title: Temporal association between sleep apnea-hypopnea and sleep bruxism events.
abstract: There is some evidence suggesting that obstructive sleep apnea-hypopnea syndrome is concomitant with sleep bruxism. The aim of this study was to investigate the temporal association between sleep apnea-hypopnea events and sleep bruxism events. In an open observational study, data were gathered from 10 male subjects with confirmed obstructive sleep apnea-hypopnea syndrome and concomitant sleep bruxism. Polysomnography and audio-video recordings were performed for 1 night in a sleep laboratory. Breathing, brain, heart and masticatory muscle activity signals were analysed to quantify sleep and sleep stage duration, and number and temporal distribution of apnea-hypopnea events and sleep bruxism events. Apnea-hypopnea events were collected within a 5-min time window before and after sleep bruxism events, with the sleep bruxism events as the pivotal reference point. Two temporal patterns were analysed: (i) the interval between apnea-hypopnea events termination and sleep bruxism events onset, called T1; and (ii) the interval between sleep bruxism events termination and apnea-hypopnea events onset, called T2. Of the intervals between sleep bruxism events and the nearest apnea-hypopnea event, 80.5% were scored within 5 min. Most intervals were distributed within a period of <30 s, with peak at 0-10 s. The T1 interval had a mean length of 33.4 s and was significantly shorter than the T2 interval (64.0 s; P < 0.05). Significantly more sleep bruxism events were scored in association with the T1 than the T2 pattern (P < 0.05). Thus, in patients with concomitant obstructive sleep apnea-hypopnea syndrome and sleep bruxism, most sleep bruxism events occurred after sleep apnea-hypopnea events, suggesting that sleep bruxism events occurring close to sleep apnea-hypopnea events is a secondary form of sleep bruxism.
authors.affiliation: Department of Gnatho-occlusal Function, Graduate School of Dental Medicine, Hokkaido University, Sapporo, Japan.
authors.forename: Miku
authors.initials: M
authors.lastname: Saito
authors.forename: Taihiko
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Saki
authors.initials: S
authors.lastname: Mikami
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Watanabe
authors.forename: Akihito
authors.initials: A
authors.lastname: Gotouda
authors.forename: Kazuki
authors.initials: K
authors.lastname: Okada
authors.forename: Ryuki
authors.initials: R
authors.lastname: Hishikawa
authors.forename: Eiji
authors.initials: E
authors.lastname: Shibuya
authors.forename: Gilles
authors.initials: G
authors.lastname: Lavigne
keywords: masseter muscle; rhythmic masticatory muscle activity; sleep apnea-hypopnea syndrome; sleep bruxism; sleep-disordered breathing; tooth grinding