Composite Resection

The classic technique for nasal hump reduction was first introduced by Joseph in 1931. This procedure involves an en bloc resection of the dorsal hump. A scalpel is used to cut through the cartilaginous dorsal septum and upper lateral cartilages, and an osteotome is used to resect the bony dorsum. The resected hump is discarded and lateral osteotomies are used to medialize the bony side walls and close the open roof deformity. Although effective for hump reduction, this method can be wrought with adverse sequelae including uneven resection of the dorsum, inadvertent over-resection, destabilization of the keystone area, creation of dorsal irregularities, excessive dorsal narrowing, and midvault collapse, resulting in both an unnatural appearance and poor nasal function.

Push-Down Technique

In response, Cottle introduced his push down technique in 1954, aimed at reducing the dorsal profile while preserving the nasal dorsum and midvault. In this technique, lateral osteotomies are performed and an inferior strip of the septum is removed, allowing for mobilization of the entire bony and cartilaginous nasal pyramid. The nasal pyramid is then pushed down into the piriform aperture, reducing the dorsal profile. Although this technique did not disturb the native dorsum or midvault, the amount of reduction was limited and it did not gain widespread popularity in the United States.

The Skoog Technique

In 1966, Skoog introduced an alternative method for dorsal hump reduction that similarly aimed to preserve the nasal dorsum and midvault. In this method, an en bloc resection of the cartilaginous and bony dorsum is performed in the same manner as that described by Joseph. The mucosa is then removed from the undersurface of the resected composite dorsum. The lateral walls of the hump are shaped, leaving the dorsum with the desired width. The bony and cartilaginous septum are then removed from the undersurface with a Ronguer, allowing the angle between the bone and cartilage to flatten. The remaining flattened dorsum is then replaced over the dorsum as a free graft. Although this technique minimized dorsal irregularities, the upper lateral cartilages were not resuspended, and nasal function continued to suffer.

Understanding the Internal Nasal Valve

Although first described by Mink in 1903, the importance of maintaining the internal nasal valves for proper nasal function was not fully understood until more recently. This new appreciation further impacted the evolution of dorsal hump reduction and created a greater emphasis on preserving the middle vault to achieve not only excellent aesthetic results but functional outcomes as well.

The internal nasal valve, bound by the septum, upper lateral cartilage, head of the inferior turbinate, and nasal floor, is the narrowest portion of the nasal airway ( Fig. 1 ). As such, it regulates upper airway resistance and thus nasal airflow. In accordance with Poiseuille’s law, resistance is inversely proportional to the radius of cross-sectional area to the fourth power. Thus, small changes in internal nasal valve area can have profound changes on resistance. This was confirmed by Roithmann and colleagues through the use of acoustic rhinometry and rhinomanometry. Furthermore, as the cross-sectional area of the valve decreases, a greater negative pressure is generated within the nasal cavity during inspiration owing to the Bernoulli effect. This pressure in turn can result in a dynamic collapse of the nasal sidewall, depending on the strength of the cartilaginous framework and nasal musculature resisting this pressure. Reduction rhinoplasty was found to be the second most common cause of internal nasal valve obstruction, second only to trauma, and a study by Grymer and colleagues demonstrated an average 22% decrease in the cross-sectional area at the internal nasal valve by acoustic rhinometry 6 months after standard reduction rhinoplasty.

Internal nasal valve. The internal nasal valve in cross-section ( right ) is bound by the septum, upper lateral cartilages, head of the inferior turbinate, and nasal floor.

Midvault Grafts

With this new understanding in mind, a number of techniques were introduced to reconstruct the middle vault and internal nasal valves after dorsal hump reduction. In 1984, Sheen introduced spreader grafts to reconstruct the middle vault. Spreader grafts have gained widespread popularity and have been shown to improve nasal airflow. In 1999, Alsarraf and Murakami described onlay spreader grafts from septal or conchal cartilage, and more recently, in 2004, the concept of a component dorsal hump resection in which the upper lateral cartilages are released from the septum before hump takedown and then used as autospreader grafts was introduced. These advances have greatly advanced the reconstruction of the middle vault and patency of the internal nasal valves, resulting in improved aesthetic and functional outcomes following dorsal hump reduction; however, they still have the heightened risk of creating dorsal irregularities, particularly in patients with thin skin.