Temporomandibular disorder symptoms and their association with quality of life of dental patients in Malaysia.

OBJECTIVE: To assess the prevalence of temporomandibular disorders (TMD) and their effects on quality of life (QoL) of dental patients. METHODS: A survey consisting of two validated questionnaires was distributed to dental patients registered at the University of Malaya Faculty of Dentistry. The Fonseca Anamnestic Index (FAI) evaluates the prevalence and severity of TMD, while the Oral Health Impact Profile - Temporomandibular Disorder (OHIP-TMD) appraises the effects of TMD on oral health-related QoL. RESULTS: Out of 342 patients (aged 16 to 50 years, 45% male and 55% female) enrolled in the survey, 50.9% had varying degrees of TMD. All 7 domains of OHIP-TMD showed a statistically significant correlation with TMD severity. CONCLUSION: TMD seems to be prevalent among Malaysian dental patients. Not only does TMD affect the QoL of an individual, but the more severe the degree of reported symptoms, the poorer their perceived oral health QoL.

Temporomandibular Disorders, Bruxism and Headaches.

Temporomandibular disorders (TMDs) and headache disorders are highly prevalent in the population. TMDs can present headache symptoms as a secondary headache and, in addition, be comorbid with primary headache disorders. This overlap has significant clinical implications for which it is essential for the physician to be aware, and they should screen for the potential presence of TMDs in a headache patient. Bruxism is a parafunctional behavior also prevalent in the population which has a role in TMDs and may influence headache symptomatology, but it is still necessary to clarify this relationship.

Temporomandibular disorders among Ehlers-Danlos syndromes: a narrative review.

This narrative review aims to demonstrate and summarize the complex relationship between Ehlers-Danlos syndromes (EDS) and temporomandibular disorders (TMD) by reviewing the results of observational studies and case reports. EDS are a set of hereditary connective tissue disorders, where generalized joint hypermobility (GJH), especially in the hypermobile subtype (hEDS), is a key symptom. Mutations have been identified in genes that impact the production or assembly of collagen for all subtypes except hEDS. While the correlation between GJH and TMD has been analysed in various studies, fewer studies have examined TMD in patients with EDS, with most showing an increased prevalence of TMD. In case-control studies, an elevated prevalence of myalgia, arthralgia and disc-related disorders was found in individuals with EDS. Various therapeutic interventions have been reported within the literature in the form of case reports and observational studies, but there are no long-term clinical trials with results on the efficacy of different therapeutic approaches to date. This review demonstrates the high prevalence of different TMDs in different subtypes of EDS, but also shows that little is known about the success of treatment thus far. Further clinical research is necessary to provide adequate guidance on targeted treatment.

[Temporomandibular dysfunction and bruxism in patients with early rheumatoid arthritis and at-risk patients: a cross-sectional study]. / Temporomandibulaire disfunctie en bruxisme bij patiënten met vroege reumatoïde artritis en risicopatiënten: een cross-sectioneel onderzoek.

What is the prevalence of temporomandibular dysfunction in patients with early rheumatoid arthritis and individuals at risk of rheumatoid arthritis? 3 groups (of 50 participants each) were examined for a possible TMD diagnosis: 1. patients with early rheumatoid arthritis, 2. at-risk individuals, and 3. healthy controls. A possible association with bruxism, determined on the basis of self-reporting and clinical features, was also examined. At-risk patients had a higher prevalence of TMD pain diagnoses compared to healthy controls (p = 0.046). Within the early rheumatoid arthritis group, seronegative patients had a higher prevalence of TMD pain diagnoses than seropositive patients (p = 0.048). No further differences in the prevalence of TMD diagnoses were found between the groups. Participants with a TMD pain diagnosis were more often diagnosed with probable sleep bruxism than those without a TMD pain diagnosis. The prevalence of TMD pain is increased in individuals at risk of rheumatoid arthritis and seronegative early rheumatoid arthritis patients, and is associated with signs of bruxism.

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.

INTRODUCTION: This 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. METHODS: In 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. RESULTS: Pregnant 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. DISCUSSION: The 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.

Impact of professional, recreational and nonsinging on temporomandibular disorders - a comparative study based on a self-assessment questionnaire.

