Polymorphisms in eruption sequence of permanent teeth in American children.
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 greater than or equal to 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.
Museum of Anthropology, University of Michigan, Ann Arbor 48109.
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D000293:Adolescent; D044383:Black People; D002648:Child; D002675:Child, Preschool; D003766:Dental Occlusion; D003817:Dentition; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D012737:Sex Factors; D014078:Tooth Eruption; D044465:White People