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 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 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 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 .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 . 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

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©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 –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 -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

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©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- minor contributor (Figure 7). ent in every specimen, were the occipitalis and trapezius muscles and the temporalis and sternocleidomastoid fas- COMMENT ciae. Partial absence of the trapezius muscle has been re- ported but is thought to be extremely rare.15 The trape- The occipitalis, trapezius, sternocleidomastoid, and au- zius and sternocleidomastoid muscles arise from a common ricular muscles have previously been described as being premuscle mass during gestation, and there have been re-

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©2004 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/27/2021 Figure 4. The type 4 pattern is very similar to the type 3 pattern, except that the platysma contribution was absent from the postauricular muscle complex in this case.

Figure 5. In this pattern, all 3 of the minor contributors to the postauricular muscle complex were absent. Notably, the occipitalis muscle fascia extended forward and fused with both the temporalis muscle fascia superiorly and the sternocleidomastoid muscle fascia inferiorly.

ports of anomalies within these muscles.15-17 The fascial double-bellied flat muscle with an intervening liga- provisions of the major contributors to the PMC were noted ment.2 In 1 specimen, this muscle was identified as hav- to be strong, reliable, and capable of holding sutures. The ing 4 separate bundles. Similar variations have been ob- presence and components of the minor contributors to the served by others.7 Also, the minor contributors to the PMC PMC were more variable than those of the major con- were found to be completely absent in 1 case (type 5). tributors. In the group of minor contributors, the muscle The anterior fascial extension of the occipitalis muscle found most consistently was the posterior auricular muscle, to the temporalis fascia served to replace these compo- which was present in 38 (95%) of the 40 cases. The ex- nents. In 1 case, extension of the occipitalis muscle fas- trinsic auricular muscles have been well documented.3-5 cia occurred concurrently with a posterior auricular The posterior auricular muscle has been described as a muscle (type 7).

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©2004 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/27/2021 Figure 6. In the type 6 pattern, the occipitalis fascia extended forward and fused with the fascia of the temporalis muscle. A posterior auricular muscle is present in this pattern and is enveloped by fascial extensions from the occipitalis and sternocleidomastoid muscle fasciae, forming the postauricular muscle complex.

Figure 7. In this case, the occipitalis fascial extensions appeared normal, but no posterior auricular muscle was noted on dissection. A dense fascial band replaced the muscle. This structure developed as a thickening of the postauricular fascia that extended from above and below.

Absence or dysfunction of auricular muscles has been rial, although intrinsic and extrinsic auricular muscles implicated in the pathogenesis of certain ear deformi- play major roles in the ultimate shape and position of the ties.11-14 Of note, none of our cadavers was found to have auricle. Functionally, in vertebrates, postauricular muscles abnormalities of the external ear, implying that despite are used to identify potential mates and predators, as well variations, patients may not manifest obvious deformi- as in fight-or-flight reflexes. In humans, extrinsic muscles ties of the auricle. Based on our dissections, it appears respond to sound stimuli when studied with electromyo- that other structures involved in the PMC can compen- graphic techniques and maintain involuntary func- sate for the deficient extrinsic muscles (types 5 and 7). tion.14 There is a linear relationship between ear projec- The etiology of protruding and lop ears is multifacto- tion and insertion site of the posterior auricular muscle

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©2004 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/27/2021 in patients with and without protruding ears.18 How- thetic and reconstructive otologic surgery, and in pro- ever, Furnas19 and Mustarde20 recommend resection of viding strong and reliable grafts in restoration of the globe. the posterior auricular muscle in correction of the promi- Further study is needed to fully understand the relation- nent ear. An alternative reconstruction for protruding ears ship of the variations described and their potential ef- involves transposing the insertion of the posterior au- fects on flap complications. ricular muscle onto the concha.21 In principle, this tech- nique corrects valgus of the concha and underfolding of Accepted for publication June 10, 2004. the antihelix. Azad et al22 have combined transposition Correspondence: Aldo Benjamin Guerra, MD, Aes- with anterior conchal scoring and concha-mastoid su- thetic Surgical Associates, 3939 Houma Blvd, No. 216, Metai- tures. Anterior transposition of the posterior auricular rie, LA 70006. muscle has been found to be a useful adjunct in our hands. Patients with patterns 5 and 6 are not candidates for trans- REFERENCES position because they lack a posterior auricular muscle.

