Deglutitive tongue movement after correction of mandibular protrusion

To investigate any change in deglutitive tongue movement following the correction of malocclusion by orthognathic surgery. The subjects were nine patients with mandibular protrusion. A control group consisted of 10 individuals with a similar age range and normal occlusion. Swallowing events before and after mandibular setback via sagittal split ramus osteotomy were recorded by cineradiography, and the tongue movement was analyzed. Time and linear measurements were compared before and after surgical treatment by the Wilcoxon signed rank test; control and test subjects were compared with the Mann-Whitney U-test. Tongue-palate contact and the tongue-tip position changed after orthognathic surgery and became similar to those of the controls. Movements of the anterior and middorsal regions of the tongue did not change after orthognathic surgery and remained different from those of the controls. Our findings suggest that tongue-palate contact and tongue-tip position during deglutition adapted to the corrected oral and maxillofacial morphology, but the anterior and middorsal regions of the tongue during deglutition may have been affected by pharyngeal constrictors rather than by the oral and maxillofacial morphology.