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Journal of Plastic, Reconstructive & Aesthetic Surgery (2014) xx, 1e7
Anatomic and histological study of great auricular nerve and its clinical implication Hun-Mu Yang a, Hee-Jin Kim b, Kyung-Seok Hu b,* a
Department of Anatomy, College of Medicine, Dankook University, Cheonan, South Korea Division in Anatomy and Developmental Biology, Department of Oral Biology, Yonsei University College of Dentistry, Seoul, South Korea
b
Received 16 June 2014; accepted 19 October 2014
KEYWORDS Great auricular nerve; Parotidectomy; Rhytidectomy; Nerve graft; Nervous anastomosis
Summary Background: The great auricular nerve (GAN) is often sacrificed during parotidectomy, rhytidectomy, and platysma flap operation. Transection of the nerve results in a wooden numbness of preauricular region, pain, and neuroma. The aim of this study was to describe the branching patterns and distribution area of the GAN. Methods: Twenty-five embalmed, adult hemifacial Korean cadavers (16 males, nine females; mean age 62.5 years) were used in this study. The branching of the GAN was determined through careful dissection. The histological structure of the GAN was also examined by harvesting and sectioning specimens, and then viewing them with the aid of a light microscope. Results: The branching pattern of the anterior, posterior, deep, and superficial branches of the GAN could be classified into five types: type I (20%), where the deep branches arose from the anterior branch; type II (24%), where all branches originated at the same point; type III (28%), where the deep branch arose from the posterior branch; type IV (8%), where the superficial branches arose from the posterior branch; and type V (20%), where the anterior and posterior branches ran independently. A connection between the GAN and the facial nerve trunk was observed in all specimens, and a connection with the auriculotemporal nerve was observed in a few specimens. The total fascicular area of both regions decreased from proximal (1.42 mm2) to distal (0.60 mm2). There were 2.5 and 5 fascicles in the proximal and distal regions, respectively. Conclusion: The results reported herein will help toward preservation of the GAN during surgery in the region of the parotid gland. Furthermore, the histologic findings suggest that the GAN would be a good donor site for nerve grafting. ª 2014 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
* Corresponding author. Room 601, Department of Oral Biology, Yonsei University College of Dentistry, 50 Yonseiro, Seodaemun-gu, Seoul 120-752, South Korea. Tel.: þ82 2 22283047; fax: þ82 2 3938076. E-mail address: [email protected] (K.-S. Hu). http://dx.doi.org/10.1016/j.bjps.2014.10.030 1748-6815/ª 2014 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
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Introduction The great auricular nerve (GAN) is the largest of the four cervical cutaneous nerves. It emerges through the superficial cervical fascia on the posterior border of the sternocleidomastoid muscle (SCM), and distributes to the mandibular angle, the skin over the parotid gland, the parotid gland, and the skin of the auricle.1 Clinically, iatrogenic or inevitable amputation of the GAN during rhytidectomy or parotidectomy would incur significant complications such as dysesthesia or allodynia in the involved skin area, otalgia, discomfort on cold exposure, and traumatic neuroma.2e7 McKinney and Gottlieb (1980) reported that the GAN was positioned deep to the layer containing the superficial musculoaponeurotic system (SMAS), and thus manipulating the SMAS during facelift surgery was thought to be relatively safe.6 However, there have been numerous reports of GAN impingements during facelift surgery. Ozturk et al. (2012) found that injury to the GAN can result in more severe distress than injury to cutaneous nerves in other areas, although the incidence of GAN injury is low, reportedly ranging from 0% to 2.6%.7 Barbour et al. (2013) reported that GAN injury is a common complication, occurring at a rate of 6% during rhytidectomy, and that a recently introduced, minimally invasive technique for producing a short scar has an increased risk of GAN injury.2 In addition, it was reported that the rate of sensory disorders resulting from nerve damage during parotidectomy has increased significantly.3 Traumatic neuroma can also occur after amputation of the GAN.4,8,9 Moss at al. (2000) reported that traumatic neuroma following sacrifice of the GAN occurred at a rate of 6% after surgery on the parotid gland, while de Chalain and Nahai (1995) described a large neuroma at the distal end of a transected GAN in a 56-year-old female patient that was detected 9 years after full rhytidectomy.4,9 On the other hand, the GAN is known to be a good donor nerve because it is easily accessible due to its convenient location beneath the platysma muscle, and it can be harvested during nerve graft surgical procedures of the head and neck region without the necessity for additional surgery. Its relatively large cross-sectional area renders the GAN a frequent candidate for replacing the facial nerve (FN), inferior alveolar nerve, and accessory nerve.10e15 The purpose of this study was to describe the branching patterns of the GAN and its topographic relationships to other nearby structures, with the aim of providing critical reference data for surgical procedures to the head and neck. Furthermore, the histomorphometric characteristics of the GAN were explored in the context of nerve grafting.
Materials and methods In total, 25 sides of formalin-fixed necks from Korean cadavers (11 bilateral specimens, three unilateral specimens) were used in this study. The subjects included 16 males and nine females, with an average age of 62.5 years. The precise course of the GAN and the extent of its innervation and communication were established by careful dissection of these cadaveric specimens, which
H.-M. Yang et al. had no history of trauma or any surgical procedures on the face and neck. The dissections were performed with the specimens in the oblique lateral position. The parotid fascia and the superficial cervical layer were exposed by dissection of the whole dermal layer from the neck to the face. The cervical cutaneous nerves were particularly carefully dissected and sketched, with special attention being paid to the course of the GAN on the SCM muscle. Along with the course of the GAN, the nerve branches were exposed clearly, and further fine dissection was performed to identify the fine nerve branches of the GAN on the parotid fascia and the nerve branches to the auricle. In addition, after removal of the skin from the anterior and posterior aspects of the specimens, the fine nerve branches from the GAN could be identified. The distribution area of the GAN to the auricle was also explored through the dissection. At the parotid region, the parotid parenchyma was removed and the region dissected further to expose the FN trunk and its divisions, and the fine terminal nerve branches from the GAN. The communicating nerve twigs among the nerve branches of the GAN, the FN, and the nerve branches of the trigeminal nerve were examined. All of the microdissections were performed with the aid of a surgical microscope (OPMI, Zeiss, Germany). Sections were prepared for histomorphometric analysis by first harvesting the intraparotid terminal nerve branches of the GAN (including the FN trunk) from five specimens, and from the point at which the GAN emerges at the posterior border of the SCM (i.e., the proximal region of the GAN) and the region prior to the furcation point of the GAN on the SCM (i.e., the distal region of the GAN) from 10 dissected specimens. These specimens were postfixed for 72 h with 4% paraformaldehyde and then embedded in paraffin wax. Transverse 5-mm-thick sections were mounted on glass slides, and then stained with hematoxylineeosin and Luxol fast blue. Histologic observations were performed with the aid of a light microscope, and photographs were taken. No distinction was made between the male and female cadavers. All photographs and diagrams in this article are of structures viewed from the left side of the specimen.
