Adaptive functional changes in the swallowing pattern of the tongue following expansion of the maxillary dental arch in subjects with and without cleft palate.

In seven subjects with unilateral cleft lip and palate (UCLP), two subjects without cleft but with complete lingual crossbite, and two subjects with normal occlusion, tongue contact patterns against the hard palate, lingual surfaces of maxillary and mandibular teeth, and mandibular lingual mucosa during swallowing were analyzed three-dimensionally using electropalatography (EPG), before and after lateral expansion of the maxillary dental arch and after 3 months of retention. Before maxillary lateral expansion, all of the subjects with cleft palate showed no palate-tongue contact at rest, and limited movement of the tongue anteriorly and upward through the entire swallow cycle. Furthermore, the tongue contacted the hard palate for a relatively brief time during swallowing compared with the subjects without cleft with normal occlusion. After expansion, the tongue was seen to contact all areas of the hard palate and the lingual surface of the maxillary dentition for a longer period of time. After 3 months of retention, the tongue maintained contact with all lingual areas of the mandibular and maxillary arches and the hard palate.