Periodontal diseases are more prevalent in men than in women. However, in a population-based epidemiological study, we found that, on average, women have fewer teeth than men. The aim of this study was to test different hypotheses that could explain this obvious paradox.
In 4,290 randomly selected participants from the normal population (Study of Health in Pomerania), we determined diagnostic periodontal parameters, attachment loss, and number of teeth. Behavioral and environmental risk factors were assessed by interviews and questionnaires. Use of estrogens was assessed, and urinary excretion of collagen cross-links was determined.
Multiple regression analyses adjusted for caries and periodontitis revealed that in the women of this population, there is an inverse association between the number of children born and the number of teeth (P < 0.01). This relationship depends on socioeconomic status, bone metabolism, and the use of estrogens. In the group of the youngest (20-40 years), the bone turnover rate is positively related to the number of children born (P < 0.01). In postmenopausal women treated with estrogens, the number of teeth was higher than in men of the same age group. Only in women without hormone treatment were there fewer teeth.
The apparent paradox of having fewer teeth despite better periodontal health in women compared with men is related to an increased bone turnover rate and socioeconomic conditions such as low education and low social status. Periodontal health is even worse if these factors are combined.