Quantification of Gravitational Effects on Nasal Tip Geometry

Abstract

It is widely accepted in plastic surgery that patient positioning can affect the geometry of the nasal tip due to downward gravitational forces. However, empirical data supporting this principle is lacking. The primary objective of this study is to quantify gravitational effects on nasal tip geometry by calculating changes in tip rotation and projection between the supine and upright positions. This analysis will help further assess whether gravity affects the actual positional rotation of the nasal tip or if its impact is solely relative to neighboring landmarks. This study is a prospective case series that obtains upright and supine nasal measurements in 20 subjects. The nasolabial, nasofrontal, and columellar-facial angles, as well as the Goode, Crumley, Simon, and Powell ratios are used to calculate nasal tip rotation and projection changes. Mean nasolabial angle demonstrated a statistically significant tip derotation of 3.2° in the upright position relative to supine. Mean nasofrontal angle and mean columellar-facial angle did not significantly differ between positions. The nasal tip appeared relatively less projected in the upright position using the Simon and Crumley methods, whereas no significant difference was seen with the Powell and Goode methods. Gravity can influence the apparent nasal tip geometry by altering lip position and length, but it does not impact the true nasal tip geometry when the upper lip is excluded as a reference point.