Survey of permanent tooth eruption status of down syndrome in Japan: Comparison with the Japanese National Survey of Dental Diseases

Introduction

Down syndrome (DS) can cause irregular dental eruption patterns and hypodontia. However, data on permanent tooth eruption in DS patients in Japan are insufficient. This study aimed to predict the dental characteristics of DS by conducting a nationwide survey in Japan.

Methods

Questionnaires were used to collect information about the age, sex, number of present teeth, and dental formula with DS from facilities providing dental care for the disabled. The findings were compared with the Survey of Dental Diseases and used as control survey.

Results

Data were collected from 3348 patients aged 5–69 years. The mean number of permanent teeth was highest (N = 25.2) at 19, 20–24, and 25–29 years. At 5–19 years, the increase in the eruption rates was slower with DS compared to that in the control survey. At 25–29 years, the difference in eruption rates between the two surveys exceeded 20 % in the mandibular lateral incisors and maxillary second molars, except for third molars. Most of the second premolars were unerupted when the primary second molars were retained. Noneruption of the permanent canines and some adjacent teeth was observed when the maxillary primary canines were retained.

Conclusion

This study demonstrates the eruption status of permanent teeth with DS. The eruption of permanent teeth is delayed, the number of permanent teeth is low, and early tooth loss may be seen with DS. Thus, it is important to determine the overall eruption status and provide adequate support based on their age.