Results In all specimens, the GAN ascended toward the parotid gland from the posterior border of the SCM. In terms of the topographic relationship with surrounding structures, the GAN emerged from the posterior border of the SCM, and was located behind the external jugular vein in every case. The GAN divided into the anterior and posterior branches in its course on the SCM. The anterior branch then further divided into the superficial and deep branches. The superficial branch distributed to the skin and surface of the parotid gland, while the deep branch entered the parenchyma of the parotid gland. The branching patterns of these nerve branches could be classified into five categories (Figure 1): Type I e The GAN divided into the anterior and posterior branches, and then the anterior branch bifurcated into
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Anatomy of great auricular nerve
3 of the anterior branch. This pattern was observed in six of the specimens (24%; Figure 1(B)). Type III e The deep branch originated from the posterior branch of the GAN (Figure 1(C)). This was the most frequently observed pattern, occurring in seven of the specimens (28%). Type IV e The superficial branch arose from the posterior branch of the GAN. This pattern was observed in two specimens (8%; Figure 1(D)). Type V e The GAN had already bifurcated into the anterior and posterior branches by the time it had emerged onto the SCM through the superficial cervical fascia (Figure 1(E)). This pattern was found in five of the specimens (20%). The distribution areas of the superficial branch of the GAN were dissected and examined. These nerve branches ran upward from the mandibular angle and they distributed fibers to the parotid gland and the skin covering it. The superficial branch from the GAN was located on the superficial fascia of the parotid gland and ran toward the anterior margin of the parotid gland. The fine, terminal nerve twigs of the superficial branch of the GAN extended to the surface of the masseter muscle and its fascia (Figure 2). Relatively small nerve twigs from the deep branch of the GAN were distributed to the deep layer of parotid gland. The main branches from the deep branch of the GAN ascended and ran toward the auricle, distributing fibers to its posterior aspect (Figure 3(A)). The deep branch of the GAN is generally known to be distributed to the inferior part of the ear. However, in 20 of the specimens in this study (80%) it also supplied the middle
Figure 1 The five branching patterns of the great auricular nerve. AeE, Branching pattern types IeV, respectively. G, great auricular nerve; A (in photograph), anterior branch; P, posterior branch; S, superficial branch; D, deep branch; SCM, sternocleidomastoid muscle; EJV, external jugular vein.
the superficial and deep branches (Figure 1(A)). This category is the most commonly described one in most anatomy textbooks, but was only observed in five of the specimens in this study (20%). Type II e The GAN trifurcated at a single point into the posterior branch and the superficial and deep branches
Figure 2 The distribution area of the superficial branches of the great auricular nerve. Arrowheads indicate superficial branches. G, great auricular nerve; P, posterior branch; S, superficial branch; D, deep branch.
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Figure 3 The distribution area of the deep branch of the great auricular nerve. The arrow indicates the deep branch. A, Deep branch entering the ear and then ascending toward the inferior part of the auricle. B, Deep branch supplying the middle of the posterior aspect of the auricle. C, Deep branch supplying the upper and middle of the posterior aspect of the auricle. Arrowheads indicate a point where the deep branch is entering the parotid gland. P, posterior branch; D, deep branch; L, lesser occipital nerve; PA posterior auricular nerve.
of the posterior aspect of the auricle (Figure 3(B)). In the remaining five specimens (20%), the deep nerve branches were distributed to the middle and upper portions of the posterior aspect of the auricle (Figure 3(C)). Most of the posterior branches were also distributed to the anterior surface of the ear (Figure 4). These nerve branches divided into two branches below the level of the lobule e the superficial and deep subbranches e that entered the auricle above the otobasion inferius (Figure 4(A)). Thereafter, the superficial nerve subbranch ran horizontally and ascended through the groove between the helix and the antihelix above the ear cartilage, and the
deep nerve subbranch further divided into two separate nerve twigs: upper and lower. The upper nerve twig ascended and distributed to the inferior two-thirds of the auricle below the ear cartilage, while the lower nerve twig was distributed to the ear lobule (Figure 4(B)). A unique and novel finding of this study was communication between the GAN and the FN trunk. In every specimen, the deep branch of the GAN communicated with the FN trunk (Figure 5(A)). In a rare case, the deep branch of the GAN communicated with the posterior auricular nerve, and the anterior branch simultaneously communicated with the auricular temporal nerve (Figure 5(B)).
Figure 4 The distribution area of the posterior branch of the great auricular nerve. Arrows indicate the deep nerve subbranches, and arrowheads indicate the superficial nerve subbranches.
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Anatomy of great auricular nerve
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Figure 5 The communication between the great auricular nerve (GAN) and the facial nerve (FN). The white arrowheads indicate the deep branch of the GAN, which communicates with the FN trunk. The black arrowheads indicate the small branch of the anterior branch, which communicates with the auricular temporal nerve (ATN). The black arrows indicate the small branch of the deep branch, which communicates with the PAN. A black dotted circle indicates the point where the deep branch meets the ATN. A white dotted circle indicates the point where the deep branch meets the PAN. ATN, anterior temporal nerve; PAN, posterior auricular nerve; A, anterior branch; D, deep branch; FN, facial nerve.
Nerve specimens were harvested from proximal (point of emergence on the posterior border of the SCM) and distal (prior to the point of bifurcation into the anterior and posterior branches) regions along the course of the GAN, and prepared for histomorphometric analysis. The average number of fascicles was 2.5 (range, 1e4) at the proximal region of the GAN and 5 (range, 2e8) at the distal region; the total fascicular areas were 1.42 mm2 (range, 0.84e1.75 mm2) and 0.6 mm2 (range, 0.54e0.64 mm2), respectively. Thus, the total number of fascicles increased from proximal to distal in this nerve, whereas the total fascicular area decreased (Figure 6, Table 1), with a
substantial difference in an average fascicle area between the two regions (0.57 vs. 0.12 mm2).
