Bone changes in the temporomandibular joints of older adults: A cone-beam computed tomography study

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.

A study on volumetric change of mandibular condyles with osteoarthritis using cone-beam computed tomography

This study aimed to quantitatively assess three-dimensional changes in the mandibular condyle with osteoarthritis using cone-beam computed tomography (CBCT). Pre- and post-treatment CBCT images of temporomandibular joints (TMJs) from 66 patients were used to assess longitudinal changes in condylar volume within individual patients using 3D slicer software. Total volume difference (dV), net increase (dV + , bone deposition), and net decrease (dV- , bone resorption) after treatment were analyzed based on clinical and radiological factors. Condyles with surface erosion at their first visit showed significantly decreased volume after treatment compared to condyles without erosion (p < 0.05). Amounts of bone resorption and deposition were higher in condyles with surface erosion (both p < 0.01). In patients with condylar erosion, the presence of joint pain was associated with a decrease in condylar volume and an increase in net resorption (both p < 0.01). When both joint pain and condylar erosion were present, patients with parafunctional habits showed reduced condylar volume after treatment (p < 0.05). Condylar volume change after treatment was negatively correlated with the duration of pain relief (R = - 0.501, p < 0.05). These results indicate that condylar erosion and TMJ pain could be significant variables affecting TMJ volume changes after treatment. Establishing appropriate treatment strategies is crucial for managing condylar erosion and TMJ pain.

Correlations with clinical and radiologic findings and prevalence of osteopenia/osteoporosis in the patients with bilateral temporomandibular joint osteoarthritis

This study aimed to evaluate the prevalence of osteopenia/osteoporosis in patients with bilateral temporomandibular joint osteoarthritis (TMJ-OA) and its correlations with clinical and radiological findings. A total of 95 patients with bilateral TMJ-OA diagnosed by CBCT were included in the study. Clinical and radiological findings and bone mineral density (BMD) scores were recorded. Descriptive statistics and the Spearman rho correlation tests were performed. Osteopenia/osteoporosis was found in 44 of 95 patients (46.32 %) (30, osteopenia; 14 osteoporosis). Osteopenia/osteoporosis is significantly associated with postmenopausal status and age over 40 years, but it is not associated with clinical and radiological findings of TMJ-OA. Patients with bilateral TMJ-OA have a high prevalence of osteopenia/osteoporosis.

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

BACKGROUND

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

OBJECTIVES

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

The effect of myotonic dystrophy type 1 on temporomandibular joint and dentofacial morphology: A CBCT analysis

BACKGROUND

Myotonic dystrophy type 1 (DM1) is a neuromuscular multisystem disease. Early involvement of facial muscles may produce an extra load on the temporomandibular joint (TMJ) in DM1.

OBJECTIVES

This study aimed to investigate the morphological analyses of the bone components of temporomandibular joint (TMJ), and dentofacial morphology in myotonic dystrophy type 1 (DM1) patients by cone-beam computed tomography (CBCT).

METHODS

Sixty-six individuals (33 DM1, and 33 healthy subjects) age ranging from 20 to 69 were included in the study. Clinical examinations of the patients' TMJ regions and evaluation of dentofacial morphology (maxillary deficiency, open-bite, deep palate and cross-bite) were performed. Dental occlusion was determined based on Angle's classification. CBCT images were evaluated regarding mandibular condyle morphology (convex, angled, flat and round) and osseous changes observed in the condyle (normal, osteophyte, erosion, flattening, sclerosis). DM1-specific morphological and bony TMJ alterations were determined.

RESULTS

DM1 patients showed a high prevalence of morphological and osseous TMJ changes, and statistically significant skeletal alterations. The analysis of CBCT scans indicated the prevalent condylar shape among patients with DM1 was flat, the main osseous abnormality was flattening, there was a tendency towards skeletal Class II and a posterior cross-bite was frequently detected in DM1 patients. There was no statistically significant difference between the genders on the parameters evaluated in both groups.