BACKGROUND: This study investigates the relationship between professional and recreational singing on temporomandibular disorders (TMDs) in women compared to a nonsinging control group. METHODS: A total of 288 female subjects between the ages of 18 and 45 participated in the self-assessment questionnaire including demographic data, as well as questions on vocal practice and TMDs symptoms. Depending on the singing time per week, the (non)vocalists were assigned to the groups professional (n = 96), recreational (n = 96) and nonsingers (n = 96). RESULTS: The TMDs prevalence in professional singers (42%) was higher than that in recreational singers (31%) and noticeably higher than that in nonsingers (25%). The Fisher-Freeman-Halton exact test showed that the differences between the groups were not noticeable (p = .053) but could be formulated as tendencies. The professionals suffered much more from restricted jaw movement (p = .004; OR = 2.718; 95% CI = 1.409-5.242), temporomandibular joint sounds (p < .009; OR = 2.267; 95% CI = 1.264-4.064) and temporomandibular pain (p = .010; OR = 2.333; 95% CI = 1.264-4.308) than nonsingers. CONCLUSIONS: Singing might have an enhancing effect on the appearance of TMDs. In particular, professional singers suffered more from self-reported TMDs than recreational singers and nonsingers. In addition to the high level of physical workload if participating in professional singing, the psychosocial impact should be investigated more in further studies. No new treatment strategies resulted from this study, as the etiological significance of singing is still unclear. Knowledge about risk factors for multifactorial TMDs can help practitioners and patients prevent and treat TMDs.

Temporomandibular joint disorders in skeletal class II patients referred to orthognathic surgery: A cross-sectional study.

OBJECTIVES: The aim of this study was to assess the prevalence of Temporomandibular Disorders (TMD) in subjects with skeletal class II dentofacial deformity referred for orthognathic surgery, as well as to elucidate its association with sociodemographic and psychosocial features. METHODS: This was a cross-sectional study using the Research Diagnostic Criteria for Temporomandibular Disorders. The sample comprised class II skeletal patients referred to an Oral and Maxillofacial Surgery center in the Brazilian Northeast. RESULTS: Seventy-three subjects were enrolled and completed the data collection, which consisted of a physical examination according to Axis I of the Research Diagnostic Criteria for Temporomandibular Disorders and facial analysis. Women represented 82.2% of the sample. Among the assessed subjects, 68.5% were already undergoing orthodontic treatment, and the mean overjet of patients was 6.97 mm. The prevalence of TMD in this sample was 46.6%, with muscular disorders being the most common. Patients with an anteroposterior discrepancy greater than 7 mm showed a higher occurrence of TMD (p = 0.017). CONCLUSION: This study demonstrated a high prevalence of TMD in skeletal class II patients referred for orthognathic surgery, especially in those with a pronounced overjet, being Group I (muscular disorders) and Group III (degenerative disorders) the most prevalent.

Pain Patterns of the Temporomandibular Joint Dysfunction and Implications of Stress-Related Behaviors: A Pilot Study / Patrones de Dolor de la Disfunción de la Articulación Temporomandibular e Implicaciones de los Comportamientos Relacionados con el Estrés: Un Estudio Piloto

SUMMARY: Temporomandibular joint dysfunction interferes with the quality of life and activities of daily living among patients. The symptoms of temporomandibular dysfunction, including pain and clicking and popping sounds, are worsened during stressful events, and patients report increased pain around the temporomandibular joint. Stress-related behaviors, such as teeth clenching and teeth grinding, are commonly reported as increasing during stress. The prevalence of temporomandibular dysfunction and stress-related behaviors is reported differently in the literature. Stress in higher education is common. The purpose of this pilot study was to investigate the prevalence of temporomandibular joint dysfunction and stress-related behaviors among staff members at a local University. The study also sought to explore pain patterns described by people experiencing temporomandibular joint dysfunction and the relationship between stress-related behaviors and pain symptoms experienced. Further, the impact of stress on symptoms experienced by people with temporomandibular dysfunction was investigated in this pilot study.

