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Keywords:

  • Human dentition;
  • Tooth eruption sequence;
  • Tooth emergence

Abstract

This study provides basic descriptive data on the frequency of pairwise eruption sequences ascertained in cross-sectional examination of 6,000 black and white American children in the Ten State Nutritional Survey of 1968–1970. All sex and race groups share a distinct pattern of sequence polymorphisms in terms of location, number, and level. Teeth in eruption phase I (M1, I1, I2) rarely reverse in sequence with those in phase II (C, P1, P2, and M2). Five sequences have variants that appear at ≥20% in all groups, with M1I1 vs. I1M1 approaching maximum polymorphic values of 50%/50%. The traditional notation for eruption sequences can be modified to reflect these important variants, giving the sequence M1 I1 I2 [P1 C P2] M2 for the maxilla and [M1 I1] I2 [C P1] [P2 M2] for the mandible. The location of major polymorphisms is explicable by close timing of teeth within phase I and, separately, teeth within phase II eruption. However, strong integration of development of physically adjacent teeth apparently acts to reduce substantially the number of sequence reversals. The Ten State Survey data provide a sound descriptive basis for two populations, yet precise comparative data are available for few other human groups or primate species.