Gamers reported significantly higher screen time (Mean = 6.5 h/day) compared to non-gamers (Mean = 4.0 h/day; p < 0.001). Maximum unassisted mouth opening was greater in gamers (Mean = 48.31 mm) than in non-gamers (Mean = 46.33 mm; p = 0.04). Gamers exhibited a higher prevalence of pain on palpation of the masseter muscle (45.8% vs. 30.0%; p = 0.05). Dental wear scores were significantly higher in gamers for teeth 2.3 (upper left canine) and 3.3 (lower left canine) (p < 0.05). Positive correlations were found between hours spent gaming and maximum mouth opening (r = 0.25; p = 0.01) and dental wear (r = 0.30; p = 0.002). Logistic regression showed that gaming status significantly predicted the presence of TMD symptoms (Odds Ratio = 2.5; p = 0.03). Conclusions: Gamers exhibit greater mandibular opening, increased dental wear, and a higher prevalence of masticatory muscle pain compared to non-gamers. Prolonged gaming may contribute to altered mandibular function and increased risk of TMD symptoms. Further research is needed to explore underlying mechanisms and develop preventive strategies.

Is Ultrasonography an Effective Method for Diagnosing Degenerative Changes in the Temporomandibular Joint?

BACKGROUND

The accurate diagnosis of degenerative joint diseases (DJDs) of the temporomandibular joint (TMJ) presents a significant clinical challenge due to their progressive nature and the complexity of associated structural changes. These conditions, characterized by cartilage degradation, subchondral bone remodeling, and eventual joint dysfunction, necessitate reliable and efficient imaging techniques for early detection and effective management. Cone-beam computed tomography (CBCT) is widely regarded as the gold standard for evaluating osseous changes in the TMJ, offering detailed visualization of bony structures. However, ultrasonography (US) has emerged as a promising alternative, offering a non-invasive and radiation-free option for assessing TMJ disorders. This study aims to evaluate the diagnostic accuracy of US in identifying degenerative changes in the TMJ, with CBCT serving as the definitive diagnostic reference. By analyzing the sensitivity, specificity, and predictive values of US in detecting key degenerative markers-such as subchondral erosion, osteophytes, and joint space narrowing-this investigation seeks to assess its utility as a screening tool and its potential integration into clinical workflows.

METHODS

Forty adult patients presenting temporomandibular joint disorders were included in our cross-sectional study. Each patient underwent a clinical examination and was subjected to cone-beam computed tomography (CBCT) and ultrasonography (US). A statistical analysis was performed to compare the imaging results from CBCT and US.

RESULTS

The results are summarized in three tables. The first table presents a comparative analysis of radiological outcomes in patients with temporomandibular joint disorders using different imaging techniques. CBCT demonstrated higher sensitivity in detecting osteophytes in the right mandibular head (27.50% vs. 7.50%, p = 0.027) and higher detection rates for erosions, though without a significant advantage over US. The second table analyzes the consistency of diagnostic results between CBCT and US. A moderate agreement was observed for detecting normal bone structures, with AC1 values of 0.58 for the right and 0.68 for the left mandibular head (p < 0.001). The third table evaluates the diagnostic accuracy of US compared to CBCT. US demonstrated a positive predictive value (PPV) of 90% for detecting normal conditions, indicating its high reliability as a screening tool for normal findings. US demonstrates higher effectiveness in ruling out certain issues due to its high specificity and negative predictive value. However, its lower sensitivity in detecting abnormalities may lead to both false-positive and false-negative results.

CONCLUSIONS

US holds significant promise as a screening modality for detecting normal anatomical features of the temporomandibular joint, its limitations in identifying more complex degenerative changes necessitate a cautious and integrated approach to TMJ diagnostics.

Morphine Versus Nalbuphine as Intra-Articular Medications Following Temporomandibular Joint Arthrocentesis: A Randomized Clinical Trial

PURPOSE

This study aimed at comparing the therapeutic effect of nalbuphine in comparison to morphine after Temporomandibular joint (TMJ) arthrocentesis in patients with anterior disc displacement without reduction (ADDwoR).

MATERIALS AND METHODS

Twenty-four female patients diagnosed with ADDwoR. Patients were treated with TMJ arthrocentesis then randomly divided into parallel groups. Group (A) received an intra-articular injection of 2 mL 10 mg morphine and group (B) received an intraarticular injection of 2 mL 10 mg nalbuphine. Each patient was assessed in terms of maximum mouth opening (MMO), lateral excursions and pain according to visual analogue scale (VAS). Follow-up was made at the intervals of 1 week 1 month, 3 months and 6 months.

RESULTS

A vast improvement was attained in both groups in all assessment variables with a significant value at the end of the follow-up period in comparison to the preoperative assessment values. Yet there was an insignificant difference between both groups regarding the assessment criteria. However insignificant yet the scales tip slightly towards nalbuphine group.

CONCLUSION

Nalbuphine is a highly potent and effective analgesic to be administered post TMJ arthrocentesis in patients with closed lock and highly comparable to that of morphine.

Type V collagen exhibits distinct regulatory activities in TMJ articular disc versus condylar cartilage during postnatal growth and remodeling

Understanding matrix molecular activities that regulate the postnatal growth and remodeling of the temporomandibular joint (TMJ) articular disc and condylar cartilage will enable the development of effective regenerative strategies targeting TMJ disorders. This study elucidated the distinct roles of type V collagen (collagen V) in regulating these two units. Studying the TMJ of young adult Col5a1+/- mice, we found that loss of collagen V resulted in substantial changes in the proliferation, clustering and density of progenitors in condylar cartilage, but did not have a major impact on disc cells that are more fibroblast-like. Although loss of collagen V led to thickened collagen fibrils with increased heterogeneity in the disc, there were no significant changes in local micromodulus, except for a reduction at the posterior end of the inferior side. Following the induction of aberrant occlusal loading by the unilateral anterior crossbite (UAC) procedure, both wild-type (WT) and Col5a1+/- condylar cartilage exhibited salient remodeling, and Col5a1+/- condyle developed more pronounced degeneration and tissue hypertrophy at the posterior end than the WT. In contrast, neither UAC nor collagen V deficiency induced marked changes in the morphology or biomechanical properties of the disc. Together, our findings highlight the distinct roles of collagen V in regulating these two units during postnatal growth and remodeling, emphasizing its more crucial role in condylar cartilage due to its impact on the highly mechanosensitive progenitors. These results provide the foundation for using collagen V to improve the regeneration of TMJ and the care of patients with TMJ disorders. STATEMENT OF SIGNIFICANCE: Successful regeneration of the temporomandibular joint (TMJ) articular disc and condylar cartilage remains a significant challenge due to the limited understanding of matrix molecular activities that regulate the formation and remodeling of these tissues. This study demonstrates that collagen V plays distinct and critical roles in these processes. In condylar cartilage, collagen V is essential for regulating progenitor cell fate and maintaining matrix integrity. In the disc, collagen V also regulates fibril structure and local micromechanics, but has a limited impact on cell phenotype or its remodeling response. Our findings establish collagen V as a key component in maintaining the integrity of these two units, with a more crucial role in condylar cartilage due to its impact on progenitor cell activities.

