RESUMEN
BACKGROUND: Oral mucosa indentations can be signs of awake bruxism (AB) in adults, but this association has not yet been verified in adolescents. OBJECTIVES: To evaluate the frequency of AB in adolescents and determine whether there is an association between AB and oral mucosa indentation. METHODS: This study enrolled 66 high school students, mean age of 16.9 (±0.54) years. Clinical inspection was performed to assess the presence or absence of tongue, cheek and lip mucosa indentation. AB was assessed by the Ecological Momentary Assessment method using the WhatsApp mobile app. Messages were sent 15 times a day, 7 days, between 8:00 AM and 7:00 PM at random times to choose one of the five oral behaviours: teeth contact, teeth clenching, teeth grinding, mandible bracing and relaxed jaw muscles. The non-parametric Mann-Whitney U-test for independent samples, Friedman test for paired samples, Friedman pairwise multiple comparisons non-parametric test, Pearson's chi-squared tests, and z-test of comparisons between two proportions were performed (p < .05). RESULTS: During the week the frequency of AB behaviours was 56.20%, teeth contact was the most frequent (37.68% ± 22.26%), significantly more frequent than other AB behaviours; there was a greater frequency of cheek indentation (27.27%) and no difference between genders in oral behaviours and indentations (p > .05). A higher frequency of AB behaviours was observed in individuals with a greater frequency of cheek indentation (p < .05). CONCLUSIONS: Teeth contact and cheek indentation were the most frequent conditions among adolescents and AB behaviours are associated with this indentation.