Sibling Similarities in Dental Development

¹ Fels Research Institute, Antioch College, Yellow Springs, Ohio

1. Sibling similarities in tooth calcification and tooth movement were investigated in 170 white Ohio-born siblings and two sets of triplets.

2. Sibling correlations for tooth calcification and tooth movement were positive, for the most part significantly different from zero, and of the order of 0.30.

3. Female pairings consistently exhibited higher sibling correlations in tooth development than did the male pairings.

4. Monozygotic twin pairings proved more alike in tooth formation (r=0.91) than dizygotes (r=0.33) from the same triplet sets.

5. Since body size, nutritional status, etc., have but little bearing on tooth development, these data suggest that the timing of tooth development is in large part gene-determined.

6. Analysis of tooth development in the genotypes XO, XXY, and in various mosaics was suggested as a further step in elucidating the problem.