CONCLUSION

Adult patients with DM1 presented a high frequency of crossbite, tendency to skeletal Class II and morphological osseous alterations of TMJ. The analysis of the morphological condylar alterations in patients with DM1 may be beneficial in the diagnosis of TMJ disorders. This study reveals DM1-specific morphological and osseous TMJ alterations to provide an appropriate orthodontic/orthognathic treatment planning to patients.

Osteoarthritis of the Temporomandibular Joint: A Narrative Overview

Background and Objectives: This study reviewed the literature to summarize the current and recent knowledge of temporomandibular joint osteoarthritis (TMJOA). Methods: Through a literature review, this work summarizes many concepts related to TMJOA. Results: Although many signaling pathways have been investigated, the etiopathogenesis of TMJOA remains unclear. Some clinical signs are suggestive of TMJOA; however, diagnosis is mainly based on radiological findings. Treatment options include noninvasive, minimally invasive, and surgical techniques. Several study models have been used in TMJOA studies because there is no gold standard model. Conclusion: More research is needed to develop curative treatments for TMJOA, which could be tested with reliable in vitro models, and to explore tissue engineering to regenerate damaged temporomandibular joints.

Type VI collagen regulates endochondral ossification in the temporomandibular joint

For many years there has been a keen interest in developing regenerative treatment for temporomandibular joint–osteoarthritis (TMJ‐OA). Currently, there is no consensus treatment due to the limited self‐healing ability of articular cartilage and lack of understanding of the complex mechanisms regulating cartilage development in the TMJ. Endochondral ossification, the process of subchondral bone formation through chondrocyte differentiation, is critical for TMJ growth and development, and is tightly regulated by the composition of the extracellular matrix (ECM). Type VI collagen is a highly expressed ECM component in the TMJ cartilage, yet its specific functions are largely unknown. In this study, we investigated α2(VI)‐deficient (Col6a2‐knockout [KO]) mice, which are unable to secret or incorporate type VI collagen into their ECM. Compared with wild‐type (WT) mice, the TMJ condyles of Col6a2‐KO mice exhibit decreased bone volume/tissue volume (BV/TV) and a larger bone marrow space, suggesting the α2(VI)‐deficient condyles have a failure in endochondral ossification. Differentiating chondrocytes are the main source of bone cells during endochondral ossification. Our study shows there is an increased number of chondrocytes in the proliferative zone and decreased Col10‐expressing chondrocytes in Col6a2‐KO cartilage, all pointing to abnormal chondrocyte differentiation and maturation. In addition, RNA sequencing (RNAseq) analysis identified distinct gene expression profiles related to cell cycle and ECM organization that were altered in the mutant condyles. These data also suggest that bone morphogenetic protein 2 (BMP2) activity was deregulated during chondrocyte differentiation. Immunohistochemical analysis indicated an upregulation of Col2 and Acan expression in Col6a2‐KO cartilage. Moreover, the expression of pSmad1/5/8 and Runx2 was decreased in the Col6a2‐KO cartilage compared with WT controls. Taken together, our data indicate that type VI collagen expressed in the TMJ cartilage is important for endochondral ossification, possibly by modulating the ECM and altering/disrupting signaling pathways important for TMJ chondrocyte differentiation. Published 2022. This article is a U.S. Government work and is in the public domain in the USA. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Comparison of Clinical and Radiological Characteristics of Temporomandibular Joint Osteoarthritis in Older and Young people

Background and Objectives:

The relatively high prevalence of temporomandibular joint (TMJ) osteoarthritis (OA) in older people increases the necessity to investigate the specific characteristics of TMJ-OA in this particular population. This study aimed to analyze the longitudinal changes in clinical and radiological characteristics of TMJ-OA in older people.

Methods:

We retrospectively analyzed the clinical features and cone-beam computed tomography (CBCT) images of 76 participants with TMJ-OA. Participants were classified into two groups according to age. The older people group included 33 participants over 50 years of age, and the control group included 43 participants in their 15-29 years. We analyzed the differences in clinical features and the distribution of destructive bony changes on CBCT images between groups.

