Height, Weight and the Number of Erupted Permanent Teeth in 12-Year-Old Female Students in Hamadan, Iran

The aim of the present study was to determine the timing of eruption of permanent teeth and assess its association with the height and weight in 12-year-old female students in Hamadan (2004). This descriptive/cross-sectional study was conducted from September 2003 to April 2004. 1000 healthy female students were consecutively selected from 9 different secondary schools in Hamadan. Each student’s data was recorded in the relevant questionnaire. Measuring their height, weight and date of birth were also obtained. The height was measured in centimeter, using wall-mounted ruler on the child’s head with their back and knees completely straight, and their feet together. The weight was measured in kilogram using a commercial digital scale after removal of the shoes only. The date of birth was obtained from the school records. The dental examination was carried out using a tongue depressor under natural light for the selected child. The mean and standard deviation of tooth eruption time was estimated for all of the girls. Bivariate analysis was used to assess any significant association between tooth eruption time and demographic variables. Pearson and partial correlations were used to determine the significant relationship between tooth eruption times with height/weight. Generally, the means of height and weight of the subjects were 152 cm and 43.3 kg, respectively. The mean number of erupted teeth was 25.35. In partial correlation analysis, mean tooth eruption times were positively, but not significantly associated with height while controlling for weight, On the other hand, mean tooth eruption times were positively associated with weight while controlling for height. The correlation coefficients between height and weight and the number of erupted teeth were 0.321 and 0.25, respectively, indicating a weak correlation but significant at a level of 0.01. It can be concluded that girls with a higher height and weight compared to their peers had more erupted teeth. Although the height and of weight the girls did not show any significant influence on the tooth eruption times.