Association between temporomandibular disorders and obesity

Prevalence of temporomandibular disorders and their associated factors in Confucian heritage cultures: A systematic review and meta-analysis

BACKGROUND

Temporomandibular disorders (TMDs) may be an 'idiom' of psychological distress in Confucian heritage cultures (CHCs).

OBJECTIVES

This systematic review/meta-analysis estimated the prevalence of TMDs in CHCs and compared the differences in TMD occurrence between time periods and age groups. Additionally, the associated biopsychosocial risk factors were also examined.

METHODS

The study protocol was developed a priori following the PRISMA guidelines and Joanna Briggs Institute systematic review methodology (CRD42021245526). Electronic searches of seven databases were conducted from January 2002 to Dec 2021. Reference lists of identified studies were hand-searched for additional articles. Study selection, quality assessment, and data extraction were done. Meta-analysis was performed using the RevMan 5.4 software.

RESULTS

Forty-eight articles were included in the systematic review. Overall prevalences were: TMDs-15% (95% CI: 15-16%); TMD pain-8% (95% CI: 7-9%); TMJ sounds-24% (95% CI: 21-27%); and TMJ locking-7% (95% CI: 1-13%). While TMD prevalence appeared to have declined from 2002 to 2011 to 2012-2021, the occurrence of TMD pain, TMJ sounds, and locking increased marginally or remained constant. TMD prevalence in children/adolescents was 18% (95% CI: 14-22%) and 17% (95% CI: 16-18%) among adults. Significant associations between TMDs and bruxism/psychological distress/education levels were specified by 73%/90%/88% of the relevant studies.

CONCLUSIONS

TMDs are prevalent in CHCs and a slight increase in TMD pain (2%) and TMJ sounds (8%) were discerned over the past two decades. TMDs are related to a myriad of biopsychosocial variables, particularly psychological distress, and these factors must be addressed within the cultural context of patients.

Exploring the Association Between Physical Fitness (High Intensity and Low Intensity) and the Incidence of Temporomandibular Disorders: A Comparative Study

BACKGROUND

Temporomandibular joint disorders affect the temporomandibular joint (TMJ), masticatory muscles, and associated structures. Symptoms include TMJ pain, limited jaw movement, muscle tenderness, and referred pain. Physical activity can alleviate musculoskeletal pain. This study explored the link between physical fitness (high and low intensity) and temporomandibular disorder (TMD) incidence.

METHODOLOGY

Sixty patients were divided into three groups in this comparative study. Group I underwent 30 minutes of high-intensity aerobic training. Group II had 30 minutes of low-intensity yoga sessions weekly. Group III received health education. TMD was diagnosed using the Fonseca Anamnestic Index (FAI). Pain intensity was measured using the Visual Analogue Scale (VAS) and the Pain Self-Efficacy Questionnaire (PSEQ).

RESULTS

Of the participants, 38.1% were males and 61.9% were females. TMD severity was mild (25.0%), moderate (55.0%), and severe (20.0%). High-intensity training groups had higher TMD symptom severity than low-intensity groups (p = 0.001). VAS scores increased in group I and decreased in group II (significant). PSEQ scores decreased in group I and increased significantly in group II. Group III showed no significant differences in PSEQ scores.

CONCLUSION

High-intensity training resulted in moderate TMD symptoms. Low-intensity training was beneficial for TMD pain. The study recommends combining low-intensity physical workouts with medications to alleviate TMD.

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

BACKGROUND

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.

OBJECTIVES

This study investigated the potential causal relationship between depression/anxiety and TMD with two-sample bi-directional Mendelian randomization (MR).

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Sleep, Caffeine, BMI, and Pressure Pain Threshold in Temporomandibular Disorder Patients: An Observational Study

BACKGROUND

Temporomandibular disorders (TMDs) represent a multifactorial condition involving a multitude of symptoms of the temporomandibular joint that emanates a series of distress. Understanding the relationship between these lifestyle factors and pain perception in TMD patients is essential for optimizing their management and care. This study delves into the intricate interplay between sleep, caffeine consumption, body mass index (BMI), and the potential effect on pressure pain threshold (PPT) values among individuals with TMDs.

