Risk Of Temporomandibular Disorders Research Articles

Causal associations between sleep traits and temporomandibular disorders: a bidirectional mendelian randomization analysis.

This study aims to investigate the relationship between five sleep traits (insomnia, sleep duration, getting up in morning, snoring, and daytime nap) and temporomandibular disorders (TMD) using bi-directional Mendelian randomization. The bi-directional Mendelian randomization study was conducted in two stages. Initially, sleep traits were examined as exposures while TMD was evaluated as an outcome, whereas the second step was reversed. The inverse variance weighted (IVW) method and other Mendelian randomization methods were used for analysis. Furthermore, we performed the MR-Egger intercept, MR-PRESSO, Cochran's Q test, and "Leave-one-out" to assess the levels of pleiotropy and heterogeneity. The IVW method indicates that getting up in the morning reduces the risk of developing TMD (OR = 0.50, 95% CI 0.30-0.81, p = 0.005), while insomnia may increase the risk of TMD (OR = 2.05, 95% CI 1.10-3.85, p = 0.025). However, other sleep traits are not associated with the risk of TMD, and having TMD does not alter an individual's sleep traits. After removing outliers, the results remained robust, with no pleiotropy detected. Genetically determined difficulty in getting up in the morning and insomnia can increase the risk of TMD. By optimizing sleep, the risk of developing TMD can be reduced. This underscores the importance of sleep in preventing TMD.

The Role of Malocclusion and Oral Parafunctions in Predicting Signs and Symptoms of Temporomandibular Disorders-A Cross-Sectional Study.

The aim of this study was to examine to what extent malocclusion and parafunctional habits contribute to the development of signs and symptoms associated with temporomandibular disorders (TMD) in schoolchildren with mixed dentition in Croatia in a sample of 338 children, aged 9 to 15 years. TMD signs and symptoms assessed by the clinician were joint function and pain, masticatory muscles tenderness, range of mandibular motion, and joint sounds. To evaluate subjective symptoms and parafunctions, children and parents were asked about the presence of headaches, jaw locking, temporomandibular joint (TMJ) sounds, pain during mouth opening, or bruxism, as well as parafunctions like biting pencils or nails, chewing hard candies or ice, daily gum chewing, opening bottles with teeth, engaging in jaw play, thumb-sucking, and clenching/grinding teeth. At least one symptom of a TMD was pronounced in 142 participants (42.0%). The most commonly reported parafunction was pencil or nail biting, present in 25.1% of participants. Class II malocclusion increased the likelihood by 2.6 times, pencil or nail biting by 2.34 times, and clenching/grinding teeth by 8.9 times that the subject would exhibit at least one TMD symptom. Every child with mixed dentition should undergo a brief examination of the TMJ, especially in cases of Class II malocclusion, pencil or nail biting, and teeth clenching or grinding, as these have all been identified as significant risk factors that increase the likelihood of experiencing TMD symptoms. This highlights the need for proactive screening and assessment by healthcare providers to reduce the risk and prevalence of TMDs in affected children and ensure timely diagnosis and treatment.

Causal effects of autoimmune diseases on temporomandibular disorders and the mediating pathways: a Mendelian randomization study.

