Orofacial Motor Functions and Temporomandibular Disorders in Patients With Sjögren's Syndrome

Risk factors associated with temporomandibular joint disorder: A mendelian randomization analysis

BACKGROUND

Temporomandibular joint disorder (TMD), a prevalent orofacial disorder with complex aetiologies and considerable socioeconomic costs. This underscores the critical importance of developing a comprehensive understanding of the risk factors associated with TMD, as existing research is hindered by deficiencies in establishing causal relationships and the limitations of traditional research methodologies.

OBJECTIVES

This research explores the causal link between certain risk factors and temporomandibular joint disorder (TMD) through Mendelian randomization (MR), providing multidimensional perspectives in addressing this worldwide health issue.

METHODS

Utilizing instrumental variables, we applied advanced statistical methods, including the weighted median, inverse variance weighted (IVW) and MR-Egger, to evaluate the impact of twelve potential risk factors on TMD.

RESULTS

Our results identified a significant positive association of TMD with malocclusion (p < .001), sleeping disorders (p = .006), anxiety (p = .002), major depression (p = .0002), daily cigarettes consumption (p = .029) and autoimmune diseases (p = .039). Conversely, a negative association was observed with educational attainment (p = .003).

CONCLUSION

These findings suggest that malocclusion, sleeping disorders, anxiety, major depression, daily cigarettes consumption and autoimmune diseases, could potentially increase TMD risk while educational attainment might mitigate its increase. No direct causal relationships were established between serum 25-hydroxyvitamin D levels, menopause, frequent alcohol consumption, coffee intake and severely worn dentition and TMD.

The interaction between the nervous system and the stomatognathic system: from development to diseases

The crosstalk between the nerve and stomatognathic systems plays a more important role in organismal health than previously appreciated with the presence of emerging concept of the "brain-oral axis". A deeper understanding of the intricate interaction between the nervous system and the stomatognathic system is warranted, considering their significant developmental homology and anatomical proximity, and the more complex innervation of the jawbone compared to other skeletons. In this review, we provide an in-depth look at studies concerning neurodevelopment, craniofacial development, and congenital anomalies that occur when the two systems develop abnormally. It summarizes the cross-regulation between nerves and jawbones and the effects of various states of the jawbone on intrabony nerve distribution. Diseases closely related to both the nervous system and the stomatognathic system are divided into craniofacial diseases caused by neurological illnesses, and neurological diseases caused by an aberrant stomatognathic system. The two-way relationships between common diseases, such as periodontitis and neurodegenerative disorders, and depression and oral diseases were also discussed. This review provides valuable insights into novel strategies for neuro-skeletal tissue engineering and early prevention and treatment of orofacial and neurological diseases.

Temporomandibular disorders in immune-mediated rheumatic diseases of the adult: A systematic review

OBJECTIVE

To systematically review the literature concerning temporomandibular disorders (TMDs) in immune-mediated rheumatic diseases (IMRDs) of the adult. The temporomandibular joint (TMJ) outcomes used in clinical studies, the prevalence of TMDs in IMRDs and the risk factors for their development were qualitatively synthetized.

METHODS

A literature search on PubMed Central, Embase and Cochrane Library databases was performed for studies including TMJ outcomes in IMRDs patients compared with healthy controls, other rheumatic diseases or in the assessed IMRDs patients after follow-up and treatment. Among the IMRDs of the adult, original articles investigating TMJ involvement in inflammatory polyarthritides and/or autoimmune connective tissue diseases were considered. The quality of the studies was scored using the Newcastle-Ottawa scale (NOS).

RESULTS

Of the 3259 screened abstracts, 56 papers were included in the systematic review. Most of the papers (77%) investigated TMDs in rheumatoid arthritis (RA) with a prevalence of signs and symptoms varying from 8% to 70%. The risk factors for TMDs development in RA were female sex, younger age, anti-citrulline peptide autoantibodies (ACPA) positivity, higher disease activity, cervical spine involvement, cardiovascular and neuropsychiatric comorbidities. Ten papers (18%) evaluated TMDs in spondylarthritides (SpA) reporting a prevalence of symptoms and signs in 12%-80% of patients with higher TMDs prevalence in patients with radiographic spine involvement, skin psoriasis and HLADRB1×01 positivity. Among autoimmune connective tissue diseases (CTDs), systemic sclerosis (SSc) displayed the highest evidence of TMDs patient-reported outcomes (PROs) and clinical findings (20-93%), followed by systemic lupus erythematosus (SLE) in 18-85%, primary Sjogren's syndrome (24-54%) and idiopathic inflammatory myopathies (4-26%). In SSc and SLE, TMDs were more frequent in patients with higher disease activity and duration, correlating with the extent of skin fibrosis in SSc and with renal involvement in SLE.

