Weight, height and eruption times of permanent teeth of children aged 4–15 years in Kampala, Uganda

BACKGROUND Tooth eruption is a continuous biological process by which developing teeth emerge through the jaws and the overlying mucosa to enter into the oral cavity. Tooth eruption time and sequence are important factors in dental treatment planning, particularly in orthodontics, but also in forensic dentistry to estimate age of a child. Tooth eruption time is influenced by many factors. In this study we set out to determine the timing of eruption of permanent teeth and assess its association with the height and weight of school children aged 4-15 years in Kampala, Uganda. METHODS This was a cross sectional study comprising of 1041 healthy Ugandan children: boys/girls (520/521) who were consecutively selected from two primary schools in Kampala. The children were clinically assessed for tooth emergency through the oral mucosa as well as measuring their weight and height. The mean and standard deviation of tooth eruption time was estimated for boys and girls. Bivariate analysis was used to assess any significant association between tooth eruption time and demographic variables. Pearson and partial correlation analyses were used to assess any significant association between the tooth eruption time and anthropometric measurements of the children. RESULTS Generally, the mean eruption times for girls were lower compared to boys except for three teeth (#25, #32 and #42) which erupted earlier in boys. The average difference in mean eruption times of all teeth between boys and girls was found to be 0.8 (range, 0-1.5) years. In partial correlation analysis, mean tooth eruption times were positively, but not significantly associated with height while controlling for weight except for the mandibular left central incisor (#31). On the other hand, in partial correlation analysis, mean tooth eruption times were positively associated with weight while controlling for height except for tooth #11, #16, #26 and #41. The weight of the child was significantly correlated with mean eruption times in 50% of the teeth. CONCLUSION In the present study, the mean tooth eruption times for girls were lower compared to boys except for three teeth (#25, #32 and #42). The height of the child did not show any significant influence on the tooth eruption times while the influence of weight on tooth eruption times was non-conclusive.