The role of autoimmune diseases (ADs) in temporomandibular disorders (TMDs) has been emphasized in observational studies. However, whether the causation exists is unclear, and controversy remains about which specific disorder is destructive in TMDs. This Mendelian randomization (MR) study aims to estimate the causal effect of common ADs on TMDs. Genetic data from published genome-wide association studies for fourteen common ADs, specifically multiple sclerosis (MS, N = 15,283), ankylosing spondylitis (AS, N = 22,647), asthma (N = 408,422), celiac disease (N = 15,283), Graves' disease (N = 458,620), Hashimoto thyroiditis (N = 395,640), primary biliary cirrhosis (PBC, N = 11,375), primary sclerosing cholangitis (PSC, N = 14,890), psoriasis vulgaris (N = 483,174), rheumatoid arthritis (RA, N = 417,256), systemic lupus erythematosus (SLE, N = 23,210), Type 1 diabetes (T1D, N = 520,580), inflammatory bowel disease (IBD, N = 34,652), and Sjogren's syndrome (SS, N = 407,746) were collected. Additionally, the latest summary-level data for TMDs (N = 228,812) were extracted from the FinnGen database. The overall effects of each immune traits were assessed via inverse-variance weighted (IVW), weighted median, and MR-Egger methods, and performed extensive sensitivity analyses. Finally, 731 immune cell phenotypes (N = 3,757) were analyzed for their mediating role in the significant causality. Univariable MR analyses revealed that genetically predicted RA (IVW OR: 1.12, 95% CI: 1.05-1.19, p < 0.001) and MS (IVW OR: 1.06, 95% CI: 1.03-1.10, p = 0.001) were associated with increased risk of TMDs. Two out of 731 immune cell phenotypes were identified as causal mediators in the associations of RA with TMDs, including "CD25++ CD8+ T cell % CD8+ T cell" (mediation proportion: 6.2%) and "CD3 on activated CD4 regulatory T cell" (5.4%). Additionally, "CD127 on granulocyte" mediated 10.6% of the total effect of MS on TMDs. No reverse directions, heterogeneity, and pleiotropy were detected in the analyses (p > 0.05). This MR study provides new evidence regarding the causal impact of genetic predisposition to RA or MS on the increased risk of TMDs, potentially mediated by the modulation of immune cells. These findings highlight the importance for clinicians to pay more attention to patients with RA or MS when consulting for temporomandibular discomfort. The mediating role of specific immune cells is proposed but needs further investigation.

Bi-directional two-sample Mendelian randomization identifies causal association of depression with temporomandibular disorders.

Depression and anxiety have been suggested to be associated with temporomandibular disorders (TMD) in observational studies. However, the causal association and the direction in the relationship between depression/anxiety and TMD remain unknown. This study investigated the potential causal relationship between depression/anxiety and TMD with two-sample bi-directional Mendelian randomization (MR). Summary statistics of depression (N = 500 199), anxiety disorder (N = 17 310) and TMD (N = 195 930) were sourced from large-scale genome-wide association studies (GWAS). The primary Mendelian randomization (MR) estimation employed the inverse-variance weighted meta-analysis (IVW). Additional MR sensitivity methods and multivariate MR (MVMR) were applied to address pleiotropy. IVW results indicated a causal effect of genetically predicted depression on TMD (OR = 1.887, 95% CI = 1.504-2.367, p < .001), which was supported by other sensitivity MR approaches. MVMR results suggested that the negative effect of depression on TMD persisted after conditioning on other potential confounders. The association of anxiety disorder with TMD was not supported by our findings. In the reverse direction, we did not find compelling evidence suggesting the causal effect of TMD on depression and anxiety disorder. The present study suggests a potential causal association between genetic liability for depression and the risk of TMD. Our MR findings align with prior epidemiological research, underscoring the significance of early detection and prevention of depression in the treatment of TMD.

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

IntroductionThis 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.MethodsIn 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.ResultsPregnant 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.DiscussionThe 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.

Causal relationship between hypothyroidism and temporomandibular disorders: evidence from complementary genetic methods

