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

Abstract

Introduction

Down syndrome (DS) can cause irregular dental eruption patterns and hypodontia. However, data on primary tooth eruption with DS in Japan are insufficient. Therefore, this study aimed to conduct a questionnaire survey to predict dental abnormalities in DS based on tooth eruption status.

Methods

A questionnaire survey on the age, sex, number of present teeth, and dental formula of patients with DS was conducted at facilities providing dental care for the disabled in Japan, and the results were compared with those of the Survey of Dental Diseases used as for the control survey.

Results

A total of 3656 valid responses were received. This study was analyzed according to the age group of the Survey of Dental Diseases. At 1–14 years old, the mean number of primary teeth per patient was the highest at 4 years old (19.3 teeth). The largest difference from the control survey was at 1 year old, and the difference decreased with age until 4 years. At 3–5 years old, the rate of individual primary tooth eruptions was 14.2% lower for the mandibular primary lateral incisors than that in the control survey. At 15 years old or older, the percentage of people who had persistence of primary teeth was 19.2%. The second primary molars were the most common persistent primary teeth.

Conclusion

DS is characterized by delayed tooth eruption, high incidence of missing teeth, particularly the mandibular primary lateral incisors, and persistence of primary teeth. These findings indicate the importance of developmental support and oral management.