“Nasal dorsum anatomy of major different ethnicities – surgical implications. A multicenter radiological study.”

Abstract

Background: The heterogeneity of nasal features across different ethnical groups is evident. This large-scale multicenter study evaluates dorsal keystone area and its relation to superficial nasal anatomy, through computed tomography (CT) scans. Methods: Six different populations were included: South Caucasian, Middle Eastern, Black South African, Eastern Asian, Mestizo and Eastern European. Each center obtained CT scans performed between January 2020 and December 2022 from patients presenting a nasal hump and from an age and sex-matched control group. Osteocartilaginous measurements in relation to Ethmoidal-point and to Rhinion, as well as their relation to superficial nasal anatomy, were collected from nasal CT scans in midsagittal view. These were compared between populations and, in each center, compared between patient groups (nasal hump versus no nasal hump). Results: The study population included 600 patients (254 with nasal hump), with a mean age of 33.98 (ranging 18 – 59) years old, and 55.6% were female. The distance from the Ethmoidal-point averaged: to Rhinion 10.1(±3.5)mm; and to nasal hump beginning point 1.68 (±0.23)mm. In 96% of cases the Ethmoidal-point was cranial or no more than 5mm caudal to the beginning of the nasal hump. S-shaped nasal bones were associated with nasal hump but its angulation (kyphion angle) did not correlate with nasal hump height. Conclusions: In most patients, the nasal hump has no ethmoid bone underneath it, and it apex is located over the septal cartilage. The Ethmoidal-point is a reliable landmark and should be considered when appreciating established and new preservation and structural rhinoplasty approaches.