Occlusal and orofacial myofunctional evaluation in children with primary dentition, anterior open bite and pacifier sucking habit.

The aim of this study was to evaluate occlusal and orofacial myofunctional characteristics in children three to five years of age with anterior open bite related to a pacifier sucking habit. Sixty-nine children participated in this study: 35 with anterior open bite (Anterior Open Bite Group - AOBG) and 34 with normal occlusion (Control Group - CG). In AOBG, the mean anterior open bite was 2.96 mm, the mean overjet was 4.1 mm and the mean upper intercanine distance was 28.7 mm. In the CG, the mean overjet was 2.6 mm and the upper intercanine distance was 30.3 mm. The mean overjet was greater (p=0.001) in AOBG than in CG, and the mean upper intercanine distance was smaller (p<0.001) in AOBG. The number of children with a canine Class II relationship was greater in AOBG than in CG (p<0.001). Simple logistic regression analysis showed that greater overjet, smaller upper intercanine distance and Class II canine relationship coexisted with anterior open bite. In AOBG, the number of children with incompetent lips, inadequate lip tonus, lack of proper tongue rest position, inadequate cheek tonus, anterior tongue interposition during swallowing and speech was greater (p<0.05) than in CG. Multiple logistic regression analysis identified anterior tongue interposition during swallow and speech, as well as incompetent lips, as the main orofacial myofunctional characteristics in children with anterior open bite.