BackgroundThe role of thyroid health in temporomandibular disorders (TMDs) has been emphasized in observational studies. However, whether the causation exists is unclear, and controversy remains about which specific disorder, such as hypothyroidism or hyperthyroidism, is destructive in TMDs. This study aims to investigate the overall and specific causal effects of various thyroid conditions on TMDs.MethodsMendelian randomization (MR) studies were performed using genetic instruments for thyrotropin (TSH, N = 119,715), free thyroxine (fT4, N = 49,269), hypothyroidism (N = 410,141), hyperthyroidism (N = 460,499), and TMDs (N = 211,023). We assessed the overall effect of each thyroid factor via inverse-variance weighted (IVW), weighted median, and MR-Egger methods, and performed extensive sensitivity analyses. Additionally, multivariable MR was conducted to evaluate the direct or indirect effects of hypothyroidism on TMDs whilst accounting for TSH, fT4 and hyperthyroidism, and vice versa.ResultsUnivariable MR analyses revealed a causal effect of hypothyroidism on an increased risk of TMDs (IVW OR: 1.12, 95% CI: 1.05–1.20, p = 0.001). No significant association between genetically predicted hyperthyroidism, TSH, or fT4 and TMDs. In the multivariable MR analyses, the effects of hypothyroidism on TMDs occurrence remained significant even after adjSusting for TSH, fT4 and hyperthyroidism (multivariable IVW OR: 1.10, 95% CI: 1.03–1.17, p = 0.006). No pleiotropy and heterogeneity were detected in the analyses (p > 0.05).ConclusionsHypothyroidism might causally increase the risk of TMDs through a direct pathway, highlighting the critical role of managing thyroid health in the prevention of TMDs. Clinicians should give heightened attention to patients with hypothyroidism when seeking medical advice for temporomandibular discomfort. However, caution is warranted due to the potential confounders, pleiotropy, and selection bias in the MR study.

Correlating estrogen replacement therapy and temporomandibular disorders: a comprehensive review following PRISMA principles and cochrane handbook for systematic reviews of interventions

BackgroundEstrogen replacement therapy (ERT) is a common hormonal treatment for postmenopausal women, aimed at alleviating menopausal symptoms and reducing the health risks associated with estrogen deficiency. However, the impact of ERT on temporomandibular disorders (TMDs) remains unclear. This systematic review aims to evaluate the relationship between ERT and TMDs, including TMD occurence, pain, and associated symptoms.MethodsA comprehensive search of seven electronic databases was conducted using predefined search terms and Boolean operators. Inclusion criteria encompassed studies examining the association between ERT and TMDs. Two independent reviewers screened the identified articles, extracted data, and assessed the risk of bias using the RoB -2 tool.ResultsSearch strategy identified a total of 3 articles which met the inclusion criteria. The included studies investigated the impact of ERT on TMD occurrence and its related symptoms. The analysis revealed no significant association between ERT and TMD occurrence. A significant dose relationship was noted in one of the studies while another mentioned the possible relationship of TMD with educational status. Risk of bias among the studies was low, and the overall quality of evidence was deemed to be high.ConclusionThis systematic review suggests that there is no conclusive evidence supporting an increased risk of TMDs among women receiving ERT. The findings indicate that ERT is unlikely to have a noticeable impact on TMDs. However, due to the limited number of studies available, further research is warranted to strengthen these conclusions and explore potential factors that may influence the relationship between ERT and TMDs.

Causal effects of educational attainment on temporomandibular disorders and the mediating pathways: A Mendelian randomization study.

As one of the most important indicators of socioeconomic status, educational attainment (EA) exhibits a strong association with temporomandibular disorders (TMDs). Despite this link, there is a lack of evidence regarding the causal role of EA in either facilitating or preventing TMDs. This study aimed to investigate the causal effect of education on TMDs and explore potential mediating pathways. Utilizing summary statistics from genome-wide association studies on years of schooling (N = 766 345) and TMDs (N = 211 023), we conducted Mendelian randomization (MR) to assess the overall effect of education. Additionally, a two-step MR approach was employed to evaluate 30 potential mediators and calculate the mediation proportions in the association. Comprehensive sensitivity analyses were used to verify the robustness, heterogeneity, and pleiotropy. Univariable MR analyses revealed a causal effect of lower EA on an increased risk of TMDs (OR: 0.53, 95% CI: 0.43-0.66, p < .001). Five out of 30 modifiable factors were identified as causal mediators in the associations of EA with TMDs, including feeling nervous (mediation proportion: 11.6%), feeling tense (10.2%), depression (9.6%), feeling worry (7.6%) and daily smoking (8.9%). Meanwhile, no pleiotropy was detected in the analyses (p > .05). Our findings supported that higher EA has a protective effect on the onset of TMDs, with partial mediation by psychological disorders and daily smoking. Interventions on these factors thus have the potential of substantially reducing the burden of TMDs attributed to low education.

