Negro-Caucasoid differences in permanent tooth emergence at a constant income level.

@article{Garn1973NegroCaucasoidDI,
  title={Negro-Caucasoid differences in permanent tooth emergence at a constant income level.},
  author={Stanley M. Garn and S T Sandusky and Judit M. Nagy and Frederick L. Trowbridge},
  journal={Archives of oral biology},
  year={1973},
  volume={18 5},
  pages={609-15}
}
Three-thousand, eight-hundred and sixty-eight low-income American Negro boys and girls showed systematic permanent advancement in tooth emergence compared with 5788 low-income boys and girls of European ancestry. Further matched to within $160 per-capita yearly income, the Negro boys and girls evidenced a 0.30 standard deviation emergence advancement of non-uniform or “patterned” nature, with the greatest temporal difference for the mandibular lateral incisors (0.72473 S.D.) in both sexes.