Relationship Between Occlusal Factors and Temporomandibular Disorders: A Systematic Literature Review

Temporomandibular disorders (TMD) originate from various components within the temporomandibular joint (TMJ), causing an impact on the masticatory muscles, the joint itself, and associated structures. They are a widely prevalent issue across the world. According to epidemiological research, up to 50% of adults in the population have TMD-related symptoms. The objective of this work was to analyze the existing scientific literature regarding the association between malocclusion classes, bruxism, and tooth loss in relation to the etiology of TMD. This systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 analysis protocol. For the development of the question focus, the population, intervention, control, and outcomes (PICO) study design protocol was used. The question in focus according to the PICO format was: "Do malocclusion, tooth loss, and bruxism contribute to temporomandibular disorders?". The review was performed with articles from PubMed, Web of Science, and Google Scholar databases according to the specified inclusion and exclusion criteria. The included articles were not older than five years. The risk of bias was assessed in the included studies by using the Cochrane Risk-of-bias 2 (RoB-2) tool. Out of a total of 32 results received, 21 articles were chosen according to the established criteria after conducting a review and analysis of their full texts. The article search sequence was presented in the PRISMA 2020 flow diagram, and the outcomes of the chosen articles were presented. The literature results revealed a relationship between occlusion and the development of TMD. The influence of occlusal factors on the TMJ was explained by an examination of joint anatomy and symptoms related to TMD. This study revealed variations in TMJ factors across different malocclusion classes. Additionally, it was observed that the occurrence and attributes of TMD are influenced by the number of tooth loss quadrants and the frequency of missing teeth. Furthermore, a correlation was found between bruxism and the symptoms of TMD, including myofascial pain, disc displacement, arthralgia, and muscle disorders. This literature review provides comprehensive information on the relationship between malocclusion classes, bruxism, tooth loss, and TMDs. This prompts healthcare professionals to prioritize patients' occlusal assessment and TMJ condition.

Orthodontics and Temporomandibular Disorders: An Overview

The relationship between orthodontics and temporomandibular disorders (TMDs) constitutes a subject of paramount significance in dental and craniofacial health. This abstract embarks upon an in-depth examination of the intricate connection between orthodontic practices and TMD, primarily focusing on evaluating the impact of orthodontic treatment modalities on the health and functionality of the temporomandibular joint (TMJ). This exploration elucidates the multifaceted interplay between orthodontic interventions and TMD by traversing a landscape of scholarly research and empirical investigations. The review draws from a broad spectrum of studies to analyze the potential influence of orthodontic treatments, which encompass occlusal adjustments and alterations in jaw positioning, on the development and management of TMD symptoms. The inquiry delves into the diverse range of TMD conditions, considering the implications of orthodontic techniques on occlusal stability, condylar alignment, and overall TMJ function. Through a comprehensive synthesis of the available body of knowledge, this abstract aspires to equip dental practitioners, orthodontists, and researchers with a nuanced understanding of the complex dynamics that govern the relationship between orthodontics and TMD. This knowledge, in turn, offers a foundation for informed clinical decision-making and the formulation of effective treatment strategies for patients presenting with TMD symptoms. By shedding light on the intricate interactions between orthodontic procedures and TMJ health, this abstract contributes to the advancement of clinical practices, promoting improved patient outcomes and well-being in the context of both orthodontics and TMDs.

Changing Trends in Publication Regarding Temporomandibular Joint Dysfunction From 1975 to 2021: A Bibliometric Analysis