Results:

The duration of pain was significantly shorter in the older people group (P = .046); however, the treatment duration was significantly longer in the older people group (P = .001). There was a significant difference in the distribution of destructive bony features between groups (P = .005). In the older people group, “three or more features” (36.3%) were the most common, whereas in the control group, “erosion” (44.2%) was the most common. After treatment, there was little improvement in the frequency of “erosion” in the older people group. There was a significant difference in the proportion of erosion after treatment between the groups (P = .033).

Conclusion:

In older people with TMJ-OA, active treatment to effectively induce condylar remodeling should be considered.

Comparison of Clinical and Radiological Characteristics of Temporomandibular Joint Osteoarthritis in Older and Young people

Background and Objectives:

The relatively high prevalence of temporomandibular joint (TMJ) osteoarthritis (OA) in older people increases the necessity to investigate the specific characteristics of TMJ-OA in this particular population. This study aimed to analyze the longitudinal changes in clinical and radiological characteristics of TMJ-OA in older people.

Methods:

We retrospectively analyzed the clinical features and cone-beam computed tomography (CBCT) images of 76 participants with TMJ-OA. Participants were classified into two groups according to age. The older people group included 33 participants over 50 years of age, and the control group included 43 participants in their 15-29 years. We analyzed the differences in clinical features and the distribution of destructive bony changes on CBCT images between groups.

Results:

The duration of pain was significantly shorter in the older people group (P = .046); however, the treatment duration was significantly longer in the older people group (P = .001). There was a significant difference in the distribution of destructive bony features between groups (P = .005). In the older people group, “three or more features” (36.3%) were the most common, whereas in the control group, “erosion” (44.2%) was the most common. After treatment, there was little improvement in the frequency of “erosion” in the older people group. There was a significant difference in the proportion of erosion after treatment between the groups (P = .033).

Conclusion:

In older people with TMJ-OA, active treatment to effectively induce condylar remodeling should be considered.

Increased Risk of Temporomandibular Joint Disorder in Osteoporosis Patients: A Longitudinal Study

BACKGROUND

The objective of this study was to investigate the risk of temporomandibular joint disorder (TMD) in patients with osteoporosis.

METHODS

Data from the Korean National Health Insurance Service-Health Screening Cohort from 2002 to 2015 were collected. Participants ≥ 40 years old were enrolled, and the history of osteoporosis was evaluated. The 62,328 osteoporosis patients were matched for age, sex, income, and region of residence with 62,328 control participants. The occurrence of TMD was assessed in both the osteoporosis and control groups during the follow-up period. Stratified Cox proportional hazard analyses for TMD were conducted for the osteoporosis and control groups. The hazard ratios (HRs) of osteoporosis for TMD were further analyzed by age and sex subgroups.

RESULTS

A total of 1.2% (725/61,320) of the osteoporosis patients and 0.6% (339/61,320) of the control participants had TMD (P<0.001). Osteoporosis was associated with an elevated HR of TMD (adjusted HR=1.96, 95% CI=1.72-2.23, P<0.001). Among the age and sex subgroups, the < 60-year-old mal\e group demonstrated an adjusted HR of osteoporosis for TMD as high as 4.47 (95% CI=1.17-17.12, P=0.029). Other age and sex subgroups also showed a higher HR for TMD associated with osteoporosis (adjusted HR=2.30, 95% CI=1.90-2.78, P<0.001 for the ≥ 60-year-old female group).

CONCLUSION

Osteoporosis was related to a higher risk of TMD in the adult population. A prominent association of osteoporosis with TMD was noted in middle-aged men and older women.

The temporomandibular joints disorders in patients with osteoporosis

Background:

Osteoporosis is a skeletal and progressive behavioral disease with physically and psychologically significant consequences.

Aims of the Study:

Evaluate the presence and effects of Temporomandibular Joints Disorders in osteoporotic patients.