Arthroscopic treatment of temporomandibular dysfunction: preliminary results from a prospective follow up of over five years

Patients with refractory temporomandibular dysfunction (TMD) despite conservative therapies often require surgical intervention. Although techniques such as arthrocentesis or arthroscopy have been established for years, there remains a dearth of evidence regarding the long-term efficacy of these interventions. This preliminary prospective study aims to elucidate the outcomes of arthroscopic treatment conducted over five years ago in patients with temporomandibular dysfunction. A study involving 31 patients with temporomandibular dysfunction who underwent level II arthroscopic surgery prior to 2019 is presented. The principal objective parameter for joint function was mouth opening, while the primary subjective parameters included pain, which was measured using the visual analogue scale (VAS), and quality of life, assessed using the OHIP-14sp questionnaire. Objective parameters were assessed preoperatively at one year and five years postoperatively, while quality of life was evaluated both preoperatively and five years after the procedure. Subsequently, the long-term status of patients was analysed, including surgical outcomes and the necessity for supplementary techniques such as second arthroscopy or open surgery. The quality-of-life scores significantly improved (p < 0.001) after five years of follow up when compared with preoperative assessments. Pain levels exhibited a statistically significant decrease over the follow-up period (p < 0.001). Significant differences were observed between preoperative and both 12-months' and five-years' follow up (both p < 0.001) but not between the 12-month and five-year marks (p = 0.899). Similar trends were noted for maximum mouth opening, with differences between pre-surgery and both 12-months' and five-years' follow up (p = 0.049 and p = 0.005, respectively) but not between the 12-month and five-year assessments (p = 0.482). Mouth opening at 12 months (p = 0.003) and five years (p = 0.032), as well as OHIP results at five years (p = 0.003), demonstrated statistically significant differences between groups according to the final status. In all cases, poorer clinical outcomes post-surgery (requiring a second arthroscopy or meniscectomy) correlated with decreased mouth opening and worse OHIP results. Arthroscopy emerges as an effective technique in the long-term treatment of temporomandibular joint dysfunction, as parameters such as pain and maximum mouth opening improve, and this improvement remains stable at the five-year follow up.

The Effect of Postural Rehabilitation on Pain, Balance, Mandibular Movement, and Posture in Temporomandibular Disorder Patients: A Comparison Between Posterior Edentulous and Dentate Groups

Objective: Posterior edentulism reduces occlusal support, thus increasing the risk and symptoms of temporomandibular disorder. No previous study has explored its effect on the treatment of temporomandibular disorders. This study aimed to examine the relationship between neck posture, balance, and posterior edentulism in patients with temporomandibular disorder and compare the effectiveness of physical therapy. Methods: In a quasi-experimental controlled trial, 26 patients with temporomandibular disorder were divided into 13 in the partly edentulous group and 13 in the dentate group. Both groups received manual therapy, postural exercises, deep neck flexor stabilization, and Kinesio tapping for 6 weeks. Each participant completed 12 physiotherapy sessions, administered twice weekly, with a minimum interval of 48 hours between sessions. Outcomes were assessed at baseline and after the 6-week program, including pain, mandibular movement, posture, and balance. Results: The physical therapy program significantly improved all measured outcomes (P < .05). Furthermore, the partially edentulous group showed more remarkable improvement in pain and balance compared to the dentate group (P < .05). Conclusions: Postural exercises effectively alleviate symptoms in patients with temporomandibular disorder, with more significant improvements observed in the partially edentulous group than in the dentate group.

Vitamin D Levels and Temporomandibular Disorders: A Bidirectional Two-Sample Mendelian Randomization Analysis

Objective

Growing researches explore vitamin D's role in temporomandibular disorders (TMDs), but the link between vitamin D and TMDs remains debated. To clarify the causal relationship, we conducted a Mendelian randomization (MR) analysis using data from genome-wide association studies (GWAS).

Subjects and Methods

The GWAS dataset of vitamin D (GWAS ID: ukb-d-30890_irnt; sample size: 329247) was obtained from the IEU Open GWAS project. And that of TMDs (GWAS ID: finn-b-TEMPORO; sample size: 134280), initiated on August 25th, 2017 and publicly released on December 18th, 2023, was extracted from the FinnGen dataset, whose cases were diagnosed based on the revised International Classification of Diseases, 10th Edition (ICD-10) code K07.6. Both datasets were obtained from the European population. According to three assumptions of MR analysis, a bi-directional MR analysis was performed to measure the causal relationship, with Inverse variance weighted (IVW) as the primary method and MR Egger and Weighted median as supplement. Moreover, diverse sensitivity analyses, including Cochran's Q test, MR Egger intercept, Mendelian randomized polymorphism RESidual Sum and Outlier (MR-PRESSO), and leave-one-out analysis, were used to verify the stability of the findings.

Results

The MR analysis supported causal effects of vitamin D levels on TMDs risks within the European population using IVW method [odds ratio = 1.316; 95% confidence interval = 1.086 to 1.595; P = 0.005], supported by MR Egger and Weighted median. While there was no indication that TMDs have a direct impact on vitamin D levels [β: -0.00738, standard error = 0.00665; P = 0.568].

Conclusion

The study revealed that within the European population higher levels of vitamin D led to higher risks of developing temporomandibular disorders, but found no obvious evidence that TMDs are causally associated with vitamin D. The conclusion should be cautiously interpreted, given the selection bias of TMDs patients sample.

The "5Ts" screening tool: Enhancements and threshold values for effective TMD identification

OBJECTIVE

This study aimed to enhance the quintessential "five temporomandibular disorder (TMD) symptoms" (5Ts) screener by incorporating frequency options and distinguishing between TMJ and muscle pain. The diagnostic accuracy along with cut-off points for the effective identification of TMDs was also established.

METHODS

Participants, aged ≥18 years, were recruited from a university-based hospital. After completing surveys encompassing demographic data and the enhanced 5Ts (with frequency options [5Ts-F] and differentiation of TMJ/muscle pain [6Ts-F]), protocolized interviews and clinical examinations were performed following DC/TMD. The diagnostic accuracy and best cut-off points were determined with the area under the receiver operating characteristic curves (AUCs).

RESULTS

324 participants were recruited (mean age 30.0 ± 11.4 years). Among these, 86.4% had TMDs. 5Ts exhibited high diagnostic accuracy for detecting all TMDs (AUC = 0.92) with sensitivity/specificity values of 83.9%/88.6%. Both 5Ts-F and 6Ts-F had slightly better accuracy (AUCs = 0.95/0.96), comparable sensitivity, and superior specificity (97.7%) compared to 5Ts. The best cut-off points were 1.5 for 5Ts and 2.5 for 5Ts-F/6Ts-F.

CONCLUSIONS

Although all three TMD screeners presented high diagnostic accuracy, 5Ts-F/6Ts-F had notably improved specificity. 5Ts scores of >1.5 and 5Ts-F/6Ts-F scores of >2.5 are to be applied for screening the presence of TMDs.