MATERIALS AND METHODS

This is an observational study. Data were collected from a convenient sample of female patients at a single center in Riyadh city, between the ages of 20 and 50 years. The variables collected were based on an operator-designed questionnaire, the symptom questionnaire, and the Diagnostic Criteria for Temporomandibular Joint Disorders (DC/TMD).

RESULTS

A total of 139 participants were included in the study, appraising the occurrence of TMD and pain as per reports of caffeine intake and sleep duration. The observed outcomes indicate that the amount of sleep has a significant effect on the PPT values in TMD patients. This study highlights the substantial impact of sleep duration on lowering PPT values in individuals with TMDs. The findings highlight the importance of considering sleep duration and caffeine intake in the comprehensive management of TMD patients. There was no effect of BMI on this particular sample.

CONCLUSION

This study shows a positive correlation between sleep and pain and TMD, caffeine, and pain. A deeper understanding of these relationships could pave the way for more effective pain management strategies and personalized treatment approaches tailored to the unique needs of TMD patients. BMI had no effect.

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

BACKGROUND

Previous studies investigated the associations between obesity and temporomandibular disorders (TMDs), but the evidence for the causal inferences was unclear.

OBJECTIVE

We aimed to investigate the causal link between life course adiposity and TMDs.

METHODS

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.

RESULTS

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).

CONCLUSION

Low childhood BMI might causally increase the risk of TMDs through a direct pathway.

Statistical Methods and Machine Learning Algorithms for Investigating Metabolic Syndrome in Temporomandibular Disorders: A Nationwide Study

The objective of this study was to analyze the associations between temporomandibular disorders (TMDs) and metabolic syndrome (MetS) components, consequences, and related conditions. This research analyzed data from the Dental, Oral, Medical Epidemiological (DOME) records-based study which integrated comprehensive socio-demographic, medical, and dental databases from a nationwide sample of dental attendees aged 18-50 years at military dental clinics for 1 year. Statistical and machine learning models were performed with TMDs as the dependent variable. The independent variables included age, sex, smoking, each of the MetS components, and consequences and related conditions, including hypertension, hyperlipidemia, diabetes, impaired glucose tolerance (IGT), obesity, cardiac disease, obstructive sleep apnea (OSA), nonalcoholic fatty liver disease (NAFLD), transient ischemic attack (TIA), stroke, deep venous thrombosis (DVT), and anemia. The study included 132,529 subjects, of which 1899 (1.43%) had been diagnosed with TMDs. The following parameters retained a statistically significant positive association with TMDs in the multivariable binary logistic regression analysis: female sex [OR = 2.65 (2.41-2.93)], anemia [OR = 1.69 (1.48-1.93)], and age [OR = 1.07 (1.06-1.08)]. Features importance generated by the XGBoost machine learning algorithm ranked the significance of the features with TMDs (the target variable) as follows: sex was ranked first followed by age (second), anemia (third), hypertension (fourth), and smoking (fifth). Metabolic morbidity and anemia should be included in the systemic evaluation of TMD patients.

Job demands and temporomandibular disorders: mediating and moderating effects of psychological distress and recovery experiences

OBJECTIVES

This study examined the relationship between recovery experience, job demands, psychological distress, and temporomandibular disorders (TMD) in Japanese workers.

METHODS

It used cross-sectional data from the fourth survey of a multi-wave longitudinal project, conducted using the registered monitors of an internet research company. Finally, 1278 respondents' data were analyzed (655 males, 623 females; mean [SD] age = 41.63 [10.31] years). We utilized Sugiaski's TMD screening question to assess TMD prevalence, Brief Job Stress Questionnaire to assess job demands, Kessler Psychological Distress Scale (K6) to assess psychological distress, and the Japanese version of the Recovery Experience Questionnaire to assess recovery experiences. The moderated mediation analysis was conducted using the Process macro program for SPSS developed by Preacher and Hayes, examining the effect of job demands on TMD through psychological distress, moderated by the recovery experience.