Alexithymia, oral behaviors, and temporomandibular disorders: a dark triad?

BackgroundAlexithymia is a condition in which cognitive processing of emotions is impaired. Associations between alexithymia and temporomandibular disorders (TMD) have been described in multiple studies, yet the coexistence or influence of oral behaviors has never been addressed. This study aimed to clarify the relationship between alexithymia, oral behaviors, and temporomandibular pain disorders.ResultsA total of 264 participants were included in this study. The mean age was 25.70 ± 5.99 years, with a range from 18 to 65 years. Eighty-two (31.1%) were possibly alexithymic, and 93 (35.2%) were alexithymic. A total of 12.5% of the participants were at high risk for TMD. With respect to oral behavior risk, 62.5% were at low risk, and 35.2% were at high risk. Alexithymia appeared to be a positive predictor of TMD risk (p < 0.001). Participants with high-risk oral behaviors were found to have an increased likelihood of TMD risk (p < 0.001). Moreover, both high-risk oral behavior and alexithymia correlated with increased somatic symptom burden levels (p < 0.001). Pain disorders exert significant distress on individuals and lead to poorer quality of life.ConclusionUnderstanding the association of alexithymia, somatic symptom burden, and coping strategies with oral behaviors and temporomandibular pain disorders can help improve the management of this condition. By tailoring the chosen therapy to the dominant co-existing psychosocial comorbidities in TMD patients, the risk of treatment failure or relapse may be diminished.

ESR1 rs2234693 might be associated with TMD risk in the Turkish population, but not rs9340799

Aims: The gender and age distribution of temporomandibular disorder (TMD) suggest a possible role for the female hormonal axis in the pathogenesis. The goal of this study was to evaluate if estrogen receptor (ESR1) gene variants contribute to TMD susceptibility in the Turkish population. Methods: A total of 270 people, 130 of whom were TMD patients and 140 healthy controls, were included in the study. The ESR1 PvuII (rs2234693) and Xbal (rs9340799) variants were genotyped using the polymerase chain reaction based restriction fragment length polymorphism (PCR-RFLP). The results were evaluated statistically. Results: There were 110 women (81.48%) and 25 men (18.52%) in the patient group. We found there was a significant association between rs2234693 T/C, C/C genotypes and TMD (p=0.007). Also, the C allele was more prevalent in patients compared to controls (p=0.002). A statistically significant association was observed when the patients were compared with the controls according to TT versus TC+CC (p=0.002). There was no statistical significance between the patient and control groups in terms of rs9340799 genotype and allele distribution. Then we evaluated the relationship between genotype distributions and clinical characteristics. Both males and females had the highest rs2234693 T/C genotype (p=0.049). The majority of people with bruxism, bruxomania, and bruxism plus bruxoma carried the rs2234693 T/C genotype (p=0.025). Conclusion: Our results showed that ESR1 rs2234693 might be associated with TMD risk in the Turkish population, but not rs9340799.

Whole-genome methylation profiling reveals regions associated with painful temporomandibular disorders and active recovery processes.

