Inter‐relationships between pain‐related temporomandibular disorders, somatic and psychological symptoms in Asian youths

Does Postgraduate Education Deepen Temporomandibular Disorders Insights for Dental Professionals?

Objective: This study aims to investigate the impact of postgraduate education on the comprehension of Temporomandibular Disorders (TMDs) among dental professionals. Methods: A cross-sectional observational study was conducted, involving 348 dental professionals, including students and practicing dentists, categorized based on their educational background into two groups: bachelor's degree or lower (Group B) and master's degree or higher (Group M). Questionnaires were utilized to assess attitudes and knowledge across four TMDs-related domains. Statistical analysis was performed to compare responses between groups and identify differences in TMDs comprehension. Results: Among the 348 respondents, who participated in the study, 183 were students and 165 were practicing dentists, yielding a response rate of 79% (348/440). In the dentist group, 11 statements across every TMDs-related domain exhibited statistically significant differences in responses between Group B and Group M (p < 0.05). Only 2 responses from Group M conflicted with the standard answers, whereas Group B had 9 conflicting responses. In the student group, 11 statements also showed statistically significant differences between Group B and Group M (p < 0.05). Group M had no conflicting responses with the standard answers, while Group B had 7 conflicting responses. Conclusions: Postgraduate education deepened dental professionals' understanding of TMDs. Students improved more in the domains of "diagnosis" and "treatment and prognosis," whereas practicing dentists enhanced more in the "etiology" domain. To further advance postgraduate education, there is a need for more systematic course designs for TMDs, emphasizing the enhancement of knowledge related to examination methods and treatment options.

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.

Conceptualising TMD symptom burden in youths: Symptom duration, frequency, intensity and interference

OBJECTIVE

This study aimed to conceptualise Temporomandibular disorder (TMD) symptom burden and severity and explored their interrelationships with somatic symptoms and psychological distress.

METHODS

Participants were recruited from a local polytechnic. The quintessential five TMD symptoms (5Ts) of the Diagnostic Criteria for TMDs (DC/TMD) were appraised and extended to evaluate the duration, frequency, intensity and interference of discrete TMD symptoms. Global TMD severity (GS) was computed by totaling the points for all TMD symptoms and dimensions. TMD (TS) and somatic symptom (SS) burden were assessed based on the Somatic Symptoms Scale-8, while psychological distress was measured with the Depression, Anxiety and Stress Scales-21. Statistical analyses were performed using Kruskal-Wallis/Dunn tests and Spearman's correlation (α = .05).

RESULT

Of the 366 eligible participants (mean age 19.1 ± 2.3 years), 51.4% were 5Ts-negative and 48.6% were 5Ts-positive. Among the 5Ts-positive individuals, 25.3%/64.0% were 'bothered a little' whereas 4.5%/10.7% were 'bothered a lot' by TMD pain/headache. Correspondingly, 32.6%/12.4%/5.1% were 'bothered a little' while 2.8%/2.8%/1.1% were 'bothered a lot' by TMJ sounds/closed/open locking. TS burden was moderate-to-strongly correlated to aggregate symptom duration, frequency, intensity, interference, GS and SS burden (rs = .50-.88). While TS burden and GS were weakly associated with psychological distress (rs = .18-.36), SS burden was moderately related to depression, anxiety and stress (rs = .47-.53).

CONCLUSIONS

TS burden can serve as a proxy for global TMD severity and may be more meaningful than the mere presence of TMD symptoms in clinical and research settings.

Psychological distress and well-being: their association with temporomandibular disorder symptoms

OBJECTIVE

This study investigated the associations between temporomandibular disorder (TMD) symptoms, psychological distress, and well-being.

METHODS

A total of 372 university students were recruited and stratified into no TMD, TMD pain, TMJ sounds, and combined TMD groups. Psychological distress and well-being were assessed with the Depression, Anxiety, and Stress Scale-21 (DASS-21) and Scales of Psychological Well-being-18 (SPWB-18), respectively. Data were appraised with Kruskal-Wallis/Mann-Whitney U tests and logistic regression analysis (α = 0.05).

RESULTS

Significant differences in anxiety, stress, and autonomy scores were observed among the four groups, and psychological distress was mostly negatively correlated to psychological well-being. Multivariate analyses revealed that anxiety was associated with TMD pain, TMJ sounds, and combined TMD, while autonomy was related to TMJ sounds.

CONCLUSION

Participants with TMD symptoms generally experienced more psychological distress and lower autonomy. Anxiety appeared to increase the likelihood of TMD pain and/or TMJ sounds.

