Department of Fixed Prosthodontics, Osaka University Graduate School of Dentistry, Suita, Japan.
Sleep Medicine Center, Osaka University Hospital, Suita, Japan; Department of Psychiatry, Osaka University Graduate School of Medicine, Suita, Japan.
J Prosthodont Res. 2018 Jul;62(3):317-323. doi: 10.1016/j.jpor.2017.12.004. Epub 2018 Feb 21.
Concomitant occurrence of respiratory events can be often overlooked in the clinical practice of SB. This study assessed physiological characteristics of rhythmic masticatory muscle activity (RMMA) and concomitant respiratory events in young sleep bruxism (SB) subjects asymptomatic to obstructive sleep apnea (OSA).
Twenty-two subjects (age: 24.1±1.9years; F 8: M 14; BMI: 20.2±1.9kg/m) were polysomnographically diagnosed as moderate-severe SB. Sleep architecture, oromotor (RMMA and non-specific masseter activity [NSMA]) and apnea/hypopnea events were scored.
All subjects showed normal sleep architecture whereas 6 exhibited respiratory events at a mild level of OSA. In all subjects, RMMA predominantly occurred in Stage N1+N2 while NSMA occurred in Stage N1+N2 (approximately 60 %) and in Stage R (up to 30 %). Up to 50% of respiratory events were scored in Stage R. RMMA occurred more frequently in close association (e.g., within 10s) with respiratory events in 6 subjects with OSA than those without. The percentage of RMMA occurring closely to respiratory events was positively correlated with apnea-hypopnea index (AHI) in Stage N1+N2 only while that of NSMA was positively correlated with AHI in Stage N1+N2 and Stage R. A sub-analysis in 6 subjects with OSA, RMMA after respiratory events was followed to arousals while those before respiratory events were mostly associated with central apnea.
A subpopulation of young SB subjects can show concomitant respiratory events. Further large sample studies are needed to demonstrate that the occurrence of subclinical respiratory events represents a clinical subtype of SB.
在阻塞性睡眠呼吸暂停（OSA）的临床实践中，通常会忽略睡眠磨牙症（SB）患者中同时发生的呼吸事件。本研究评估了无症状 OSA 的年轻 SB 患者节律性咀嚼肌活动（RMMA）和同时发生的呼吸事件的生理特征。
22 名受试者（年龄：24.1±1.9 岁；F8：M14；BMI：20.2±1.9kg/m）经多导睡眠图诊断为中重度 SB。睡眠结构、口颌运动（RMMA 和非特异性咬肌活动[NSMA]）和呼吸暂停/低通气事件均进行评分。
所有受试者的睡眠结构均正常，但有 6 名受试者出现轻度 OSA 的呼吸事件。在所有受试者中，RMMA 主要发生在 N1+N2 期，而 NSMA 主要发生在 N1+N2 期（约 60%）和 R 期（高达 30%）。高达 50%的呼吸事件发生在 R 期。在 6 名 OSA 受试者中，RMMA 与呼吸事件更频繁地密切相关（例如，在 10s 内），而在没有 OSA 的受试者中则较少。仅在 N1+N2 期，RMMA 与呼吸事件密切相关的百分比与呼吸暂停低通气指数（AHI）呈正相关，而 NSMA 与 N1+N2 期和 R 期的 AHI 呈正相关。在 6 名 OSA 受试者的亚组分析中，呼吸事件后的 RMMA 随后会引起觉醒，而呼吸事件前的 RMMA 主要与中枢性呼吸暂停相关。
年轻 SB 受试者的亚群可能会出现同时发生的呼吸事件。需要进一步的大样本研究来证明亚临床呼吸事件的发生代表了 SB 的一种临床亚型。
