Temporomandibular joint involvement in children with juvenile idiopathic arthritis-Symptoms, clinical signs and radiographic findings

Akt2 inhibition alleviates temporomandibular joint osteoarthritis by preventing subchondral bone loss

BACKGROUND

This study aimed to investigate the role and mechanism of the Akt2 pathway in different stages of anterior disc displacement (ADD)-induced temporomandibular joint osteoarthritis (TMJOA).

METHODS

A rat model for TMJOA that simulates anterior disc displacement was established. For inhibit Akt2 expression in subchondral bone, rats were intravenously injected with adeno-associated virus carrying Akt2 shRNA at a titer of 1 × 1012 transducing units/mL 10 days before the ADD or sham operations. The rats were euthanized and evaluated 1 or 8 weeks after surgery, as these time points represented the early or advanced stage of ADD. Immunostaining was performed to examine the expression and location of phosphorylated Akt2 in different stages of ADD. Microcomputed tomography, hematoxylin and eosin staining, toluidine blue staining, Western blotting, immunohistochemical and immunofluorescence staining were used to elucidate the pathological changes and potential mechanisms underlying ADD-induced TMJOA.

RESULTS

In the rat model of ADD-induced TMJOA, rapid condylar bone loss occurred with increased phosphorylation of Akt2 in subchondral bone macrophages within 1 week post-surgery. At 8 weeks after surgery, abnormal remodeling of subchondral bone and degenerative changes in cartilage were observed. Inhibiting Akt2 reduced condylar bone resorption following ADD surgery while improving condylar bone morphology at 8 weeks post-surgery. Additionally, inhibition of Akt2 alleviated cartilage degeneration characterized by a decreased number of apoptotic chondrocytes, reduced expression of matrix metalloproteinases, and increased collagen type II expression in cartilage tissue.

CONCLUSIONS

The Akt2 pathway is activated mainly in subchondral bone macrophages during the early stage of ADD and plays an important role in regulating subchondral bone remodeling. Inhibition of Akt2 could serve as a prophylactic treatment to slow the progression of ADD-induced TMJOA.

Temporomandibular involvement in children and adolescents with juvenile idiopathic arthritis: a 2-year prospective cohort study

This study aimed to clinically evaluate temporomandibular joint (TMJ) involvement in juvenile idiopathic arthritis (JIA) and the ability to identify and/or predict development of TMJ-deformities over time using cone beam computed tomography (CBCT). The predictive value of self-reported TMJ pain was also assessed. A prospective longitudinal cohort study comprising 54 children with JIA, 39 girls and 15 boys, was performed. All children had active disease at baseline, 50% with the subtype oligoarthritis. Repeated clinical orofacial and CBCT examinations were performed over a two-year period. At baseline, 39% had radiographic TMJ deformities (24% unilateral, 15% bilateral), at 2-year follow-up, 42% (p > 0.05). Both progressing and improving TMJ deformities were observed. An association was found between TMJ-deformities and self-reported TMJ pain at baseline (p = 0.01). Maximum unassisted mouth opening (MUO) was smaller for children with TMJ-deformities (p < 0.05). The prevalence of palpatory muscle pain was high (48-59%) but not predictive of development of TMJ-deformities. TMJ noises increased over time and crepitations were associated with TMJ-deformities (p < 0.05). In conclusion, in children with JIA, self-reported TMJ pain and dysfunction were common and predictive of TMJ deformities. TMJ deformities were associated with smaller MUO and palpatory TMJ pain as well as crepitations. Trial registration. ClinicalTrials.gov Protocol id: 2010/2089-31/2.

Prevalence of temporomandibular disorders in juvenile idiopathic arthritis evaluated with diagnostic criteria for temporomandibular disorders: A systematic review with meta-analysis

BACKGROUND

Juvenile idiopathic arthritis (JIA) is a very common systemic inflammatory rheumatic disorder affecting the musculoskeletal system in children below 16 years of age. Joint inflammation and tissue destruction is the prime characteristic of the disease. Along with the systemic involvement in the long joints, several studies are mentioning the increased association of temporomandibular disorders (TMDs) in JIA. This current systematic review intends to find the prevalence rate of TMD in JIA-affected individuals as compared to healthy controls.

