When discussing facial aesthetics, it is wise to understand that
formulas are only guidelines to be tempered by changing aesthetics,
patient desires, and existent anatomy. Once the patient’s
objectives are understood, the surgeon can develop a goal
based on his or her experience and analysis of the anatomy of
the nasal and facial profile. First, one must understand the critical importance of examining
nasal tip projection in relation to the height of the radix.
Sheen and Sheen7 long ago recognized that in evaluating nasal
projection, the radix should not be considered a separate unit
but a “key part of a dynamic form” (Figure 2).
Figure 2. Computer-generated image demonstrates the importance of the radix in aesthetic analysis. The height and position of the radix affect each other, define the nasofacial angle, and serve as the counterpoise of the nasal base. Although projection is the same in parts A and B, the change in radix positioning causes the illusion of overprojection in part B.
The tip is only
projected in relation to the projection of dorsal height at the nasion.
More recently, Byrd and Hobar2 and McKinney and Sweiss3
have also discussed the importance of the radix height. As such,
one needs to consider not only the height and position of the
radix but also the nasofacial angle produced in its relation to the
nasal tip. One must subsequently ensure that other complicating
dynamics that give the illusion of overprojection are not in
place. In addition to a low radix, a tension septum, saddle-nose
deformity, retrognathia, and short upper lip also give the illusion
of overprojection and must be excluded. Whentrue overprojection is determined, the surgeon can then
perform an objective analysis. Components of the nasal anatomy
that lead to tip overprojection can include (1) overelongated alar
cartilages, including lateral crura, medial crura, angle of divergence
(intermediate crura), or a combination; (2) a tension nose
with overdeveloped quadrangular cartilage; (3) a combination
of these components; and (4) trauma or iatrogenic injury. Having completed analysis of nasal projection, the next step
is to determine whether rotation is adequate or will need to be
addressed, as many deprojection techniques can or will alter
rotation. The nose is further examined for tip asymmetries, tip
shape, size and contour, skin thickness, dorsal humps and irregularities,
nasal valve competence, and other functional components.
With the analysis complete, the surgeon proceeds to the algorithm to determine how to best achieve nasal deprojection
while controlling the extent of rotation.