La disfunción de la articulación temporomandibular interfiere con la calidad de vida y las actividades de la vida diaria entre los pacientes. Los síntomas de la disfunción temporomandibular, incluidos el dolor y los chasquidos, empeoran durante los eventos estresantes, y los pacientes informan un aumento del dolor alrededor de la articulación temporomandibular. Los comportamientos relacionados con el estrés, como apretar y rechinar los dientes, suelen aumentar durante el estrés. La prevalencia de la disfunción temporomandibular y los comportamientos relacionados con el estrés se informa de manera diferente en la literatura. El estrés en la educación superior es común. El propósito de este estudio piloto fue investigar la prevalencia de la disfunción de la articulación temporomandibular y los comportamientos relacionados con el estrés entre los miembros del personal de una universidad local. El objetivo del estudio además fue explorar los patrones de dolor descritos por personas que experimentan disfunción de la articulación temporomandibular y la relación entre los comportamientos relacionados con el estrés y los síntomas de dolor experimentados. Además, en este estudio piloto se investigó el impacto del estrés en los síntomas que experimentan las personas con disfunción temporomandibular.

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.

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

BACKGROUND: 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. OBJECTIVE: This study aimed to investigate the causal effect of education on TMDs and explore potential mediating pathways. METHODS: 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. RESULTS: 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). CONCLUSION: 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.

Machine learning analysis with population data for the associations of preterm birth with temporomandibular disorder and gastrointestinal diseases.

This study employs machine learning analysis with population data for the associations of preterm birth (PTB) with temporomandibular disorder (TMD) and gastrointestinal diseases. The source of the population-based retrospective cohort was Korea National Health Insurance claims for 489,893 primiparous women with delivery at the age of 25-40 in 2017. The dependent variable was PTB in 2017. Twenty-one predictors were included, i.e., demographic, socioeconomic, disease and medication information during 2002-2016. Random forest variable importance was derived for finding important predictors of PTB and evaluating its associations with the predictors including TMD and gastroesophageal reflux disease (GERD). Shapley Additive Explanation (SHAP) values were calculated to analyze the directions of these associations. The random forest with oversampling registered a much higher area under the receiver-operating-characteristic curve compared to logistic regression with oversampling, i.e., 79.3% vs. 53.1%. According to random forest variable importance values and rankings, PTB has strong associations with low socioeconomic status, GERD, age, infertility, irritable bowel syndrome, diabetes, TMD, salivary gland disease, hypertension, tricyclic antidepressant and benzodiazepine. In terms of max SHAP values, these associations were positive, e.g., low socioeconomic status (0.29), age (0.21), GERD (0.27) and TMD (0.23). The inclusion of low socioeconomic status, age, GERD or TMD into the random forest will increase the probability of PTB by 0.29, 0.21, 0.27 or 0.23. A cutting-edge approach of explainable artificial intelligence highlights the strong associations of preterm birth with temporomandibular disorder, gastrointestinal diseases and antidepressant medication. Close surveillance is needed for pregnant women regarding these multiple risks at the same time.

Prevalence of temporomandibular disorders diagnosis in patients treated with Herbst appliance: a systematic review and meta-analysis.

BACKGROUND: The Herbst appliance is an excellent therapy for treating class II malocclusions with increased overjet. Its mechanics involve propelling the mandibular bone using two pistons the patient cannot remove. The so-called bite-jumping keeps the mandible in a more anterior position for a variable period, usually at least 6 months. This appliance does not inhibit joint functions and movements, although there are scientific papers in the literature investigating whether this appliance can lead to temporomandibular disorders. This systematic review aims to evaluate whether Herbst's device can cause temporomandibular diseases by assessing the presence of TMD in patients before and after treatment. METHODS: A literature search up to 3 May 2023 was carried out on three online databases: PubMed, Scopus and Web of Science. Only studies that evaluated patients with Helkimo scores and Manual functional analysis were considered, as studies that assessed the difference in TMD before and after Herbst therapy. Review Manager version 5.2.8 (Cochrane Collaboration) was used for the pooled analysis. We measured the odds ratio (OR) between the two groups (pre and post-Herbst). RESULTS: The included papers in this review were 60. Fifty-seven were excluded. In addition, a manual search was performed. After the search phase, four articles were considered in the study, one of which was found through a manual search. The overall effect showed that there was no difference in TMD prevalence between pre-Herbst and post-Herbst therapy (OR 0.74; 95% CI: 0.33-1.68). CONCLUSION: Herbst appliance seems not to lead to an increase in the incidence of TMD in treated patients; on the contrary, it appears to decrease it. Further studies are needed to assess the possible influence of Herbst on TMDs.

