The triangularity of the tip depends on the presence of an unbroken line from a narrower nasal tip to a wider nasal base.

In most noses, the frontal and base views reveal a triangular shape of the nose in which the nasal base (interface of nose and face) is wider than the tip and dorsal line.

The base view also provides information about the shape and size of the columella, alar base, nostrils, and infratip lobule ( Figs. Tissue of a similar thickness, color, and consistency should be used to reconstruct these defects. Than replace only the primary defect, even if this requires removal of areas of healthy tissue. This may require a surgeon to resect and replace an entire subunit (or subunits) involved, rather During reconstruction, effort should be made to place scars within subunit borders whenever possible, as the human eye is more apt to discern a scar that traverses across a subunit than one that outlines it. Nonetheless, it is crucial for the nasal surgeon to identify them in preoperative assessment, particularly in external nasal reconstruction. The subunits do not necessarily have sharply defined boundaries and do not mirror exactly the underlying anatomic structures. Human visual processing depends on these light-dark contrasts to form a perception of the nose. These areas are defined by the shadows and highlights cast by incident light. These consist of the nasal dorsum, sidewalls, tip, columella, ala/sill, and soft triangles ( Fig. The external topography of the nose is divided into six subunits.

Normal nose sketch