Variability of the Postauricular Muscle Complex Analysis of 40 Hemicadaver Dissections
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ORIGINAL ARTICLE Variability of the Postauricular Muscle Complex Analysis of 40 Hemicadaver Dissections Aldo Benjamin Guerra, MD; Stephen Eric Metzinger, MD; Rebecca Crawford Metzinger, MD; Chen Xie, MD; Yue Xie, MHA; Peter Lister Rigby, MD; Thomas Naugle, Jr, MD Background: The postauricular area is often explored and sternocleidomastoid fasciae, and the superior and by reconstructive and otologic surgeons. We previously posterior auricular and platysma muscles. Major con- reported on the use of postauricular tissues as a graft for tributors to the PMC were present in every specimen. wrapping hydroxyapatite implants in orbital reconstruc- Minor contributors were more variable in their pres- tion. This procedure reduced the incidence of implant ence and contributions. The posterior auricular exposure, while achieving acceptable cosmetic results. muscle was identified as having several muscle Although much is known about the postauricular area, bundles in 1 specimen and absent in 2 specimens muscle and fascial relationships and potential varia- (5%). The occipitalis fascia was seen to insert superior tions in anatomy remain ill defined. to the auricle and to blend with the deep temporal fas- cia in 3 cases (7%). The platysma muscle contributed Objectives: To identify and analyze variations in the to the PMC in 8 cases (20%). patterns of the postauricular muscle complex (PMC) and to study the relationships of the fascial contributions from the components that make up the PMC. Conclusions: This study demonstrated important varia- tions in the presence and contributions of 7 previously Methods: Dissections were performed using 40 fresh known muscular structures and their role in forming the specimens. Muscular and fascial components of the PMC PMC. Seven distinct patterns are identified, and the po- were dissected, analyzed, and photographed. tential clinical implications of these anatomical varia- tions are illustrated. Results: The PMC receives contributions from the occipitalis and trapezius muscles, the deep temporal Arch Facial Plast Surg. 2004;6:342-347 HE POSTAURICULAR AREA IS transfers are safely carried out. Retroauricu- frequented in clinical prac- lar grafts, on the other hand, can be used tice for otologic, reconstruc- as alternatives to vascularized tissue, de- tive, and aesthetic pur- pending on recipient site requirements. For poses. Important structures instance, small retroauricular grafts have in this area include the trapezius, occipita- been used successfully in lip augmenta- T 10 lis, and extrinsic auricular muscles and the tion. Also, agenesis, hypoplasia, neuro- temporalis and sternocleidomastoid fas- muscular dysfunction, and proximal inser- ciae.1-5 Investigators in previous studies have tion of the posterior auricular muscle have found these structures to be reliable.2 How- been implicated in the etiology of protrud- ever, descriptions of potential anatomical ing ears.11-13 Similarly, it has been sug- variations and the relationships that these gested that absence of the superior auricu- From the Aesthetic Surgical musculofascial structures share with each lar muscle plays a role in the pathogenesis 11-14 Associates, Metairie, La other have not been fully elucidated. Ana- of lop ear. Potential therapeutic maneu- (Drs Guerra and S. E. tomical variations in the postauricular area vers in the treatment of the protruding ear Metzinger), the Department may alter the results and design of vascu- are likely to be influenced by the underly- of Ophthalmology, Tulane larized flaps and musculofascial grafts har- ing surgical anatomy. University Medical Center, vested from this area. Also, these varia- New Orleans, La (Drs R. C. tions could have clinical implications in METHODS Metzinger and Naugle), and the otologic and otoplastic surgery. Department of Otolaryngology Vascularized tissue transfers from the Forty fresh hemicadaver heads were used in this (Dr Xie and Mr Xie) and the anatomical study. To standardize the experi- postauricular area have various applica- Department of Surgery, Section 6-9 ment, 1 surgeon (C.X.) performed all the dis- of Plastic and Reconstructive tions in reconstructive surgery. As with sections. Photographs were obtained using a Surgery (Dr Rigby), Louisiana any other part of the body, a sound under- 35-mm camera with a 105-macro lens for all State University Health standing of the anatomy of the postauricu- specimens. Distance and lighting were stan- Sciences Center, New Orleans. lar area is necessary to ensure that such dardized in all cases. The ethnicity and sex of (REPRINTED) ARCH FACIAL PLAST SURG/ VOL 6, SEP/OCT 2004 WWW.ARCHFACIAL.COM 342 ©2004 