Unlocking the link between temporomandibular disorders and suicide ideation in pre-orthodontic patients: A moderated mediation model of depression and anxiety.

BACKGROUND: Temporomandibular disorders (TMD) are a series of musculoskeletal diseases with high prevalence. A few studies have reported the correlation between TMD and suicide ideation (SI). However, the underlying mechanism of the relationship lacks in-depth exploration. METHODS: A cross-sectional study was conducted among 954 pre-orthodontic patients. TMD assessment was based on the quintessential five TMD symptoms (5Ts) questionnaire. Anxiety, depression and pain catastrophizing was evaluated by Seven-item Generalized Anxiety Disorder Scale (GAD-7), Nine-item Patient Health Questionnaire (PHQ-9), and Pain Catastrophizing Scale (PCS), respectively. Correlational and moderated mediated analysis was preformed to demonstrate the relationship between TMD and SI. RESULTS: In pre-orthodontic patients, 31.87 % reported having TMD symptoms and 6.50 % declared SI during the past two weeks. The SI prevalence was 10.53 % in participants with TMD and 4.62 % in those without TMD. Intra-articular TMD, rather than pain-related TMD were especially related with SI. Individuals with TMD had higher risk to SI (rs = 0.112, adjusted OR = 2.213, p < 0.001). The effect of TMD on SI was fully mediated through depression (ß = 0.445, 95 % CI = [0.326, 0.563]). Anxiety exerted a negative moderating effect on the depression-SI relation (ß = -0.033, 95 % CI = [-0.047, -0.019]). LIMITATIONS: This study was a single-centered and cross-sectional survey. The data collection relied on self-reporting methods. CONCLUSIONS: A positive link between TMD and SI was disclosed. The effect of TMD on SI was fully mediated through depression with anxiety as a negative moderator.

Clinical features of chronic primary pain in individuals presenting painful temporomandibular disorder and comorbidities.

BACKGROUND: The diagnosis of chronic primary pain (CPP), according to the recently released International Classification of Disease (ICD-11) criteria, refers to conditions with complex aetiologies. CPP is characterized by specific clinical features such as generalized sensory hypersensitivity and widespread pain, and is associated with functional disability and emotional distress. OBJECTIVE: This study investigated clinical features of CPP in individuals with painful temporomandibular disorders (TMD) and comorbidities (fibromyalgia, migraine and/or tension-type headache). METHODS: This cross-sectional study was conducted with a sample of 129 individuals. Painful TMD, fibromyalgia and primary headaches were evaluated based on well-established international criteria. Generalized sensory hypersensitivity was assessed using psychophysical tests. Symptoms of anxiety and depression were assessed by the Generalized Anxiety Disorder-7 and Patient Health Questionnaire-9. The Central Sensitization Inventory was applied to assess central sensitization-related symptoms and the Pittsburg Sleep Quality Index to evaluate the quality of sleep. The presence of widespread pain was assessed using a body map. The sample was stratified into three groups: control (n = 25), TMD-painful TMD only (n = 35) and TMD + Cm-painful TMD and comorbidities (n = 69). Statistical analysis was performed using one-way ANOVA, chi-squared test and ANCOVA, considering gender as a covariate (α = .05). RESULTS: Compared to controls, individuals presenting painful TMD and comorbidities showed lower pressure pain thresholds in all evaluated areas (p ≤ .012) and a higher number of painful areas in the body (p = .001). They presented more symptoms of anxiety (p = .040) and depression (p = .018), and a higher score in the Central Sensitization Inventory (p ≤ .006) than the other groups. CONCLUSION: Individuals with painful TMD and comorbidities presented more clinical features of CPP compared to those affected by TMD only.

Prevalence of temporomandibular disorders in clear aligner patients using orthodontic intermaxillary elastics assessed with diagnostic criteria for temporomandibular disorders (DC/TMD) axis II evaluation: A cross-sectional study.

