The subunit principle in nasal reconstruction.

The nasal surface is made up of several concave and convex surfaces separated from one another by ridges and valleys. Gonzalez-Ulloa has designated the nose an aesthetic unit of the face. These smaller parts (tip, dorsum, sidewalls, alar lobules, and soft triangles) may be called topographic subunits. When a large part of a subunit has been lost, replacing the entire subunit rather than simply patching the defect often gives a superior result. This subunit approach to nasal reconstruction causes unsatisfactory border scars of flaps to mimic the normal shadowed valleys and lighted ridges of the nasal surface. Furthermore, as trapdoor contraction occurs, the entire reconstructed subunit bulges in a way that simulates the normal contour of a nasal tip, dorsal hump, or alar lobule. Photographs show five patients in whom this principle was followed and one in whom it was not.