Reading Dr Rob on the physical exam of the ears, I noticed that there are a couple of young men who could use a setback otoplasty. But before we get to that procedure and other ear reconstruction procedures, let's start with the anatomy.
The relationships, dimensions, and proportions of the external ear have been thoroughly reviewed by Tolleth. At birth the ear is the same size in both sexes, but by the end of the first year boys' ears are larger than girls'. The full width of a boy's ear develops by age 13 and the full length by age 15. In girls, width is complete at age 10 and length at age 13. Ear width is approximately 55 percent of length. The long axis of the ear is tilted posteriorly from the vertical axis of the face at an angle ranging from 2-30 degrees. The axis of the ear and the nasal bridge, although similar, are not identical. The angle between them approximates 15 degrees, with the ear more vertical. The helical rim protrudes 1 to 2 cm from the skull, with the projection increasing from superior to inferior. In a normal ear, the rim is positioned 10 to 12 mm from the mastoid at the superior helix, 16 to 18 mm from the mastoid at midear, and 20 to 22 mm from the mastoid in the lower third. Although these measurements are most commonly used as a reference in setback otoplasty to avoid the classic
“telephone” deformity, they must also be carefully assessed and reproduced for an anatomically correct ear reconstruction in patients with microtia.
- Grey's Anatomy, The External Ear (both photos from this link)
- Core Curriculum Syllabus: Review of Anatomy - Temporal Bone and Ear--Baylor College of Medicine
- Auricular Reconstruction for Microtia: Part I. Anatomy, Embryology, and Clinical Evaluation; Beahm, Elisabeth K. M.D.; Walton, Robert L. M.D.; Plastic & Reconstructive Surgery. 109(7):2473-2482, June 2002.
- Artistic anatomy, dimensions, and proportions of the external ear.; Tolleth, H; Clin. Plast. Surg. 5: 337, 1978.