BACKGROUND: The objective of this investigation is to assess the relationship between the utilisation of orthodontic intermaxillary elastics and temporomandibular disorder (TMD) symptoms in clear aligner patients and to examine the correlation between the elastic usage time with the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD)-Axis II Evaluation Forms. METHODS: This study was carried out on a total of 40 clear aligner patients using intermaxillary elastics in the experimental group and 30 clear aligner patients who did not use any intermaxillary elastics in the control group. The data were evaluated using the Mann-Whitney U, chi-square, Fisher's exact chi-square, and Fisher Freeman Halton exact chi-square tests. RESULTS: The characteristic pain intensity, mastication, mobility, communication, global and PHQ-9 scores of the experimental group were significantly higher than those of the control group (p < .05). The characteristic pain intensity score, interference score and chronic pain grade score of patients using Class III elastics were statistically significantly higher than those of patients using Class II elastics (p < .05). Patients who used elastics for less than 6 months had statistically significantly higher PHQ-9 scores than those who used elastics for more than 6 months (p < .05). CONCLUSIONS: Orthodontic treatment may affect occlusion, bite force and jaw movement, which may cause or worsen TMD symptoms, and the DC/TMD questionnaires can determine if orthodontic patients acquire TMD by assessing their psychosocial state and pain-related problems.

Bruxism and oro-facial pain not related to temporomandibular disorder conditions: Comorbidities or risk factors?

INTRODUCTION: Bruxism has historically been of particular interest to the field of dentistry, primarily due to the inferred damage it may cause to the dentition and supporting periodontal structures. The definition of bruxism itself has undergone multiple changes over time. In addition, the effects of bruxism as it relates to oro-facial pain conditions has remained a debatable topic. PURPOSE: To review the available literature relating to bruxism and non-temporomandibular disorder (TMD) pain conditions. METHODS: A literature search was conducted with the assistance of an expert librarian. The following databases were reviewed: PubMed, MEDLINE, EMBASE and Google Scholar. For additional references, articles were also retrieved by hand search from the selected papers. Any articles that were not published in English, or the focus were related to temporomandibular disorders were excluded. CONCLUSIONS: While bruxism and certain headache conditions do tend to occur together frequently, evidence relating to any clear common pathophysiological mechanism has yet to be fully elucidated. Robust evidence as it relates to the relationship between bruxism and other non-TMD oro-facial pains is also lacking.

Temporomandibular joint involvement in psoriatic arthritis: a prospective clinical and ultrasonographic study.

OBJECTIVES: To evaluate the prevalence of temporomandibular disorders (TMD) in a monocentric cohort of patients affected by psoriatic arthritis (PsA), and to investigate the accuracy of temporomandibular joint (TMJ) ultrasound (US) compared with clinical evaluation and clinimetric composite index in assessing TMJ involvement. METHODS: We conducted a prospective cohort study of patients diagnosed with PsA who underwent at least one TMJ US examination and maxillofacial surgeon's evaluation between 2018 and 2021. The rheumatology physician's interpretation of each TMJ US exam (presence/absence of TMD) was compared with psoriatic arthritis disease activity indexes and maxillofacial surgeon's clinical judgement (presence/absence of TMD signs and/or symptoms). RESULTS: 142 psoriatic arthritis patients were included. 111 patients were totally asymptomatic for TMD, but 58.5% of them already showed TMJ US changes; moreover, 103 patients passed the maxillofacial surgeon's examination in the absence of any relevant findings but again, of these, 55.3% already presented US signs of TMD. Univariate analysis of subgroups with and without TMJ synovitis and with and without active power Doppler signal showed a significant prevalence of peripheral enthesitic involvement in patients affected by TMD (95.7% vs. 4.3%, p=0.001; and 72.2% vs. 27.3%, p=0.007, respectively). Multivariate regression analysis confirmed the results (p=0.01 and p=0.013, respectively). CONCLUSIONS: Peripheral enthesitic involvement may represent a potential risk factor for the development of TMJ synovitis in PsA patients. Since TMD often develops asymptomatically, TMJ US may detect early signs of TMD, ensuring precocious and adequate management.