Effects of Hyaluronic Acid (HA) and Platelet-Rich Plasma (PRP) on Mandibular Mobility in Temporomandibular Joint Disorders: A Controlled Clinical Trial

Hyaluronic acid (HA) is a glycosaminoglycan composed of D-glucuronic acid and N-acetylglucosamine with an up-to-several-million-Daltons chain-length responsible for the lubricating properties of the temporomandibular joint (TMJ) synovial fluid. Arthritis results in the predominance of HA degradation over synthesis leading to temporomandibular disorders (TMDs). TMD injection treatments are divided into HA supplementation and platelet-rich plasma (PRP) inflammation suppression. We questioned whether either approach lubricated the TMJ better and answered it in a two-arm equal-allocation trial with a non-concurrent active treatment control (two groups of 39 patients each). HA statistically significantly improved (p < 0.01) and PRP did not statistically significantly change (0.06 ≤ p ≤ 0.53) articular mobility compared to baselines in 128 TMJs. Statistically significant inter-group discrepancies were observed for abduction (MD = -4.05 mm; SE = 1.08; p = 0.00; d = -0.85) and protrusion (MD = -0.97 mm; SE = 0.43; p = 0.03; d = -0.51) but not for rightward (MD = -0.21; SE = 0.43; p = 0.63; d = -0.11) and leftward (MD = -0.30; SE = 0.42; p = 0.47; d = -0.16) movements. HA supplementation proved superior to PRP autografting in ad hoc TMJ lubrication and hence is more appropriate in hypomobile TMD cases of symptomatic treatment.

Effect of transcutaneous electrical nerve stimulation therapy on condylar position and myofascial pain in patients with temporomandibular joint disorders-A pilot clinical trial

OBJECTIVE

Temporomandibular joint disorders (TMD) are a type of disorder that affects the temporomandibular joint, muscles, and nerves leading to persistent facial pain. Transcutaneous electrical nerve stimulation (TENS) therapy is an alternative treatment for pain relief in TMD patients. The aim of the study was to assess the condylar position changes and pain levels occurring in TMD patients after TENS therapy.

MATERIALS AND METHODOLOGY

According to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) criteria, a total of seven patients with TMD were included in this study. Routine diagnostic investigations were taken for each patient along with joint vibration analysis (JVA), electromyography (EMG), and a cone beam computed tomography (CBCT) at rest position. Using the Dolphin software (version 11.95), the temporomandibular joint spaces were measured on the CBCT for the right and left sides individually for each patient. These patients were then subjected to TENS therapy, and an EMG reading was taken post-TENS therapy to evaluate the effect on muscle strain. A CBCT was taken after the TENS therapy to assess its effect on the condylar position. The statistical significance of the pre- and post-temporomandibular joint spaces and the EMG readings post-TENS therapy were assessed using paired t-tests, respectively.

RESULTS

There was a change in the anterior, middle, and posterior dimensions observed radiographically, before and after TENS. However, the results were found to be statistically significant only in the anterior region on the right joint space (P = 0.03) and posterior region of the left joint space (P = 0.04).

CONCLUSION

TENS therapy has been found to bring about a change in the condylar position and pain intensities by relieving inadvertent muscle activity in the temporomandibular region. Therefore, further studies with larger sample sizes and control are required to fully ascertain the role of inadvertent muscle activity on the TMJ.

The effects of dry needling and face yoga on pain, depression, function, and sleep quality in patients with temporomandibular dysfunction

CONTEXT

Temporomandibular joint dysfunction (TMD) poses significant challenges due to its diverse symptoms and impact on patients' daily lives.

OBJECTIVE

This study aimed to explore the effectiveness of two innovative interventions, dry needling and face yoga, in managing TMD-related issues such as pain, depression, and sleep quality.

DESIGN AND STUDY PARTICIPANTS

Ninety patients with TMD symptoms were enrolled in a prospective randomized controlled trial. The patients were divided into three groups: dry needling, face yoga, and a control group. Various assessments, including Visual Analog Scale for pain, Beck Depression Inventory for depression, and Pittsburgh Sleep Quality Index for sleep quality, were conducted before and 6 weeks after the interventions.

RESULTS

A decrease in pain levels and a statistically significant increase in jaw joint movements (mouth opening, protrusive movement, lateral movements) were observed in the dry needling and face yoga groups after treatment (p <0.05). Additionally, improvements in sleep quality were observed (p <0.05).

CONCLUSION

Dry needling and face yoga interventions demonstrated efficacy in managing TMD symptoms, including pain relief and improved jaw movement. The findings suggest that these interventions can be valuable additions to the treatment regimen for patients suffering from TMD-related issues. However, further research is warranted to explore the long-term effects and mechanisms underlying these interventions in TMD management.

Association of Malocclusion with Temporomandibular Disorders: A Cross-Sectional Study

Background/Objectives: Temporomandibular disorders (TMD) encompass a range of musculoskeletal and neuromuscular conditions affecting the temporomandibular joint (TMJ) and associated structures. This cross-sectional study, conducted in a Portuguese TMD department, aimed to assess the relationship between malocclusion and TMD severity. Methods: Data on demographic variables, TMD clinical symptoms, and malocclusion classes were collected using the EUROTMJ database. The Chi-square test (χ2) identified associations, with their intensity measured by Cramér's V (φc). Results: The study included 1170 patients (932 females and 238 males), with a mean age of 41.73 ± 16.80 years. Most patients exhibited Angle Class I malocclusion (85.5%), followed by Angle Class II (13.5%) and Angle Class III (1.1%). Class II malocclusion was associated with increased TMD severity (p < 0.001), higher myalgia levels (p = 0.002), more frequent disc displacement without reduction (p = 0.002) and lower maximum mouth opening values (Class II: 38.13 ± 7.78 mm, Class I: 39.93 ± 8.67 mm). Significant associations were also found between malocclusion type and arthralgia (p = 0.021), mouth-opening limitation (p = 0.016), and TMJ crepitus (p = 0.017). In cases of malocclusion, the presence of oral signs of bruxism explained the degree of myalgia, disc displacement, and severity (p = 0.003; p = 0.048; p = 0.045). Conclusions: This study highlights that (1) the most common type of dental malocclusion in TMD patients was Class I; (2) Class II malocclusion was associated with increased TMD severity and oral signs of bruxism; and (3) Class III was rarely observed in TMD consultation. The findings suggest that bruxism behavior in cases of malocclusion may be significant in TMD.

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.

Exploring the gut microbiota's effect on temporomandibular joint disorder: a two-sample Mendelian randomization analysis

Background

Temporomandibular joint disorders (TMD) are highly prevalent among people. Numerous investigations have revealed the impact of gut microbiota in many diseases. However, the causal relationship between Temporomandibular joint disorders and gut microbiota remains unclear.

Methods

Genome-Wide Association Studies (GWAS) refer to the identification of sequence variations, namely single nucleotide polymorphisms (SNPs), existing across the entire human genome. GWAS data were collected on gut microbiota and TMD. Then, instrumental variables were screened through F-values and removal of linkage disequilibrium. These SNPs underwent mendelian analysis using five mathematical models. Sensitivity analysis was conducted to further verify the stability of the results. Pathogenic factors of TMD mediate the causal relationship between gut microbiota and TMD were explored through a two-step Mendelian randomization analysis. Finally, reverse mendelian analysis was conducted to account for potential reverse effects.

