TikTok contains many videos about bruxism that may help raise the level of awareness on the topic. However, the quality of these videos' information represents the greatest concern. The present cross-sectional analysis aimed to systematically assess the reliability and educational suitability of TikTok videos as a source of information on bruxism. TikTok was searched for relevant videos uploaded until 6 March 2024, using the hashtags #bruxism, #grindingteeth and #jawclenching. Independent pre-calibrated operators conducted video inclusion and data collection, noting videos' characteristics, source, popularity, content, reliability (assessed through the DISCERN scoring system) and educational value (assessed through the Global Quality Score [GQS]). The Kruskal-Wallis test was adopted to compare videos from different sources. Videos with low and high educational value were compared using the Mann-Whitney U-test. Tests were considered significant when the p-value was < 0.05. A total of 105 bruxism videos were analysed. Most videos covered bruxism management and clinical features, and more than 60% were uploaded by healthcare professionals. According to the DISCERN and GQS scoring, the videos' reliability and educational value were judged to be very poor and low, respectively, but on average they were higher for videos uploaded by healthcare professionals compared to those uploaded by laypeople. When comparing videos with high educational value to those with low educational value, differences were found in popularity, content and reliability. The present results suggest the need for greater control of information disseminated on social media to fulfil its potential role in educating laypeople about bruxism.