CONCLUSION

TMDs in IMRDs display a significant relevance in the rheumatological clinical practice even if often misdiagnosed. This burden is epidemiologically important in terms of PROs and clinical findings which correlate with disease activity in RA, SpA, SSc and SLE. The early recognition and multidisciplinary management of TMDs is warranted and should be aimed at hindering the TMJ structural damage maximizing the quality of life of patients.

Masticatory Function in Individuals with Temporomandibular Disorders: A Systematic Review and Meta-Analysis

The literature search was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) protocol in the PubMed, Cochrane Library, LILACS, EBSCO, Scielo, between 2012 and 2022. The methodological quality was assessed by using the Newcastle-Ottawa Study Quality Assessment Scale. Mean differences and 95% confidence intervals were calculated and combined in meta-analyses. A total of 1202 participants were included in this systematic review (690 with TMD; 512 without TMD), with 22 articles being included in the qualitative analysis. Only three studies enabled the comparative analysis of the results. Ten articles showed a high methodological quality and a low risk of bias, and twelve had a low methodological quality and an increased risk of bias. The meta-analysis showed that the differences between the intervention and control groups were not statistically significant for the percentage overlapping coefficient of the anterior temporal muscle, for the masseter, and for the torque coefficient. The parameters analyzed with the compound technique for chewing showed altered mandibular functions in individuals with TMD. With the EMG method, it was possible to suggest that TMD in adult individuals causes compensatory muscle behaviors, and several changes in the masticatory function were found.

Quantitative Measurement of Swallowing Performance Using Iowa Oral Performance Instrument: A Systematic Review and Meta-Analysis

Swallowing is a complex but stereotyped motor activity aimed at serving two vital purposes: alimentary function and the protection of upper airways. Therefore, any impairment of the swallowing act can represent a significant clinical and personal problem that needs an accurate diagnosis by means of reliable and non-invasive techniques. Thus, a systematic review and meta-analysis was performed to investigate the reliability of the Iowa Oral Pressure Instrument (IOPI) in distinguishing healthy controls (HC) from patients affected by swallowing disorders or pathologies and conditions that imply dysphagia. A comprehensive search was conducted following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines and using PubMed, Scopus, Web of Science, Cochrane, and Lilacs databases. Overall, 271 articles were identified and, after a three-step screening, 33 case-control and interventional studies reporting IOPI measurements were included. The methodological quality of the retrieved studies resulted in being at a low risk of bias. The meta-analysis on case-control studies showed that maximum tongue pressure (MIP) values were always higher in HC than in patients, with an overall effect of the MIP difference of 18.2 KPa (17.7–18.7 KPa CI). This result was also confirmed when the sample was split into adults and children, although the MIP difference between HC and patients was greater in children than in adults (21.0 vs. 15.4 KPa in the MIP mean difference overall effect, respectively). Tongue endurance (TE) showed conflicting results among studies, with an overall effect among studies near zero (0.7 s, 0.2–1.1 s CI) and a slight tendency toward higher TE values in HC than in patients. Among the intervention studies, MIP values were higher after treatment than before, with a better outcome after the experimental tongue training exercise than traditional treatments (the MIP mean difference overall effect was 10.8 and 2.3 KPa, respectively). In conclusion, MIP values can be considered as a reliable measure of swallowing function in adults and in children, with a more marked MIP difference between HC and patients for the children population. MIP measures in patients are also able to detect the best outcome on the tongue function after the training exercise compared to traditional training.

Oral health and orofacial function in patients with rheumatoid arthritis

The aim of the study was to describe the oral health and orofacial function of Mexican patients with rheumatoid arthritis (RA) and their association with clinical and radiological aspects of the disease. Patients with RA received a complete odontological exam, which also included a clinical and radiographic assessment of the temporomandibular joint (TMJ). The rheumatologic assessment included detailed profiling of the disease and serological and radiographic parameters. The study included 62 RA patients; the median (min-max) age was 51 (18-72) years old and 8.5 (1-39) years of disease duration. The 63.6% of the patients had DAS28 ≥ 3.2, and a median (min-max) of Sharp/van der Heijde score (SvdHS) of 41 (0-214). 98.3% of the patients presented caries, which were severe in 53.3% of the cases. The 73.8% of the patients were missing teeth due to caries, with a median (min-max) of 4 (0-32) teeth missing per patient. Oral hygiene was classified as bad in 49.1% of patients and only 15.3% of them had a healthy periodontium. The TMJ function was abnormal in 98.4% of the patients and 62.9% of them presented moderate or severe TMJ disorder (TMD). The radiographic damage of the TMJ correlated positively with the SvdHS. No correlations were found between disease activity or structural progression and orofacial variables, including periodontitis. There are severe oral and orofacial health problems in RA patients despite having medical attention for their disease. Multidisciplinary management remains an area of opportunity for both the medical specialists and the health system in our country.