Sleep-related bruxism and sleep variables: a critical review.

Relationships between sleep-related bruxing, electroencephalographic phenomena, and other physiologic variables are reviewed. Bruxing occurs during all sleep stages but occurs disproportionately during stage 2 and REM. Bruxing during deeper sleep stages frequently is followed by a transition to lighter sleep. Bruxing occurs in conjunction with K-complexes in the EEG, tachycardia and peripheral blood volume changes, and gross body movements; however, the exact nature of the relationship between bruxing and "arousal" is unknown. Methodological problems are pervasive. On-line computer-based event recording is called for along with time series analyses of moment-to-moment psychophysiologic data.