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Original Investigation
Jul/Aug 2016

Estimation of Nasal Tip Support Using Computer-Aided Design and 3-Dimensional Printed Models

Author Affiliations
  • 1Medical student, University of California, Irvine, School of Medicine
  • 2Beckman Laser Institute and Medical Clinic, University of California, Irvine, School of Medicine
  • 3Department of Otolaryngology–Head and Neck Surgery, University of California, Irvine, School of Medicine

Copyright 2016 American Medical Association. All Rights Reserved. Applicable FARS/DFARS Restrictions Apply to Government Use.

JAMA Facial Plast Surg. 2016;18(4):285-291. doi:10.1001/jamafacial.2016.0215

Importance  Palpation of the nasal tip is an essential component of the preoperative rhinoplasty examination. Measuring tip support is challenging, and the forces that correspond to ideal tip support are unknown.

Objective  To identify the integrated reaction force and the minimum and ideal mechanical properties associated with nasal tip support.

Design, Setting, and Participants  Three-dimensional (3-D) printed anatomic silicone nasal models were created using a computed tomographic scan and computer-aided design software. From this model, 3-D printing and casting methods were used to create 5 anatomically correct nasal models of varying constitutive Young moduli (0.042, 0.086, 0.098, 0.252, and 0.302 MPa) from silicone. Thirty rhinoplasty surgeons who attended a regional rhinoplasty course evaluated the reaction force (nasal tip recoil) of each model by palpation and selected the model that satisfied their requirements for minimum and ideal tip support. Data were collected from May 3 to 4, 2014.

Results  Of the 30 respondents, 4 surgeons had been in practice for 1 to 5 years; 9 surgeons, 6 to 15 years; 7 surgeons, 16 to 25 years; and 10 surgeons, 26 or more years. Seventeen surgeons considered themselves in the advanced to expert skill competency levels. Logistic regression estimated the minimum threshold for the Young moduli for adequate and ideal tip support to be 0.096 and 0.154 MPa, respectively. Logistic regression estimated the thresholds for the reaction force associated with the absolute minimum and ideal requirements for good tip recoil to be 0.26 to 4.74 N and 0.37 to 7.19 N during 1- to 8-mm displacement, respectively.

Conclusions and Relevance  This study presents a method to estimate clinically relevant nasal tip reaction forces, which serve as a proxy for nasal tip support. This information will become increasingly important in computational modeling of nasal tip mechanics and ultimately will enhance surgical planning for rhinoplasty.

Level of Evidence  NA.