Diagnostic Comparison and Threshold Optimization of 5Ts and 6Ts TMD Screeners

Concise and reliable screening tools are essential for temporomandibular disorder (TMD) detection, triage, and surveillance. The Diagnostic Criteria for TMDs (DC/TMD) includes the TMD Pain Screener (TPS), but this instrument is restricted to pain-related conditions (Schiffman et al. 2014). The Five TMD Symptoms (5Ts) screener, derived from the DC/TMD Symptom Questionnaire, assesses pain, headache, joint sounds, and closed or open locking. When validated against the DC/TMD, it demonstrated excellent diagnostic accuracy across pain-related and intra-articular TMDs (AUC ≥ 0.98; sensitivity ≥ 96%; specificity 100%) (Yap et al. 2022). Initially dichotomized, the 5Ts was later refined with binary scoring and a cut-point of 1.5 to indicate TMD presence (Liu et al. 2024). Differentiating myalgia from arthralgia is clinically important given their distinct pathophysiology, psychosocial correlates, and therapeutic implications (Yap et al. 2021; Minervini et al. 2024). Myalgia often requires muscle-focused strategies, whereas arthralgia necessitates joint-directed interventions. To address this, the expanded Six TMD Symptoms (6Ts) screener separates jaw muscle (S1a) from joint (S1b) pain, though its diagnostic accuracy had not been established. We therefore compared the reliability and diagnostic performance of the 6Ts with the 5Ts, determined optimal cut-off points, and evaluated their suitability for clinical and research use. In a case–control study of 344 adults (mean age 30.5 years; 76.7% women), both screeners were administered alongside DC/TMD examinations. Controls comprised 18.6%, while 81.4% were cases: pain-related only (14.8%), intra-articular only (40.4%), and combined pain-related with intra-articular TMDs (26.2%). A subsample of 38 participants repeated the questionnaires after 1 week. Diagnoses were independently confirmed by a calibrated DC/TMD examiner, with imaging performed where indicated. Reliability was assessed with Cronbach's alpha and intra-class correlation coefficients (ICCs); diagnostic accuracy with ROC analysis, sensitivity, specificity, predictive values, and likelihood ratios. The 5Ts demonstrated modest internal consistency (α = 0.53) and moderate reproducibility (ICC = 0.70). The 6Ts improved overall consistency (α = 0.62) and reproducibility (ICC = 0.73). Separating pain into S1a and S1b strengthened the domain (α = 0.62; ICC = 0.89), enhancing interpretive clarity. Diagnostic accuracy was excellent for both screeners in detecting all TMDs (AUC ~0.94; sensitivity ~85%; specificity ~89%–91%). Positive predictive values exceeded 97%, while negative predictive values were modest (56%–58%). Optimal cut-off points were 1.5 for all TMDs and 0.5 for pain-related and intra-articular conditions (Table 1). These findings confirm that both screeners are robust, brief instruments with excellent diagnostic accuracy. The 6Ts offers modest but meaningful gains in reliability, particularly for pain-related items, and enhances clinical utility by distinguishing muscle from joint pain. Although predictive values and likelihood ratios were largely equivalent, the added reliability and conceptual precision support the 6Ts as the preferred tool for clinical practice and research. Its advantages strengthen its role in early detection, triage, telemedicine, and surveillance, positioning the 6Ts as a more effective instrument for advancing TMD screening strategies. Adrian Ujin Yap: conceptualization, methodology, data curation, validation, formal analysis, supervision, visualization, writing – original draft, resources. Jie Lei: methodology, investigation, data curation, formal analysis, visualization, validation, supervision, project administration, funding acquisition, software, writing – review and editing, resources. Chengge Liu: conceptualization, methodology, software, data curation, investigation, validation, formal analysis, visualization, writing – review and editing. Kai Yuan Fu: conceptualization, methodology, data curation, investigation, validation, resources, supervision, project administration, funding acquisition, writing – review and editing, formal analysis. The authors have nothing to report. This work was supported by National Key R&D Project of China, Ministry of Science and Technology of the People's Republic of China (No. 2023YFC2509200), Clinical Research Foundation of Peking University School and Hospital of Stomatology (PKUSS-2023CRF206) and Program for New Clinical Techniques and Therapies of Peking University School and Hospital of Stomatology (PKUSSNCT-24A03). This project is supported by the Biomedical Institutional Review Board of Peking University School and Hospital of Stomatology (PKUSSIRB-202272026). Written informed consent was obtained from all participants. The authors declare no conflicts of interest. The data that support the findings of this study are available from the corresponding author upon reasonable request.