Effect of Oral Behavior and Maintenance on Salivary Mutans Streptococci Levels in Infants

Yoshimori Uchikawa, Terumi Yamazaki, Yuko Umezu, Toshiomi Shirase
Pediatric Dentistry, Nippon Dental University Hospital, Tokyo, Japan

Background: Mutans streptococci (MS) has been implicated as the principal bacterial component responsible for dental caries. The purpose of this study was to assess the effect of the oral behavior of infants on their salivary level of MS.

Methods: Ninety-seven children participated in this study. All children were clinically examined at both 2 and 4 years of age. Dental caries scores (dmfs) were calculated according to the criteria defined by the WHO. During each examination, the child’s salivary MS (SMS) level was measured using the Dentocult-SM Strip Mutans test (Orion Diagnostica). When the child was 2 years old, the subjects’ parents were asked to a questionnaire concerning age of the infant at the start of weaning, age of the infant at the completion of weaning, whether they used a pacifier, dietary habits, oral hygiene, etc. The Wilcoxon signed rank test was used to statistically analyze the data. A logistic regression analysis was used to identify associations between the SMS level in the 4-year-olds and the results of the questionnaire when the children were 2 years old.

Results: The means (SD) dmfs in the children was 0.98 (3.05) at 2 years of age and 4.77 (9.22) at 4 years of age. In the 4-year-olds the dmfs associated with scores 2 and 3 were significantly higher than those associated with scores 0 and 1. The logistic regression analysis yielded a significant odds ratio for the age at which weaning was completed.

Conclusions: These results suggest that delaying the completion of weaning beyond 15.5 months affect on MS levels in the child.

Yoshimori Uchikawa