The nose is an osteocartilaginous vault that is divided into two chambers by the median septum. Its inner surfaces are lined by mucous membranes and its outer surfaces are covered with skin. The important external landmarks include the glabella, nasion, dorsum, lower tip including the tip, nostrils, columella, nasolabial angle, alae and alar grooves (Figure 10–1). The quality of the skin is a major factor in determining the final appearance after rhinoplasty. Skin varies in its thickness, presence of sebaceous glands, and subcutaneous fat. The vestibule is the inferior cavity of the nose. It is lined with hair follicles called vibrissae and sebaceous glands. In the vestibule, the stratified squamous epithelium of the nares transitions to mucosa. It is in this region of the nose that air filtration, warming, and humidification are begun.
The external landmarks of the nose. (Reproduced, with permission, from Rees TD, LaTrenta GS, eds. Aesthetic Plastic Surgery, 2nd edition, Volume I. Philadelphia: W.B. Saunders Company; 1994:40.)
Rhinoplasty has both aesthetic and physiologic implications because the nose serves several functions, including air modification, immune defense, olfaction, and phonation. For instance, the nose modulates the temperature of inspired air, filters, and humidifies it. In the unoperated nose, the majority of air flows over the inferior turbinate. The temperature of the mucosa is regulated by vasodilation or vasoconstriction. Filtration occurs via the vibrissae, which are small hairs that exclude particulate matter (such as soot, plant debris, and insects). Dust, pollen, and powder are trapped on the mucosal surface. A mucociliary elevator then moves them toward the posterior pharynx. They are eventually swallowed. IgA is secreted along the mucosal surface and helps protect the person against infection by bacteria and viruses. Olfaction occurs in the root of the nasal vault along the olfactory membrane well clear of the area of dissection during the usual rhinoplasty. The nose also greatly affects vocalized sounds, exemplified by how different one sounds when suffering from the common cold.
A paired set of nasal bones form the superior aspect of the dorsum of the nose. Each one is trapezoidal in shape. Superiorly, they descend from the nasal process of the frontal bone. Laterally, they attach to the nasal process of the maxilla. Inferiorly, they attach to the upper lateral cartilages (Figure 10–2). Together, the paired nasal bones and the nasal processes of the maxilla form the piriform aperture. The nasofrontal angle is where the frontal bone meets the dorsum of the nose. The nasofrontal angle is also known as the nasion. Altering the nasion is difficult given the thick nature of the frontal bone.
The nasal bones attach superiorly to the frontal bone, laterally to the nasal process of the maxilla, and ...