Some characteristics of endoscopic and radiological systems used in elaboration of the diagnosis of velopharyngeal incompetence.

The characteristics of rigid and flexible endoscopes have been studied with reference to their suitability for nasal pharyngoscopy in the assessment of velopharyngeal incompetence taking into account a number of fallacies which are known to exist. It is concluded that the ability to achieve correct positioning of the rigid endoscope and the wide angle field of view of the 70 degrees Storz-Hopkins nasopharyngoscope, in particular, made it the best single instrument at present available for this work despite the greater ease of introduction of the flexible endoscopes. The characteristics of the information obtained by radiological examination were studied and in comparison with endoscopic information it was concluded that endoscopic information was more reliable for qualitative and radiological for quantitative analysis. The systems were considered to be mutually complementary and simultaneous examination with, preferably, synchronous recording provided the advantages of optimal placement of the endoscope and the possibility of measurement of the velopharyngeal isthmus.