Morphometric nasopharyngeal characteristics in facial clefts.

A morphometric assessment of the nasopharynx was carried out on 194 X-ray films of adult males with cleft lip and/or palate. According to the type and extent of the cleft they were subdivided into seven groups and compared with a control group of 50 normal males matched in age. The findings showed a reduction of the nasopharyngeal airway in all groups with cleft palate, which corresponded to the decrease in depth of the nasopharyngeal bony framework without participation of soft tissues. In cleft lip and palate the decrease was due exclusively to the posterior displacement of the maxilla, in isolated cleft palate it was due to several factors and was less marked. The height of the bony nasopharynx and the thickness of the nasopharyngeal posterior wall tissues remained unchanged in all types of clefts. In cleft palate the length of the velum was always reduced with a slighter reduction of the height of the body of the sphenoid bone. No changes were found in cleft lip alone. Pharyngeal flap surgery failed to influence the anteroposterior position of the maxilla or nasopharyngeal parameters. The length of the soft palate was not changed after this procedure, but the velum was displaced in posterior direction and its distance from the pharyngeal posterior wall was significantly reduced. The reduction was so marked that it could limit the air flow capacity of the airways. In individuals without pharyngeal flap surgery the velum was displaced in the anterior direction and its position could be influenced by the pushback of the mandible.