Relationship between maxillofacial morphology and deglutitive tongue movement in patients with anterior open bite.

We reported previously that patients with anterior open bite had tongue tip protrusion, slower movement of the rear part of the dorsal tongue, and earlier closure of the nasopharynx during deglutition. In the present study, the relationship between this characteristic tongue movement and maxillofacial morphology in patients with anterior open bite was investigated. The subjects were 10 female patients with anterior open bites and 10 women with normal overbites as controls. Maxillofacial morphology was measured by cephalometric radiography, and tongue movement during deglutition was analyzed by cineradiography. The relationship between each value obtained by cephalometric radiography and cineradiography was evaluated by simple correlation analysis. In the patients with anterior open bite, there were significant correlations between mandibular plane angle, ramus height of the mandible, or anteroposterior dimension of the maxilla and movement of the front part of the dorsal tongue during deglutition. Furthermore, there were also significant correlations in these patients between mandibular plane angle, gonial angle, or ramus height of the mandible and the change in the contact between tongue and palate during deglutition. The controls did not have the correlations like these. Our study suggests that characteristic tongue movements during deglutition in patients with anterior open bites are closely related to their morphological features.