Discussion There have been considerable efforts made to preserve the GAN in order to reduce postoperative complications at the para-auricular area.7,9,16e21 Murphy et al. (2012) observed that the GAN was located an average of 0.60 cm anterior to the posterior border of the platysma muscle and 1.17 cm posterior to the external jugular vein. By contrast, in all specimens examined in this study the GAN was located posterior to the external jugular vein. The surgical approach for procedures around the parotid gland should therefore be posterior to the external jugular vein in order to preserve the GAN. Numerous studies have been performed to establish the location of the GAN relative to the SCM muscle with a view to improving the safety of various surgical procedures. McKinney and Katrana (1980) reported that the GAN crossed the midtransverse belly of the SCM at 6.5 cm inferior to the
Table 1 The metric value of the histologic findings of great auricular nerve.
Proximal Figure 6 Histologic findings of the great auricular nerve. G, great auricular nerve; L, lesser occipital nerve; T, transverse cervical nerve; S, supraclavicular nerve.
Distal
Fascicular number
Total fascicular area
5 mm (ranging from 2 to 8 mm) 2.5 mm (ranging from 1 to 4 mm)
0.6 mm2 (ranging from 0.54 to 0.64) 1.42 mm2 (ranging from 0.84 to 1.75)
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6 lowermost point of the bony external auditory meatus (EAM), and Lefkowitz et al. (2013) noted that in most cases the GAN crossed the upper one-third area of the SCM, ramifying into the superior and inferior branches.6,19 Ozturk et al. (2014) demonstrated that the GAN proceeded across the upper, middle, and lower one-third areas of the SCM in 53.9%, 26.9%, and 15.4% of cases, respectively. They also determined the location of the GAN at various points on the SCM relative to the EAM: the distance between the EAM and GAN was 4.9 cm at the anterior border of the SCM, 7.3 cm at the midbelly of the SCM, and 9.8 cm at the emergence of the GAN onto the SCM.7 Conversely, the cervical cutaneous nerves have been treated with relatively little interest because they are considered relatively unimportant clinically. Likewise, there are no detailed descriptions of the patterns of innervation of the cervical cutaneous nerves either in the literature or in anatomy textbooks. In the present study, we found that the GAN divided into three branches (superficial, deep, and posterior branches) e this differs from what has been described in the literature thus far. In anatomy textbooks, the typical case is described as division of the GAN into the anterior and posterior branches; this pattern was observed in only 20% of the cases in this study (Standring, 2008). In fact, the most frequently observed pattern was where the deep branch originated from the posterior branch of the GAN (type III, 28%). The nerves distributing to the anterior facial skin were divided into two branches: superficial and deep. However, these two branches originated from the GAN in several ways (i.e., types IeV), among which the superficial branch originated from the anterior branch of the GAN in 10 of the specimens (types I þ V; 40%). The superficial branch originated from the already separated anterior branches on the SCM (type V, five cases). In the remainder (n Z 15, 60%), the superficial branch originated directly from the GAN. The superficial branches supplied the superficial facial skin above the parotid fascia anterior to the auricle. The deep branch, which was a small nerve, divided into two or three smaller nerve twigs on the posterior margin of the parotid gland, and ran deep to the parotid gland parenchyma. Its branching patterns were similar to those described for the superficial branch, in that they originated either from the anterior branch (10 cases, 40%) or directly from the GAN (15 cases, 60%). The topography of the GAN around the ear is also very important because preauricular incisions may extend to the anterior surface of the ear. Furthermore, discomfort with cold exposure has been reported after amputation of the GAN. Thus, the anatomical relationship between the GAN and the ear need to be elucidated. In this study, some subbranches of the GAN posterior branches distributed to the inferior two-thirds of the auricle below the ear cartilage and the ear lobule after proceeding over the anterior surface of the ear. It is generally thought that the GAN is distributed to the inferior part of the posterior aspect of the auricle, while the lesser occipital nerve is distributed to the superior and middle parts of the auricle. However, we observed that the middle inferior part of the posterior aspect of the auricle was distributed by the GAN in only 20% of the specimens. In these cases, the lesser occipital nerve distributed to the lateral part of the occipital region
H.-M. Yang et al. posterior to the auricle. Thus, rather than remove all branches of the GAN, it may be possible for the surgeon to instead preserve the posterior branches of the GAN if its three branches occur separately (i.e., as the superficial, deep, and posterior branches). When a nerve-graft procedure results in damage to the FN and the other trigeminal nerve branches, the GAN is the first choice of donor nerve because it is easily accessed and has a large cross-sectional area.14 In nerve grafting, the total fascicular area of the donor nerve is always larger than that of the recipient nerve. Colbert et al. (2013) reported that there was a significant correlation between the widths of the GAN and FN, which would allow prediction of the FN width using the GAN width.17 They reported that the average widths of the GAN and the FN were 2.75 and 2.83 mm, respectively, and the total fascicular area of the five branches of the FN (i.e., the temporal, zygomatic, buccal, marginal mandibular, and cervical branches) was approximately 1.00 mm2.22 In the present study, the total fascicular area of the GAN decreased between its proximal and distal portions, from 1.42 to 0.61 mm2. Therefore, harvesting of the GAN for nerve grafting should be performed from a position of its greatest width and area, where it lies adjacent to the SCM. The GAN communicates with several cranial nerves in the following manner: the nerve branch from GAN sends a small nerve twig (or several small twigs) into the parotid parenchyma and connects with the FN, the auricular branch of the vagus nerve, and the posterior auricular nerve branch of the FN.23 In every specimen in the present study, the deep branch from the GAN gave off a small twig (or several small twigs) to communicate with the FN trunk. This communication between a sensory nerve and a motor nerve on the craniofacial region has also been reported elsewhere.24e29 In some of the specimens in the present study, the superficial branch of the GAN communicated with the auricular temporal nerve and the deep branch of the GAN communicated with the posterior auricular nerve of the FN, simultaneously. The communication between the superficial branch and the auricular temporal branch was a communication between sensory nerves, while that between the deep branch of the GAN and the posterior auricular nerve was a communication between branches of a sensory nerve and a motor nerve. The function of such sensoryemotor nerve communications has yet to be determined. Yang et al. (2013) proposed that the sensory nerve might be involved in the coordination of proprioception information from the muscle via the motor nerve with which it communicates. However, further functional anatomic studies are required to clarify the nerve communication between peripheral and cranial nerves.29
Conclusion A more detailed knowledge of GAN anatomy is particularly important when using complex approaches in facial surgery and nerve grafting. Recognition of the existence of interconnections between the other peripheral and cranial nerves within the parotid gland could require reconsideration of the conventional approach to parotid resection. The surgeon may also consider that microscopic dissection of
Please cite this article in press as: Yang H-M, et al., Anatomic and histological study of great auricular nerve and its clinical implication, Journal of Plastic, Reconstructive & Aesthetic Surgery (2014), http://dx.doi.org/10.1016/j.bjps.2014.10.030
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Anatomy of great auricular nerve the nerve to preserve all branches and connections could be better in itself than amputation, in addition to being a strategy for limiting the consequences of partial intraparotid nerve branch resection because of tumor involvement or technical difficulties. Familiarity with these common variations in GAN anatomy is an absolute necessity for safe and successful dissection, preservation of the GAN branches, and complete removal of tumors during parotidectomy.
