Sleep bruxism and daily life behaviors in university students: a cross-sectional analysis of free time management, sedentary behaviors, and smartphone use

Sleep Bruxism (SB) is increasingly conceptualized as a biopsychosocial phenomenon, emerging from the complex interaction of biological predispositions, psychological factors, and lifestyle-related behaviors. This study aimed to examine the differences between university students with and without SB regarding free time management (FTM), sedentary behaviors, smartphone addiction, and the severity of temporomandibular disorders (TMDs). A total of 113 healthy university students (59 female, 54 male) participated in this cross-sectional study. Participants were screened for possible SB using the Fonseca Anamnestic Index (FAI). Data were collected using the FAI to assess TMDs severity, the Free Time Management Scale (FTMS), the Sedentary Behavior Questionnaire (SBQ), and the Smartphone Addiction Scale-Short Version (SAS-SV). Independent samples t-tests and Pearson Chi-square tests were utilized for group comparisons. No statistically significant differences were observed between SB and non-SB groups in terms of total FTMS scores, sedentary behaviors, sleep onset time, or total daily sleep duration (p > 0.05). However, students in the SB group exhibited significantly higher smartphone addiction scores (30.94 ± 10.03) compared to the non-SB group (27.25 ± 8.68) (p = 0.04). Furthermore, a strong positive association was found between the presence of SB and TMDs severity (p < 0.001). Bruxers were significantly more likely to report moderate-to-severe TMDs symptoms, with an odds ratio of 10.9 compared to non-bruxers. While FTM and general sedentary habits appear homogeneous among university students, excessive smartphone use emerges as a significant behavioral factor associated with SB. These findings suggest that SB is linked to modern technological lifestyle habits and contributes to increased TMDs severity. Clinical management of bruxism should incorporate a broader biopsychosocial perspective, including digital wellness and behavioral modifications.