Results

The analysis of the data in this article suggests that some gut microbiota, including Coprobacter, Ruminococcus torques group, Catenibacterium, Lachnospiraceae, Turicibacter, Victivallis, MollicutesRF9, Methanobacteriales, Methanobacteriaceae, FamilyXI, Methanobacteria were identified as risk factors, while Peptococcaceae provides protection for TMD.

Conclusion

The research reveals the relation of gut microbiota in TMD. These findings provide insights into the underlying mechanisms and suggest potential therapeutic strategy.

Efficacy of High-intensity laser therapy in patients with temporomandibular joint disorders: A systematic review and meta-analysis

This study aimed to assess the effects of High-intensity laser therapy (HILT) on individuals suffering from temporomandibular joint disorders (TMDs). A search was conducted across six electronic databases for randomized controlled trials (RCTs) focusing on HILT for TMDs: PubMed, Scopus, Web of Science, ScienceDirect, EBSCOhost, Cochrane Library, the PEDro database and Google Scholar (last updated on July 18, 2024). Eligible studies were chosen by independent reviewers, and their quality was assessed with the Cochrane risk of bias tool (RoB). The main outcome was pain intensity (VAS), with secondary outcomes including mouth opening (mm), disability (JFLS-20), and quality of life (OHIP-14). A meta-analysis was conducted to assess the pooled effect by calculating mean differences (MD) for these variables (95% confidence level). The heterogeneity of the meta-analyses was explored using the I2 statistic. Three studies met the selection criteria and were included in the meta-analysis. The main RoB was the blinding of participant and treaters. Statistically significant differences (p < 0.05) in favor of HILT were observed for VAS and maximum mouth opening. The pooled effect showed an MD of -14.8 mm (95% CI:-27.1,-2.5) for pain intensity and 3.7 mm (95% CI:0.9,6.5) for mouth opening, changes that were assessed as clinically important. According to GRADE, the evidence was rated as important, and the certainty was moderate due to the heterogeneity between studies. A sensitivity analysis was not performed to address heterogeneity, primarily due to the limited availability of RCTs. HILT has been found effective in short-term pain relief and improvement of jaw opening in TMDs, potentially enhancing quality of life by facilitating activities such as chewing, jaw mobility, and communication. However, further research is needed to confirm its long-term effectiveness. Combining HILT with interventions such as occlusal splints or therapeutic exercises could potentially enhance its effects, leveraging the existing evidence supporting these treatments. It is important to note that the high RoB associated with the lack of blinding of participants and treaters may influence data collection, compromising the internal validity of findings in some studies.

Treatment of temporomandibular joint internal derangement using MESNA injection

INTRODUCTION

The development of temporomandibular disorders specifically emphasizes the biochemical changes occurring in the synovial fluid at different stages of temporomandibular joint disease. Research has indicated that inflammation may be a primary reason behind the pain and dysfunction in temporomandibular joint diseases. Since its clearance several years ago, MESNA (sodium 2-mercaptoethanesulfonate) has been used in various formulations as a mucolytic drug in the respiratory domain. It operates by disrupting the disulfide bonds present between polypeptide chains within mucus. MESNA exhibits minimal tissue distribution, with the material being swiftly and thoroughly eliminated via the kidneys.

OBJECTIVES

To assess the efficacy of injecting MESNA directly into the Temporomandibular Joint to treat internal derangement.

MATERIALS AND METHODS

A randomized clinical trial was conducted on sixty patients who exhibited non-responsiveness to conventional treatment and were diagnosed with TMJ anterior disc displacement with reduction. The patients were chosen from the outpatient clinic of the Oral and Maxillofacial Surgery Department at Tanta University Faculty of Dentistry. Two equal groups of patients were randomly assigned to each other. Group I (Mesna group) received intra-articular injection with MESNA solution. Group II (Standard group) received arthrocentesis with lactated ringer solution followed by injection of Hyaluronic Acid (HA). The data was gathered by functional examinations such as maximum interincisal opening (MIO) and clicking. A Visual Analogue Scale (VAS) assessed pain severity before and after treatments.

RESULTS

Both MESNA and HA showed significant improvement up to six months of the follow-up compared to preoperative status, as evidenced by better mouth opening, lateral excursion, lower clicking, and reduced pain score in patients with TMDs. MESNA showed significant improvement during follow-up compared to HA.

CONCLUSION

Compared to HA, MESNA showed a more noticeable improvement during the follow-up period.

Effectiveness of Ultrasound Therapy, TheraBite Device, Masticatory Muscle Exercises, and Stabilization Splint for the Treatment of Masticatory Myofascial Pain: A Randomized Controlled Trial

BACKGROUND

Myofascial pain syndrome (MPS) is a particular type of temporomandibular joint disorder. Research findings comparing various treatment approaches are scarce and controversial. Therefore, this study aimed to compare the effectiveness of ultrasound therapy, stabilization splint, TheraBite device, and masticatory muscle exercises in reducing pain intensity and improving mandibular mobility in patients with MPS.

METHODS

It was a single-blind, randomized, parallel-group, active-controlled trial that took place between April 2023 and October 2023 at the Department of Fixed Prosthodontics, Damascus University. Patients older than 18 years old with myofascial pain accompanied by limited jaw opening and pain lasting for at least 6 months were included. Eighty patients were randomly assigned into four groups using online randomization software: ultrasound therapy, stabilization splint, TheraBite device, and masticatory muscle exercises. Only outcome assessors were masked to treatment allocation. The exercise regimen was the exercise program for patients with TMD. The following primary outcome measures were considered at the baseline (t0), at the first (t1), second (t2), and fourth (t3) week of treatment, and at the second (t4) and fifth (t5) month of follow-up: pain intensity using the visual analogue scale, maximum interincisal opening, right lateral movement, and left lateral movement measured in millimeters.

RESULTS

The pain level changed from severe to mild at t3 in ultrasound therapy, stabilization splint, and TheraBite device groups. In the masticatory muscle exercises group, it changed to moderate, with a significant difference between ultrasound therapy (p = 0.012) and stabilization splint (p = 0.013) groups. In addition, the mandibular mobility continued to improve at the subsequent follow-up periods (t4 and t5).

CONCLUSIONS

All therapies are equally effective after 5-month follow-up. However, ultrasound therapy and stabilization splints have the benefit of achieving rapid improvement.

TRIAL REGISTRATION

ISRCTN20833186.

The application of extracorporeal shock wave therapy in the treatment of temporomandibular joint disorders in a preliminary, small sample study

OBJECTIVE

The aim of this study was to investigate the efficacy of low-intensity, high-frequency shock waves in the treatment of temporomandibular joint disorders.

