HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Services Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Hughes, T.E. Articles by Townsend, G.C. PubMed PubMed Citation Articles by Hughes, T.E. Articles by Townsend, G.C.

Strong Genetic Control of Emergence of Human Primary Incisors

¹ School of Dentistry, The University of Adelaide, Frome Rd., Adelaide, Australia 5005;
² School of Dentistry, The University of Queensland, Australia; and
³ School of Medicine, The University of Notre Dame, Australia

^* corresponding author, toby.hughes{at}adelaide.edu.au

Our understanding of tooth eruption in humans remains incomplete. We hypothesized that genetic factors contribute significantly to phenotypic variation in the emergence of primary incisors. We applied model-fitting to data from Australian twins to quantify contributions of genetic and environmental factors to variation in timing of the emergence of human primary incisors. There were no significant differences in incisor emergence times between zygosity groups or sexes. Emergence times of maxillary central incisors and mandibular lateral incisors were less variable than those of maxillary lateral incisors and mandibular central incisors. Maxillary lateral incisors displayed significant directional asymmetry, the left side emerging earlier than the right. Variation in timing of the emergence of the primary incisors was under strong genetic control, with a small but significant contribution from the external environment. Estimates of narrow-sense heritability ranged from 82 to 94% in males and 71 to 96% in females.

KEY WORDS: genetic • twins • teeth • eruption • asymmetry