Bruxism is associated with nicotine dependence: a nationwide Finnish twin cohort study

• Published in: Nicotine & tobacco research Vol. 12; no. 12; p. 1254
• Main Authors: Rintakoski, K, Ahlberg, J, Hublin, C, Broms, U, Madden, P A F, Könönen, M, Koskenvuo, M, Lobbezoo, F, Kaprio, J
• Format: Journal Article
• Language: English
• Published: England 01.12.2010
• Subjects: Aged; Bruxism - epidemiology; Causality; Cohort Studies; Comorbidity; Diseases in Twins - epidemiology; Female; Finland - epidemiology; Humans; Logistic Models; Male; Middle Aged; Smoking - epidemiology; Tobacco Use Disorder - epidemiology; Twins; Finland
• ISSN: 1469-994X
• DOI: 10.1093/ntr/ntq190

To investigate the association of smoking with bruxism while controlling for genetic and environmental factors using a co-twin-control design. Especially, the role of nicotine dependence was studied in this context. The material derives from the Finnish Twin Cohort consisting of 12,502 twin individuals who responded to a questionnaire in 1990 (response rate of 77%). All were born in 1930-1957, the mean age being 44 years. The questionnaire covered 103 multiple choice questions, 7 dealing with tobacco use and 22 with sleep and vigilance matters, including perceived bruxism. In addition, a subsample derived from the Nicotine Addiction Genetics Finland Study containing 445 twin individuals was studied. In age- and gender-controlled multinomial logistic regression, both monthly and rarely reported bruxism associated with both current cigarette smoking (odds ratio [OR] = 1.74 and 1.64) and former cigarette smoking (OR = 1.64 and 1.47). Weekly bruxism associated with current smoking (OR = 2.85). Current smokers smoking 20 or more cigarettes a day reported weekly bruxism more likely (OR = 1.61-1.97) than those smoking less. Among twin pairs (N = 142) in which one twin was a weekly bruxer and the cotwin a never bruxer, there were 13 monozygotic pairs in which one twin was a current smoker and the other twin was not. In all cases, the bruxer was the smoker (p = .0003). Nicotine dependence associated significantly with bruxism. Our twin study provides novel evidence for a possible causal link between tobacco use and bruxism among middle-aged adults. Nicotine dependence may be a significant predisposing factor for bruxism.