Temporomandibular joint (TMJ) is a bicondylar joint. Various conditions have the same clinical presentation as TMJ dysfunction, which requires a thorough assessment of active and passive movements and palpation of the joints surrounding the joint. Many times, TMJ dysfunction occurs due to an alteration in the cervical spine. The patient complains of clicking or popping sound at the jaw and a reduced maximum mouth opening. The conditions that lead to TMJ dysfunction include bruxism, arthritis, stress, injury to the jaw, and overuse. The trend of the available literature has changed from 1972 to 2021 to assess changing trends in the publication on TMJ about authors, country, collaboration of the institutes, and the journal. We have done this bibliometric assessment. The articles were collected from the PubMed database; the keywords used were temporomandibular dysfunction (TMD), neck pain, physiotherapy, and rehabilitation. A total of 437 articles were found from 1975 to 2021, which were then converted into pictorial forms using the CiteSapce R software, and the data were interpreted. The analysis of the bibliometrics of publications on TMD, neck pain, and functional disability between the years 1975 and 2021 shows a total of 437 articles were published. The articles were from 196 sources; the highest number of publications were seen from 2014 until 2021, with the highest number of published papers by author Yoo WG and the highest number of articles published by the Journal of Physical Therapy Science. This bibliometric analysis depicts that the quantity of literature on TMD and the forward head has increased, as has the effectiveness of physical therapy interventions on the forward head in terms of correcting temporomandibular dysfunction.

Psychologic Impact of Chronic Orofacial Pain: A Critical Review

AIMS

To explore the prevalence of clinically significant anxiety and depression in adult patients with chronic orofacial pain (COFP) conditions.

METHODS

A systematic online search of the Medline (PubMed) and Ovid databases was performed for articles published from 2006 to 2019. Observational studies- including cross-sectional, case-control, and case series-and longitudinal prospective studies were included. A total of 118 articles were selected for inclusion, and the prevalence rates of clinically significant anxiety and depression were summarized.

RESULTS

Most studies focused on temporomandibular disorder (TMD) pain and less often on neuropathic COFP conditions. Prevalence rates varied widely across studies according to OFP condition and assessment measure; most questionnaire-based assessments yielded rates of clinically significant depression and anxiety in, respectively, 40% to 60% and 40% to 65% of individuals with TMD and in 20% to 50% and 25% to 55% of patients with neuropathic, mixed, or idiopathic/atypical COFP conditions. Rates of anxiety and depression were lower in studies using diagnostic instruments and in TMD studies with nonpatient samples. Most controlled studies showed a higher prevalence of anxiety and depression in individuals with COFP than in those without. Higher COFP pain levels and the presence of comorbid conditions such as migraines or widespread pain increased the likelihood of anxiety and/or depressive symptoms in individuals.

CONCLUSION

Clinically significant anxiety and depression were commonly observed in patients with COFP, were present at higher rates than in pain-free participants in controlled studies, and were closely linked to pain severity. More research is needed to evaluate the psychologic impact of multiple COFP conditions in an individual and the prevalence of precondition psychologic morbidity.

Graded Chronic Pain Scale: Validation of 1-Month Reference Frame

OBJECTIVES

The 1-month Graded Chronic Pain Scale (GCPS) commonly used in clinical studies has never been validated. This study compares the GCPS 1-month with the 6 months version for reliability and validity.

METHODS

The Validation Project included 521 participants with at least one temporomandibular disorder for cross-sectional data and 74 participants for test-retest data. Internal reliability, stability, and construct validity were used for testing the 1-month version. Comparisons were made between the 2 versions for characteristic pain intensity (CPI), interference, and chronic pain grade (CPG).

RESULTS

For GCPS 1-month, internal consistency for pain intensity and interference was high (Cronbach α=0.87 and 0.94, respectively), and temporal stability was high for CPI (intraclass correlation coefficient [ICC]=0.91), interference (ICC=0.85), and CPG (weighted κ=0.88). ICC or κ between the 2 versions was 0.78 (CPI), 0.66 (interference), and 0.69 (CPG); high-impact pain, in contrast, was 0.50. Construct validity exhibited higher correlations with predictor variables for 1-month version attributes of CPI, interference, and CPG. Modified Bland-Altman plots indicated that both versions measure CPI well.

DISCUSSION

Overall, reliability of the 1-month GCPS is equal to or better than the 6-months version for pain intensity, disability days, pain interference, CPG, and high-impact pain. However, consistency between versions is lower for measures of disability days and interference, and for the derived measures of CPG and high-impact pain; highly skewed distributions and increasing disagreement in reported status over the time periods affect the measures of function. Therefore, we recommend that GCPS-1 month only be used to calculate pain intensity and pain interference.

