Figure 1.

A = the canalis sinuosus (CS) course identified in the coronal section (blue arrows).
B = axial view of the maxillary arch, with the white arrow indicating the diameter of the CS opening.
C = sagittal section showing measurements from the CS opening: the yellow line represents the distance to the nasal cavity floor, the green line represents the distance to the buccal cortical bone, and the red line represents the distance to the alveolar ridge crest.