DENTITION IN THE LOW BIRTHWEIGHT INFANT

Abstract

Two hundred twenty seven infants with birthweights <1501g showed a similar timing and pattern of primary tooth eruption as reported for normal full term infants. The average number of erupted teeth at the post-term age of 6,9,12, and 18 months were 0.5±1.0, 2.9±2.2, 5.8±2.3, and 11.6±3.6 respectively. There was no sex difference. The 40 IUGR infants had significantly fewer teeth at 9 and 18 months post-term than the rest of the sample (p <0.05). The results suggest that the timing of tooth eruption is determined by post-conceptional age but may be delayed by prolonged malnutrition. Enamel development in primary teeth was studied in another sample of 106 children <1501g birthweight at ages 2 to 8 years. 37% showed hypoplasia in the maxillary anterior teeth located predominantly in the incisal half. Less than 10% of the other teeth were affected. Similar lesions have been reported in 1-9% of full term children. Permanent incisors were present in 37 children: 21 (58%) showed areas of enamel hypocalcification compared with 3 of 40 full term controls. The location of both the hypoplasia in primary tooth enamel and the hypocalcification in the permanent enamel suggest a neonatal origin specific to prematurity, but no statistical relationship could be shown with the degree of prematurity, IUGR or neonatal calcium levels.