The Caucasian Hump: Radiologic Study of the Osteocartilaginous Vault versus Surface Anatomy. Clinical Implications in Structured and Preservation Rhinoplasty.

[BACKGROUND] The relation between the osteocartilaginous nasal vault and nasal hump characteristics has not been fully investigated.

[METHODS] Measurements were collected from computed tomographic nasal scans in the midsagittal plane in adult Caucasian patients seeking rhinoplasty because of nasal hump from January of 2015 to December of 2018. Measurements were compared to those of sex- and age-matched patients not seeking rhinoplasty (control group). Patients with other significant nasal deformities were excluded. The correlations between nasal hump length, height, and osteocartilaginous nasal vault measurements were assessed. Distances from the beginning of the nasal hump to the kyphion and ethmoidal points were measured as well. The location of the nasal hump apex in relation to the keystone area structures was detailed.

[RESULTS] The study included 134 Caucasian patients, with 67 presenting nasal hump. The mean patient age was 32.9 years and 69.6 percent were female patients. Nasal hump measured a mean 17 ± 2.7 mm in length and 1.8 mm (range, 1.1 to 3.8 mm) in height. Nasal hump length correlated with nose length and nasal bone length. Nasal hump height correlated with nose length and the angle over the kyphion. In 97 percent of patients, the nasal hump began caudal to the ethmoidal point, and in all patients, the kyphion was underneath the nasal hump. The nasal hump is not a symmetric structure and, in all patients, its apex was situated above the septal cartilage.

[CONCLUSIONS] The nasal hump characteristics are mainly attributable to the septal cartilage, and this should be the cornerstone of any dorsal hump reduction strategy. The caudal aspect of the nasal bones contributes to the nasal hump, whereas the posterior ethmoidal plate rarely does.