This study was undertaken to compare eaxh maximum biting force and to investigate its relationship with the facial skeketal form, unmver and position of thooth contact between anterioi openbite and nomal occlusion adults, using the T-scan system and the lateral cephalogram. The subjects of this study consisted of a group of 25 individuals wuth normal occlusion and another group of 14 with anterioi openbite. The obtained results of this study were as follows : 1. The maximum biting force of anterior openbite adults was less than that of normal occlusion adults. 2. In anterior openbite adults, there were negative correlations between the maximum biting force and SN/MP, FMA,l PP/MP mesurement of lareral cephalogram. 3. In anterior openbite adults, as the mesial angulation of lower first molar ahaints the occlusal plane incresed, the more the biting force decreased. 4. In both groups, the greater the number of tooth contact, the more the biting force increased. 5. In both groups, the center of effort for anteroposterior occlusal contact was located on the forst molar region.