Ethnic differences in the morphology of the pinna

Abstract

Metric features of the ear are important for diagnosis of congenital malformations, pre-operative planning and design of hearing devices. Non-metric features including earlobe attachment is a marker of population genetics. Although these features vary with sex and populations, it’s unclear whether they show ethnic variations. This study describes ethnic differences in the morphology of the pinna. Both ears of one hundred and forty-eight (148) medical students (80males and 68 females) [recruited from four ethnic groups: Kenyan Indian, Kenyan Arab, Kikuyu and Luhya] were studied. Ear projection, heights and widths of ear, earlobe and concha were measured. For the Kenyan Indians, Arabs, Kikuyus and Luhyas respectively, proportion of free earlobes was 70.1%, 48.6%, 37.8%, 43.2%, attached lobes was 21.6% 27.1%, 42.9%, 32.4%. Mean earlobe height was 18.2mm, 16.7mm, 15.8mm, 15.8mm (p=0.001), ear projection at mid-tragus was 14.5mm, 13.5mm, 12.5mm, 12.6mm (p=0.035). Ethnic differences are present in earlobe height, attachment type and ear projection at mid-tragus. Earlobe height among indigenous Kenyans is significantly smaller compared to Kenyan Indians and Arabs. The attached earlobe is most prevalent among Kenyan indigenous while the free earlobe is most prevalent among Kenyan Indians. These features ought to be considered in aesthetic reconstruction of ear during earlobe rejuvenation and correction of projected ears.

Keywords: Pinna morphology, Ethnic difference, Variations