Abstract
The purpose of the present study was to clarify the changing process of the relationshipbetween the velar length and the nasopharyngeal depth as anatomical factors in veloph aryngeal closure.Lateral X-ray cephalograms taken at rest were collected from 80 patients with clefts (UCLP) and 82non-cleft controls, and all of the subjects were classified into 4 developmental stages, stage 1 (4 yearsold), stage 2 (8 years old), stage 3 (12 years old) , and stage 4 (17 years old). The results were as follows
1. Dimensional growth of the velar length in the non-cleft controls showed a consistent increasethroughout the 4 stages, but there were no growth differences in the cleft group in any stage.
2. Dimensional growth of the pharyngeal depth showed remarkable increase during the stages 1-3in the non-cleft controls and during stages 1-2 and 3-4 in the cleft group.
3. Adequate ratio in the non-cleft controls showed no changes thr oughout the 4 stages consistently,but the cleft groups showed a tendency to decrease to 1.1 in stage 4.
The results suggest that the patients with clefts who had attained competent velopharyngeal closureduring childhood are predisposed to velopharyngeal incompetence in adolescence.