Conflicts of interest statement None of the authors have financial or private relationships with commercial, academic, or political organizations or people that could have improperly influenced this research. All authors were well informed of the WMA Declaration of Helsinki e Ethical Principles for Medical Research Involving Human Subjects e and confirmed that the present study firmly fulfilled the declaration. All cadaveric objects in this study were legally donated to Yonsei Medical Center and Dankook University College of medicine.
Funding This study was supported by the Yonsei University College of Dentistry Fund (6-2014-0086).
References 1. Ginsberg LE, Eicher SA. Great auricular nerve: anatomy and imaging in a case of perineural tumor spread. Am J Neuroradiol 2000;21:568e71. 2. Barbour JR, Iorio ML, Halpern DE. Surgical decompression of the great auricular nerve: a therapeutic option for neurapraxia following rhytidectomy. Plast Reconstr Surg 2014;133:255e60. 3. Christensen NR, Jacobsen SD. Parotidectomy. Preserving the posterior branch of the great auricular nerve. J Laryngol Otol 1997;111:556e9. 4. De Chalain T, Nahai F. Amputation neuromas of the great auricular nerve after rhytidectomy. Ann Plast Surg 1995;35: 297e9. 5. Domet MA, Connor NP, Heisey DM, Hartig GK. Anastomoses between the cervical branch of the facial nerve and the transverse cervical cutaneous nerve. Am J Otolaryngol 2005; 26:168e71. 6. McKinney P, Katrana DJ. Prevention of injury to the great auricular nerve during rhytidectomy. Plast Reconstr Surg 1980; 66:675e9. 7. Ozturk CN, Ozturk C, Huettner F, Drake RL, Zins JE. A failsafe method to avoid injury to the great auricular nerve. Aesthetic Surg J 2014;34:16e21. 8. Manstein CH, Manstein G. Bilateral neuromata of the great auricular nerves 8 years following face lift. Plast Reconstr Surg 1985;76:937e8. 9. Moss CE, Johnston CJ, Whear NM. Amputation neuroma of the great auricular nerve after operations on the parotid gland. Br J Oral Maxillofac Surg 2000;38:537e8.
7 10. Eppley BL, Snyder RV. Microanatomic analysis of the trigeminal nerve and potential nerve graft donor sites. J Oral Maxillofac Surg 1991;49:612e8. 11. Fisch U, Lanser MJ. Facial nerve grafting. Ototlaryngol Clin North Am 1991;24:691e708. 12. Guo CB, Zhang Y, Zou LD, Mao C, Peng X, Yu GY. Reconstruction of accessory nerve defects with sternocleidomastoid musclegreat auricular nerve flap. Br J Palst Surg 2005;58:233e8. 13. Koshima I, Nanba Y, Tsutsui T, Takahashi Y, Itoh S. New onestage nerve pedicle grafting technique using the grear auricular nerve for reconstruction of facial nerve defects. J Reconstr Microsurg 2004;20:357e61. 14. Rayatt SS, King TT, O’Connor AF. Histological analysis of the greater auricular nerve and its use as a graft. Clin Otolaryngol Allied Sci 1998;23:368e71. 15. Shultz J, Dodsen TB, Meyer RA. Donor site morbidity of greater auricular nerve graft harvesting. J Maxillofac Surg 1992;50: 803e5. 16. Biglioli F, D’Orto O, Bozzetti A, Brusati R. Function of the great auricular nerve following surgery for benign parotid disorders. J Craniomaxillofac Surg 2002;30:308e17. 17. Colbert S, Parry DA, Hale B, Davies J, Brennan PA. Does the great auricular nerve predict the size of the main trunk of the facial nerve? A clinical and cadaveric study. Br J Oral Maxillofac Surg 2014;52:230e5. 18. Izquierdo R, Parry SW, Boydell CL, Almand J. The great auricular nerve revisited: pertinent anatomy for SMAS-platysma rhytidectomy. Ann Plast Surg 1991;27:44e8. 19. Lefkowitz T, Hazani R, Chowdhry S, Elston J, Yaremchuk MJ, Wilhelmi BJ. Anatomical landmarks to avoid injury to the great auricular nerve during rhytidectomy. Aesthetic Plast Surg 2013;33:19e23. 20. Murphy R, Dziegielewski P, O’Connell D, Seikaly H, Ansari K. The great auricular nerve: an anatomic and surgical study. J Otolaryngol Head Neck Surg 2012;41:S75e7. 21. Nusair YMH, Dickenson AJ. Great auricular causalgia: an unusual complication of excision of the submandibular gland. Br J Oral Maxillofac Surg 2003;41:334e5. 22. Lineaweaver W, Rhoton A, Habal MB. Microsurgical anatomy of the facial nerve. J Craniofac Surg 1997;8:6e10. 23. Standring S. Gray’s anatomy: the anatomical basis of clinical practice. 40th ed. Edinburgh: Churchill Livingstone; 2008. p. 532. 24. Hu KS, Kwak HH, Song WC, et al. Branching patterns of the infraorbital nerve and topography within the infraorbital space. J Craniofac Surg 2006;17:1111e5. 25. Hwang K, Hwang JH, Cho HJ, Kim DJ, Chung IH. Horizontal branch of the supraorbital nerve and temporal branch of the facial nerve. J Craniofac Surg 2005;16:647e9. 26. Hwang K, Jin S, Park JH, Kim DJ, Chung IH. Relation of mental nerve with mandibular branch of the facial nerve. J Craniofac Surg 2007;18:165e8. 27. Martin H, Helsper JT. Spontaneous return of function following surgical section or excision of the seventh cranial nerve in the surgery of parotid tumors. Ann Surg 1957;146:715e27. 28. Namking M, Boonruangsri P, Woraputtaporn W, Gu ¨ldner FH. Communication between the facial and auriculotemporal nerves. J Anat 1994;185:421e6. 29. Yang HM, Won SY, Kim HJ, Hu KS. Sihler staining study of anastomosis between the facial and trigeminal nerves in the ocular area and its clinical implications. Muscle Nerve 2013;48: 545e50.