Use of the retroauricular fascial layer in transfer of vas- 1. Clemente CD. The ear. In: Gray’s Anatomy of the Human Body. Media, Pa: Lea & cularized tissues for various reconstructive procedures has Febiger; 1985:1315-1318. been reported.23-25 Clearly, a thorough knowledge of the 2. Davis J. Surgical anatomy and technique. In: Aesthetic and Reconstructive Oto- plasty. New York, NY: Springer-Verlag NY Inc; 1986:80-90. vasculature of these flaps is important for successful flap 3. Hollinshead HD. The ear, orbit and nose. In: Textbook of Anatomy. Philadelphia, transfer.5,7,26-29 However, based on our findings, we esti- Pa: Harper & Row Publishers Inc; 1985:943-946. mate that retroauricular fasciae and its variations play a sig- 4. Netter FH. Atlas of Human Anatomy. Summit, NJ: CIBA-Geigy Co; 1985:21. 5. Allison GR. Anatomy of the external ear. Clin Plast Surg. 1978;5:419-422. nificant role in providing an additional margin of safety in 6. Naugle TC, Lee AM, Haik BG, Callahan MA. Wrapping hydroxyapatite orbital im- flap transfer. This margin of safety is evident in clinical re- plants with posterior auricular muscle complex grafts. Am J Ophthalmol. 1999; 128:495-501. ports, which use fasciae to carry random-pattern or axial 7. Talmi YP, Horowitz Z, Bedrin L, Kronenberg J. Auricular reconstruction with a 26-29 circulation to skin components. To access the vessels postauricular myocutaneous island flap: flip-flop flap. Plast Reconstr Surg. 1996; and to free the deeper (temporalis) fascia, which carries the 98:1191-1199. 8. Farrior JB. Postauricular myocutaneous flap in otologic surgery. Otolaryngol Head flap, the more superficial structures must be divided, as pre- Surg. 1998;118:743-746. viously described.29 If the superficial anatomy of the ret- 9. Krespi YP, Ries WR, Shugar JMA, Sisson JA. Auricular reconstruction with roauricular area is aberrant, the flap vasculature may be dam- postauricular myocutaneous flap. Otolaryngol Head Neck Surg. 1983;91:193- 196. aged during surgery, as the appropriate dissection plane 10. McCollough EG. Facelifting: evolution of a personal technique. Paper presented may be difficult to identify. Venous insufficiency is also re- at: 11th Annual Minimally Invasive Facial Aesthetic Course; May 22, 2004; New Orleans, La. lated to the underlying muscle and fascial anatomy as well 11. Smith DW, Takashima H. Ear muscles and ear form. Birth Defects Orig Artic Ser. 27 as to greater anatomical variability of veins. Although we 1980;16:299-302. did not specifically describe the relationships between the 12. Smith DW, Takashima H. Protruding auricle: a neuromuscular sign. Lancet. 1978; 1:747-749. PMC and the venous drainage, we believe that the fascial 13. Zerin M, Van Allen MI, Smith DW. Intrinsic auricular muscles and auricular form. structures and their variations play an important role in dis- Pediatrics. 1982;69:91-93. sipating venous congestion. Several authors have already 14. Seiler R. Muscles of the external ear and their function in man, chimpanzees and macaca [in German]. Gegenbaurs Morphol Jahrb. 1974;120:78-122. recommended widening the amount of fascia harvested to 15. Emsley JG, Davis MD. Partial absence of the trapezius muscle in a human ca- increase venous drainage.29,30 daver. Clin Anat. 2001;14:383-386. 