Background: In recent times, smartphones have become a major part of our lives due to its various benefits such as easy accessibility of information, social connectivity, convenience, smaller size etc. Smartphone overuse can cause stress in a student which can invariably lead to clenching or grinding of teeth and temporomandibular disorder. Objective: The aim of this study was to evaluate the association between smartphone use, stress due to over-usage, bruxism and temporomandibular disorders among dental students in a private dental institution in Chennai, India. Material and methods: The present cross-sectional study was conducted among Dental undergraduates and postgraduates studying in a private dental institution in Chennai about smartphone usage. The sample included 121 undergraduate and postgraduate dental students. A self-administered pre-tested questionnaire containing 18 questions was filled out by the participants and was followed by a clinical examination for Bruxism and Temporomandibular disorder. Descriptive statistics was used and the association was assessed using Pearson’s Chi-Square test. Statistics were done using SPSS version 23.0 and the p-value was set at 0.05. Results: Out of the total 121 participants, 80 (66.1%) were males and 41 (33.9%) were females. 99 (81.8%) were undergraduates and 22 (18.2%) were postgraduates. 90 (74.4%) felt stressed when unable to use their smartphone whereas 31 (25.6%) did not feel so. Bruxism was determined in 95 (78.5%) of the study participants, including 87 out of 90 (96.7%) in those feeling stressed and 8 out of 31 (25.8%) in those not feeling stressed when unable to use a smartphone (p=0.0005). Conclusions: In the present study, a significant association was found between stress over not being able to use a smartphone and bruxism. Using smartphones for learning purposes is definitely beneficial when used appropriately.