Whiplash trauma did not predict jaw pain after 2 years: an explorative study

OBJECTIVES

To explore predictive factors for the development and maintenance of jaw pain over a 2-year period.

METHODS

One hundred nineteen cases (73 women) and 104 controls (59 women), mean age 34.9 years (SD 13.9), attended baseline and 2-year follow-up examinations. The whiplash cases visited the emergency department at Umeå University Hospital, Sweden, with neck pain within 72 h following a car accident, and baseline questionnaires were answered within a month after trauma. Controls were recruited via advertising. Inclusion criteria were age 18-70 years, living in Umeå municipality and Swedish speaking. The exclusion criterion was neck fracture for cases and a previous neck trauma for controls. Validated questionnaires recommended in the standardized Research Diagnostic Criteria for temporomandibular disorders were used. Jaw pain was assessed by two validated screening questions answered with "yes" or "no." A logistic regression analysis was used to predict the outcome variable jaw pain (yes/no) after 2 years.

RESULTS

Whiplash trauma did not increase the odds of development of jaw pain over a 2-year period (OR 1.97, 95% CI 0.53-7.38). However, non-specific physical symptoms (OR 8.56, 95% CI 1.08-67.67) and female gender (OR 4.89, 95% CI 1.09-22.02) did increase the odds for jaw pain after 2 years.

CONCLUSION

The development and maintenance of jaw pain after whiplash trauma are primarily not related to the trauma itself, but more associated with physical symptoms.

CLINICAL RELEVANCE

The development of jaw pain in connection with a whiplash trauma needs to be seen in a biopsychosocial perspective, and early assessment is recommended.

Correlates between temporomandibular disorder severity, emotional distress, and eudaimonic well-being among young adults

OBJECTIVES

This study examined the correlates between severity of temporomandibular disorders (TMDs), emotional distress, and eudaimonic well-being.

SUBJECTS AND METHODS

TMD severity, negative emotions, and eudaimonia were assessed with the Fonseca Anamnestic Index (FAI), Depression, Anxiety, Stress Scales-21 (DASS-21), and Psychological Well-being Scale-18 (PWBS-18) in a cohort of community young adults. Statistical evaluations were done with non-parametric tests/correlation and multivariate regression analyses (α = 0.05).

RESULTS

Amongst the 873 participants (mean age 19.8 ± 1.66 years), 40.7%, 49.0%, and 10.3% had no (NT), mild (MT), and moderate-to-severe (ST) TMD, respectively. Significant differences in total-DASS, depression, anxiety, and stress were ST ≥ MT > NT. Significant variances in total-PWSB and self-acceptance were NT > MT > ST while that for environmental mastery, positive relations, and purpose in life were NT > MT, ST. An inverse relationship was discerned between total-DASS and total-PWBS (correlation coefficient = -0.54). The prospect of ST was increased by anxiety but reduced by positive relations and self-acceptance.

CONCLUSIONS

Young adults with mild and moderate-to-severe TMD experienced substantially higher emotional distress and lower eudaimonia than those with no TMD. As emotional distress and eudaimonic well-being are interrelated, positive psychological interventions may be beneficial for managing TMD-related psychosocial disabilities.

Painful temporomandibular disorders in Confucian-heritage cultures: Their inter-relationship with bodily pain, psychological well-being and distress

BACKGROUND

Temporomandibular disorders (TMDs) are common and affect individuals negatively.

OBJECTIVES

This study investigated the inter-relationship of painful TMDs with bodily pain, psychological well-being and distress in young people from a Confucian-heritage culture (CHC).

METHODS

Adolescents/young adults were recruited from a polytechnic in Singapore. While the presence/severity of painful TMDs and bodily pain were established with the DC/TMD Pain Screener (TPS) and Maciel's Pain Inventory, psychological well-being and distress were evaluated with the Scales of Psychological Well-being-18 (SPWB-18) and Patient Health Questionnaire-4 (PHQ-4). Statistical explorations were conducted using chi-square/Mann-Whitney U tests, Spearman's correlation and logistic regression analyses (α = .05).

RESULTS

Among the 225 participants (mean age 20.1 ± 3.9 years) examined, 11.6% had painful TMDs and 68.9% experienced multisite bodily pain. Though painful TMDs were accompanied by a higher occurrence of multisite bodily pain, the overall/discrete number of bodily pain sites did not differ substantially between the 'no TMD pain' (NT) and 'with TMD pain' (WT) groups. Besides ear pain, differences in overall/discrete bodily pain scores were also insignificant. However, significant differences in environmental mastery, overall psychological distress, depression and anxiety subscale scores were discerned between the NT and WT groups. Psychological well-being and distress were moderately and negatively correlated (rs  = -.56). Multivariate analysis indicated that ear pain and psychological distress increased the prospect of painful TMDs.

