A cineradiographic study of deglutition of the post-operative cleft palates

Using the cineradiographic study, the characteristics of the deglutition pattern and the coordinated function of oral structures were evaluated for post-operative cleft palates. Nineteen patients (10 males and 9 females) were provided and 17 normals (15 males and 2 females) were selected as a control group. The clefts were divided into 2 groups (good and poor) according to the velopharyngeal competency. The movements of oral structures were analyzed quantitatively frame by frame, and the time points which were physiologically significant during the deglutition were set up. The tongue's function was evaluated by the tongue depression rate and the patterns of the hyoid bone movement. In the cleft palate groups, oral weakness and/or hesitation of swallowing were observed. The poor group showed significantly more overall time of deglutition than the normal group. The time relationship between velopharyngeal closure (VPC) and tongue depression (TD) was one of the most specific features. In the normal group, VPC occurred definitely earlier than TD, but in the poor group, it was delayed, to a large extent. In the good group, the delay was rather small. The tongue depression rates in the cleft palates were larger than those of the normal group. The poor group showed the largest rate which seemed to be compensatory efforts of velopharyngeal incompetency. The patterns of the hyoid bone movements were also different among the three groups corresponding to their tongue function. The results suggested that the abnormal pattern of tongue movements might depend on the velopharyngeal incompetency, and there was a loss of coordinated function between the VPC and TD during the deglutition caused by the malfunction of the velopharyngeal closure. (author)