Comparison of tongue postures at rest position between anterior cross-bite and normal bite

Abstract

Objective To compare tongue positions at rest between normal occlusion people and patients with anterior cross-bite malocclusions,and to explore whether there is any abnormality in the tongue position of the anterior cross-bite malocclusions.Methods Twenty adults of normal bite (8 males and 12 females,with an average age of 23.8 years) and 20 adults of anterior cross-bite (1 1males and 9 females,with an average age of 24.6 years) were involved in this study.The position habits of tongue were investigated by a questionnaire.The tongue positions,which were enhanced by applying barium to tongue and palatal surface,were compared by cephalometric roentgenogram.Two groups were compared by t-test to determine the variation of anterior cross-bite. Results In normal occlusion group,the dorsum of tongues was sealed with all palatal surfaces except uvula site.In anterior cross bite group,tongues were far from palate,and were difficult to lift.The profile of tongue showed standing upright forward and up in normal occlusion group,while inclining back and low in anterior cross-bite group.The tops of tongue dorsum sites were at the border of soft and hard palate in normal occlusion group.While in anterior cross bite group,the tops of tongue dorsum sites were at the border of uvula and soft palate.In anterior cross-bite group,the tongue-to palate distance was bigger than that of normal occlusion group (P＜0.01).However,both length and height of the tongue had no significant differences between two groups (P＞0.05).Conclusions In anterior cross-bite patients,tongue positions were lower than that of normal occlusion people. Key words: Anterior cross bite; Tongue position; Rest position; Normal bite