Temporomandibular disorders (TMDs), collectively representing one of the most common chronic pain conditions, have a substantial genetic component, but genetic variation alone has not fully explained the heritability of TMD risk. Reasoning that the unexplained heritability may be because of DNA methylation, an epigenetic phenomenon, we measured genome-wide DNA methylation using the Illumina MethylationEPIC platform with blood samples from participants in the Orofacial Pain: Prospective Evaluation and Risk Assessment (OPPERA) study. Associations with chronic TMD used methylation data from 496 chronic painful TMD cases and 452 TMD-free controls. Changes in methylation between enrollment and a 6-month follow-up visit were determined for a separate sample of 62 people with recent-onset painful TMD. More than 750,000 individual CpG sites were examined for association with chronic painful TMD. Six differentially methylated regions were significantly ( P < 5 × 10 -8 ) associated with chronic painful TMD, including loci near genes involved in the regulation of inflammatory and neuronal response. A majority of loci were similarly differentially methylated in acute TMD consistent with observed transience or persistence of symptoms at follow-up. Functional characterization of the identified regions found relationships between methylation at these loci and nearby genetic variation contributing to chronic painful TMD and with gene expression of proximal genes. These findings reveal epigenetic contributions to chronic painful TMD through methylation of the genes FMOD , PM20D1 , ZNF718 , ZFP57 , and RNF39 , following the development of acute painful TMD. Epigenetic regulation of these genes likely contributes to the trajectory of transcriptional events in affected tissues leading to resolution or chronicity of pain.

Causal relationship between psychiatric traits and temporomandibular disorders: a bidirectional two-sample Mendelian randomization study

ObjectivesThis study was to investigate the causal relationship between temporomandibular disorders (TMD) and psychiatric disorders by Mendelian randomization (MR) analysis.Materials and methodsA two-sample bidirectional MR analysis was adopted to systematically explore the causal relationship between TMD and eight psychiatric traits, including anxiety disorder (AD), panic disorder (PD), major depressive disorder (MDD), neuroticism, attention deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), bipolar disorder (BIP), and schizophrenia (SCZ). Inverse variance weighted (IVW), weighted median, and MR-Egger regression were used in my study. Furthermore, we also performed three sensitivity analyses to illustrate the reliability of the analysis.ResultsTwo psychiatric traits have risk effects on TMD: PD (OR = 1.118, 95% CI: 1.047–1.194, P = 8.161 × 10−4, MDD (OR = 1.961, 95% CI: 1.450–2.653, P = 1.230 × 10−5). Despite not surpassing the strict Bonferroni correction applied (P > 0.00625), we could think that there was a suggestive causal effect of neuroticism and SCZ increasing the risk of TMD. On the reverse MR analysis, we found no significant evidence of causal effects of TMD on these psychiatric traits. Except for heterogeneity in the causal analysis for SCZ on TMD, no heterogeneity and horizontal pleiotropy were detected in the other analyses.ConclusionsOur two-sample MR study has provided further evidence of PD and MDD being related to a higher risk of TMD.Clinical relevanceThese findings highlight the importance of closely monitoring mental traits during future TMD treatments to prevent an increased risk of TMD.

Causal effects of life course adiposity on temporomandibular disorders: A Mendelian randomization study.

Previous studies investigated the associations between obesity and temporomandibular disorders (TMDs), but the evidence for the causal inferences was unclear. We aimed to investigate the causal link between life course adiposity and TMDs. Mendelian randomization (MR) studies were performed using genetic instruments for birth weight (BW) (N = 261 932), childhood body mass index (BMI) (N = 39 620), childhood body size (N = 454 718), adult BMI (N = 99 998), body fat percentage (N = 454 633) and TMDs (N = 211 023). We assessed the overall effect of each life course adiposity factor via inverse-variance weighted (IVW), weighted median, and MR-Egger methods and performed extensive sensitivity analyses. Additionally, multivariable MR was conducted to evaluate the direct and indirect effects of childhood BMI on TMDs while accounting for BW and adult BMI, and vice versa. Univariable MR analyses revealed a causal effect of low childhood adiposity on an increased risk of TMDs (childhood BMI: IVW OR: 0.65, 95% CI: 0.54-0.78, p < .001; childhood body size: IVW OR: 0.56, 95% CI: 0.43-0.73, p < .001). No causal association existed between genetically predicted BW, adult BMI, or body fat percentage and TMDs. In the multivariable MR analyses, the effects of childhood BMI on TMDs occurrence remained significant and direct, even after adjusting for BW and adult BMI (multivariable IVW OR: 0.78, 95% CI: 0.61-0.99, p = .048). No pleiotropy and heterogeneity were detected (p > .05). Low childhood BMI might causally increase the risk of TMDs through a direct pathway.