Is low back pain a risk/prognostic factor for the development and/or progression of temporomandibular disorders? A systematic review with meta-analysis.

OBJECTIVES: To evaluate the association between low back pain (LBP) and painful temporomandibular disorders (TMDs). METHODS: Systematic review of observational studies. Searches were conducted using OVID MEDLINE, CINHAL, Web of Science and PUBMED databases up to 21 October 2022. Qualitative and quantitative analyses were performed. Risk of bias (RoB) was assessed using the Quality in Prognosis Studies tool (QUIPS). RESULTS: Eight studies were included in the present review with meta-analysis. The first onset of TMDs was more likely in patients with previous chronic LBP (hazard ratio (HR) 1.53 [95% confidence interval (CI): 1.28; 1.83, p < .00001]). In addition, patients with chronic LBP had 3.25 times the odds (OR) [95% CI: 1.94; 5.43, p < .00001] of having chronic TMDs than those who did not have chronic LBP. In addition, the higher the exposure to chronic LBP, the higher the risk of developing a first onset of TMDs. CONCLUSIONS: Chronic LBP can be considered a risk/contributing factor for painful TMDs. Although there is a high certainty in the evidence linking chronic LBP with the risk of a first onset of TMDs, there are insufficient studies to draw definitive conclusions. Furthermore, while an association between chronic LBP and chronic TMDs and a dose-effect was observed between these two conditions, a limited number of studies and evidence exist to support these findings. Future studies are needed to increase the body of evidence.

Associations Between Temporomandibular Pain and Biobehavioral Variables in Dental Students in Response to an External Stressor.

AIMS: To assess changes in temporomandibular disorder (TMD) pain and multiple biobehavioral variables relevant to TMDs in response to an external stressor. METHODS: Self-reported data using online DC/TMD questionnaires were collected from volunteer dentistry graduate students. Data collection was performed on two occasions: during a non-exam period of the semester and during the subsequent exam period. Changes in the proportion of students with pain, differences in pain grade, and severity of biobehavioral status were measured and compared over the two periods. The association between severity of non-exam-period biobehavioral status and pain presence was also tested to assess whether biobehavioral variables can predict pain occurrence or persistence. Chi-square test, Wilcoxon signed-rank test, ANOVA, and Kruskal-Wallis tests were used for data analysis. P < .05 was considered significant. RESULTS: Of the 213 enrolled students, 102 remained after data reduction. In the non-exam period, the proportion of individuals with pain was 24.5%; in the exam period, the proportion was 54.9%, and more students had a higher pain grade. The severity of all biobehavioral variables was higher in the exam period, but there was no association between changes in the presence of pain and changes in biobehavioral variables. Higher anxiety and parafunction levels were found in those who reported pain on both occasions. CONCLUSION: Exam periods initiate readily measurable changes in the psychologic status of many students, as well as alterations in their temporomandibular pain. Higher levels of anxiety and oral behaviors during non-exam periods seem to be predictors for persisting pain.

Prevalence and severity of temporomandibular joint disorder in partially versus completely edentulous patients: A systematic review.

Temporomandibular joint disorders (TMDs) following tooth loss may or may not be prevalent, but the risk of developing these disorders is always there due to changes in occlusion and vertical dimension, leading to changes in the disc-fossa relationship. The purpose of this systematic review was to evaluate the prevalence and severity of temporomandibular joint (TMJ) disorder in partially versus completely edentulous patients. An elaborated literature search was conducted in PubMed/Medline, Scopus, Web of Science, Lilacs, and Google Scholar databases including all articles about varied effects of partial and complete edentulism on the TMJ published from January 1, 2000, to January 1, 2022. After the meticulous screening, only publications which fulfilled the inclusion parameters were ultimately selected for full-text evaluation and tested for bias using the Joana Briggs Institute Appraisal tools for cross-sectional, case-control, and cohort studies. A total of 547 articles from various electronic databases and manual searches were found. After eliminating the duplicates and thorough screening, 13 studies were included for qualitative synthesis. Most of the studies demonstrated at least one or two signs of the presence of TMDs following tooth loss, the intensity/frequency of which increased in proportion to the number of missing teeth.