Osaka University Graduate School of Dentistry, Department of Oral Anatomy and Neurobiology, Suita, Japan.
J Prosthodont Res. 2013 Apr;57(2):69-81. doi: 10.1016/j.jpor.2013.03.001. Epub 2013 Apr 17.
Occlusal overload during sleep is a significant clinical issue that has negative impacts on the maintenance of teeth and the longevity of dental prostheses. Sleep is usually viewed as an 'out-of-functional' mode for masticatory muscles. However, orodental structures and prostheses are not free from occlusal loads during sleep since masticatory muscles can be activated at a low level within normal sleep continuity. Thus, an increase in masticatory muscle contractions, by whatever the cause, can be associated with a risk of increased occlusal loads during sleep. Among such conditions, sleep bruxism (SB) is a type of sleep-related movement disorders with potential load challenge to the tooth and orofacial structures. Patients with SB usually report frequent tooth grinding noises during sleep and there is a consecutive increase in number and strength of rhythmic masticatory muscle activity (RMMA). Other types of masticatory muscle contractions can be non-specifically activated during sleep, such as brief contractions with tooth tapping, sleep talking, non-rhythmic contractions related to non-specific body movements, etc.; these occur more frequently in sleep disorders. Studies have shown that clinical signs and symptoms of SB can be found in patients with sleep disorders. In addition, sleep becomes compromised with aging process, and a prevalence of most sleep disorders is high in the elderly populations, in which prosthodontic rehabilitations are more required. Therefore, the recognition and understanding of the role of sleep disorders can provide a comprehensive vision for prosthodontic rehabilitations when prosthodontists manage complex orodental cases needing interdisciplinary collaborations between dentistry and sleep medicine.
睡眠时的咬合过载是一个重要的临床问题，对牙齿的维护和义齿的寿命都有负面影响。睡眠通常被认为是咀嚼肌的“非功能”模式。然而，在睡眠中，口颌结构和义齿并不免受咬合负荷的影响，因为咀嚼肌在正常睡眠连续性内可以低水平激活。因此，无论原因如何，咀嚼肌收缩的增加都可能与睡眠时咬合负荷增加的风险相关。在这些情况下，磨牙症（SB）是一种与睡眠相关的运动障碍，对口颌结构有潜在的负荷挑战。磨牙症患者通常在睡眠中报告频繁的磨牙噪音，并且节律性咀嚼肌活动（RMMA）的次数和强度连续增加。其他类型的咀嚼肌收缩也可能在睡眠中非特异性激活，例如短暂的叩齿收缩、睡眠说话、与非特异性身体运动相关的非节律性收缩等；这些在睡眠障碍中更常见。研究表明，睡眠障碍患者可能存在 SB 的临床体征和症状。此外，随着年龄的增长，睡眠质量会下降，大多数睡眠障碍在老年人中发病率较高，需要进行更多的修复治疗。因此，认识和理解睡眠障碍的作用可以为修复医生在管理需要牙科学和睡眠医学跨学科合作的复杂口颌病例时提供全面的修复视野。
