Developmental patterns of human dental morphological traits.
A longitudinal series of casts of the deciduous and permanent dentitions of 827 children from Burlington Growth Centre study was examined for 5 traits: shovel-shape of the incisors, cusp six, cusp seven and protostylid of the mandibular molars, and Carabelli trait of the maxillary molars. The changing trait frequencies found support the concept of morphogenetic gradients of expression for non-metric traits from deciduous to permanent teeth. Tests of association showed that if shovelling was present on the deciduous incisors it would usually appear on the permanent successors. Tests of association between the other 4 traits on deciduous second molars and the permanent molars support the view that the second deciduous molar belongs to the total molar tooth district. This gradient expression of morphological traits would fit either the field or clone concepts, but it, and the intra-individual discordances for trait presence, probably reflects the great temporal spacing of dental development seen in man.
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007180:Incisor / Q000033:anatomy & histology / Q000254:growth & development; D008137:Longitudinal Studies; D008963:Molar / Q000033:anatomy & histology / Q000254:growth & development; D009811:Odontometry; D014070:Tooth / Q000033:anatomy & histology / Q000254:growth & development*; D014094:Tooth, Deciduous / Q000033:anatomy & histology / Q000254:growth & development