Fig. 7From: The crown-root morphology of central incisors in different skeletal malocclusions assessed with cone-beam computed tomographyThe various Collum angle in central incisor, the long axis of the root can deviate to the labial side (a) or lingual side (c) of the long axis of the crown, or coincidence (b). The schematic diagram indicates that the root bends toward lingual cortical alveolar because of Collum angle (d). The schematic diagram elucidates that the more obvious Collum angle accompanies with the greater labial surface curvature of the crown (e)Back to article page