Fig. 2From: CBCT evaluation of root canal morphology and anatomical relationship of root of maxillary second premolar to maxillary sinus in a western Chinese populationType III according to the classification of Shahbazian. When the roots exactly adjoined the maxillary sinus floor, the curvature of root in the sagittal section. a The root is straight, b the root is mesially curved (17.7% of all type III cases)Back to article page