Methods: Two raters with experience in scoring standard sleep records received extensive training in scoring of bruxism-related events and other oromotor activities based on research criteria (Lavigne et al, 1996). Following training and initial calibration, second night sleep records were selected from four participants in a case control study of sleep bruxism in painful TMD. Records were selected for a repeat scoring, on the basis of a first rater's identification of frequent sleep bruxism or other oromotor activities. Raters scored sleep records using EMG recordings from bilateral masseter and temporalis muscles, as well as audiovisual records. Raters scored the presence of RMMA activity with (grinding) or without sound, as well as tonic (clenching) events and other types of oromotor events. Data were analyzed as RMMA episodes or other specific types of oromotor events, collapsed over subjects, identified at discrete time points by either rater. Reliability in observed activity between raters at each of those time points was indexed by Cohen's kappa.
Results: A total of 700 events were identified. For detecting the presence of RMMA, with or without grinding sound, kappa was .68. For detection of RMMA with grinding sound, kappa was .57, while RMMA without grinding sound was .45.
Conclusion: The inter-rater reliability of identification of RMMA with or without (grinding) sound, as well as RMMA with sound, were both good, while RMMA without sound was only fair. Results raise questions about the extent to which subtypes of sleep bruxism events may be reliably differentiated.
Supported by NIDCR DE018569.