Associations between sleep bruxism, sleep quality, and exposure to secondhand smoke in Japanese young adults: a cross-sectional study

Abstract

Objective: Sleep bruxism, a major sleep disorder that causes serious harm to oral health, is considered a multifactorial disease. Sleep bruxism can be induced by smoking, which also adversely affects sleep quality. The objective of present study was to clarify the associations between sleep bruxism, sleep quality, and exposure to secondhand smoke (SHS). Methods: To assess the prevalence of sleep bruxism, sleep quality, and SHS exposure, we conducted oral examinations and self-report questionnaires on university students in Japan. Sleep bruxism and quality were screened using the Japanese version of the Pittsburgh Sleep Quality Index (PSQI) and the third edition of the International Classification of Sleep Disorders (ICSD-3). The inclusion criteria were adults aged between 18 and 19 years, non-smokers and non-alcohol drinkers. The exclusion criteria was failing to complete the questionnaire in full. Results: We analyzed a total of 1781 Japanese young adults. Young adult females who had been exposed to SHS had worse sleep quality (p ¼ 0.019) than those who had not. Young adult female with worse sleep quality showed a higher prevalence of sleep bruxism (p ¼ 0.034) than those with better sleep quality. Using structural equation modeling, direct associations were identified between SHS exposure and poor sleep quality (standardized coefficients, 0.153; p ¼ 0.008) and between sleep bruxism and poor sleep quality (standardized coefficients, 0.187; p ¼ 0.022) in young adult females. However, no association was found among young adult males. Conclusion: SHS exposure is indirectly associated with sleep bruxism through poor sleep quality in Japanese young adult females.

Association between Sleep Quality and Duration and Periodontal Disease among University Students: A Cross-Sectional Study

“…The PSQI-J is a valid, reliable, and standardized self-reported questionnaire to measure sleep quality over the last month. Previously, it was used to assess the sleep quality of Japanese young adults [20]. The PSQI-J comprises seven component scores (range of subscale scores: 0-3) as follows: (i) sleep quality, (ii) sleep latency, (iii) sleep duration, (iv) habitual sleep efficiency, (v) sleep disturbances, (vi) use of sleeping medication, and (vii) daytime dysfunction.…”

Impact of the COVID-19 Pandemic on Stress, Sleep, and Oral Health in University Students

“…Despite the concern about the disease, only 1.6% (6) of the students have not left home since the beginning of the pandemic. A significant number of students, 64.3% (238), say they can partially respect social distancing, by going out only when it is necessary to shop for essential items, while 25.9% (96) need to go out to work and 8.1% (30) of the students are always leaving and are unable to respect social distancing (Figure 1). The questionnaire also revealed that only 18.1% (67) of the students had been interns in hospitals or clinics during the pandemic so far.…”

Assessment of the association of bruxism with caffeine consumption and nicotine intake

“…In contrast to our results, some studies (9) did not find an association. Others (19,22) reported associations between heavy smoking and sleep bruxism (12,13,1). Other studies pointed out that neither smoking nor caffeine consumption was associated with sleep or awake bruxism (14).…”

“…In smokers, nicotine accumulates in their bodies during the daytime, decreasing gradually during sleep. In turn, higher levels of smoking, leading to increased levels of nicotine and dopamine release, could be more strongly related to bruxism (21,22). The increase in caffeine-containing food products has increased the importance of caffeine and its potential cumulative effects on behavior and physiology.…”