The Force of a Lip Closure in Children

(IV) The Relationship between the force of a Lip Closure and state of a lip closure in daily life in primary school children.

Abstract

The aim of the present study was to investigate the relationship between changes based on age in the force of a lip closure and breathing in daily life in childhood. The subjects in this study were 467children from 6 to 12 years old and their guardians. We measured the children with respect to the force of a lip closure and investigated the questionnaires which the guardians had answered. The following results were obtained:
1. There was no significant change in the force of lip closure of the group less than 9 years old concerning all items of the questionnaire.
2. In the group of 9 years of age or more, the force of the lip closure of the children who were always opening their mouth was significantly smaller than that of children who occasionally opened their mouth and children who constantly closed their mouth. The force of the lip closure of children who breathed through the mouth and children who breathed through both the mouth and the nose was significantly smaller than that of children who breathed through the nose.
These results suggest that acquiring a correct way of breathing until approximately 9 years old leads to the improvement of the force of a lip closure and the prevention of malocclusion etc.