Prior experimental studies have verified that sleep deprivation exacerbates periodontitis progression, accompanied with a downregulated BMAL1 and an upregulated oxidative stress and apoptosis.13 Additionally, circadian disruption caused by jetlag affects periodontitis by modulating macrophage activity and alveolar bone homeostasis.14 Consistently, our finding demonstrated that the circadian disruption by disturbed light-dark cycles, which aims to simulate shift work conditions, accelerates periodontal tissue destruction. This evidence concerns the gene BMAL1 and periodontitis.