CONCLUSION

The prevalence of multi-site bodily pain was high in young people from CHCs irrespective of the painful TMDs' presence of painful TMDs. Enhancing environmental mastery and relieving depression/anxiety may help manage TMD pain.

Personality, psychosocial and oral behavioural risk factors for temporomandibular disorder symptoms in Asian young adults

BACKGROUND

The relation between personality, psychosocial factors, somatisation, andoral behaviours as risk factors to temporomandibular disorder symptoms have notbeen well established.

OBJECTIVES

This study examined the association of temporomandibular disorder (TMD) symptoms with personality traits, psychological distress, somatisation and oral behaviours. The psychosocial and oral behavioural risk factors for TMD symptoms were also established in Asian young adults.

METHODS

Participants were recruited from a large private University. Based on the quintessential five TMD symptoms (5Ts) of the DC/TMD, the participants were stratified into those with no (NT), painful (PT), dysfunctional (DT) and mixed (MT) TMD symptoms. Personality traits, psychological distress, somatisation and oral behaviours were evaluated with the Big Five Inventory-10 (BFI-10), Depression, Anxiety, Stress Scales-21 (DASS-21), Patient Health Questionnaire-15 (PHQ-15) and Oral Behaviours Checklist (OBC) accordingly. Data were examined using Kruskal-Wallis/Mann-Whitney U and Chi-squared tests, as well as multivariate logistic regression analysis (α = .05).

RESULTS

Of the 420 young adults (mean age 22.7 ± 1.1 years) evaluated, 41.4% had no TMD symptoms, while 17.4%, 20.0% and 21.2% reported PT, DT and MT, respectively. Though personality traits did not vary notably, participants with MT and PT had significantly higher levels of negative affectivity, anxiety and stress than the NT group. Moreover, those with MT and PT presented significantly greater somatisation and more oral behaviours than the DT and NT groups. Multivariate regression analyses indicated that anxiety, somatisation, sleep-related and waking-state nonfunctional oral activities were associated with painful and/or dysfunctional TMD symptoms.

CONCLUSIONS

Except for sleep-related oral activity, psychosocial and oral behavioural risk factors differed for painful, dysfunctional and mixed TMD symptoms in Asian young adults.

Association of stress, anxiety, and depression levels with sleep quality in patients with temporomandibular disorders

OBJECTIVE

To examine the psychological symptoms of TMD and their effects on sleep quality in patients with temporomandibular disorders.

METHODS

The study was carried out with 425 consecutive TMD patients who sought care at the oral and maxillofacial surgery clinic of a faculty of dentistry. Perceived Stress Scale-14, Beck Anxiety Scale, and Beck Depression Scale were used to evaluate the psychological state. Sleep quality was evaluated with the Pittsburgh Sleep Quality Index.

RESULTS

The mean sleep score of all participants was 6.52. As the level of anxiety and depression increased, the scores of both total sleep quality and sleep quality components increased significantly p < 0.01. On the other hand, those with poor sleep quality had significantly higher stress, anxiety, and depression levels than those with good sleep quality p < 0.01.

CONCLUSION

Negative emotional situations such as stress, anxiety, and depression seriously impair sleep quality in TMD patients.

Use of the Depression Anxiety Stress Scale-21 in young people with temporomandibular disorders: Reliability and dimensionality

OBJECTIVE

The reliability and dimensionality of the Depression Anxiety Stress Scale-21 (DASS-21) were explored in adolescents/young adults with temporomandibular disorders (TMDs).

METHODS

TMD presence was established with the Fonseca Anamnestic Index. Reliability of the DASS-21 for participants with (WT) and without (NT) TMDs was assessed by the Cronbach alpha test, while dimensionality was examined using exploratory factor analysis.

RESULTS

Data from 400 participants (mean age 18.8 ± 1.5 years; 52.2% women) comprising 47.0% with and 53.0% without TMDs were evaluated. Total-DASS and the 3 subscales showed acceptable to high internal consistencies for the WT and NT groups, with alphas of 0.78-0.94 and 0.66-0.92, respectively. Although 3 factors contributed to about half the variance for both groups, scalar and item discrepancies in the primary anxiety-stress factor existed.

CONCLUSION

The DASS-21 has good reliability but may comprise only 2 dimensions, specifically anxiety-stress and depression, instead of the 3 originally asserted.