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Journal of Plastic, Reconstructive & Aesthetic Surgery (2014) xx, 1e7
Anatomic and histological study of great auricular nerve and its clinical implication Hun-Mu Yang a, Hee-Jin Kim b, Kyung-Seok Hu b,* a
Department of Anatomy, College of Medicine, Dankook University, Cheonan, South Korea Division in Anatomy and Developmental Biology, Department of Oral Biology, Yonsei University College of Dentistry, Seoul, South Korea
b
Received 16 June 2014; accepted 19 October 2014
KEYWORDS Great auricular nerve; Parotidectomy; Rhytidectomy; Nerve graft; Nervous anastomosis
Summary Background: The great auricular nerve (GAN) is often sacrificed during parotidectomy, rhytidectomy, and platysma flap operation. Transection of the nerve results in a wooden numbness of preauricular region, pain, and neuroma. The aim of this study was to describe the branching patterns and distribution area of the GAN. Methods: Twenty-five embalmed, adult hemifacial Korean cadavers (16 males, nine females; mean age 62.5 years) were used in this study. The branching of the GAN was determined through careful dissection. The histological structure of the GAN was also examined by harvesting and sectioning specimens, and then viewing them with the aid of a light microscope. Results: The branching pattern of the anterior, posterior, deep, and superficial branches of the GAN could be classified into five types: type I (20%), where the deep branches arose from the anterior branch; type II (24%), where all branches originated at the same point; type III (28%), where the deep branch arose from the posterior branch; type IV (8%), where the superficial branches arose from the posterior branch; and type V (20%), where the anterior and posterior branches ran independently. A connection between the GAN and the facial nerve trunk was observed in all specimens, and a connection with the auriculotemporal nerve was observed in a few specimens. The total fascicular area of both regions decreased from proximal (1.42 mm2) to distal (0.60 mm2). There were 2.5 and 5 fascicles in the proximal and distal regions, respectively. Conclusion: The results reported herein will help toward preservation of the GAN during surgery in the region of the parotid gland. Furthermore, the histologic findings suggest that the GAN would be a good donor site for nerve grafting. ª 2014 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
* Corresponding author. Room 601, Department of Oral Biology, Yonsei University College of Dentistry, 50 Yonseiro, Seodaemun-gu, Seoul 120-752, South Korea. Tel.: þ82 2 22283047; fax: þ82 2 3938076. E-mail address: [email protected] (K.-S. Hu). http://dx.doi.org/10.1016/j.bjps.2014.10.030 1748-6815/ª 2014 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
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Introduction The great auricular nerve (GAN) is the largest of the four cervical cutaneous nerves. It emerges through the superficial cervical fascia on the posterior border of the sternocleidomastoid muscle (SCM), and distributes to the mandibular angle, the skin over the parotid gland, the parotid gland, and the skin of the auricle.1 Clinically, iatrogenic or inevitable amputation of the GAN during rhytidectomy or parotidectomy would incur significant complications such as dysesthesia or allodynia in the involved skin area, otalgia, discomfort on cold exposure, and traumatic neuroma.2e7 McKinney and Gottlieb (1980) reported that the GAN was positioned deep to the layer containing the superficial musculoaponeurotic system (SMAS), and thus manipulating the SMAS during facelift surgery was thought to be relatively safe.6 However, there have been numerous reports of GAN impingements during facelift surgery. Ozturk et al. (2012) found that injury to the GAN can result in more severe distress than injury to cutaneous nerves in other areas, although the incidence of GAN injury is low, reportedly ranging from 0% to 2.6%.7 Barbour et al. (2013) reported that GAN injury is a common complication, occurring at a rate of 6% during rhytidectomy, and that a recently introduced, minimally invasive technique for producing a short scar has an increased risk of GAN injury.2 In addition, it was reported that the rate of sensory disorders resulting from nerve damage during parotidectomy has increased significantly.3 Traumatic neuroma can also occur after amputation of the GAN.4,8,9 Moss at al. (2000) reported that traumatic neuroma following sacrifice of the GAN occurred at a rate of 6% after surgery on the parotid gland, while de Chalain and Nahai (1995) described a large neuroma at the distal end of a transected GAN in a 56-year-old female patient that was detected 9 years after full rhytidectomy.4,9 On the other hand, the GAN is known to be a good donor nerve because it is easily accessible due to its convenient location beneath the platysma muscle, and it can be harvested during nerve graft surgical procedures of the head and neck region without the necessity for additional surgery. Its relatively large cross-sectional area renders the GAN a frequent candidate for replacing the facial nerve (FN), inferior alveolar nerve, and accessory nerve.10e15 The purpose of this study was to describe the branching patterns of the GAN and its topographic relationships to other nearby structures, with the aim of providing critical reference data for surgical procedures to the head and neck. Furthermore, the histomorphometric characteristics of the GAN were explored in the context of nerve grafting.
Materials and methods In total, 25 sides of formalin-fixed necks from Korean cadavers (11 bilateral specimens, three unilateral specimens) were used in this study. The subjects included 16 males and nine females, with an average age of 62.5 years. The precise course of the GAN and the extent of its innervation and communication were established by careful dissection of these cadaveric specimens, which
H.-M. Yang et al. had no history of trauma or any surgical procedures on the face and neck. The dissections were performed with the specimens in the oblique lateral position. The parotid fascia and the superficial cervical layer were exposed by dissection of the whole dermal layer from the neck to the face. The cervical cutaneous nerves were particularly carefully dissected and sketched, with special attention being paid to the course of the GAN on the SCM muscle. Along with the course of the GAN, the nerve branches were exposed clearly, and further fine dissection was performed to identify the fine nerve branches of the GAN on the parotid fascia and the nerve branches to the auricle. In addition, after removal of the skin from the anterior and posterior aspects of the specimens, the fine nerve branches from the GAN could be identified. The distribution area of the GAN to the auricle was also explored through the dissection. At the parotid region, the parotid parenchyma was removed and the region dissected further to expose the FN trunk and its divisions, and the fine terminal nerve branches from the GAN. The communicating nerve twigs among the nerve branches of the GAN, the FN, and the nerve branches of the trigeminal nerve were examined. All of the microdissections were performed with the aid of a surgical microscope (OPMI, Zeiss, Germany). Sections were prepared for histomorphometric analysis by first harvesting the intraparotid terminal nerve branches of the GAN (including the FN trunk) from five specimens, and from the point at which the GAN emerges at the posterior border of the SCM (i.e., the proximal region of the GAN) and the region prior to the furcation point of the GAN on the SCM (i.e., the distal region of the GAN) from 10 dissected specimens. These specimens were postfixed for 72 h with 4% paraformaldehyde and then embedded in paraffin wax. Transverse 5-mm-thick sections were mounted on glass slides, and then stained with hematoxylineeosin and Luxol fast blue. Histologic observations were performed with the aid of a light microscope, and photographs were taken. No distinction was made between the male and female cadavers. All photographs and diagrams in this article are of structures viewed from the left side of the specimen.
