Nasal base symmetry: a three dimensional anthropometric study.

AIM: The aim of this paper was to evaluate directional and fluctuating asymmetry, nostril and alar divergence in the nasal base of healthy young adults. To estimate nostril area and to investigate its relationships with cutaneous nasal area. METHODS: Three-dimensional plaster models of the nose of 20 young healthy white adults were obtained, digitized and mathematically reconstructed using Non Uniform Rational B-Splines (NURBS) curves. Linear distances (alar length, nostril axis length), angles (interalar angle, interaxial angle; angle between each nostril and alar axes), and surface areas (cutaneous nasal surface; right and left nostril area) were computed using NURBS-reconstructed models. RESULTS: The left side nasal structures were somewhat larger than the homologous right side ones (P<0.05). Nostril axis was approximately 60% of the corresponding alar length. Nostril area was approximately 3% of cutaneous nasal area. Alar length explained 31-36% of the individual variations in nostril axis length. Cutaneous nasal area explained 54-56% of nostril area, while the interalar angle explained 35% of the variations in interaxial angle. CONCLUSIONS: The method provided simple measurements of nasal base dimensions and asymmetry; some asymmetry was found also in healthy adults; only moderate relationships between nostril and alar dimensions and angles, as well as between nasal and nostril areas, were found, thus pointing to the necessity of detailed nostril assessments.