The Nasal Dorsum
Creating a normal apprearing dorsum postoperatively requires an understanding of the surgical anatomy and characteristic relationships that dertermine nasal appearance in relation to the brow, the eyes, the upper lip and the chin. As such, Dr Sam Rizk, a new york rhinoplasty surgeon, will discuss these relationships and the concept of nasal and facial balance. The nasal dorsum is formed by the nasal bones and the dorsal septum and upper lateral cartilages. It is normally wider in the middorsum and narrower at the radix and supratip areas. The dorsal nasal bones and dorsal upper laterals have two components that contribute to the external appearance of the dorsum-a vertical component and a horizontal component. The vertical component determines the visual height of the dorsum The transverse component of the dorsal nasal bones and upper laterals determines the width of the dorsum in frontal view. The junction of the bony with cartilaginous dorsum is where the upper lateral cartilages are widest. The upper lateral cartilages become narrower towards the supratip area of the nose. It is difficult to completely smooth out this keystone area or junction of bony and cartilaginous nasal dorsum because the bony component typically overlapps the cartilaginous component in this area. Precisely controlling this area intraoperatively is difficult, and postoperative dorsal irregularities occur most commonly in this region of the dorsum. To complicate or accentuate irregularities even further is the thinness of the skin in the rhinion which usually corresponds to this keystone area.
Maintaining a normal anatomic dorsum is one of the most difficult aspects of rhinoplasty, mainly because of the complex shapes and curves of the normal dorsum. Good primary rhinoplasty entails taking all precautions to prevent secondary deformities. The following are examples of unplanned secondary deformities and how they are created in an attempt to prevent their occurrence.
The excessively straight and narrow dorsum- the nasal dorsum should follow the brow-tip line with a slight curvature on front view which flares a little as it progresses down to the tip. If the front view is too straight, the nose will visually appear longer. This deformity usually occurs after reduction of a dorsal hump and osteotomies to close the open roof . Sometimes it is necessary to use spreader grafts in the middle nasal vault to prevent this deformity in certain patients. This deformity is more prevalent if the nasal bones are short (cephald to caudal) and lateral osteotomies are done. Sometimes preserving the dorsal upper lateral cartilages during initial dorsal reduction provides another option for creating an anatomic appearing dorsum. The upper lateral cartilages can be folded over medially creating a horizontal segment.
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