METHODS

Twenty-six patients with temporomandibular joint disorder admitted to the Second Hospital of Shanxi Medical University from August 2022 to December 2022 were selected as study subjects and randomly divided into two groups, A and B, with 13 patients each. In Group A, there were 5 males and 8 females with an average age of 38.85 ± 11.03 years. In Group B, there were 4 males and 9 females with an average age of 39.15 ± 11.16 years. Group A was the control group, which received routine treatment (manual massage + transcutaneous electrical nerve stimulation + ultrashort wave therapy) plus sham shock wave therapy; Group B was the experimental group, which received routine treatment (manual massage + transcutaneous electrical nerve stimulation + ultrashort wave therapy) plus shock wave therapy. The routine treatment was administered once/day, five times per week for a total of 2 weeks of treatment. In addition, shock wave therapy was administered once every 5 days, and the treatment was administered three times. The treatment period was 2 weeks, and the two groups were compared before treatment, at the end of the treatment period, and 4 weeks after treatment. The pain level of the two groups was assessed by the visual analogue scale (VAS) before and after treatment, and the temporomandibular opening index (TOI) before and after treatment was compared between the two groups. VAS and TOI scores were evaluated using the Mann-Whitney U-test, the Kruskal-Wallis H-test and two-way ANOVA.

RESULTS

There was no significant difference in the VAS score and temporomandibular opening index between the two groups before treatment (p = .829 and .75, respectively). After 2 weeks of treatment, the VAS score and temporomandibular joint opening index of both groups were significantly improved compared to those before therapy. In addition, the VAS score and temporomandibular joint opening index in the experimental group were significantly better than those in the control group (p < .001 and <.001, respectively). There was a small increase in scores 4 weeks after the treatment compared to just after the treatment period, but the difference was not significant.

CONCLUSION

This is a preliminary small sample study that demonstrates the positive effect of using low-intensity, high-frequency shock waves on the treatment of temporomandibular joint disorders and is worthy of clinical promotion.

A regenerative approach for temporomandibular joint repair: An in vitro and ex vivo study

BACKGROUND

Current clinical approaches to regenerate temporomandibular joint (TMJ) articulating cartilage defects only treat the symptoms (i.e. pain and dysfunction) and do not seek to restore joint integrity for long-term relief. Therefore, we investigated a novel self-assembling tissue-engineered cartilage to overcome this significant clinical issue for TMJ regenerative purposes.

OBJECTIVES

Examine the maturation of dynamic self-regenerating cartilage (dSRC) using auricular chondrocytes and evaluate a novel combinatorial approach with fractional laser treatment and dSRC implantation for TMJ cartilage repair.

MATERIALS AND METHODS

A suspension of 107 freshly harvested rabbit ear chondrocytes was cultured under a continuous reciprocating motion to form the dSRC. After 2, 4 and 8 weeks of culture, dSRC samples were stained with H&E, Safranin-O and Toluidine Blue. Immunohistochemistry (IHC) was performed for collagens type I and II. Channels (300-500 μm diameter and 1.2-1.5 mm depth) were created in six freshly harvested condyles using a fractional Erbium laser. Two groups were tested: dSRC in a laser-ablated lesion (experimental) and an empty laser-ablated channel (control). TMJ condyles were cultured for up to 8 weeks and analysed as described above.

RESULTS

H&E staining showed a high cell density in dSRC compared to native cartilage. All dSRC groups demonstrated intense Safranin-O staining, indicating high glycosaminoglycan (GAG) production and intense Toluidine Blue staining showed high proteoglycan content. IHC confirmed that dSRC consisted predominantly of collagen type II. The experimental group showed improved cartilage repair at both time points compared to the empty channels.

CONCLUSION

dSRC viability and successful matrix formation were demonstrated in vitro. The combination of fractional laser ablation and dSRC implantation enhanced cartilage repair.

Challenges of therapeutic applications and regenerative capacities of urine based stem cells in oral, and maxillofacial reconstruction

Urine-derived stem cells (USCs) have gained the attention of researchers in the biomedical field in the past few years . Regarding the several varieties of cells that have been used for this purpose, USCs have demonstrated mesenchymal stem cell-like properties, such as differentiation and immunomodulation. Furthermore, they could be differentiated into several lineages. This is very interesting for regenerative techniques based on cell therapy. This review will embark on describing their separation, and profiling. We will specifically describe the USCs characteristics, in addition to their differentiation potential. Then, we will introduce and explore the primary uses of USCs. These involve thier utilization as a platform to produce stem cells, however, we shall concentrate on the utilization of USCs for therapeutic, and regenerative orofacial applications, providing an in-depth evaluation of this purpose. The final portion will address the limitations and challenges of their implementation in regenerative dentistry.

Efficacy of acupuncture on craniomandibular myofascial pain in temporomandibular disorder patients: A systematic review

Background

This systematic review aimed to answer the question, "What is the efficacy of acupuncture treatment in patients with temporomandibular disorder (TMD) with myofascial pain?".

Data sources and study selection

This study followed PRISMA guidelines and was registered in PROSPERO. The electronic search strategy was applied to the Scopus, PubMed, Embase, and Science Direct databases. As inclusion criteria, were selected randomized clinical articles that evaluated patients with myofascial pain symptoms treated by acupuncture without the restriction of time and language.

Results

The search in the databases resulted in 286 articles, after removing the duplicates 251 were analyzed by title and abstract. Twenty were selected for full reading and 10 were included in the systematic review. The studies evaluated acupuncture treatments by puncture and laser, auriculotherapy by puncture and laser, and an occlusal device for treating myofascial TMD.

Conclusions

Comparing acupuncture with placebo acupuncture, it was observed that it is effective for subjective pain relief and palpation of orofacial structures with immediate results; it should be noted that there is still no specific protocol and that the duration of treatment must be personalized. When comparing it with the occlusal device, the associated treatment has enhanced the results. Future studies are suggested by the current literature gap that prevents the determination of clinical guidelines for effective acupuncture treatment in TMD patients with myofascial pain.

Practical implications

Laser and needle puncture acupuncture treatment and laser and needle puncture auriculotherapy have shown favorable results in short-term myofascial pain relief. The need for long-term studies to assess benefits and reduce possible biases is highlighted.

Clinical trial registry name

PROSPERO (CRD42021271505).

Is There a Relationship between Salivary Cortisol and Temporomandibular Disorder: A Systematic Review

BACKGROUND

This systematic review examines and evaluates the relationship between salivary cortisol levels and temporomandibular disorder (TMD) in young adult patients.

METHOD

Six databases-PubMed, Scopus, Web of Science, Google Scholar, ProQuest, and Cochrane Library-were utilized to screen eligible studies. A systematic search was performed based on PECO questions and eligibility criteria. The research question for this review was "Do salivary cortisol levels correlate with TMD in individuals aged 18-40?" The risk of bias for quality assessment was determined by the Cochrane tool. PRISMA guidelines were followed while performing this review.

RESULT

A total of fourteen studies were included in this review. Of these, eleven were observational studies (four cross-sectional and seven case-control), and three were randomized control trials. Eleven of the included studies presented a low to moderate risk in the qualitative synthesis. The total sample size of the included studies was 751 participants. The included studies suggest higher salivary cortisol levels in TMD patients than in healthy individuals.

CONCLUSIONS

The findings of this review indicate higher salivary cortisol levels in adult patients with TMD than in healthy controls. Thus, supportive psychological treatment and clinical modalities should be provided to patients with TMD. Moreover, higher-quality studies with low heterogeneity are required to support this finding.