RESULTS

The results showed that 13.1% (n = 168) of the respondents had TMD. Mediation analysis indicated high job demands were associated with an increased TMD prevalence through psychological distress. The moderated mediation analysis revealed that relaxation and control moderated the relationship between job demands and psychological distress.

CONCLUSIONS

This cross-sectional study established the relationship between job demands, psychological distress, and TMD among Japanese workers. The findings suggest that increased job demands contribute to high TMD prevalence through the mediation of psychological distress, moderated by relaxation and control.

Prevalence of temporomandibular disorders (TMD) in obesity patients: A systematic review and meta-analysis

OBJECTIVE

Obesity is a growing epidemic in the world. It increases the risk for severe health conditions, including diabetes, heart disease and stroke. Recent research has found that obesity is associated with an increased risk for temporomandibular disorders (TMDs). The purpose of this literature review with meta-analysis is to analyse the possible association between obesity and temporomandibular disorders.

MATERIALS AND METHODS

Pubmed, Web of Science and Lilacs were systematically searched until 01/03/2000. Articles dealing with TMD and obesity were selected, and numbers that might be useful in the meta-analysis were extracted.

RESULTS

Fifty articles were chosen after using all three search engines. Thirty-five articles were considered during the initial screening step. Four papers were chosen for title and abstract screening based on the PECO model. A manual search of bibliographies and the Cochrane database was also carried out, but no publications that matched the inclusion criteria were located. The articles and meta-analysis did not show a clear association between obesity and temporomandibular disorders.

CONCLUSION

There is no evidence regarding the reliability of either method. Both have superimposable results.

Is acupuncture an effective treatment for temporomandibular disorder?: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Acupuncture is used for treating various disorders, but its effects on temporomandibular disorder (TMD) remain unclear. This study aimed to assess the effectiveness and safety of acupuncture for TMD via a systematic review of randomized clinical trials.

METHODS

A total of 11 Korean and worldwide databases were searched to identify acupuncture studies in adults with TMD. A Cochrane risk of bias assessment was performed on all articles; a meta-analysis, which involved the categorization according to the type of control used (inactive control, active control, or add-on), was subsequently performed. The quality of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluation methodology.

RESULTS

The qualitative analysis of randomized clinical trials with acupuncture as the intervention included 32 articles, 22 of which were included in the quantitative analysis (471 participants). Acupuncture significantly improved outcomes (effect rate, relative risk [RR]: 7.00, 95% confidence interval [CI]: 1.91, 25, 62; visual analog scale, standardized mean difference: 0.49, 95% CI: 0.24, 0.73) versus active controls (effect rate, RR: 1.19; 95% CI: 1.12, 1.27). In the analysis of add-ons, acupuncture significantly improved the effect rate and pain intensity (effect rate, RR: 1.36; 95% CI: 1.04, 1.77; visual analog scale, mean difference: -1.23; 95% CI -1.79, -0.67). However, the quality of evidence was determined to range from low to very low.

CONCLUSION

Acupuncture in TMD significantly improved outcomes versus active controls and when add-on treatments were applied. However, as the quality of evidence was determined to be low, well-designed clinical trials should be conducted in the future.

Obesity and temporomandibular joint disorders: a systematic review and meta-analysis

BACKGROUND

Temporomandibular joint disorders (TMD) is the most common non-dental pain complaint in the maxillofacial region, which presents a variety of symptoms and signs, including temporomandibular joints (TMJ) and masticatory muscle pain, joint noise, tinnitus, headaches, irregular or restricted mandibular function, masticatory difficulty, and restricted mouth opening. When comes to the relationship between obesity and TMD, it has remained controversial and inconsistent, therefore, we first conducted this meta-analysis to estimate the unclear relationship between obesity and TMD.

