Background: Sleep bruxism (SB) affects the dentition and could be the cause of temporomandibular disorders (TMD). Due to its nocturnal nature, the diagnosis of SB is mainly based on history taken from patients and bed partners. A verified clinical examination is still needed to help confirm the diagnosis.

Objective: To determine the validity of upper canine's cusp-tip wear for the diagnosis of SB using Brux Checker^® as the reference diagnostic tool.

Materials and Methods: Eighty dental patients were screened for SB using ICSD-3 criteria. The wear at upper canine's cusp tip as well as any matched wear facets during eccentric movements were examined and scored according to Johansson et al. (1993). They were subsequently prescribed to wear Brux Checker^® for 7 consecutive nights. The abraded and perforated areas on Brux Checker^® were used to identify 'current' bruxers. The sensitivity, specificity and AUC/ROC were determined with respect to ICSD-3 criteria and Brux Checker^® perforation by day 1, day 2, and day 7 (P1, P2, P7).

Results: Prediction with good sensitivity (0.875) was found when Brux Checker^® perforation was compared to ICSD-3 criteria (AUC =0.773). Mean wear scores could predict SB diagnosed by ICSD-3 criteria (AUC =0.789; sensitivity =0.789-0.875, specificity =0.641-0.703) but did not show any significant predictive values with respect to Brux Checker^® perforation. However, the tooth-level wear score ³1, with the presence of matched wear facets, could predict P2, and P7 (AUC =0.599-0.626; sensitivity = 0.776-0.842, specificity =0.410-0.422).

Conclusion: Mean wear score at upper canine's cusp tip seems to be a good indicator of SB based on ICSD-3 whereas individual tooth wear combined with the presence of matched wear facets could be a fair indicator of 'current' SB as indicated by Brux Checker^® perforation.

Keywords: Sleep bruxism, Tooth wear, Brux Checker^®