Materials and Methods:

Fifty-eight (58) patients with osteoporosis participated in this study as they were already diagnosed by Rheumatologists, physical and sport Rehabilitation physicians in Merjan Medical city/Babylon – Iraq between period February and August 2019.

Results:

Twenty-seven (27) patients with T. M. J clicking as anterior disk displacements, Seventeen (17) patients with spasm in muscles of mastication, and then finally Fourteen (14) out of 58 patients with subluxation and dislocation.

Conclusions:

Osteoporosis can have a significant impact on oral health.

Bidirectional relationship between temporomandibular disorder and ankylosing spondylitis: a population-based cohort study

OBJECTIVES

This study aimed to determine the relation between temporomandibular disorder (TMD) and ankylosing spondylitis (AS) bidirectionally and ascertain the important comorbidities for AS occurrence in TMD patients.

MATERIALS AND METHODS

We conducted this population-based cohort study through Longitudinal Health Insurance Database, Taiwan. Study 1 investigated the risk of TMD in AS patients. Study 2 assessed the risk of AS in TMD patients.

RESULTS

In total, 3204 AS patients and 12,816 age-matched and gender-matched comparisons were enrolled in study 1. The TMD incidence in the AS cohort was 2.88-fold higher when compared with the comparisons (1.54 vs. 0.53 per 10,000 person-years). After adjusting for age, gender, and comorbidity, the AS cohort had a 2.66-fold (95% CI = 1.79-3.97) increased risk of TMD occurrence (P < 0.0001). The second study recruited 4998 TMD patients and 19,991 age-matched and gender-matched comparisons. Both TMD and comparison cohorts showed similar AS risk (HR = 1.49, 95% CI = 0.91-2.43, P = 0.1108) in the adjusted model. Study 2 identified a 3.66-fold increased risk of AS occurrence in TMD patients with comorbidity, including parapsoriasis, rheumatoid arthritis, osteoporosis, Cushing's syndrome, and climacteric arthritis (P < 0.012).

CONCLUSIONS

AS appears to significantly impact the occurrence of TMD. TMD might play a synergic role in AS development.

CLINICAL RELEVANCE

Clinicians have to be vigilant about the increased risk of TMD in AS patients and take care of AS disease activity and prognosis. The symptoms and signs of TMD could be a predictor of AS in patients with the aforementioned comorbidities.

Overexpression of MMPs, cytokines, and RANKL/OPG in temporomandibular joint osteoarthritis and their association with joint pain, mouth opening, and bone degeneration: A preliminary report

OBJECTIVE

This study aimed to determine the expression of distinct matrix metalloproteinases, cytokines, and bone resorptive factors in temporomandibular joint osteoarthritis (TMJ-OA) patients and their association with joint pain, mouth opening, and subchondral bone degeneration.

MATERIALS AND METHODS

Twelve patients affected with TMJ-OA (n = 5), disk displacement without reduction (DDWoR) (n = 3), or disk displacement with reduction (DDWR) (n = 4) were selected. Joint pain was quantified by using visual analog scale, mouth opening was quantified at the maximum pain-free aperture, and bone degeneration was quantified using joint imaging. Synovial fluid samples were collected and immediately processed for cell and synovial fluid recovering. From cells, the MMP-1, MMP-2, MMP-8, MMP-13, IL-6, IL-23, and TNF-α expression was quantified by qPCR. From synovial fluid, the RANKL and OPG levels were quantified by ELISA.

RESULTS

Higher levels of MMP-1, MMP-8, MMP-13, IL-6, IL-23, TNF-α, and RANKL/OPG ratio were detected in TMJ-OA compared with DDWoR and DDWR patients (p < .05). Joint pain significantly correlated with TNF-α levels (r = .975, p = .029). Besides, imaging signs of bone degeneration significantly correlated with RANKL/OPG ratio (r = .949, p = .042). Conversely, mouth opening did not correlate with any of the analyzed mediators.

CONCLUSION

During TMJ-OA, a pathological response characterized by the overexpression of TNF-α and RANKL/OPG could be involved in joint pain and subchondral bone degeneration.