METHODS

Searches were conducted in PubMed, Web of Science, Embase, and Cochrane Library. Subjects were divided into five groups according to BMI level in this study, including the normal weight group: 18.5 ≤ BMI < 25, overweight group: 25 ≤ BMI < 30, obesity group: BMI ≥ 30, control group: BMI < 25, and overweight and obesity group: BMI ≥ 25. Statistics analyses were conducted using Stata (15.0). The number of PROSPERO was CRD42022368315.

RESULTS

Eight studies were included in this study, and six articles with a total of 74,056 participants were synthesized for meta-analysis. Compared to normal weight individuals, overweight and obesity together decreased the risk of TMD (OR = 0.66, 95% CI = 0.46-0.95), and it was significantly decreased by obesity alone (OR = 0.58). Moreover, it was lower in obesity compared with control subjects (OR = 0.83, 95% CI = 0.73-0.94). Furthermore, in overweight and obese individuals, it was much lower in obesity than in overweight (OR = 0.82, 95% CI = 0.71-0.94).

CONCLUSIONS

Obesity is not a risk factor for TMD, and maybe a protective factor for TMD, of which patients with larger BMI are less likely to suffer from TMD pain. Therefore, the value of BMI should be taken into consideration in the assessment of TMD.

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

BACKGROUND

Observational 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.

METHODS

We 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.

RESULTS

In 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).

CONCLUSION

A 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.

Temporomandibular disorders, bite force and osseous changes of the temporomandibular joints in patients with hypermobile Ehlers-Danlos syndrome compared to a healthy control group

Background

Ehlers‐Danlos syndrome (EDS) is a hereditary disorder that affects the connective tissue and collagen structures in the body characterised by joint hypermobility, skin hyperextensibility and tissue fragility.

Objective

The aim was to investigate temporomandibular disorders (TMD), bite force, teeth in occlusal contact and osseous changes of the temporomandibular joints (TMJs) in 26 patients with hypermobile EDS (hEDS), differentiated by a genetic test, compared to 39 healthy controls.

Methods

Clinical examination according to Diagnostic Criteria for Temporomandibular Disorders (DC/TMD), radiological examinations of the TMJs by cone‐beam‐computed tomographic (CBCT) scans, registration of bite force and teeth in occlusal contact was performed. Statistical analyses included Fisher's Exact Test, multiple logistic and linear regression models adjusted for age, gender and Body Mass Index (BMI).

Results

Single symptoms and signs of TMD occurred significantly more often in hEDS (p = .002; p = .001; p = .003; p = <.0001; p = .012) and maximum mouth opening was significantly smaller in hEDS compared to controls (p = <.0001). The DC/TMD diagnosis myalgia, myofascial pain with referral, arthralgia, headache attributed to TMD, disc displacement disorders and degenerative joint disease occurred significantly more often in hEDS compared to controls (p = .000; p = .008; p = .003; p = .000; p = <.0001; p = .010, respectively). No significant differences were found in bite force and in teeth in occlusal contact between the groups (p > .05). On CBCT of the TMJs, subcortical sclerosis occurred significantly more often in hEDS compared to controls (p = .005).

Conclusion

Symptoms and signs of TMD and osseous changes of the TMJs occurred significantly more often in hEDS. Bite force and teeth in occlusal contact were comparable to controls.

Association between Temporomandibular Joint Disorder and Weight Changes: A Longitudinal Follow-Up Study Using a National Health Screening Cohort

This study aimed to investigate BMI changes following a temporomandibular joint disorder (TMJD) diagnosis. The Korean National Health Insurance Service-Health Screening Cohort from 2002 to 2015 was used. In Study I, 1808 patients with TMJD (TMJD I) were matched with 7232 participants in comparison group I. The change in BMI was compared between the TMJD I and comparison I groups for 1 year. In study II, 1621 patients with TMJD (TMJD II) were matched with 6484 participants in comparison group II participants. The change in BMI was compared between the TMJD II and comparison II groups for 2 years. In Study I, the BMI change was not associated with TMJD. In Study II, the BMI change was associated with TMJD in the interaction of the linear mixed model (p = 0.003). The estimated value (EV) of the linear mixed model was −0.082. The interaction was significant in women < 60 years old, women ≥ 60 years old, and the obese I category. TMJD was not associated with BMI changes after 1–2 years in the overall population. In women and obese patients, TMJD was associated with a decrease in BMI after 2 years.