The Impact of Temporomandibular Disorders on Orthodontic Management: A Systematic Review and Meta-Analysis.

The literature on the impact of temporomandibular disorders (TMDs) on orthodontic management or vice versa lacks clarity. This study presents a review that aims to evaluate the influence of TMDs on orthodontic management and explore the association between TMDs and various aspects of orthodontic treatment. A systematic search was conducted across multiple databases to identify relevant articles documenting the correlation between TMD incidence and orthodontic treatment to achieve the objectives. The selection process followed predefined criteria, and the selected studies underwent bias assessment using the AXIS tool and Cochrane risk of bias (RoB) tool.Among the articles identified, nine studies were deemed suitable for inclusion in the review. The findings from the subsequent meta-analysis indicated a significant overall effect, suggesting that orthodontic treatment may increase the risk of developing TMD. Furthermore, the analysis revealed that patients with TMD had higher odds of experiencing orthodontic issues than those without TMD. Subgroup analysis further demonstrated that orthodontic treatment could have a negative impact on the psychological well-being of TMD patients, while its effect on TMD incidence was found to be negligible.The results highlight the need for additional research to gain a better understanding of the underlying mechanisms and develop appropriate interventions aimed at minimizing the risk of TMD in patients undergoing orthodontic treatment. Clinicians should be aware of TMD as a potential complication of orthodontic treatment and implement appropriate monitoring strategies.

Causal association between body mass index and temporomandibular disorders: a bidirectional two-sample Mendelian randomization analysis

BackgroundObservational studies have shown that body mass index (BMI) is highly correlated with the occurrence of temporomandibular disorders (TMDs). However, these studies failed to present a causal relationship. Thus, we aimed to performed a Mendelian randomization (MR) study to investigate causality between BMI and TMDs.MethodsWe performed a two-sample bidirectional MR analysis using large-scale genome-wide association studies (GWAS). Data were obtained from a large-scale BMI dataset (N = 322,154), TMDs dataset (N = 134,280). The causal effects were estimated with inverse-variance weighted (IVW) method, MR Egger, weighted median. Sensitivity analyses were implemented with Cochran’s Q test, MR-Egger intercept test, MR-PRESSO, leave-one-out analysis and the funnel plot.ResultsIn the forward MR analysis, a genetic prediction of low BMI was causally associated with a higher risk of TMDs (IVW OR: 0.575, 95% CI: 0.415–0.798, p: 0.001). Similar results were obtained using other complementary methods (MR Egger OR: 0.270, 95% CI: 0.104–0.698, p: 0.009; weighted median OR: 0.496, 95% CI: 0.298–0.826, p: 0.007). In the reverse MR results, TMDs was shown to have no significant effect on BMI (all p > 0.05). No pleiotropy and heterogeneity were detected in the bidirectional analysis (p > 0.05).ConclusionA lower BMI might be causally associated with increased risk of TMDs, supporting the importance of weight control for the prevention of TMDs. Clinicians should pay more attention to the low-BMI patients among those seeking medical advice due to temporomandibular joint discomfort.

Association of Serum Vitamin D Level with Temporomandibular Disorder Incidence: A Retrospective, Multi-Center Cohort Study Using Six Hospital Databases.

