Microtia and Otoplasty


Key Points

Otoplasty Options

  • 1.

    Tape and wax reshaping in the neonatal period

  • 2.

    Incisionless otoplasty for ears that correct easily with finger pressure

  • 3.

    Open or traditional otoplasty

  • 4.

    Creative options such as grafting to cover skin defects or slide rotational flaps to borrow cartilage when it is deficient

  • 5.

    Autologous rib grafting for microtia or traumatic deformities

  • 6.

    Awareness of, and colleagues working with, prosthetics and bone-anchored hearing aid placement for patients with microtia/atresia

Questions

What is otoplasty?

Otoplasty is the manipulation of abnormally shaped cartilages to achieve a more natural-appearing shape of the external ear. This can be achieved by surgical and nonsurgical methods.

What are the indications for otoplasty?

Otoplasty is not based on the ear shape but rather the patient’s perception of the ear shape. If the ears are asymmetric or if their shape draws attention to the ears instead of the person’s face, otoplasty may be indicated. If the patient sees only his or her ears in the mirror or is teased because of their size or shape, otoplasty can improve self-esteem.

Which anatomic landmarks of the external ear are important in otoplasty? ( Fig. 55.1 )

The circumference of the external ear is described by the helix, lobule, and tragus. The inner folds of the ear consist of the antihelix and antitragus. The antihelix divides the external ear superiorly into the superior and inferior crus. Between the crura is the fossa triangularis. Between the helical rim and the antihelical fold is the scaphoid fossa. Between the antihelix and the tragus is the conchal bowl, which is divided by the root of the helix into the concha cymba above and the concha cavum below. The tragus overlies the ear canal opening.

Fig. 55.1, Landmarks of the external ear: (1) superaurale, (2) subaurale, (3) preaurale, (4) postaurale, (5) otobasion superius, (6) otobasion inferius, (7) deepest point on the notch on upper margin of tragus, (8) lowest point on the lower border of tragus, (9) protragion, (10) concha superior (the intersection of the lower edge of the anterior end of the crus antihelicis inferius and the posterior border of crus helicus, (11) incisura intertragica inferior (the deepest point in the incisura intertragica), (12) incisura anterior auris posterior (the most posterior point on the edge of incisura anterior auris), (13) strongest antihelical curvature, (14) deepest lateral border of external auditory meatus, (15) lobule anterior (ear attachment line is drawn joining the otobasion superior and inferior – the point on this line just below the incisura intertragica where the cartilage ends is the landmark), and (16) lobule posterior (the most posterior point on the margin of lobule perpendicular to lobule anterior).

How are external ear malformations classified?

Various grading systems have been proposed for congenital malformations of the auricle. Most reliable for documentation or discussion between health care providers is an anatomic description of the abnormality, since no staging system is widely recognized. Description of the abnormality can help direct thought about reconstruction or correction. Commonly used terms are protruding or prominent ears, lop ears, Stahl’s ears, constricted ears, cryptotia, microtia, and anotia .

Describe the dimensions of a normal ear.

Ears are fully grown by 9 years of age. They do not change shape spontaneously beyond 12 months of age. Whereas no one size or shape is normal for all people, some approximate measurements can be helpful in assessing the degree of abnormality of an ear. Ear height is typically 55 to 65 millimeters, and width is from 30 to 45 millimeters. Width is usually 50% to 60% of the height. The ear is rotated so that the top is 15 to 30 degrees more posterior than the earlobe. At its midpoint, the ear protrudes from the scalp approximately 18 to 20 millimeters. The angle of protrusion of the ear from the head is usually <21 degrees in a female and <25 degrees in a male. The root of the helix is usually 75 to 95 millimeters posterior to the lateral canthus of the eye.

What is a prominent or protruding ear deformity?

This common external malformation is diagnosed when the angle of the ear to the head is >35 degrees. It is most commonly a result of the lack of antihelical fold development. The ear then protrudes more than the 20 millimeters expected from the scalp and takes over the frontal profile. Instead of seeing a person’s face, the eyes of the observer are drawn to the ears. A normal ear shape and angle of protrusion can be attained by gentle repositioning of the ear with finger pressure.

What is a constricted or cup ear deformity?

This ear deformity is characterized by the inability of gentle finger pressure to attain a normal shape or position of the ear. A deficiency of skin, cartilage, or both restricts the opening up or “unfolding” of the ear into a normal shape with finger pressure.

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