METHODS

We have searched in PubMed, Scopus and Ovid SP for articles published between the timeframe 1 January 1990 and 1 June 2023. All the searched articles were subjected to the Population, Exposure, Comparison, and Outcome model (PECO) based on which inclusion or exclusion is carried out. Participants (P) are children below 18 years of age, Exposure (E) is children or adolescents with a diagnosis of JIA, Comparator is age and gender-matched healthy controls who has no JIA or any systemic disorder, Outcome (O) is the prevalence of TMD. Only the studies that evaluated TMD using diagnostic criteria for evaluation of TMD (DC/TMD) were included in the analysis. We have set the exclusion to the following reasons- diagnostic sensitivity studies, case reports, and systematic reviews. The software Review Manager Version 5.4 (Cochrane Collaboration) was used to perform the pooled analysis. We measured the risk ratio (RR) between the two groups (JIA and no JIA) for the outcome TMD.

RESULTS

The pooled total included subjects were 366 in this review with an established diagnosis of JIA as evaluated by DC/TMD. The overall effect of the pooled data suggests that there is a significant difference in the TMD prevalence in the JIA group when compared to the control, results suggest that TMD is more prevalent in the JIA group RR 3.86; 95% CI [2.59, 5.76].

CONCLUSION

Overall, based on the data we can suggest a positive relationship between JIA and TMD, hence presence of JIA can be a risk factor for the development of TMD. The sensitivity of DC/TMD is low when compared to magnetic resonance imaging.

Magnetic resonance imaging texture analysis for quantitative evaluation of the mandibular condyle in juvenile idiopathic arthritis

OBJECTIVES

Juvenile idiopathic arthritis (JIA) is a chronic inflammatory disease that affects the joints and other organs, including the development of the former in a growing child. This study aimed to evaluate the feasibility of texture analysis (TA) based on magnetic resonance imaging (MRI) to provide biomarkers that serve to identify patients likely to progress to temporomandibular joint damage by associating JIA with age, gender and disease onset age.

METHODS

The radiological database was retrospectively reviewed. A total of 45 patients were first divided into control group (23) and JIA group (22). TA was performed using grey-level co-occurrence matrix (GLCM) parameters, in which 11 textural parameters were calculated using MaZda software. These 11 parameters were ranked based on the p value obtained with ANOVA and then correlated with age, gender and disease onset age.

RESULTS

Significant differences in texture parameters of condyle were demonstrated between JIA group and control group (p < 0.05). There was a progressive loss of uniformity in the grayscale pixels of MRI with an increasing age in JIA group.

CONCLUSIONS

MRI TA of the condyle can make it possible to detect the alterations in bone marrow of patients with JIA and promising tool which may help the image analysis.

Salivary biomarkers in children with juvenile idiopathic arthritis and healthy age-matched controls: a prospective observational study

Monitoring the immune system's regulation and signaling using saliva could be of interest for clinicians and researchers. Saliva, a biofluid with close exchange with serum, is influenced by circadian variance and oral factors such as masticatory function. This study investigated the detectability and concentration of cytokines and chemokines in saliva in children with juvenile idiopathic arthritis (JIA) as well as saliva flow and the influence of orofacial pain on saliva flow. Of the 60 participants (7-14 years old) enrolled, 30 had a diagnosis of JIA and active disease, and 30 were sex- and age-matched healthy controls. Demographic data and three validated questions regarding presence of orofacial pain and dysfunction were recorded. Stimulated whole saliva was collected and analyzed using a customized R&D bead-based immunoassay with 21 targeted biomarkers. Fourteen of these were detectable and showed similar levels in both children with JIA and controls: TNF-alpha, TNFRSF1B, MMP-2, MMP-3, IL-1alpha, IL-1beta, IL-6R alpha, IL-8, S100A8, CCL2, CCL3, IL-10, CCL11, and CXCL9. In addition, there was no difference in salivary flow rate between groups, but there was an association between orofacial pain and reduced saliva flow rate for both groups.Trial registration: ClinicalTrials.gov Protocol id: 2010/2089-31/2.