Assessment of Long-Term Effects and Patient Satisfaction following TMJ Disc Replacement Surgery

Objectives

The purpose of this research is to evaluate patient satisfaction and long-term consequences after temporomandibular joint (TMJ) disc replacement surgery in a tertiary care environment.

Methods

500 patients who had TMJ disc replacement surgery at a tertiary care facility between 2010 and 2015 were the subject of a retrospective investigation. Pre-operative clinical features, demographic information, and intraoperative information were gathered. Standardized measurements were used to evaluate functional results, pain levels, and patient-reported outcomes. Descriptive statistics, paired t-tests, and significance set at P < 0.05 were all used in the statistical analysis.

Results

There were notable improvements in functional outcomes, with a mean increase in lateral excursion from 8.7 mm to 12.6 mm (P < 0.001) and maximal incisal opening from 30.5 mm to 40.2 mm (P < 0.001). The pain level was found to have greatly diminished, as evidenced by the VAS scores falling from 7.8 to 3.2 (P < 0.001). The Jaw Function Limitation Scale scores (42.6 to 21.8, P < 0.001) and patient-reported outcome measures scores (58.3 to 76.5, P < 0.001) exhibited significant increases in patient-reported outcomes.

Conclusion

In conclusion, tertiary care TMJ disc replacement surgery shows positive long-term outcomes, such as enhanced jaw function, less discomfort, and high patient satisfaction. This research supports the ongoing use of TMJ disc replacement surgery as a potential therapy for refractory TMJ disease, although noting its limitations.

Evaluation of body composition and bone mineral density in patients with and without idiopathic condylar resorption of temporomandibular disorders by dual energy X-ray absorptiometry

Background/purpose

The impact of temporomandibular joint (TMJ) osseous destruction on bone mineral density (BMD) remains unclear due to controversial findings. Besides, no previous study has explored the relationship between idiopathic condylar resorption (ICR) and body composition. This study aimed to investigate the relationship between ICR and BMD or body composition.

Materials and methods

Between July 2018 and August 2022, patients evaluated by an experienced dentist and diagnosed with temporomandibular disorders (TMDs) were referred to our center. They were recruited while they received the magnetic resonance image (MRI) examination, BMD and body composition completely. Patients were further categorized into TMDs with or without ICR groups according to MRI findings. One-way analysis of variance was used to compare the variables of BMD and body composition in the two groups.

Results

In total, 67 patients were included in the analysis, with 42 categorized as TMDs with ICR and 25 as TMDs without ICR. Patients with ICR had a significantly higher lean mass percentage and lower fat mass percentage; lower android/gynoid fat ratio, and visceral adipose tissue area than those without ICR (P < 0.05). Besides, patients above age 30 with ICR had lower Z scores (P = 0.017) compared with subjects without ICR.

Conclusion

TMDs patients with ICR show a relationship with body composition and affect the lean and fat mass distribution, especially android/gynoid fat ratio. The pathophysiological mechanism remains unclear. Further researches to investigate teeth binding, malocclusion and dietary habits are important to understand the association of ICR, BMD and body composition.

Effects of Mask Usage During the COVID-19 Pandemic on Sign and Symptoms of Temporomandibular Joint Disorder: A Survey Study

Objective

To evaluate possible temporomandibular disorders (TMD) symptoms that may occur due to mask use in dentists during the coronavirus disease-2019 pandemic period and identify potentially effective factors.

Methods

An online questionnaire consisting of three parts was sent to dentists and clinical dental students. The first part included questions regarding sociodemographic information. In the second part, questions were asked to evaluate stress levels, TMD symptoms, and treatment of TMD, if any, before (T0) and during the pandemic (T1). In the last part, professional mask choice, mask-related parafunctional movements, and breathing patterns while wearing a mask were evaluated.

Results

TMD symptoms and stress levels were significantly higher at T1. An increase in mouth breathing and mask-related parafunctional movements was reported during the use of N95 masks compared with daily life in dentists whose professional mask selection was an N95 respirator. The change in temporomandibular joints pain and muscle pain at rest between T0 and T1 was higher in those whose professional mask choice was N95 respirators than in those who chose to wear one surgical mask.

Conclusion

The increase in mouth breathing and mask-related parafunctional movements during the use of N95 respirators may increase TMD.

Autologous Fat Transfer in Craniofacial Surgery

Over the past two decades, autologous fat transfer has garnered significant recognition and widespread adoption within esthetic and reconstructive surgical domains. In craniofacial surgery, fat transplantation is frequently employed to address soft tissue volumetric deficiencies and asymmetries that influence facial contours. While adipose tissue (AT) is widely regarded as an optimal choice for augmentation due to its abundant availability and biocompatibility, the unpredictability and heightened resorption rates observed with traditional lipofilling techniques present a challenge for clinicians. Adipose-derived stem cells (ASCs) housed within the grafted tissue play a pivotal role in graft survival and offer avenues for tissue repair due to their angiogenic, anti-inflammatory, and immunosuppressive properties. Micro Fragmentation of Adipose Tissue (MFAT), utilized in several FDA-approved processing devices, has demonstrated promising outcomes in treating osteoarthritic joints, with success primarily attributed to enhanced paracrine function of ASCs via preservation of the perivascular niche. Currently, its application for treating bone or articular defects in the craniofacial region, including abnormalities of the temporomandibular joint, remains limited. This scarcity underscores the need for further investigation prior to its widespread integration into clinical practice.

Anatomical factors influencing temporomandibular joint clicking in young adults: temporomandibular joint structure disorder or lateral pterygoid muscle dysfunction?

Objective: This study aimed to investigate the selected anatomical factors that can potentially influence temporomandibular joint (TMJ) clicking in young adults by assessing TMJ structures and lateral pterygoid muscle (LPM) function using magnetic resonance imaging (MRI). Methods: The patients were divided into four groups: the healthy control group; the clicking on mouth opening group; the clicking on mouth closing group; and the clicking on mouth opening and closing group. Additionally, we used clinical palpation to evaluate the masticatory muscles' functional state and employed MRI using the OCOR-T1WI-FSE-CLOSED, OSAG-PDW-FSE-CLOSED, and OSAG-PDW-FSE-OPEN sequences to analyze the texture of the lateral pterygoid muscle (LPM). Results: The proportion of any articular disc or condylar morphology class did not differ significantly between the TMJ clicking and HC groups. The articular disc position did not differ significantly between the TMJ clicking and HC groups. In the TMJ clicking group, the presence of masticatory muscle dysfunction differed significantly between the clicking and non-clicking sides. Moreover, the LPM accounted for the highest proportion among masticatory muscles with tenderness in all TMJ clicking subgroups (77.78%-100%). Therefore, in the TMJ clicking group, the LPM texture was less defined, more uniform in gray scale, and more similar to local texture (p < 0.0001). Conclusion: The occurrence of TMJ clicking in young adults is unrelated to the TMJ structure but related to the function of masticatory muscles, particularly the LPM.

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.

Clinical effect of digitalized designed and 3D-printed repositioning splints in the treatment of anterior displacement of temporomandibular joint disc

OBJECTIVE

To compare the treatment effectiveness of digitized and 3D-printed repositioning splints with that of conventional repositioning splints in the treatment of anterior displacement of the temporomandibular joint disc.