Results In all specimens, the GAN ascended toward the parotid gland from the posterior border of the SCM. In terms of the topographic relationship with surrounding structures, the GAN emerged from the posterior border of the SCM, and was located behind the external jugular vein in every case. The GAN divided into the anterior and posterior branches in its course on the SCM. The anterior branch then further divided into the superficial and deep branches. The superficial branch distributed to the skin and surface of the parotid gland, while the deep branch entered the parenchyma of the parotid gland. The branching patterns of these nerve branches could be classified into five categories (Figure 1): Type I e The GAN divided into the anterior and posterior branches, and then the anterior branch bifurcated into
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Anatomy of great auricular nerve
3 of the anterior branch. This pattern was observed in six of the specimens (24%; Figure 1(B)). Type III e The deep branch originated from the posterior branch of the GAN (Figure 1(C)). This was the most frequently observed pattern, occurring in seven of the specimens (28%). Type IV e The superficial branch arose from the posterior branch of the GAN. This pattern was observed in two specimens (8%; Figure 1(D)). Type V e The GAN had already bifurcated into the anterior and posterior branches by the time it had emerged onto the SCM through the superficial cervical fascia (Figure 1(E)). This pattern was found in five of the specimens (20%). The distribution areas of the superficial branch of the GAN were dissected and examined. These nerve branches ran upward from the mandibular angle and they distributed fibers to the parotid gland and the skin covering it. The superficial branch from the GAN was located on the superficial fascia of the parotid gland and ran toward the anterior margin of the parotid gland. The fine, terminal nerve twigs of the superficial branch of the GAN extended to the surface of the masseter muscle and its fascia (Figure 2). Relatively small nerve twigs from the deep branch of the GAN were distributed to the deep layer of parotid gland. The main branches from the deep branch of the GAN ascended and ran toward the auricle, distributing fibers to its posterior aspect (Figure 3(A)). The deep branch of the GAN is generally known to be distributed to the inferior part of the ear. However, in 20 of the specimens in this study (80%) it also supplied the middle
Figure 1 The five branching patterns of the great auricular nerve. AeE, Branching pattern types IeV, respectively. G, great auricular nerve; A (in photograph), anterior branch; P, posterior branch; S, superficial branch; D, deep branch; SCM, sternocleidomastoid muscle; EJV, external jugular vein.
the superficial and deep branches (Figure 1(A)). This category is the most commonly described one in most anatomy textbooks, but was only observed in five of the specimens in this study (20%). Type II e The GAN trifurcated at a single point into the posterior branch and the superficial and deep branches
Figure 2 The distribution area of the superficial branches of the great auricular nerve. Arrowheads indicate superficial branches. G, great auricular nerve; P, posterior branch; S, superficial branch; D, deep branch.
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Figure 3 The distribution area of the deep branch of the great auricular nerve. The arrow indicates the deep branch. A, Deep branch entering the ear and then ascending toward the inferior part of the auricle. B, Deep branch supplying the middle of the posterior aspect of the auricle. C, Deep branch supplying the upper and middle of the posterior aspect of the auricle. Arrowheads indicate a point where the deep branch is entering the parotid gland. P, posterior branch; D, deep branch; L, lesser occipital nerve; PA posterior auricular nerve.
of the posterior aspect of the auricle (Figure 3(B)). In the remaining five specimens (20%), the deep nerve branches were distributed to the middle and upper portions of the posterior aspect of the auricle (Figure 3(C)). Most of the posterior branches were also distributed to the anterior surface of the ear (Figure 4). These nerve branches divided into two branches below the level of the lobule e the superficial and deep subbranches e that entered the auricle above the otobasion inferius (Figure 4(A)). Thereafter, the superficial nerve subbranch ran horizontally and ascended through the groove between the helix and the antihelix above the ear cartilage, and the
deep nerve subbranch further divided into two separate nerve twigs: upper and lower. The upper nerve twig ascended and distributed to the inferior two-thirds of the auricle below the ear cartilage, while the lower nerve twig was distributed to the ear lobule (Figure 4(B)). A unique and novel finding of this study was communication between the GAN and the FN trunk. In every specimen, the deep branch of the GAN communicated with the FN trunk (Figure 5(A)). In a rare case, the deep branch of the GAN communicated with the posterior auricular nerve, and the anterior branch simultaneously communicated with the auricular temporal nerve (Figure 5(B)).
Figure 4 The distribution area of the posterior branch of the great auricular nerve. Arrows indicate the deep nerve subbranches, and arrowheads indicate the superficial nerve subbranches.
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Anatomy of great auricular nerve
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Figure 5 The communication between the great auricular nerve (GAN) and the facial nerve (FN). The white arrowheads indicate the deep branch of the GAN, which communicates with the FN trunk. The black arrowheads indicate the small branch of the anterior branch, which communicates with the auricular temporal nerve (ATN). The black arrows indicate the small branch of the deep branch, which communicates with the PAN. A black dotted circle indicates the point where the deep branch meets the ATN. A white dotted circle indicates the point where the deep branch meets the PAN. ATN, anterior temporal nerve; PAN, posterior auricular nerve; A, anterior branch; D, deep branch; FN, facial nerve.
Nerve specimens were harvested from proximal (point of emergence on the posterior border of the SCM) and distal (prior to the point of bifurcation into the anterior and posterior branches) regions along the course of the GAN, and prepared for histomorphometric analysis. The average number of fascicles was 2.5 (range, 1e4) at the proximal region of the GAN and 5 (range, 2e8) at the distal region; the total fascicular areas were 1.42 mm2 (range, 0.84e1.75 mm2) and 0.6 mm2 (range, 0.54e0.64 mm2), respectively. Thus, the total number of fascicles increased from proximal to distal in this nerve, whereas the total fascicular area decreased (Figure 6, Table 1), with a
substantial difference in an average fascicle area between the two regions (0.57 vs. 0.12 mm2).
