Identifying phenotypes in persons with temporomandibular disorders, using latent class analyses: Temporomandibular disorders and phenotypes.

BACKGROUND: The heterogeneity of persons with temporomandibular disorders (TMD) and the lack of effective treatments have called for a biopsychosocial model and the development of a more personalised treatment approach. Emphasis on phenotypes might be a beneficial approach. OBJECTIVE: Identifying phenotypes among persons with TMD using potential prognostic factors, including personal characteristics and responses to clinical tests. Additionally, examining the distribution of TMD diagnoses within the identified phenotypes. METHODS: A cross-sectional study including 208 persons (85% females) seeking physiotherapy for problems in the temporomandibular area. All participants were examined clinically and answered questionnaires electronically. The phenotypes were identified using latent class analysis based on seven potential prognostic factors selected within pain, function and psychological domains. Table analysis was used to explore the distribution of TMD diagnoses within the identified phenotypes. RESULTS: Most participants fit into one of three identified phenotypes. Phenotype 1 (32%) was characterised by functional disability, low psychosocial scores and low risk for developing chronicity and future work disability; Phenotype 2 (29%) by parafunctional habits, low psychosocial score and seeking treatment to reduce pain; and Phenotype 3 (39%) by high levels of mental distress, fear avoidance and a large risk of future work disability. Intra-articular disorders dominated Phenotype 1, myalgia and TMD-related headache Phenotype 2, while Phenotype 3 included all the different TMD diagnoses. CONCLUSION: The knowledge about the three identified phenotypes might be useful for clinicians treating persons with TMD and for the development of preventive strategies and more personalised treatment.

The Dental stick test - Useful to reveal intra-articular conditions in persons with temporomandibular disorder?

BACKGROUND: There is a need for clinical tests that can reveal intra-articular conditions in the temporomandibular joint to be able to give proper treatment. The Dental stick test, where participants bite with their molars on a wooden stick, is a pain provocation test for the temporomandibular joint. OBJECTIVE: The purpose of this study was to explore if the Dental stick test can be used to reveal intra-articular conditions in the temporomandibular joint in persons with long-lasting painful disorders. DESIGN: Cross-sectional. MATERIALS AND METHODS: Forty persons with pain in one or both temporomandibular areas were examined using the Dental stick test. The participants were between 18 and 70 years, and had 65 symptomatic joints. Sensitivity, specificity, false positive and false negative responses, and area under the curve were calculated for the Dental stick test with MRI and/or CT as reference standards. The phi-correlation coefficient (phi) was used to measure the correlation between the Dental stick test and intra-articular findings. RESULTS: The sensitivity and specificity for the Dental stick test, revealing intra-articular findings, were 0.62 and1.0 respectively. False positive and false negative responses were 0 and 0.41 respectively, and the area under the curve 81% with p < 0.001. The correlation between a positive Dental stick test and intra-articular findings was not significant (phi = 0.60). CONCLUSIONS: When the Dental stick test is positive, intra-articular findings will most probably be present on MRI/CT, but the test alone cannot reveal intra-articular conditions in persons with long-lasting painful temporomandibular disorder.

International consensus on the most useful assessments used by physical therapists to evaluate patients with temporomandibular disorders: A Delphi study.

