Emergence stages of permanent teeth in twins: A comparative study.

Background: The relative effects of genetic factors on the timing of tooth eruption can be demonstrated through twin studies; however, twin studies on the eruption time of permanent teeth were limited.

Aim: To compare the emergence stages of permanent teeth in twins and non-twin children.

Design: A total of 480 patients aged from 5.0 to 13.11 years who attended to the Department of Pediatric Dentistry for any dental reason were included in the study. Twins were compared with the control group in terms of the emergence stages for all permanent teeth.

Results: At the age of 5 years, girls in the control group showed statistically significant differences related to the central incisors, the first molars in the mandibular dentition and the first molars in the maxillary dentition, showing more advanced emergence stages. In the 6- to 8- and 12- to 13-year-old age groups, no gender-related differences in emergence stages were observed. Gestation age was found to have a statistically significant effect on the emergence stages of permanent teeth. There were no statistically significant differences between birthweights and tooth emergence stages in twins.

Conclusion: Longitudinal studies are needed to determine whether there is a strong genetic effect on emergence stages of permanent teeth in twins.