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/27/2021 Figure 1. Photograph of cadaver specimen demonstrating the type 1 pattern, which was seen 68% of the time and was the most common pattern noted. The illustration demonstrates the presence of the major and minor contributors to the postauricular muscle complex. In this pattern, the platysma muscle is not part of the complex. White indicates fascial confluence; green, occipitalis; pink, temporalis; blue, trapezius; striped, sternocleidomastoid; dark red, posterior auricular; dark blue, superior auricular; and sky blue, platysma. the specimens were recorded. Incisions were made along the cular bundles were seen in 1 posterior auricular postauricular crease starting 3 mm above the auricle. Two hori- muscle specimen. The occipitalis muscular fascia zontal incisions were extended from the superior and inferior extended anteriorly to cover the temporalis fascia in 3 aspect of the auricle to facilitate elevation of the skin–soft tis- cases (7%). sue envelope. The skin and subcutaneous tissues were dis- We classified the patterns into 7 distinct types as sected from the underlying muscular and fascial structures and the cranium. Each hemicadaver dissection was plotted to docu- follows: ment the different patterns of muscle and fascia contributing Type No. (%)* to the postauricular muscle complex (PMC). 1 27 (68) 2 7 (18) 3 1 (2) RESULTS 4 1 (2) 5 1 (2) Twenty male and 20 female hemicadaver heads were 6 2 (5) dissected. One female specimen was Hispanic, and 1 7 1 (2) male specimen was African American. The rest of the *Percentages do not total 100 because of rounding. specimens were white. In all specimens, the PMC was found to have contributions from the occipitalis In type 1, which was the most common pattern seen muscle, trapezius muscle, temporalis fascia, and ster- (68%), the specimens contained the 4 major contribu- nocleidomastoid muscular fascia. These 4 musculofas- tors: the occipitalis and trapezius muscles, the tempora- cial components were considered to be the major con- lis and sternocleidomastoid fasciae, and the extrinsic tributors to the area. Minor contributors to the PMC auricular muscles without platysma (Figure 1). In were the posterior auricular, superior auricular, and type 2, which was the second most common pattern platysma muscles. The minor contributors were mus- seen (18%), the specimens contained all the major and cular and did not contribute significant fascial com- minor contributors (Figure 2). In type 3, the speci- ponents to the PMC. The greatest variability occurred men contained all the major and minor components as a result of the presence or absence of minor con- except for the superior auricular muscle (Figure 3). tributors and occipitalis muscle-fascial components. The type 4 specimen contained all the major contribu- Interestingly, all these muscle groups are located tors, with the posterior auricular muscle being the only more superficially in the retroauricular area and in minor contributor (Figure 4). The type 5 specimen the same plane as the superficial musculoaponeu- lacked all 3 of the minor contributors, with the occipi- rotic system and platysma of the face. The platysma talis muscular fascia extending forward to the superior muscle contributed to the PMC only 20% of the time. point of the auricle and blending with the temporalis The superior auricular muscle was present in 35 speci- muscle fascia (Figure 5). In type 6 specimens, the mens (88%), and the posterior auricular muscle was posterior auricular muscle was found along with the present in 38 specimens (95%). Also, 4 separate mus- anterior occipitalis muscular fascial extension that (REPRINTED) ARCH FACIAL PLAST SURG/ VOL 6, SEP/OCT 2004 WWW.ARCHFACIAL.COM 343 ©2004 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/27/2021 Figure 2. The second most common pattern noted was type 2 (18%). In this case, the major and minor contributors to the postauricular muscle complex are present. The platysma muscle contributes to the inferior portion of the complex. In this particular specimen, the posterior auricular muscle was noted to be broad, and final dissection revealed 4 separate muscle bundles, with an intervening ligament between the 2 inferiorly located bundles. Figure 3. In 1 case, the postauricular muscle complex was made up of all the minor and major contributors, except for the superior auricular muscle. No obvious external ear deformity was noted in this specimen. blends with the temporalis fascia (Figure 6). The significant components of the PMC. Our study demon- type 7 specimen contained all the major contributors, strated that 7 structures can contribute to the PMC. In our with the superior auricular muscle being the only study, the major contributors to the PMC, which were pres-