The Force of Lip Closure in Children

(2) The relationship between the force of lip closure and occlusion

Abstract

The aim of the present study was to investigate the relationship between the forces of the lip closure and the occlusion through the process of dentition. The subjects in this study were 560 nursery school and primary school children from II A to IV A according to Hellman's dental stage. The forces of the lip closure were measured using the “LIP DE CUM®”. The following results were obtained:
1. The forces of the lip closure were related to the Hellman's dental stage and the occlusion.
2. The forces of the lip closure increased with the dental stage.
3. The forces of the lip closure with the anterior openbite and the maxillary protrusion was significantly lower than the normal occlusion and another malocclusion after III A.
4. The forces of the lip closure with the anterior openbite showed almost no increase after III A.
5. A close relationship was observed between the morphology of the dentition and the function of the muscle in orally after the eruption of the anterior permanent teeth.