Growth-related changes in familial resemblance of maxillofacial morphology.

: We investigated changes in resemblance between Japanese parents and their growing children with regard to maxillofacial morphology. Lateral roentgenographic cephalograms taken from 963 children (336 male and 627 female) over 6 years of age and their parents were used as samples. Based on the age of the children, there were six groups--I: 6-7 years of age; II: 8-9; III: 10-11; IV: 12-13; V: 14-15; and VI: over 16. Parent-offspring heritabilities (h2) were computed for 35 variables representing maxillofacial and dentoalveolar traits, and group comparisons were also made. The following results were obtained: (1) there were more significant heritabilities for maxillofacial variables than those for dentoalveolar ones; (2) in general, additive genetic effects were more prominent in controlling maxillofacial and dentoalveolar structure of on-growing children, with increasing age.