Muscle-Bone Relationship in Temporomandibular Joint Disorders after Partial Discectomy

OBJECTIVES

Temporomandibular joint osteoarthritis (TMJ-OA) causes degenerative changes in TMJ tissues. The inter-tissue crosstalk that exacerbates illness and organic changes in bone secondary to TMJ-OA potentially affects the muscles; therefore, patients with a muscular disease might also suffer from bone disease. However, knowledge gaps exist concerning muscle pathology at the onset of TMJ-OA. In this study, we documented the pathogeneses of the bone and muscle at the onset of TMJ-OA using a mouse model.

METHODS

We performed a partial resection of the TMJ disk to establish a mouse model of TMJ-OA. After the onset of TMJ-OA, we performed various measurements at 8, 12, and 16 weeks post-surgery in the defined groups.

RESULTS

The volume of the mandibular head in the TMJ-OA group was significantly greater than that in the control group. The temporal muscles in the TMJ-OA group were significantly deformed compared with those in the control group; however, between-group comparisons did not reveal significant differences in the mandibular head or temporal muscles after surgery. Therefore, we hypothesized that the degree of mandibular head hypertrophy would alter the temporal muscles. A subsequent analysis of the correlation between the bone and muscle confirmed that the deformity of the temporal muscle increased with increasing hypertrophy of the mandibular head. Temporal and masseter muscle contact was observed in 25% of surgical groups.

CONCLUSIONS

This study demonstrates that TMJ-OA progressed when organic changes occurred in bones and muscles, supporting the symbiotic relationship between bones and muscles.

Association of Temporomandibular Disorder Symptoms with Physical Fitness among Finnish Conscripts

Studies on the role of physical fitness, physical activity and obesity as risk factors for temporomandibular disorders (TMD) are scarce. The aim of the present study was to evaluate the association of TMD symptoms with physical fitness, physical activity and body mass index (BMI) among Finnish conscripts. The study sample consisted of 8685 Finnish conscripts. Data on self-reported TMD symptoms were used as outcome variables. Physical activity (questionnaire), physical fitness (measured with physical tests: Cooper test, push-ups, sit-ups and standing long jump) and body mass index (BMI) were used as explanatory variables. The associations between TMD symptoms and explanatory variables were evaluated using Chi-squared test and logistic regression analysis. The prevalence of all TMD symptoms was significantly higher among those who exercised more rarely than weekly. Pain-related TMD symptoms were also significantly more frequent among those who were overweight (BMI ≥ 25). Poor push-up results and overweight (BMI ≥ 25) were significantly associated with jaw pain and TMJ pain at jaw rest. The present study showed that good physical fitness may be a protective factor against TMD pain. Dentists should also be prepared to motivate TMD patients to physical activity and regular exercise as part of the treatment.

Evaluation of temporomandibular disorders and oral health-related quality of life with obese patients

Objective: The aim of this study was to investigate the relationship between temporomandibular disorders and oral health impact profile in healthy, overweight, and obese patients.Methods: This study was carried out on 1528 individuals divided into three groups as healthy, overweight, and obese patients. Diagnostic Criteria for Temporomandibular Disorders, Fonseca's questionnaire, and Oral Health Impact Profile-14 (OHIP-14) forms were used.Results: Gender, classification, pain, temporomandibular joint noise, and open-lock of the jaw of healthy, overweight, and obese groups were found to be related. The differences in the Fonseca and the OHIP-14 total scores according to the groups were found to be statistically significant. The correlation between the Fonseca total score and age was positive and significant.Conclusion: In the obese patients, both total Fonseca and OHIP-14 values were found to be higher. Also, the presence of pain in the obese patients was found to be higher.