METHODS

This retrospective study included 96 patients with disc displacement of the anterior temporomandibular joint. They were treated with either digitally designed and 3D-printed repositioning splints or traditional splints and followed up for at least six months. Changes in signs and symptoms such as pain and mouth opening before and after treatment were recorded to evaluate treatment outcomes.

RESULTS

During the first month of treatment, both the digitally designed and 3D-printed repositioning splint groups (Group B) and the traditional repositioning splint group (Group A) showed significant increases in mouth opening, with increases of 4.93 ± 3.06 mm and 4.07 ± 4.69 mm, respectively, and there was no significant difference between the two groups. Both groups had a significant reduction in visual analog scale (VAS) pain scores, with Group B showing a greater reduction of 1.946 ± 1.113 compared to 1.488 ± 0.978 in Group A (P < 0.05). By the sixth month, Group B's mouth opening further improved to 38.65 ± 3.22 mm (P < 0.05), while Group A's mouth opening did not significantly improve. Regarding pain, Group A's VAS score decreased by 0.463 ± 0.778 after one month, and Group B's score decreased by 0.455 ± 0.715; both groups showed significant reductions, but there was no significant difference between the two groups.

CONCLUSION

Compared with traditional repositioning splints, digitally designed and 3D-printed repositioning splints are more effective at reducing patient pain and improving mouth opening. 3D-printed repositioning splints are an effective treatment method for temporomandibular joint disc displacement and have significant potential for widespread clinical application.

The Adaptive, Pain Sensitive, and Global Symptoms Clusters: Evidence from a Patient-Based Study

OBJECTIVES

The largest epidemiologic study conducted about painful temporomandibular disorders (pTMDs) to date identified 3 clusters of individuals with similar symptoms-adaptive, pain sensitive, and global symptoms-which hold promise as a means of personalizing pain care. Our goal was to compare the clinical and psychological characteristics that are consistent with a pTMD clinical examination among patients who are seeking care and assigned to the different clusters.

METHODS

This cross-sectional study used data from the medical records of patients attending Duke Innovative Pain Therapies between August 2017 and April 2021 who received a pTMD diagnosis (i.e., myalgia) and consented to have their data used for research. Data included orofacial and pain-related measures, dental features, and psychological measures. We used the Rapid OPPERA Algorithm to assign clusters to patients and multinomial regression to determine the likelihood (odds ratios [OR] and 95% confidence intervals [CI]) of being assigned to the pain sensitive or global symptoms cluster attributed to each measure.

RESULTS

In total, 131 patients were included in this study and assigned a cluster: adaptive (n = 54, 41.2%), pain sensitive (n = 49, 37.4%), and global symptoms (n = 28, 21.4%). The PS cluster displayed greater numbers of temporomandibular joint sites (OR, 1.29; 95% CI, 1.01 to 1.65) and masticatory (1.48; 1.19 to 1.83) and cervical (1.23; 1.09 to 1.39) muscles with pain evoked by palpation. The GS cluster displayed greater scores of pain catastrophizing (1.04; 1.01 to 1.06) and perceived stress (1.23; 1.03 to 1.46) and was more likely to report persistent pain (16.23; 1.92 to 137.1) of higher impact (1.43; 1.14 to 1.80).

CONCLUSION

Our findings support that care-seeking patients with pTMDs who are assigned to the GS cluster display a poorer psychological profile, even though those assigned to the PS cluster display more measures consistent with orofacial pain. Findings also establish the PS cluster as a group that does not display psychological comorbidities despite being hypersensitive.

KNOWLEDGE TRANSFER STATEMENT

This study informs clinicians that patients seeking care for painful temporomandibular disorders, in specific cases of myalgia, can be classified into 1 of 3 groups that display unique profiles of symptoms. Most importantly, it emphasizes the importance of examining patients with painful temporomandibular disorders in a holistic manner that includes assessing symptoms of psychological distress. Patients with greater psychological distress will likely benefit from multidisciplinary treatment strategies that may include psychological treatments.

The relationship between pregnancy and temporomandibular disorder (TMD) through diagnostic criteria for temporomandibular disorders (DC/TMD) axis II evaluation: a case-control cross-sectional study

INTRODUCTION

This study focuses on temporomandibular disorders (TMDs), which affect the temporomandibular joint and related muscles and have multiple causes. Recent studies have examined the connection between menstrual cycles, estrogen levels, and TMDs, but results are inconsistent, highlighting the need for more research. The aim is to explore the prevalence of TMDs in pregnant women and consider how hormonal changes during pregnancy might influence these disorders.

METHODS

In this cross-sectional case-control study, we compared 32 pregnant women with 35 non-pregnant women. We evaluated several TMD-related factors such as pain levels, chronic pain classification, scores on the Jaw Functional Limitation Scale-20 and Oral Behaviors Checklist, and psychological health. We used various statistical methods including descriptive statistics, chi-square tests, linear regression, and adjustments for multiple comparisons to analyze the data.

RESULTS

Pregnant women showed different pain perceptions, generally reporting less pain and lower severity. Nonetheless, these differences were not uniform across all TMD-related measures. Linear regression did not find a consistent link between pregnancy and TMD scores, except for chronic pain grade, which was not significant after adjusting for multiple comparisons. There was a significant relationship between depression and TMD severity, emphasizing the need to consider mental health in TMD evaluations.

DISCUSSION

The findings suggest that pregnancy is neither a risk nor a protective factor for TMD. Differences in pain perception, functional status, and psychological health were observed in pregnant women but were not consistent for all TMD-related aspects. The role of estrogen in TMJ health and TMD risk is complex and requires further study. The research highlights the necessity of including mental health, especially depression, in TMD assessments. More comprehensive research with larger sample sizes is essential to better understand the connections between pregnancy, TMD, and hormones, aiming to improve TMD management in pregnant women and others.

Comparative Efficacy of Non-Invasive Therapies in Temporomandibular Joint Dysfunction: A Systematic Review

Temporomandibular disorder (TMD) is a multifaceted disorder impacting the temporomandibular joint (TMJ), causing substantial discomfort and functional limitations. This systematic review aims to comprehensively assess the effectiveness of non-invasive treatment modalities for TMJ dysfunction, prioritizing a definitive protocol to ensure patient safety and enhance quality of life. Employing the PRISMA guidelines, we meticulously analyzed 20 studies from a pool of 1,417 articles sourced from databases such as PubMed, Google Scholar, ScienceDirect, and Medline. These studies underscore the multifarious nature of TMD and the varied responses to treatments such as physical therapy, laser therapy, ultrasound and electrical stimulation, splint therapy, injections, and arthrocentesis. Notably, the review highlights the paramount importance of precise diagnosis, often through surface electromyography, followed by a tailored treatment approach integrating manual therapy, counseling, and splint therapy. The systematic analysis revealed that while certain treatments such as transcutaneous electrical nerve stimulation and low-level laser therapy showed limited efficacy, combination therapies, especially those involving manual therapy, counseling, and splint therapy, demonstrated substantial improvement in reducing pain, depression, and anxiety. The findings advocate for a non-invasive, patient-centric approach, emphasizing education and symptom management before considering more invasive procedures such as injections and arthrocentesis. The review identifies the need for more comprehensive, longitudinal studies to establish a standardized, evidence-based treatment protocol for TMJ dysfunction, aiming to improve patient outcomes holistically.

