Postnatal changes of the human bony labyrinth morphology.

It has been suggested that the inner ear attains its final morphology already in utero and that environmental factors do not influence its size or shape after birth. Thus, direct comparison between the adult and the subadult bony labyrinths can be made. Herein, this hypothesis was tested in a sample of 170 subadult individuals. Three-dimensional (3D) models of the labyrinths were created for 170 French and Greek juveniles. Ten linear measurements of the 3D models were taken and the labyrinthine shape was evaluated by calculating 10 shape indices. All variables were subsequently analyzed in the context of postnatal development. Significant positive correlation between the chronological age and several variables was noted suggesting that age-related changes of the bony labyrinth occur in the postnatal period. Our findings contradict the simplified assumption that the bony labyrinth retains a stable morphology after birth. Further research should concentrate on evaluating postnatal changes to the temporal bone and their influence on the labyrinthine morphology.