To investigate associations between occlusal relationships during sleep bruxism (SB) and orofacial system diseases.

In this cross-sectional study, 50 young/middle-aged SB participants (mean age 29.5 years; 51.5% female) underwent polysomnographic for SB confirmation. Occlusal relationships were quantified using BruxChecker® scoring. Logistic regression models were used to assess relationships between occlusal relationships and dental/periodontal/temporomandibular disorders.

Group-grinding occlusion significantly predicted condylar displacement (Odds Ratio[OR] 10.70, 95% confidence intervals[95%CI]: 1.31–20.45) and abnormal morphology (OR 7.64, 95%CI: 4.72–10.38). Non-working side Occlusal interferences correlated with vertical alveolar bone loss (OR 6.56, 95%CI: 3.07–14.79) and periodontal probing depth >3 mm (OR 6.42, 95%CI: 3.71–11.35). Discordance in cusp guidance slope increased risks of: Dental caries (OR 9.01, 95%CI: 5.30–15.56), Non-Carious Cervical Lesion (OR 4.66, 95%CI: 0.96–16.72), Tooth crack (OR 3.99, 95%CI: 2.38–6.68), Attrition (OR 9.36, 95%CI 6.69–13.24). Anxiety, low mandibular plane angle, and flat occlusal plane amplified orofacial disorder risks.

Occlusal relationship during SB significantly impacts orofacial system diseases. Understanding the relationship between occlusal patterns during SB and orofacial damage may inform future preventive strategies.

Our findings reveal distinct biomechanical pathways linking specific occlusal relationship during SB to orofacial diseases, which may guide future research into mechanism-based management approaches.