Comparative clinical study evaluating lip-closure forces in association with tongue pressure in children

ObjectiveThe aim of this study was to examine the relationship between lip-closing forces and tongue pressures in children with normal and reverse occlusions.Study designThe children were pediatric 30 patients treated at the Kyushu Dental University hospital, Kitakyushu City, Japan. Their age range was 8–11 years and they were considered old enough for measurement with a multidirectional lip-closing force measurement system. Fifteen patients had normal occlusions and 15 had reversed occlusions. A multidirectional lip-closing force measurement system was used to determine lip pressures. To evaluate tongue motions, tongue movements to the palate were evaluated using a tongue pressure scale.ResultsThe average total lip-closing force in children with normal occlusions was 5.031 ± 1.629 Ns and that in children with reversed occlusions was 2.770 ± 1.167 Ns. There was a slight correlation between tongue pressures and total lip closing forces.ConclusionThe lower lips are dominant in lip closing in children with normal occlusions, while the upper lips are dominant in those with reversed occlusions. This study demonstrated a weak correlation between lip-closing forces and tongue pressures in the normal and reversed occlusion groups.