CHAPTER 33 Otoplasty
Although protruding ears are considered a sign of good fortune by some Asians, in most other cultures, they are associated with feelings of anxiety, social discomfort, and even abnormal behavior.1 They are frequently a source of teasing or social ridicule, especially for young children.
Today there are techniques that allow for correction of this deformity with minimal pain and disruption of lifestyle. Achieving success as an otoplasty surgeon requires an appreciation of facial aesthetics, intimate knowledge of ear anatomy, a firm understanding of the rationale for the surgical technique employed, and meticulous attention to technical detail (Fig. 33-1).
Figure 33-1. Anatomic landmarks of the normal ear.
(Adapted from Adamson PA, Tropper GJ, McGraw BL. Otoplasty. In: Krause CJ, Mangat DS, Pastorek N, eds. Aesthetic Facial Surgery. Philadelphia: J. B. Lippincott; 1991:709.)
History
Otoplasty has a long history. The Indian method of auricular reconstruction was described as early as the 7th century in the writings of Sushruta.2 Sushruta’s writings were some of the earliest on the topic of Ayurveda (Indian medicine), and many of modern plastic surgery’s roots stem directly from these ancient Indian teachings. In 1597, Tagliacozzi3 published “De Curtorum Chirurgia,” which described techniques of auricular and other reconstruction and became known as the Italian method. However, in the early 1800s the Prussian surgeon Johann Friedrich Dieffenbach described the first technique for treating prominent ears. His techniques were published in the treatise “Die Operative Chirurgie,” an extraordinary two-volume work that encompassed all types of reconstructive and general surgical methods.4 He specified setting back the pinna by suturing the auricular cartilage to the mastoid periosteum once the postauricular skin had been excised.
A few years later, Ely described his treatment of protruding ears with an anterior approach involving a fusiform excision of skin and cartilage.5 Monks redefined this approach and treated children with a skin-only excision in the postauricular sulcus and adults with an excision of skin with cartilage.6
In the early 1900s, Morestin7 devised a method of excising the conchal cartilage at the medial wall to break the “spring” of the cartilage; this served to medialize the antihelix and decrease the projection of the concha. In 1910, Luckett8 reported on his method of reestablishing the antihelix with an excision of cartilage and plication of the edges. In 1937, Davis and Kitlowski9 reported on their technique, which combined cartilage excision, incision, and shaving; these, in addition to postauricular skin removal and sutures through the cartilage, were used to create a new antihelix. Becker10 sought to avoid unnatural cartilaginous ridging with incisions through the cartilage and reported on his technique in 1949. In 1955, Converse11 created a new antihelix with two parallel incisions along with suturing; he used a wire brush to round off the edges. In 1958, Gibson and Davis12 reported that making relaxing incisions in the cartilage resulted in a bending on the opposite side. In 1959, Farrior13 recorded his excision of cartilage wedges to break the cartilage spring before stabilizing the antihelix with a suture. In 1963, Stenstrom14 reported his findings that scoring the cartilage anteriorly facilitated the posterior plication; this method was particularly applicable to strong, stiff cartilage. In 1967, Kaye15 reported on his technique, which involved anterior scoring and posterior plication with removal of a vertical ellipse of the conchal cartilage (Fig. 33-2).
Surgery for the treatment of protruding ears has since evolved. More modern techniques center on less invasive therapies and recognize the underlying anatomic defects. This is evident, in particular, with the Mustarde method of reestablishing the antihelical relief and the Furnas conchal setback method. Mustarde16 published his method in 1963 and described using suture plication at three points without incision of the cartilage. The Furnas17 technique was published in 1968 and introduced correction of conchal excess by suturing the concha to the mastoid (Fig. 33-3).
Incidence
The incidence of microtia is 1 in 20,000; however, protruding ears are much more prevalent and may be the most common congenital deformity of the head and neck.18 In the white population, the incidence is 5%,18 with the unfurled helix being the most common abnormality.17 The hypertrophic protruding conchal bowl is the second most common deformity and is often present with the deformity of the antihelix.
Etiology
Genetic predisposition plays a role in this development; this is clearly seen in families with auricular deformities in both the parents and the children. In one study, 59% of otoplasty patients had a positive family history,19 and it has been shown that the inheritance is autosomal dominant with variable penetrance.20
Anatomy and Embryology
The pinna is an appendage that is composed of fibroelastic cartilage covered in very thin skin. On the anterior aspect the skin attaches to the perichondrium, whereas posteriorly there is a thin layer of areolar connective tissue underlying the skin. The auricular cartilage is an extension of the cartilage of the external auditory canal; it is invested in perichondrium and secured to the head by several ligaments and muscles. An anterior ligament stabilizes the tragus and helical root at the zygomatic process, and a posterior ligament stabilizes the concha to the mastoid. The “bowl” of the ear consists of three component concavities: the cavum concha inferiorly and the cymba concha and fossa triangularis superiorly. The pinna is defined by the series of folds and prominences on its anterior surface, with the major landmarks being the lobule, the helix and the antihelix, the tragus and the antitragus, the triangular fossa, the scapha, and the helical crus. Sensory innervation is through cranial nerves V (the auriculotemporal nerve), VII (the facial nerve), X (Arnold’s nerve), as well as C2 and C3 (the cervical plexus). The main blood supply comes from the external carotid artery via the posterior auricular and the superficial temporal arteries with additional contributions from the occipital artery. The lobule, which lies caudal to the cartilaginous structure, is made up of soft fibrofatty tissue and typically can protrude slightly. A cartilaginous protuberance at the helix is called “Darwin’s tubercle” and is the vestigial remnant that corresponds with the tip of an animal’s ear.21
The otic placode is the first hint of a future ear and is present during the third week of intrauterine growth. The auricle emanates from the mesoderm of the first and second branchial arches; its growth occurs through the development of the six hillocks of His at week 6.22 The following six structures evolve from these hillocks: (1) the tragus, (2) the helical crus, (3) the helix, (4) the antihelix, (5) the antitragus, and (6) the lobule. By week 12, the hillocks have fused. When these fuse inappropriately, a preauricular sinus tract can result.
Cartilage formation begins at week 7. The concha derives from the ectoderm of the first branchial groove. The upper portion forms the cymba concha, the middle portion forms the cavum concha, and the lowest portion forms the intertragal incisura. Malformation of the conchal bowl contributes to excessive protrusion of the pinna from the head. Additionally, the helical margin may develop separately from a skinfold caudal to hillocks 4 and 5,23 which then develops rapidly during weeks 8 through 12. Finally, the helix furls during the sixth month. The antihelix furls during weeks 12 through 16; it is the failure of it to do so that results in a protruding scapha.
Normally the pinna is positioned about 15 to 20 mm from the helical rim to the scalp. From the frontal view, the rim is posterior to the antihelix laterally by about 2 to 5 mm. The auriculocephalic angle is 30 degrees in the cosmetic ideal, with the normal range being between 25 and 35 degrees. Ears that exceed 40 to 45 degrees are typically considered abnormal.24
By the time a person is 3 years old, 85% of auricular growth is complete,25,26 and the cartilaginous growth is almost complete by age 5 years.27 The average vertical dimension is 5 cm in infants, whereas in adults it is 6 cm.24 Because of these growth characteristics, surgical intervention can be accomplished at the age of 5 or 6 years without hindering additional growth; this is also the time that other children start to note such abnormalities in others, and, in the social milieu of school, teasing may begin.
