The interproximal contact (IC) is a keystone in the Begg theory and in Andrew's six keys to normal occlusion. However, the anatomical characteristics of the IC have never been described. A novel method was developed to measure IC in-vivo. IC was examined in 30 adult subjects. All ICs of the permanent dentition were spatially screened according to shape, size, location and orientation. IC size, shape and orientation differed significantly (p<0.001) between groups of teeth. The IC was more buccally located in 87.5% of the teeth and correlations were found between several IC variables. This study demonstrated that several dental malalignments are related to IC characteristics.