The external ear is made up of the pinna or auricle, and the auditory canal, or meatus. The pinna serves to collect the sound waves that travel through the air, and the meatus guides these vibrations to the middle ear. The concave outer surface of the pinna consists of a series of depressions and convexities that result from the folding of its fibrocartilaginous structure. Specifically, the lobule (commonly known as the ear lobe), located below the antitragus, is composed of tough areolar and adipose tissue, and lacks the developed structure of the rest of the pinna1 Fig. 23-1.
Variations in the basic structure of the external ear.
The auditory canal or meatus, extends approximately 1 inch from the bottom of the concha to the tympani or middle ear. The meatus forms an S-shaped curve and is composed of cartilage, membrane and bone, and is lined by skin.1
In analyzing the aesthetic variations of the ear, it is important to understand the anatomic variations of the human ears. Ears may be categorized into specific types, “hyper-,” “hypo-,” and “meso-”based on their appearance. In “hyper”- ear types, the helix is pressed down toward the head, the anti-helix protrudes beyond the helix, the lower helix and lobule bend toward the head, and the tragus and anti-tragus protrude and turn outward. In “hypo”- ear types, the helix is protruding, the anti-helix is pressed in toward the head, the lower helix and lobule point outward almost horizontally, and the tragus and anti-tragus press inward in comparison to the surrounding parts of the ear. In “meso”- ear types both the helix and anti-helix protrude from the head, the lower helix and lobule evert from the head at an angle slightly less than the horizontal angle of the hypo-type, and the tragus and anti-tragus are in an intermediate position.2
Understanding different ear types can aid in more accurate and aesthetic auricular reconstruction. A study conducted at Tulane University compared specific attributes of the human ear observed among 67 Caucasian men and 120 African American men, both living and deceased. In analysis of the measurements of total ear length, ear width, ear base, and concha length and width, it was observed that Caucasians generally have long, narrow ears and Americans of African descent have shorter, broader ears. The average length and width of the ear respectively were 64.18 mm and 37.19 mm for Caucasian men, and 58.58 mm and 37.43 mm for African American men. Americans of African descent had minimal-to-no hair on the ear in comparison to Caucasian ears. The helix was observed to be broader in African Americans, whereas the antihelix was more prominent in Caucasians.2 As the blending of races, cultures, and ethnicities has become more common, such differences have become less pronounced. When doing ...