Rhinoplasty - Nasal Analysis

Nasal Analysis

The surgical management of nasal defects and deformities divides the nose into six (6) anatomic subunits: (i) the dorsum, (ii) the sidewalls (paired), (iii) the hemilobules (paired), (iv) the soft triangles (paired), (v) the alae (paired), and (vi) the columella. Surgical correction and reconstruction comprehend the entire anatomic subunit affected by the defect (wound) or deformity, thus, the entire subunit is corrected, especially when the resection (cutting) of the defect encompasses more than 50 per cent of the subunit. Aesthetically, the nose — from the nasion (the midpoint of the nasofrontal junction) to the columella-labial junction — ideally occupies one-third of the vertical dimension of the person’s face; and, from ala to ala, it ideally should occupy one-fifth of the horizontal dimension of the person’s face.

The nasofrontal angle, between the frontal bone and the nasion usually is 120 degrees; the nasofrontal angle is more acute in the male face than in the female face. The nasofacial angle, the slope of the nose relative to the plane of the face, is approximately 30–40 degrees. The nasolabial angle, the slope between the columella and the philtrum, is approximately 90–95 degrees in the male face, and approximately 100–105 degrees in the female face. Therefore, when observing the nose in profile, the normal show of the columella (the height of the visible nasal aperture) is 2 mm; and the dorsum should be rectilinear (straight). When observed from below (worm’s-eye view), the alar base configures an isosceles triangle, with its apex at the infra-tip lobule, immediately beneath the tip of the nose. The facially proportionate projection of the nasal tip (the distance of the nose’s tip from the face) is determined with the Goode Method, wherein the projection of the nasal tip should be 55–60 per cent of the distance between the nasion (nasofrontal junction) and the tip-defining point. A columellar double break might be present, marking the transition between the intermediate crus of the lower-lateral cartilage and the medial crus.

The Goode Method determines the extension of the nose from the facial surface by comprehending the distance from the alar groove to the tip of the nose, and then relating that measurement (of nasal-tip projection) to the length of the nasal dorsum. The nasal projection measurement is obtained by delineating a right triangle with lines parting from the nasion (nasofrontal juncture) to the alar–facial–groove. Then, a second, perpendicular delineation, that traverses the tip-defining point, establishes the ratio of projection of the nasal tip; hence, the range of 0.55:1 to 0.60:1, is the ideal nasal-tip-to-nasal-length projection.