Investigation of morphometric features of auricle in newborns and etiology of auricle deformity

ABSTRACT Importance The diagnosis of congenital auricular deformity often relies on the clinical experience of clinicians, leading to a high incidence of misdiagnosis and missed diagnosis due to the lack of quantitative diagnostic criteria. Objective To characterize auricle morphology in newborns from southern China and explore the underlying etiology of congenital auricle deformity. Methods A total of 636 neonates (1272 ears) with less than seven days old were included. The auricles of each infant were measured and photographed. The relationship between maternal factors and the occurrence of congenital auricle deformity was analyzed. Results The incidence of auricular deformity in southern China was 79.87%. Helical rim deformity and mixed deformity had the highest incidence (17.30% each), while cryptotia had the lowest incidence (0.31%). Among mixed deformities, lop ear with conchal crus ear was the most common (22.73%). Each type of auricle deformity had distinct measurement indicators: the vertical distance of cephalo‐auricular was 73.97% longer and cephalo‐superaurale was 70.00% longer in protruding ears compared to normal auricle; the vertical distance of cephalo‐auricular was 10.96% less in lop ears, 15.07% less in conchal crus ears, and 41.1% longer in cup ears; the distance between helix and antihelix was 22.35% less in constricted ear, 12.94% greater in helical rim deformity, and 43.53% greater in Stahl's ear. Family history of hereditary ear deformity and paternal smoking were significant factors associated with ear deformity in southern China. Interpretation The incidence of auricle deformities is high in southern China, with significant differences in the morphometric structures of different auricle types. This study characterizes newborn ear morphology in southern China, revealing a 79.87% incidence of auricular deformities, with distinct morphometric differences among types and associations with family history and paternal smoking.