A 15-Year Nationwide Cohort Study from Taiwan Exploring the Link Between Primary Sjögren’s Syndrome and Temporomandibular Disorder and the Impact of Hydroxychloroquine Treatment

Background The relationship between primary Sjögren’s syndrome (pSS) and temporomandibular disorder (TMD) has received little attention in previous studies. Therefore, we investigated this association using data from a large, population-based cohort. In addition, we examined the therapeutic effect of hydroxychloroquine on patients with pSS. Methods This retrospective cohort study analyzed data from Taiwan’s Longitudinal Generation Tracking Database for the period 2000–2015. Patients with pSS (n = 36,195) were compared with matched controls (n = 144,780). Cox regression analysis estimated the risk of TMD, adjusting for hydroxychloroquine use and comorbidities. Results pSS was significantly associated with an increased risk of TMD (adjusted hazard ratio [aHR] = 1.95, 95% confidence interval = 1.42–2.59, p < 0.001). Stratified analysis showed that pSS patients receiving hydroxychloroquine had the highest TMD risk (aHR = 2.08), followed by untreated pSS patients (aHR = 1.68), relative to the controls. Depression, diabetes, and hypertension further contributed to TMD development. Conclusions The findings of this study demonstrated a notable link between pSS and TMD, with hydroxychloroquine treatment potentially affecting the associated risk. Further studies are necessary to investigate the underlying mechanisms and their clinical relevance.