16. Goss CM. Anatomy of the Human Body. Media, Pa: Lea & Febiger; 1973:372- The retroauricular fascia can also be extremely use- 396. ful as a graft. While variations do exist, the fascial layer is 17. Sarikcioglu L, Donmez BO, Ozkan O. Cleidooccipital muscle: an anomalous muscle consistently thick enough to provide for a durable graft.6,7 in the neck region. Folia Morphol (Warsz). 2001;60:347-349. 18. Guyuron B, Deluca L. Ear projection and the posterior auricular muscle inser- The PMC fascia grafts are important in challenging situa- tion. Plast Reconst Surg. 1997;100:457-460. tions, such as the wrapping of hydroxyapatite spheres in 19. Furnas DW. Otoplasty for orotruding ears, cryotopia, or Stahl’s ear. In: Evans postenucleation socket reconstruction. Long-term fol- GRD, Gregory RD, eds. Operative Plastic Surgery. New York, NY: McGraw-Hill Co Inc; 2000:417-448. low-up has demonstrated the reliability of this tech- 20. Mustarde JC. Correction of prominent ears using buried mattress sutures. Clin nique.6 As substitutes for other tissues, postauricular fas- Plast Surg. 1978;5:459-464. 21. Nicoletis C, Guerin-Surville H. Prominent ears: transposition of the postauricular cia grafts are thought to be superior alternatives to dermal muscle on the scapha: a new technique. Aesthetic Plast Surg. 1978;2:295-299. fat grafts and superficial musculoaponeurotic system grafts 22. Azad S, Edwin A, Kumar PV. Posterior auricular muscle—a useful adjunct in oto- in cosmetic lip augmentation.10 Retroauricular fascia is plasty. Br J Plast Surg. 2003;56:722-723. 23. Yoshimura K, Ouchi K, Wakita S, Uda K, Harii K. Surgical correction of cryptopia thicker and sturdier than both dermal fat grafts and super- with superiorly based superficial mastoid fascia and skin paddle. Plast Reconstr ficial musculoaponeurotic system grafts and seems to re- Surg. 2000;105:836-841. sist the dynamic forces of the .10 Other 24. Park C, Shin SK, Kang HS, Lee YH, Lew JD. A new arterial flap from the post- auricular surface: its anatomic basis and clinical application. Plast Reconstr Surg. authors have used the strong fascial layer for placement of 1988;82:498-505. sutures in otoplatsy, with great reliability.19 25. Guyuron B. Retroauricular island flap for eye socket reconstruction. Plast Re- constr Surg. 1985;76:527-533. We used fresh human cadavers to study the varia- 26. Yang D, Morris SF. Vascular basis of the retroauricular flap. Ann Plast Surg. 1998; tions and relationships of the muscular and fascial com- 40:28-33. ponents of the PMC. Our findings were obtained from a 27. Kolhe PS, Leonard AG. The posterior auricular flap: anatomical studies. Br J Plast Surg. 1987;40:562-569. small sample size, primarily elderly whites. Different eth- 28. Yotsuyanagi T, Watanabe Y, Yamashita K, Urushidate S, Yokoi K, Sawada Y. Ret- nic groups may display patterns that are different from roauricular flap: its clinical application and safety. Br J Plast Surg. 2001;54:12-19. those observed in the present study. Knowledge of these 29. Song R, Song Y, Qi K, Jiang H, Pan F. The superior auricular and retro- auricular arterial island flaps. Plast Reconstr Surg. 1996;98:657-669. anatomical variations can help in the planning and safe 30. Marty F, Montandon D, Gumerer R, Zbrowski A. in the : transfer of vascularized tissue, in maneuvers for aes- anatomical, physiological and clinical study. Ann Plast Surg. 1986;16:368-376.

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