Abstract: Objective: To study the sagittal size and characteristics of tongue under tongue resting position in the subjects with deep-overbite and normal occlusion. Methods: By tongue-dorsum barium sulfate filming method, the subjects were taken lateral cephalometric films in order to record the position, length and height of the body of tongue. And then the difference between two groups was compared. Results: In the deep-overbite group, the front and middle parts of tongue were in the relatively low position and the front parts were retruded. And their length and height were relatively smaller than those of normal occlusion group. The difference was statistically significant. Conclusion: Different characteristics between deep-overbite group and normal occlusion group may correlate with the occlusion.

Key words: Tongue, Deep-overbite, Normal occlusion, Lateral cephalometric film