OBJECTIVE: To identify assessment tools used to evaluate patients with temporomandibular disorders (TMD) considered to be clinically most useful by a panel of international experts in TMD physical therapy (PT). METHODS: A Delphi survey method administered to a panel of international experts in TMD PT was conducted over three rounds from October 2017 to June 2018. The initial contact was made by email. Participation was voluntary. An e-survey, according to the Checklist for Reporting Results of Internet E-Surveys (CHERRIES), was posted using SurveyMonkey for each round. Percentages of responses were analysed for each question from each round of the Delphi survey administrations. RESULTS: Twenty-three experts (completion rate: 23/25) completed all three rounds of the survey for three clinical test categories: 1) questionnaires, 2) pain screening tools and 3) physical examination tests. The following was the consensus-based decision regarding the identification of the clinically most useful assessments. (1) Four of 9 questionnaires were identified: Jaw Functional Limitation (JFL-8), Mandibular Function Impairment Questionnaire (MFIQ), Tampa Scale for Kinesiophobia for Temporomandibular disorders (TSK/TMD) and the neck disability index (NDI). (2) Three of 8 identified pain screening tests: visual analog scale (VAS), numeric pain rating scale (NRS) and pain during mandibular movements. (3) Eight of 18 identified physical examination tests: physiological temporomandibular joint (TMJ) movements, trigger point (TrP) palpation of the masticatory muscles, TrP palpation away from the masticatory system, accessory movements, articular palpation, noise detection during movement, manual screening of the cervical spine and the Neck Flexor Muscle Endurance Test. CONCLUSION: After three rounds in this Delphi survey, the results of the most used assessment tools by TMD PT experts were established. They proved to be founded on test construct, test psychometric properties (reliability/validity) and expert preference for test clusters. A concordance with the screening tools of the diagnostic criteria of TMD consortium was noted. Findings may be used to guide policymaking purposes and future diagnostic research.

Inter-tester reliability of selected clinical tests for long-lasting temporomandibular disorders.

OBJECTIVE: Clinical tests used to examine patients with temporomandibular disorders vary in methodological quality, and some are not tested for reliability. The purpose of this cross-sectional study was to evaluate inter-tester reliability of clinical tests and a cluster of tests used to examine patients with long-lasting temporomandibular disorders. METHODS: Forty patients with pain in the temporomandibular area treated by health-professionals were included. They were between 18-70 years, had 65 symptomatic (33 right/32 left) and 15 asymptomatic joints. Two manual therapists examined all participants with selected tests. Percentage agreement and the kappa coefficient (k) with 95% confidence interval (CI) were used to evaluate the tests with categorical outcomes. For tests with continuous outcomes, the relative inter-tester reliability was assessed by the intraclass-correlation-coefficient (ICC3,1, 95% CI) and the absolute reliability was calculated by the smallest detectable change (SDC). RESULTS: The best reliability among single tests was found for the dental stick test, the joint-sound test (k = 0.80-1.0) and range of mouth-opening (ICC3,1 (95% CI) = 0.97 (0.95-0.98) and SDC = 4 mm). The reliability of cluster of tests was excellent with both four and five positive tests out of seven. CONCLUSION: The reliability was good to excellent for the clinical tests and the cluster of tests when performed by experienced therapists. The tests are feasible for use in the clinical setting. They require no advanced equipment and are easy to perform.

Validation of clinical tests for patients with long-lasting painful temporomandibular disorders with anterior disc displacement without reduction.

OBJECTIVE: To evaluate the validity of single clinical tests and cluster of tests used to identify anterior disc displacement without reduction (ADDWOR). METHODS: Treatment-seeking patients with temporomandibular pain and limited mouth-opening were recruited among patients from health-professionals in the region of Oslo in 2012. Thirty-five persons, aged 18-70 years, with 58 symptomatic joints or pain in surrounding area were included. The examinations were performed by one experienced manual therapist. Magnetic resonance imaging (MRI) was used as reference standard. Sensitivity, specificity, false positive, false negative and likelihood-ratios (LRs) with 95% confidence intervals (CIs) were calculated for single and cluster of tests. Receiver Operating Curve - ROC analysis were used to see how well pain provocation tests discriminated between positive and negative ADDWOR. RESULTS: The main result is that a cluster of 7 clinical tests (5 positive) can be used to diagnose ADDWOR with an accuracy of 71%. The dental stick test is the best single test with equal sensitivity as the cluster, but with lower specificity. CONCLUSION: To reveal ADDWOR in patients with TMD, we recommend using the cluster of the dental stick test, the isometric test, the joint provocation test, the joint sound test, the deviation test, the laterotrusion test and joint mobility test. PRACTICE AND IMPLICATIONS: The tests require no advanced equipment, they are easy to perform and suitable for use in clinical settings. MRI can be seen as more of a supplement to the clinical tests than a necessity to start a clinical intervention.