The Effect of Central Sensitization on Long-Term Prognosis and Comorbidity Levels in Temporomandibular Disorders: A Prospective Longitudinal Study.

BACKGROUND: Temporomandibular disorders (TMD) have the potential to progress to a chronic form associated with various comorbidities. Prolonged symptoms may lead to central sensitization (CS), resulting in decreased treatment response and highlighting the need for personalized treatment strategies. OBJECTIVE: This study evaluated psychological conditions and comorbidities in TMD patients based on CS-related symptom levels measured by the Central Sensitization Inventory (CSI) and investigated the association between these levels and long-term treatment outcomes. MATERIALS AND METHODS: CS-related symptom levels were assessed using the CSI in 112 TMD patients (score ≥ 40 indicating significant levels of CS symptoms). Psychological, sleep, autonomic and pain-related comorbidities were evaluated by validated questionnaires. Participants received standardized conservative treatment, including behavioural, physical, stabilization splint and pharmacological therapies. After 6 months, patients were re-evaluated for clinical signs. Data were statistically compared between the high (n = 40) and low (n = 72) CSI groups and associations between clinical characteristics and CSI levels were analyzed. Longitudinal changes were analyzed using Generalized Estimating Equations. RESULTS: High CSI (35.7%) was associated with higher McGill Pain Questionnaire (MPQ) scores, widespread pain and higher levels of anxiety, depression, somatization and autonomic symptoms (all padj < 0.05 after Bonferroni correction). At 6-month follow-up, the high CSI group showed a trend toward a smaller reduction in pain (group × time interaction, χ2 = 5.587, p = 0.018), suggesting a potentially less favourable treatment response to conservative therapy. CONCLUSION: TMD patients with higher CSI scores exhibit more multidimensional comorbidities and diminished response to conservative therapy. Early identification of CS-related symptoms may be beneficial for establishing personalized treatment strategies.