Association Between Nociplastic Pain Criteria and Clinical and Physiological Features in Temporomandibular Disorders: A Cross-Sectional Study

<b>Background/Objective:</b> Emerging evidence indicates that temporomandibular disorders (TMD) patients may present features of nociplastic pain (NP), characterized by central sensitization (CS)-related symptoms. This study aims to identify factors associated with CS-related symptoms and pain sensitivity in patients with TMD and NP-related features. <b>Methods:</b> In this cross-sectional study, 43 TMD patients were assessed for CS-related symptoms (CSI), proximal, distal, global pressure pain threshold (PPTs, algometer), orofacial pain intensity (VAS), jaw impairment (FAI), maximal isometric strength of four muscle groups (dynamometer), resting heart rate (RHR, chest band), kinesiophobia (TKS-11), physical activity level (IPAQ), anxiety (HADS), and sleep quality (PSQI). Associations were analyzed using linear regression models adjusted for gender, age, and symptoms duration. <b>Results:</b> Multivariate analysis showed that higher CSI was significantly associated with greater jaw impairment (Estimate 0.09, 95% CI 0.01 to 0.18) and higher pain intensity (Estimate 0.26, 95% CI 0.14 to 0.38). Lower PPT was significantly associated with lower grip strength (Proximal: Estimate 0.03, 95% CI 0.01 to 0.05; Distal: Estimate 0.07, 95% CI 0.01 to 0.14; Global: Estimate 2.44, 95% CI 0.57 to 4.31), and proximal PPT with higher RHR (Estimate -0.02, 95% CI -0.03 to 0). <b>Conclusions:</b> Association was found between CS-related symptoms and pain intensity and jaw impairment, while lower PPTs were related to decreased maximal isometric grip strength and elevated RHR, thus highlighting the need for multimodal treatment in TMD patients.