Relationship between temporomandibular disorders, widespread palpation tenderness, and multiple pain conditions: a case-control study

The multiple bodily pain conditions in temporomandibular disorders (TMD) have been associated with generalized alterations in pain processing. The purpose of this study was to examine the relationship between the presence of widespread body palpation tenderness (WPT) and the likelihood of multiple comorbid pain conditions in TMD patients and controls. This case-control study was conducted in 76 TMD subjects with WPT, 83 TMD subjects without WPT, and 181 non-TMD matched control subjects. The study population was also characterized for clinical pain, experimental pain sensitivity, and related psychological phenotypes. Results showed that: 1) TMD subjects reported an average of 1.7 comorbid pain conditions compared to .3 reported by the control subjects (P < .001); 2) Compared to control subjects, the odds ratio (OR) for multiple comorbid pain conditions is higher for TMD subjects with WPT [OR 8.4 (95% CI 3.1-22.8) for TMD with WPT versus OR 3.3 (95% CI 1.3-8.4) for TMD without WPT]; 3) TMD subjects with WPT presented with reduced pressure pain thresholds (PPTs) in both cranial and extracranial regions compared to TMD subjects without WPT; and 4) TMD subjects with WPT reported increased somatic symptoms. These findings suggest that pain assessment outside of the orofacial region may prove valuable for the classification, diagnosis, and management of TMD patients.

PERSPECTIVE

TMD subjects with WPT experience a greater level of multiple comorbid pain conditions, compared to TMD subjects without WPT and non-TMD controls. Integration of bodily pain assessments can be informative for evaluation, diagnosis, and management of TMD.

Assessment and further development of RDC/TMD Axis II biobehavioural instruments: a research programme progress report

A symposium was held in Toronto, 2008, in which research progress regarding the biobehavioural dimension of the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) was presented. An extended workshop was held in April 2009 in which further recommendations were made from an expert panel, using the 2008 symposium material as a base. This paper is a summary of the 2008 symposium proceedings with elaborations based on further developments. Seven studies were conducted between 2001 and 2008, in which the following were investigated: (i) basic properties of Axis II instruments, (ii) reliability and criterion validity of Axis II instruments, (iii) expansion of predictors, (iv) metric equivalence of the depression and non-specific physical symptoms subscales in the RDC/TMD, (v) laboratory investigation of oral behaviours, (vi) field data collection of oral behaviours, and (vii) functional limitation of the jaw. Methods and results for each of these studies are described. Based on the results of these studies that have been published, as well as the direction of interim results from the few studies that await completion and publication, the biobehavioural domain of the RDC/TMD, as published in 1992, is reliable and valid. These results also provide strong evidence supporting the future growth of the biobehavioural domain as the RDC/TMD matures into subsequent protocols for both clinical and research applications.

Critical appraisal of methods used in randomized controlled trials of treatments for temporomandibular disorders

AIMS

To evaluate the quality of methods used in randomized controlled trials (RCTs) of treatments for management of pain and dysfunction associated with temporomandibular muscle and joint disorders (TMJD) and to discuss the implications for future RCTs.

METHODS

A systematic review was made of RCTs that were implemented from 1966 through March 2006, to evaluate six types of treatments for TMJD: orthopedic appliances, occlusal therapy, physical medicine modalities, pharmacologic therapy, cognitive-behavioral and psychological therapy, and temporomandibular joint surgery. A quality assessment of 210 published RCTs assessing the internal and external validity of these RCTs was conducted using the Consolidated Standards of Reporting Trials (CONSORT) criteria adapted to the methods of the studies.

RESULTS

Independent assessments by raters demonstrated consistency with a mean intraclass correlation coefficient of 0.63 (95% confidence interval). The mean percent of criteria met was 58%, with only 10% of the RCTs meeting the four most important criteria.

CONCLUSIONS

Much of the evidence base for TMJD treatments may be susceptible to systematic bias and most past studies should be interpreted with caution. However, a scatter plot of RCT quality versus year of publication shows improvement in RCT quality over time, suggesting that future studies may continue to improve methods that minimize bias.