Abstract
Various studies of lip closure in children have recently been reported, though few have given attention to child patients with open bite. We investigated 15 children with normal occlusion and 15 with open bite ranging in age from 8 to 11 years old who were treated at Kyushu Dental College. The purpose of this study was to examine lip closing force in children with open bite.We determined lip closure force using a multidirectional lip closing force measurement system and tongue pressure with a simple tongue pressure measuring assembly, and also examined hearing ability. Our results showed that lip closing force from the lower jaw was significantly greater than that from the upper jaw in both the normal occlusion and open bite groups.In a review of previous reports, muscle pressure from the lower lip was shown to be significantly greater than that from the upper lip, and children with open bite and puckered lips showed the same results as found in the present study. We consider that movement of neighboring soft tissues during lip closure in children with open bite is similar to that in those with normal occlusion.Results of tongue pressure measurements revealed no significant difference between children with normal and open bite. In regard to tongue elevation to the palate, our results suggest that children with an open bite have similar characteristics as those with normal occlusion.In addition, questionnaire findings showed that children with an open bite have easier mouth opening and tend to breathe through the nose. There are various causes of open bite development, and we intend to investigate its association between mouth breathing and open bite in a future study.
