Growth change and functional morphology of the osseous choanal boundaries of humans: A 3D geometric morphometric study

Infants are essentially obligate nose breathers due to intranarial position of the larynx. Understanding the normal growth and functional morphology of the choanal boundaries is of great clinical importance in treating conditions such as cleft palate and choanal atresia. This study tested for growth changes in relative choanal dimensions from infancy to adulthood. Three‐dimensional landmark coordinate data were collected from a growth series of 260 dry crania representing Stage 1 (between birth and the eruption of di1), Stage 2 (eruption of deciduous dentition), Stage 3 (eruption of M1), Stage 4 (eruption of M2), and Stage 5 (eruption of M3). Coordinate data underwent Procrustes scaling (over centroid size) so that linear dimensions may be directly compared between growth stages. Results show that choanal width and index (width/height X 100) decreased only between Stages 1 and 2. Nonetheless, changes in choanal height and area continued until Stage 3, approximately 6 years of age. There was no observed growth change in midline angulation of the choanae, which suggests that choanal orientation may be under genetic control. The results show that the choanae attain adult proportions at approximately age two, contemporaneously with known changes in laryngeal descent and basicranial flexion. Future research will focus on this early growth period within the context of developmental disorders. Grant Funding Source : NYCEP Research Grant