The Force of Lip Closure in Children

Part VI : Changes in the maximum force of lip closure of various occlusions from the age of children to adults

Abstract

An analysis of the force of lip closure in children and the effect on oral function and integration of dentition in the period of growth has been carried out. The aim of this study was to clarify the changing properties of the maximum force of lip closure of normal occlusions and a variety of malocclusions from the age of children to adults, and also to clarify the relationship between maximum the force of lip closure and occlusions. Anterior occlusions and the maximum force of lip closure were evaluated in 533 children of nursery school and elementary school, and 69 male adults. We obtained the results as follows :1.The Hellman's dental stage is a significant factor for the maximum force of lip closure, showing a rising tendency with the dental stage.2.The maximum force of lip closure was affected by occlusion after the IIIA dental stage. The contribution ratio of adults was higher than that of children.3.After the IIIA dental stage, the maximum force of lip closure of open bite and maxillary protrusion was lower than that of normal occlusion, while that of cross bite and deep over bite was higher than that of normal occlusion.The above indicates that a marked relationship between lip closing function and integration of dentition begins to be seen from the stage that occlusion of anterior permanent teeth is established, suggesting that function and morphology are affecting mutually during the period of growth.