Discussion There have been considerable efforts made to preserve the GAN in order to reduce postoperative complications at the para-auricular area.7,9,16e21 Murphy et al. (2012) observed that the GAN was located an average of 0.60 cm anterior to the posterior border of the platysma muscle and 1.17 cm posterior to the external jugular vein. By contrast, in all specimens examined in this study the GAN was located posterior to the external jugular vein. The surgical approach for procedures around the parotid gland should therefore be posterior to the external jugular vein in order to preserve the GAN. Numerous studies have been performed to establish the location of the GAN relative to the SCM muscle with a view to improving the safety of various surgical procedures. McKinney and Katrana (1980) reported that the GAN crossed the midtransverse belly of the SCM at 6.5 cm inferior to the
Table 1 The metric value of the histologic findings of great auricular nerve.
Proximal Figure 6 Histologic findings of the great auricular nerve. G, great auricular nerve; L, lesser occipital nerve; T, transverse cervical nerve; S, supraclavicular nerve.
Distal
Fascicular number
Total fascicular area
5 mm (ranging from 2 to 8 mm) 2.5 mm (ranging from 1 to 4 mm)
0.6 mm2 (ranging from 0.54 to 0.64) 1.42 mm2 (ranging from 0.84 to 1.75)
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6 lowermost point of the bony external auditory meatus (EAM), and Lefkowitz et al. (2013) noted that in most cases the GAN crossed the upper one-third area of the SCM, ramifying into the superior and inferior branches.6,19 Ozturk et al. (2014) demonstrated that the GAN proceeded across the upper, middle, and lower one-third areas of the SCM in 53.9%, 26.9%, and 15.4% of cases, respectively. They also determined the location of the GAN at various points on the SCM relative to the EAM: the distance between the EAM and GAN was 4.9 cm at the anterior border of the SCM, 7.3 cm at the midbelly of the SCM, and 9.8 cm at the emergence of the GAN onto the SCM.7 Conversely, the cervical cutaneous nerves have been treated with relatively little interest because they are considered relatively unimportant clinically. Likewise, there are no detailed descriptions of the patterns of innervation of the cervical cutaneous nerves either in the literature or in anatomy textbooks. In the present study, we found that the GAN divided into three branches (superficial, deep, and posterior branches) e this differs from what has been described in the literature thus far. In anatomy textbooks, the typical case is described as division of the GAN into the anterior and posterior branches; this pattern was observed in only 20% of the cases in this study (Standring, 2008). In fact, the most frequently observed pattern was where the deep branch originated from the posterior branch of the GAN (type III, 28%). The nerves distributing to the anterior facial skin were divided into two branches: superficial and deep. However, these two branches originated from the GAN in several ways (i.e., types IeV), among which the superficial branch originated from the anterior branch of the GAN in 10 of the specimens (types I þ V; 40%). The superficial branch originated from the already separated anterior branches on the SCM (type V, five cases). In the remainder (n Z 15, 60%), the superficial branch originated directly from the GAN. The superficial branches supplied the superficial facial skin above the parotid fascia anterior to the auricle. The deep branch, which was a small nerve, divided into two or three smaller nerve twigs on the posterior margin of the parotid gland, and ran deep to the parotid gland parenchyma. Its branching patterns were similar to those described for the superficial branch, in that they originated either from the anterior branch (10 cases, 40%) or directly from the GAN (15 cases, 60%). The topography of the GAN around the ear is also very important because preauricular incisions may extend to the anterior surface of the ear. Furthermore, discomfort with cold exposure has been reported after amputation of the GAN. Thus, the anatomical relationship between the GAN and the ear need to be elucidated. In this study, some subbranches of the GAN posterior branches distributed to the inferior two-thirds of the auricle below the ear cartilage and the ear lobule after proceeding over the anterior surface of the ear. It is generally thought that the GAN is distributed to the inferior part of the posterior aspect of the auricle, while the lesser occipital nerve is distributed to the superior and middle parts of the auricle. However, we observed that the middle inferior part of the posterior aspect of the auricle was distributed by the GAN in only 20% of the specimens. In these cases, the lesser occipital nerve distributed to the lateral part of the occipital region
H.-M. Yang et al. posterior to the auricle. Thus, rather than remove all branches of the GAN, it may be possible for the surgeon to instead preserve the posterior branches of the GAN if its three branches occur separately (i.e., as the superficial, deep, and posterior branches). When a nerve-graft procedure results in damage to the FN and the other trigeminal nerve branches, the GAN is the first choice of donor nerve because it is easily accessed and has a large cross-sectional area.14 In nerve grafting, the total fascicular area of the donor nerve is always larger than that of the recipient nerve. Colbert et al. (2013) reported that there was a significant correlation between the widths of the GAN and FN, which would allow prediction of the FN width using the GAN width.17 They reported that the average widths of the GAN and the FN were 2.75 and 2.83 mm, respectively, and the total fascicular area of the five branches of the FN (i.e., the temporal, zygomatic, buccal, marginal mandibular, and cervical branches) was approximately 1.00 mm2.22 In the present study, the total fascicular area of the GAN decreased between its proximal and distal portions, from 1.42 to 0.61 mm2. Therefore, harvesting of the GAN for nerve grafting should be performed from a position of its greatest width and area, where it lies adjacent to the SCM. The GAN communicates with several cranial nerves in the following manner: the nerve branch from GAN sends a small nerve twig (or several small twigs) into the parotid parenchyma and connects with the FN, the auricular branch of the vagus nerve, and the posterior auricular nerve branch of the FN.23 In every specimen in the present study, the deep branch from the GAN gave off a small twig (or several small twigs) to communicate with the FN trunk. This communication between a sensory nerve and a motor nerve on the craniofacial region has also been reported elsewhere.24e29 In some of the specimens in the present study, the superficial branch of the GAN communicated with the auricular temporal nerve and the deep branch of the GAN communicated with the posterior auricular nerve of the FN, simultaneously. The communication between the superficial branch and the auricular temporal branch was a communication between sensory nerves, while that between the deep branch of the GAN and the posterior auricular nerve was a communication between branches of a sensory nerve and a motor nerve. The function of such sensoryemotor nerve communications has yet to be determined. Yang et al. (2013) proposed that the sensory nerve might be involved in the coordination of proprioception information from the muscle via the motor nerve with which it communicates. However, further functional anatomic studies are required to clarify the nerve communication between peripheral and cranial nerves.29
Conclusion A more detailed knowledge of GAN anatomy is particularly important when using complex approaches in facial surgery and nerve grafting. Recognition of the existence of interconnections between the other peripheral and cranial nerves within the parotid gland could require reconsideration of the conventional approach to parotid resection. The surgeon may also consider that microscopic dissection of
Please cite this article in press as: Yang H-M, et al., Anatomic and histological study of great auricular nerve and its clinical implication, Journal of Plastic, Reconstructive & Aesthetic Surgery (2014), http://dx.doi.org/10.1016/j.bjps.2014.10.030
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Anatomy of great auricular nerve the nerve to preserve all branches and connections could be better in itself than amputation, in addition to being a strategy for limiting the consequences of partial intraparotid nerve branch resection because of tumor involvement or technical difficulties. Familiarity with these common variations in GAN anatomy is an absolute necessity for safe and successful dissection, preservation of the GAN branches, and complete removal of tumors during parotidectomy.
