1993 Volume 13 Issue 4 Pages 380-404
To determine the degree of misarticulation in cleft palate patients undergoing prosthetic therapy, static palatography was used to identify contact patterns of tongue-to-palate and tongue-to-teeth movements during the production of sounds.
To accomplish this, a black vinyl sheet, vacuum molded to cover the palate and the occlusal surface of the maxillary teeth and coated with a white, alginate powder, was inserted into the mouth of the tested subject. Then, the subject was asked to pronounce a certain sound, and as the sound was produced, the movements of the tongue wet the powdered vinyl surface, thereby providing a palatogram of that sound. After taking 5 palatograms of each sound, the samples were averaged by an image processor.
The palatograms of each sound were then compared with palatograms of the same sound produced by normal subjects and evaluated for excessive or insufficient tongue contact with the palate and/or the dental arch in the production of phonemes. Aberrations in the palatogram pattern were graded on the basis of a numerical scale, with zero representing the least aberrant pattern and five representing the most aberrant pattern.
This palatographic method was used to evaluate speech in 5 cleft palate patients at three stages that follow : stage A, prior to the start of prosthetic treatment ; stage B, while wearing temporary dentures ; and at stage C, while wearing the final dental prostheses.
An analysis of these palatograms revealed that patterns indicating an abnormality were very apparent at stage A, particularly on pronunciation of the sounds /sa, ∫i, ta/, but, less so at stage B, and the patterns almost approximated normal patterns at stage C.