The relationship between serum vitamin D levels and temporomandibular disorders (TMDs) remains unclear. Therefore, this study aimed to investigate the association between serum 25-hydroxyvitamin D (25[OH]D) levels and TMD incidence using large-scale health data. Clinical data from the electronic health records of six secondary or tertiary hospitals in Korea were used to evaluate the relationship between serum 25(OH)D levels and TMD incidence. The data were converted to the Observational Medical Outcomes Partnership Common Data Model. A cohort study was designed using the Cox proportional hazards model to examine the hazard ratio (HR) of TMD development after propensity score matching (PSM). An aggregate meta-analysis of the HR was subsequently performed. After 1:4 PSM, a target group with deficient 25(OH)D levels (<20 ng/mL) (N = 34,560) and comparator group with non-deficient 25(OH)D levels (≥20 ng/mL) (N = 47,359) were pooled from six hospital databases. HR meta-analysis demonstrated a significant association between deficient 25(OH)D levels and TMD incidence (pooled HR: 1.50; 95% confidence interval: 1.07-2.12). In conclusion, deficient 25(OH)D levels were found to be associated with an increased TMD risk. Therefore, vitamin D deficiency is a potential risk factor for TMD development.

Prevalence of temporomandibular disorders (TMD) in pregnancy: a systematic review with metanalysis.

Over the past few years, researchers have investigated whether varying menstrual statuses and estrogen levels could affect the likelihood of temporomandibular disorders (TMDs), with conflicting results. While some studies suggest a potential link between increased estrogen levels and higher TMD risk, others have found no correlation. It is worth noting that estrogen levels can impact the structure and function of the temporomandibular joint (TMJ). In light of these findings, our study seeks to investigate the prevalence of TMDs among pregnant women. We searched in PubMed, Web of Science and Lilacs for articles published from the inception until January 20, 2023. We applied the Population, Exposure, Comparator, and Outcomes (PECO) model to assess the document eligibility: P) Participants: female human subjects. E) Exposure: pregnancy. C) Comparison: pregnant women compared to non-pregnant women in the childbearing age. O) Outcome: TMDs diagnosis. Only study providing data about the prevalence in both group (pregnant and non-pregnant) were included. We set the following exclusion criteria: 1) diagnosis of rheumatic diseases or chronic inflammatory disorders (e.g., rheumatoid arthritis, juvenile, idiopathic arthritis, psoriatic arthritis); 2) diagnosis of fibromyalgia; 3) congenital abnormality or neoplastic conditions in the TMJ region; 4) studies including subjects undergoing arthrocentesis or intra-articular infiltrations; 5) studies including local pressure pain assessment; 6) studies including women in menopause in the control group 7) cross-over study design; 8) language different from English; 8) full- text unavailability (i.e., posters and conference abstracts); 9) studies involving animals; 10) review (topical or systematic) article; 11) case reports/series; 12) studies evaluating TMDs prevalence in subjects not pregnant. The software Review Manager version 5.2.8 (Cochrane Collaboration, Copenhagen, Denmark; 2014) was used to perform the pooled analysis. We measured the risk ratio (RR) between the two group (pregnant and non-pregnant). The included subjects in this review were 440. Among them, 244 were pregnant while the remaining 196 were age matched non-pregnant women. Among those pregnant 102 presented sign/symptoms of TMD or TMD diagnosis (41,8 %) whereas 80 of those not pregnant were diagnosed with (40,8%). The overall effect showed that there was no difference in TMD prevalence between pregnant and non-pregnant women in childbearing age (RR 1.12; 95% CI: 0.65- 1.93), suggesting that pregnant is neither a risk factor nor a protective factor for TMD. Overall, we did not find an association between TMD and pregnancy, neither positive nor negative. Further studies on larger samples are needed to clarify our results.

Stomatognathic Risk Factors and Clinical Manifestations of Temporomandibular Disorders in Indian Population: A Case-control Study.

