BackgroundUsing data from a large-scale community-based Japanese population, we attempted to identify factors associated with tooth loss in middle-aged and elderly men.MethodsA total of 8352 men aged 40 to 79 years who lived in the north of the main island of Japan and underwent health checkups were enrolled between 2002 and 2005. Number of teeth was assessed by the question, “How many teeth do you have (0, 1–9, 10–19, or ≥20)?”. On the basis of the answer to this question, participants were classified into 2 groups (≤19 teeth or ≥20 teeth). Using multivariate logistic regression, factors related to having 19 or fewer teeth were estimated.ResultsThe numbers (percentages) of participants who had 0, 1 to 9, 10 to 19, and 20 or more teeth were 1764 (21.1%), 1779 (21.3%), 1836 (22.0%), and 2973 (35.6%), respectively. Among the participants overall and those aged 65 to 79 years, having 19 or fewer teeth was significantly associated with older age, smoking status (current smoking and ex-smoking), and low education level. In addition, men with 19 or fewer teeth were more likely to have a low body mass index and low serum albumin level and less likely to be current alcohol drinkers. Among men aged 40 to 64 years, but not men aged 65 to 79 years, those with 19 or fewer teeth were more likely to have a low serum high-density lipoprotein cholesterol level and high glycosylated hemoglobin (HbA1c) level.ConclusionsSmoking, low education level, and poor nutritional status were associated with tooth loss among middle-aged and elderly Japanese men.

The number of teeth is an important predictive factor for mortality among middle-aged Japanese men.