Conflicts of interest statement None of the authors have financial or private relationships with commercial, academic, or political organizations or people that could have improperly influenced this research. All authors were well informed of the WMA Declaration of Helsinki e Ethical Principles for Medical Research Involving Human Subjects e and confirmed that the present study firmly fulfilled the declaration. All cadaveric objects in this study were legally donated to Yonsei Medical Center and Dankook University College of medicine.
Funding This study was supported by the Yonsei University College of Dentistry Fund (6-2014-0086).
References 1. Ginsberg LE, Eicher SA. Great auricular nerve: anatomy and imaging in a case of perineural tumor spread. Am J Neuroradiol 2000;21:568e71. 2. Barbour JR, Iorio ML, Halpern DE. Surgical decompression of the great auricular nerve: a therapeutic option for neurapraxia following rhytidectomy. Plast Reconstr Surg 2014;133:255e60. 3. Christensen NR, Jacobsen SD. Parotidectomy. Preserving the posterior branch of the great auricular nerve. J Laryngol Otol 1997;111:556e9. 4. De Chalain T, Nahai F. Amputation neuromas of the great auricular nerve after rhytidectomy. Ann Plast Surg 1995;35: 297e9. 5. Domet MA, Connor NP, Heisey DM, Hartig GK. Anastomoses between the cervical branch of the facial nerve and the transverse cervical cutaneous nerve. Am J Otolaryngol 2005; 26:168e71. 6. McKinney P, Katrana DJ. Prevention of injury to the great auricular nerve during rhytidectomy. Plast Reconstr Surg 1980; 66:675e9. 7. Ozturk CN, Ozturk C, Huettner F, Drake RL, Zins JE. A failsafe method to avoid injury to the great auricular nerve. Aesthetic Surg J 2014;34:16e21. 8. Manstein CH, Manstein G. Bilateral neuromata of the great auricular nerves 8 years following face lift. Plast Reconstr Surg 1985;76:937e8. 9. Moss CE, Johnston CJ, Whear NM. Amputation neuroma of the great auricular nerve after operations on the parotid gland. Br J Oral Maxillofac Surg 2000;38:537e8.
7 10. Eppley BL, Snyder RV. Microanatomic analysis of the trigeminal nerve and potential nerve graft donor sites. J Oral Maxillofac Surg 1991;49:612e8. 11. Fisch U, Lanser MJ. Facial nerve grafting. Ototlaryngol Clin North Am 1991;24:691e708. 12. Guo CB, Zhang Y, Zou LD, Mao C, Peng X, Yu GY. Reconstruction of accessory nerve defects with sternocleidomastoid musclegreat auricular nerve flap. Br J Palst Surg 2005;58:233e8. 13. Koshima I, Nanba Y, Tsutsui T, Takahashi Y, Itoh S. New onestage nerve pedicle grafting technique using the grear auricular nerve for reconstruction of facial nerve defects. J Reconstr Microsurg 2004;20:357e61. 14. Rayatt SS, King TT, O’Connor AF. Histological analysis of the greater auricular nerve and its use as a graft. Clin Otolaryngol Allied Sci 1998;23:368e71. 15. Shultz J, Dodsen TB, Meyer RA. Donor site morbidity of greater auricular nerve graft harvesting. J Maxillofac Surg 1992;50: 803e5. 16. Biglioli F, D’Orto O, Bozzetti A, Brusati R. Function of the great auricular nerve following surgery for benign parotid disorders. J Craniomaxillofac Surg 2002;30:308e17. 17. Colbert S, Parry DA, Hale B, Davies J, Brennan PA. Does the great auricular nerve predict the size of the main trunk of the facial nerve? A clinical and cadaveric study. Br J Oral Maxillofac Surg 2014;52:230e5. 18. Izquierdo R, Parry SW, Boydell CL, Almand J. The great auricular nerve revisited: pertinent anatomy for SMAS-platysma rhytidectomy. Ann Plast Surg 1991;27:44e8. 19. Lefkowitz T, Hazani R, Chowdhry S, Elston J, Yaremchuk MJ, Wilhelmi BJ. Anatomical landmarks to avoid injury to the great auricular nerve during rhytidectomy. Aesthetic Plast Surg 2013;33:19e23. 20. Murphy R, Dziegielewski P, O’Connell D, Seikaly H, Ansari K. The great auricular nerve: an anatomic and surgical study. J Otolaryngol Head Neck Surg 2012;41:S75e7. 21. Nusair YMH, Dickenson AJ. Great auricular causalgia: an unusual complication of excision of the submandibular gland. Br J Oral Maxillofac Surg 2003;41:334e5. 22. Lineaweaver W, Rhoton A, Habal MB. Microsurgical anatomy of the facial nerve. J Craniofac Surg 1997;8:6e10. 23. Standring S. Gray’s anatomy: the anatomical basis of clinical practice. 40th ed. Edinburgh: Churchill Livingstone; 2008. p. 532. 24. Hu KS, Kwak HH, Song WC, et al. Branching patterns of the infraorbital nerve and topography within the infraorbital space. J Craniofac Surg 2006;17:1111e5. 25. Hwang K, Hwang JH, Cho HJ, Kim DJ, Chung IH. Horizontal branch of the supraorbital nerve and temporal branch of the facial nerve. J Craniofac Surg 2005;16:647e9. 26. Hwang K, Jin S, Park JH, Kim DJ, Chung IH. Relation of mental nerve with mandibular branch of the facial nerve. J Craniofac Surg 2007;18:165e8. 27. Martin H, Helsper JT. Spontaneous return of function following surgical section or excision of the seventh cranial nerve in the surgery of parotid tumors. Ann Surg 1957;146:715e27. 28. Namking M, Boonruangsri P, Woraputtaporn W, Gu ¨ldner FH. Communication between the facial and auriculotemporal nerves. J Anat 1994;185:421e6. 29. Yang HM, Won SY, Kim HJ, Hu KS. Sihler staining study of anastomosis between the facial and trigeminal nerves in the ocular area and its clinical implications. Muscle Nerve 2013;48: 545e50.
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