Sagittal area of the vocal tract in young female children.

OBJECTIVE To measure the sagittal areas of the front and back cavities of the vocal tract in children acquiring speech. PATIENTS AND METHODS Ten female children were selected from the Serial Experimental collection of the Burlington Growth Centre in Toronto, Canada. Each of the 10 children was seen annually from ages 3 through 8. Data collections included lateral cephalograms in occlusion. We traced those cephalograms and identified landmarks to delineate the front and back cavities. The sagittal areas of the front and back cavities were calculated. A measure of the angle of the head to the cervical vertebrae was made. RESULTS Front cavities were larger and grew faster. For both front and back cavities, age, angle measure, and the interaction of age and angle measure were significant. CONCLUSION Space available for the tongue to maneuver is greater anteriorly than posteriorly even when the jaw is maximally elevated.