Activation of the Mesencephalic Trigeminal Nucleus Contributes to Masseter Hyperactivity Induced by Chronic Restraint Stress

Psychological stress is commonly accepted to be closely associated with masticatory muscle disorder, which is the main symptom of temporomandibular disorder (TMD). Previous studies have confirmed that exposure to stress may cause masticatory muscle hyperactivity. However, the central mechanism underlying this process remains unclear. The mesencephalic trigeminal nucleus (Vme), which resides in the brainstem, is the primary afferent center for masticatory proprioception and plays a key role in oral–motor movements by projecting to the trigeminal motor nucleus (Vmo). Therefore, the present study was designed to examine the role of Vme neurons in masseter overactivity induced by chronic stress. We found that subjecting mice to restraint stress (6 h/day) for 14 days caused significant anxiety-like behavior, obvious masseter overactivity, and markedly enhanced electrophysiological excitability of Vme neurons. By using anterograde tract tracing combined with immunofluorescence staining methods, we observed vesicular glutamate transporter 1 (VGLUT1)-positive glutamatergic projections from the Vme to the Vmo. Moreover, chronic restraint stress (CRS) elevated the expression of VGLUT1 and choline acetyltransferase (ChAT) in Vmo. Furthermore, administration of VGLUT1-targeted short hairpin RNA (shRNA) into the bilateral Vme significantly suppressed the enhanced overexcitability of Vme neurons, downregulated the overexpression of VGLUT1 and ChAT in the Vmo, and attenuated the elevated overactivity of the masseter caused by CRS. Taken together, we showed that CRS can excite neurons in the Vme, enhancing glutamatergic excitatory projections from the Vme to the Vmo and resulting in masseter muscle overactivity. These findings provide us with a novel central mechanism underlying the correlation between psychological factors and TMD.

Preclinical models of deep craniofacial nociception and temporomandibular disorder pain

Chronic pain in temporomandibular disorder (TMD) is a common health problem. Cumulating evidence indicates that the etiology of TMD pain is complex with multifactorial experience that could hamper the developments of treatments. Preclinical research is a resource to understand the mechanism for TMD pain, whereas limitations are present as a disease-specific model. It is difficult to incorporate multiple risk factors associated with the etiology that could increase pain responses into a single animal. This article introduces several rodent models which are often employed in the preclinical studies and discusses their validities for TMD pain after the elucidations of the neural mechanisms based on the clinical reports. First, rodent models were classified into two groups with or without inflammation in the deep craniofacial tissues. Next, the characteristics of each model and the procedures to identify deep craniofacial pain were discussed. Emphasis was directed on the findings of the effects of chronic psychological stress, a major risk factor for chronic pain, on the deep craniofacial nociception. Preclinical models have provided clinically relevant information, which could contribute to better understand the basis for TMD pain, while efforts are still required to bridge the gap between animal and human studies.

Comparison of psychological states and oral health-related quality of life of patients with differing severity of temporomandibular disorders

BACKGROUND

Studies on temporomandibular disorder (TMD) severity in patient populations are scarce.

OBJECTIVES

This study sought to compare the psychological states and oral health-related quality of life (OHRQoL) among patients with differing TMD severity.

METHODS

Adult patients (≥18 years old) with and without (controls) TMDs were recruited from the TMD/oro-facial pain centre and prosthodontics department, respectively. The presence and severity of TMDs were established with the Fonseca Anamnestic Index (FAI), and TMD diagnoses were confirmed with the Diagnostic Criteria for TMDs (DC/TMD). Psychological states and OHRQoL were examined with the Depression, Anxiety, Stress Scales-21 (DASS-21) and Oral Health Impact Profile for TMDs (OHIP-TMD). Data were subjected to chi-square, Kruskal-Wallis/Mann-Whitney U tests and Spearman's correlation (α = .05).

RESULTS

A total of 961 participants with a mean age of 32.99 ± 13.14 years (71.19% women) were assessed. Frequencies of the various TMD categories were as follows: no TMD/controls (12.07%), mild TMD (24.56%), moderate TMD (40.37%) and severe TMD (23.00%). The three most common TMD-related symptoms were TMJ noises, mouth opening difficulty and muscle pain. Participants with moderate/severe TMD presented a higher proportion of intra-articular and/or combined disorders. They reported significantly higher levels of depression, anxiety, stress and poorer OHRQoL than their counterparts with no/mild TMD (p < .001). Moderate-to-strong correlations were observed between FAI and DASS-21/OHIP-TMD scores (rs = 0.42-0.72).

CONCLUSIONS

Patients with moderate/severe TMD had significantly higher levels of psychological disturbance and poorer OHRQoL. As OHRQoL and psychological states are correlated, psychological well-being must be considered when managing patients with moderate/severe TMDs.