Genetic taste sensitivity and salivary flow rates in oral submucous fibrosis and type 2 diabetes: A comparative cross-sectional study

Introduction: Altered taste perception and reduced salivary gland function are frequently reported in systemic and oral diseases, including oral submucous fibrosis (OSMF) and type 2 diabetes mellitus (T2DM). Genetic sensitivity to the bitter compound phenylthiocarbamide (PTC), mediated by TAS2R38 receptors, may provide insights into disease-related changes. Materials and Methods: Ninety participants were equally divided into three groups (OSMF, T2DM, and healthy controls). Taste sensitivity was tested using standardized PTC strips placed on the dorsal tongue for 10 seconds and scored on a 9-point scale (1-2 = non-tasters, 3-7 = tasters, 8-9 = super-tasters). Unstimulated saliva was collected by the spitting method for three minutes, while stimulated saliva was obtained by chewing latex pieces. Flow rates (mL/min) were recorded. Data were analyzed using SPSS v22, with p < 0.05 considered significant, and appropriate parametric and non-parametric tests. Results: Patients with OSMF showed markedly lower PTC scores (1.2 ± 0.5) and salivary flow (stimulated: 2.3 ± 0.2 mL/min; unstimulated: 0.5 ± 0.1 mL/min) compared with controls. Patients with T2DM had reduced salivary secretion (stimulated: 1.6 ± 0.3 mL/min; unstimulated: 0.4 ± 0.2 mL/min) but retained moderate taste sensitivity (5.6 ± 1.3). Healthy controls demonstrated the highest scores (7.8 ± 0.7) and flow rates. Conclusion: Both OSMF and T2DM are associated with impaired taste perception and salivary function. Phenylthiocarbamide testing may be a simple adjunctive tool in oral diagnostics, while integration of TAS2R38 genotyping could enhance future research.