Tester to Measure the Hardness of the Nasal Tip: A New Device

ABSTRACT

The nasal tip occupies important position in Asian rhinoplasty because Asian has a nasal tip featuring of round or bulbous shape, lower height and wider base compared with that of Caucasian. The hardness of the nasal tip may be increased during the course of a routine rhinoplasty by maneuvers such as incision or excision of the lower lateral cartilage, suturing, and grafting of the cartilages. Changes of the hardness may be a component of postoperative dissatisfaction. However there is no device to measure the hardness of the nasal tip. We developed a "nasal tip durometer" using Teclock Durometer GS series 701 G. The spring rate of Teclock Durometer was converted from 0.223 kgf/mm to 0.036 kgf/mm to apply to the human body. After the remote air switch was fixed to apply with the same speed in a patient's nose, we manufactured the frame attachable to the surgical operation table. The reliability, validity, and responsiveness to clinical change of our durometer were evaluated in a clinical study of 20 patients. Our durometer was highly reliable (Spearman correlation coefficient, r=0.95), valid (Spearman correlation coefficient, r= 0.85), and responsible (effect size=11.37). We concluded that nasal tip durometer was useful to measure the hardness of the nasal tip objectively.