Effectiveness of Occlusal Splint Therapy in Moderating Temporomandibular Joint Disorders With Joint Displacement: A Retrospective Analysis Using Cone Beam Computed Tomography

Background Temporomandibular joint disorders (TMD) represent a prevalent group of conditions impacting the temporomandibular joint. Among the therapeutic interventions, occlusal splint therapy has gained recognition for its potential to address TMD symptoms, particularly in cases involving joint displacement. Objective This study aims to investigate the effectiveness of occlusal splint therapy in cases of moderate TMD with joint displacement, focusing on changes in condylar position, joint morphology, and patient-reported outcomes. Methods A retrospective analysis was conducted involving 148 participants who underwent occlusal splint therapy between January 2018 and December 2020. Data were collected through cone beam computed tomography (CBCT) imaging for precise assessments of condylar position and joint morphology. Ethical approval was obtained, and participants provided informed consent. Baseline characteristics, medical history, and TMD severity were recorded. Occlusal splint therapy included individualized fabrication, occlusal analysis, adjustments for optimal fit, and prescribed wear schedules. Follow-up included CBCT scans at specified intervals (three months and six months), with participant-reported outcomes collected. The data analysis was conducted using IBM SPSS Statistics for Windows, Version 22.0 (Released 2013; IBM Corp., Armonk, NY, USA). Paired t-tests or nonparametric equivalents were employed to assess changes in condylar position and joint morphology. Subgroup analyses were conducted to explore potential factors influencing treatment outcomes. The significance level was set at p < 0.05 for all statistical tests. Results The entire cohort (n = 148) had a mean age of 32.5 years (± 8.1), with a balanced gender distribution. Changes in condylar position revealed a statistically significant improvement (p = 0.03), with a mean decrease of 0.2 mm posttreatment. Joint morphology changes indicated increased joint space width (p = 0.01), improved disc position (p = 0.02), and nonsignificant alterations in bony structures (p = 0.10). Patient-reported outcomes demonstrated significant improvements in pain levels, jaw functionality, and satisfaction (all p < 0.001). Age and gender subgroup analyses showed consistent improvements in condylar position, joint morphology, and patient-reported outcomes across different groups. Conclusion Occlusal splint therapy demonstrated effectiveness in improving condylar position, joint morphology, and patient-reported outcomes in cases of moderate TMD with joint displacement. The findings underscore the potential of occlusal splint therapy as a viable intervention for managing TMD, providing valuable insights for clinicians and researchers.

Specific tissue engineering for temporomandibular joint disc perforation

BACKGROUND

The temporomandibular joint (TMJ) disc is a critical fibrocartilaginous structure with limited regenerative capacity in the oral system. Perforation of the TMJ disc can lead to osteoarthritis and ankylosis of the TMJ because of the lack of disc protection. Clinical treatments for TMJ disc perforation, such as discectomy, hyaluronic acid injection, endoscopic surgery and high position arthroplasty of TMJ, are questionable with regard to long-term outcomes, and only three fourths of TMJ disc perforations are repairable by surgery, even in the short-term. Tissue engineering offers the potential for cure of repairable TMJ disc perforations and regeneration of unrepairable ones.

OBJECTIVES

This review discusses the classification of TMJ disc perforation and defines typical TMJ disc perforation. Advancements in the engineering-based repair of TMJ disc perforation by stem cell therapy, construction of a disc-like scaffold and functionalization by offering bioactive stimuli are also summarized in the review, and the barriers developing engineering technologies need to overcome to be popularized are discussed.

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.

Intra-Articular Injection of Adipose-Derived Stromal Vascular Fraction in Osteoarthritic Temporomandibular Joints: Study Design of a Randomized Controlled Clinical Trial

INTRODUCTION

Temporomandibular joint (TMJ) osteoarthritis is a degenerative disease of the TMJ. It is characterized by progressive degradation of the extracellular matrix components of articular cartilage, with secondary inflammatory components leading to pain in the temporomandibular region and reduced mouth opening. Current treatments do not halt disease progression, hence the need for new therapies to reduce inflammation and, consequently, improve symptoms. The aim of our randomized controlled clinical trial protocol is to investigate the efficacy of adjuvant intra-articular injections of autologous tissue-like stromal vascular fraction (tSVF), compared to arthrocentesis alone, in reducing pain and improving mouth opening in TMJ osteoarthritis patients.

MATERIALS AND METHODS

The primary endpoint analysis will consist of the visual analogue scale (VAS) for pain. The secondary endpoint analyses will include maximal interincisal mouth opening measurements; assessment of oral health and mandibular function based on the oral health impact profile (OHIP) questionnaire and mandibular functional impairment questionnaire (MFIQ); complications during the follow up; synovial cytokine analysis at baseline and after 26 weeks; and nucleated cells and tSVF (immuno)histochemistry analyses of the intervention group.

DISCUSSION

Our randomized clinical trial protocol will be applied to evaluate the efficacy of a new promising tSVF injection therapy for TMJ osteoarthritis. The safety of intra-articular injections of tSVF has been proven for knee osteoarthritis. However, since a tSVF injection is considered a heterologous application of cell therapy, the regulatory requirements are strict, which makes medical ethical approval challenging.

Efficacy of Injectable Platelet-Rich Fibrin (I-PRF) in Managing Temporomandibular Joint Pain: A Prospective Clinical Study

BACKGROUND

Temporomandibular joint (TMJ) pain is a common condition that can significantly impact an individual's quality of life. Current treatment options often fall short of providing long-lasting relief. So, this prospective clinical study aimed to investigate the efficacy of injectable platelet-rich fibrin (I-PRF) in mitigating TMJ pain.

METHODS

A total of 68 participants, aged 18-60 years, clinically diagnosed with TMJ pain, were recruited from dental clinics and specialist referrals. Participants were randomly assigned to either the intervention group (I-PRF injections) or the control group (placebo). Primary outcome measures included TMJ pain intensity and jaw function, assessed using the Visual Analog Scale and functional examinations, respectively. Secondary outcomes comprised patient-reported outcomes (PROs) on quality of life and satisfaction. Data were collected at baseline and six, 12, and 24 weeks post intervention.

RESULTS

Baseline characteristics demonstrated successful randomization, with no significant differences in age, gender, or TMJ pain duration between groups. Post intervention, the intervention group exhibited a significant and sustained reduction in TMJ pain intensity compared to controls (p<0.001). Improvements in jaw function were also notable in the intervention group at all follow-up time points (p<0.001). PROs related to quality of life and satisfaction substantially increased in the intervention group compared to controls (p<0.001).

CONCLUSION

I-PRF demonstrated significant efficacy in reducing TMJ pain intensity, improving jaw function, and enhancing PROs. These findings support the consideration of I-PRF as a valuable therapeutic intervention for individuals with TMJ pain.