Torus Palatinus in Taiwan Patients Receiving Peritoneal Dialysis and Hemodialysis: A Prospective Observational Study

PURPOSE: A consensus about the pathogenesis of torus palatinus (TP) in patients receiving dialysis still eludes the scientific community. This prospective observational study investigated the epidemiology of TP in peritoneal dialysis and hemodialysis patients and analyzed the influences of multiple pathogenic factors such as mineral and bone disorders, genetic, environmental or nutritional triggers, progression of age, heredity, climatologic or biomechanical causes, and hyperparathyroidism on the formation of TP. METHODS: Between 2013 and 2016, a total of 575 chronic dialysis patients (441 on hemodialysis and 134 on peritoneal dialysis) were recruited from Chang Gung Memorial Hospital, Taiwan. Patients were stratified into two groups based on the presence (n = 179) or absence (n = 396) of TP. Demographic, oral examination, laboratory, and dialysis data were collected for analysis. Student’s t-test was used to analyze the quantitative variables and Chi-square or Fisher’s exact test for categorical variables. Univariate binary logistic regression analysis was conducted to determine the predictors for TP and multivariate binary logistic regression analysis to identify significant associated factors. RESULTS: The prevalence of TP in dialysis patients in this study was 31.1% (28.3% for hemodialysis and 40.3% for peritoneal dialysis). Patients with TP were younger (54.6 ± 13.4 versus 58.9 ± 14.7 years, P = 0.001) and mostly female (60.3 versus 41.2%, P < 0.001). Most TP cases (55.3%) were small in size (<2 cm), with the flat shape (56.4%) being the most common followed by the spindle (17.9%), nodular (17.3%), and lobular (8.4%) shapes. A longer duration of dialysis was associated with TP ≥2 cm than with TP <2 cm (94.4 ± 85.9 versus 72.8 ± 59.1 months, P = 0.048). Multivariate logistic regression revealed that female gender (odds ratio 2.108, 95% confidence interval 1.455–3.055, P < 0.001) and younger age (odds ratio 0.982; 95% confidence interval 0.969–0.994, P = 0.005) were significant predictors for TP. CONCLUSION: The prevalence of TP in chronic dialysis patients is 31.1%, higher in patients receiving peritoneal dialysis (40.3%) than hemodialysis (28.3%). Female gender and younger age are significant predictors associated with TP.