This study was aimed to compare the risk factors and associated clinical manifestations of patients with temporomandibular disorders (TMDs) in the Indian population. A total of 52 patients were explored according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) and compared with 48 controls. The mean age of the study group was 30.96 ± 11.60 years, 41% were males and 59% were females. The mean age in the control group was 31.5 ± 9.9 years (37.5% males), measuring differences in TMD risk factors (self-perceived stress, parafunctions, occlusal interferences, history of orthodontic treatment, and/or extraction). The most common sign observed in the selected subjects was the joint sound (clicking) (42%), followed by mandibular deviation 39% as the second most common sign. Myofascial pain (MFP) (single or multiple diagnoses) was the most frequent diagnosis (n = 40, 76%), followed by disc displacement with reduction (DDWR) (32.1%), arthralgia (30%), and disc displacement without reduction (DDWoR) (7.6%). More than one DC/TMD diagnosis was established in 63.2% of the patients. The risk factors like presence of clenching, stress perception, parafunctions, tooth wear, and occlusal interferences were significantly more frequent in all the cases than in the respective controls. In the studied population, the presence of TMD was found to be positively related to factors namely female gender, parafunction, occlusal interferences, psychological stress, and tooth wear. Myofascial pain is the commonest diagnosis (either single or in combination). It is followed by DDWR (either single or in combination with others). Double diagnosis is also common. Temporomandibular disorders showed a female predilection and were found to be positively related to factors, viz., parafunction, occlusal interferences, stress, and tooth wear. Clinicians should also be aware of common clinical manifestations of TMDs and their related stomatognathic risk factors to provide comprehensive oral care and to identify such factors for disease prevention.

Association between axial spondyloarthritis and temporomandibular disorders: A systematic review.

This study aimed to assess the frequency of temporomandibular disorders (TMDs) in patients with axial spondyloarthritis (axSpA) compared with the healthy individuals. We systematically searched PubMed, Embase, Scopus, Web of Science, CINAHL, and Google Scholar databases from their inception until 2022, without language restriction. A standardized dataset was used to extract data from the observational studies. Patients were required to have axial spondyloarthritis and clinical and/or radiographic evidence of temporomandibular joint dysfunction. Meta-analysis was performed with a random effects model. A systematic review was registered under number CRD42020206283. We identified seven relevant studies, which provided data for 745 patients and 216 temporomandibular disorders events. The combined odds ratio (OR) showed that the risk of temporomandibular disorders in individuals with axial spondyloarthritis was higher than the control group (pooled OR=5.26, 95% CI 2.50-11, 06; p < 0.02; I2 =58%). Also, these individuals do not appear to refer possible temporomandibular joint symptoms to the rheumatologist or dentist. The results of this systematic review and meta-analysis suggest that patients with axial spondyloarthritis have an increased frequency of temporomandibular disorders. TMDs seem to be secondary to postural alterations rather than direct involvement of the temporomandibular joints (TMJs).

The association between problematic smartphone use and the severity of temporomandibular disorders: A cross-sectional study.

To evaluate the prevalence of different types of temporomandibular disorders (TMD) symptoms in young adults and determine their associations with problematic smartphone use (PSU). The data of the study were collected from local university students through an online questionnaire survey. Demographic information, Fonseca Anamnestic Index (FAI), Smartphone Addiction Scale-Short Version (SAS-SV), and Patient Health Questionnaire-4 (PHQ-4) responses were gathered electronically and analyzed using multiple logistic regression analysis. There were 163 male and 307 female respondents were participated in this study. The prevalence of PSU and TMD were 83.6% and 66.4%, respectively. There was a moderate statistical correlation between PSU and TMD among young adults (r = 0.31, p < 0.01). The logistic regression model revealed that the risk of TMD was 1.77 times higher in people with PSU than in those without PSU (OR = 1.77; 95% CI 1.04-3.06). PSU is a risk factor for pain-related TMD (OR = 1.81; 95% CI 1.08-3.04) but not intra-articular TMD. Subjects showed high prevalence of both TMD and PSU. People with PSU experienced more severe and frequent pain-related rather than intra-articular TMD symptoms than those without PSU. By reducing the problematic smartphone use, the risk factor of TMD might be avoided.