Temporal Branch of the Facial Nerve and Its Relationship to Fascial Layers

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ORIGINAL ARTICLE Temporal Branch of the Facial Nerve and Its Relationship to Fascial Layers

Seda T. Babakurban, MD; Ozcan Cakmak, MD; Simel Kendir, MD; Alaittin Elhan, PhD, MD; Vito C. Quatela, MD

Objectives: To eliminate the inconsistency in the no- 3 (14.3%), and 4 (14.3%) twigs in the specimens. The menclature, to anatomically and definitively describe the temporoparietal fascia had no attachment to the zygo- topographic relationship of the temporal branch of the matic arch and continued caudally as the superficial mus- facial nerve to the fascial layers and the fat pads, and to culoaponeurotic system. Adhesions were between the tem- create an effective algorithm to define the safest ap- poroparietal fascia and the superficial layer of the deep proaches and planes for surgical procedures in this area. temporal fascia around the zygomatic arch. In most specimens, the superficial layer of the deep temporal fascia con- Methods: The study was performed using 18 hemifa- tinued as the parotideomasseterica fascia, and a deep layer cial cadaveric specimens. In 12 hemifacial specimens, the abutted the posterosuperior edge of the zygomatic arch. facial halves were coronally sectioned and dissected. In 6 hemifacial specimens, planar dissection was per- Conclusion: An easy and safe surgical approach in this formed layer by layer. area is to elevate the superficial layer deep to the intermediate fat pad directly on the deep layer of the deep tem- Results: The temporal branch of the facial nerve that tra- poral fascia descending to the periosteum along the zy- versed inside the deep layers of the temporoparietal fas- gomatic arch. cia and the superficial musculoaponeurotic system coursed along the zygomatic arch as 1 (14.3%), 2 (57.1%), Arch Facial Plast Surg. 2010;12(1):16-23

HE TEMPORAL BRANCH OF fine the safest approaches and planes for the facial nerve has be- surgical procedures in this area. come of great importance with advanced techniques of deep-plane face-lifting, METHODS subperiostealT midface-lifting, endoscopic forehead-lifting, and interfascial dis- The study was performed using 18 hemifacial sections in craniofacial and trauma sur- specimens from fixed and fresh cadavers ob- gery. Injury to the temporal branch of the tained from the Department of Anatomy, Fac- facial nerve results in cosmetic defects as ulty of Medicine, Ankara University, Ankara, a result of paralysis of the corrugator su- Turkey. Before dissection, the course of the tem- percilii, frontalis, and orbicularis oculi poral branch of the facial nerve was marked on the skin of each cadaver’s face. First, the Pit- muscles. Understanding the anatomy of anguay line (connecting the lobule with one- Author Affiliations: this area and the trajectory of the tempo- half the distance between the superior border Department of ral branch of the facial nerve is critical to of the external auditory canal and the lateral Otorhinolaryngology, Faculty of preserve it from injury. Despite many stud- canthus) was drawn, and the point at which Medicine, Bas¸kent University, ies1-29 in the literature, controversy re- that line bisected the zygomatic arch was Ankara (Dr Babakurban); mains about the topographic relation- marked. Two other points that were 1.5 cm an- Department of ship of the fascias, the fat pads, and the terior and 1.5 cm posterior to the first point Otorhinolaryngology, Faculty of temporal branch of the facial nerve and its were marked, depending on the length of the Medicine, Acibadem University, nomenclature. The objectives of this study zygomatic arch. Then, second and third lines Istanbul (Dr Cakmak), and were to eliminate the inconsistency in the that bisected the second and third points sepa- Department of Anatomy, rately were drawn from the temporal region to Faculty of Medicine, Ankara nomenclature, to anatomically and defini- the cheek. These 2 coronal strips of tissue were University, Ankara (Drs Kendir tively describe the topographic relation- incised down to the temporal muscle above and and Elhan), Turkey. Dr Quatela ship of the temporal branch of the facial to the masseter muscle below, including a coro- is in private practice in nerve to the fascial layers and the fat pads, nal segment of the zygomatic arch (Figure 1). Rochester, New York. and to create an effective algorithm to de- The 2 sections were en bloc resected, and the

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Anatomic Name Synonyms Preferred Name Fascia superficialis,1 Superficial temporal Temporoparietal superficial fascia,3,7,10,12,16,17,25,26 fascia temporal fascia, or temporoparietal temporoparietal fascia,2-4,9,12,19 epicranial fascia15 aponeurosis,14 galea,20 aponeurotic fascia,11 subgaleal fascia,13,28 or superficial musculoaponeurotic system7 Fascia temporalis1 or Temporal fascia,14,15,19,21 Deep temporal temporal fascia15 deep temporal fascia fascia,3,9-11,16,17,22,26 superficial temporal fascia,20,25 or temporalis muscle fascia11 Fascia temporalis Innominate fascia,3,12 Superficial layer (lamina superficial layer of deep superficialis),1 of deep temporal temporal temporal fascia, or fascia,3,9,11,14,16,17,19,21 fascia superficial intermediate temporal laminae15 fascia,7,25 or superficial temporal fascia8 Fascia temporalis Deep layer of Deep layer of (lamina profunda),1 deep temporal deep temporal fascia, or fascia3,9,11,14,16,17,19,21 temporal Figure 1. Lines of the 2 coronal strips of tissue. deep laminae15 or deep temporal fascia fascia7,8,12,25 8 anterior and posterior halves of the coronal strips were dis- Temporoparietal fat Suprafascial fat pad, Superficial fat pad15 subaponeurotic pad sected under an operating microscope using magnification of 3,9,26 ϫ ϫ plane, loose areolar 6to 40. In 6 hemifacial specimens, planar dissection from plane,3 loose areolar the skin to the bone was performed layer by layer under the tissue,10,14 innominate operating microscope. fascia,27 superficial fat The nomenclature in the literature is inconsistent for cer- pad,7,11,17,20 or subgaleal tain fascias and the fat pads of this region. Therefore, pre- fat pad20 ferred names (given in the Table and in Figure 2) are used Superficial fat pad15 Interfascial fat pad,8,20 Intermediate fat herein to avoid confusion. superficial fat pad,3,9,14,16 pad intrafascial fat pad,20 intermediate fat RESULTS pad,7,10,11,17 middle fat pad,11 or temporal fat pad29 FASCIAL LAYERS AND FAT PADS Corpus adiposum Subfascial fat pad,8 deep Deep fat pad buccae1 fat pad,3,7,9-11,14,16,17 or The temporoparietal fascia and the deep temporal fascia buccal fat pad29 were identified on the anterior, middle, and posterior parts Temporal branch of Frontal branch,3,7,8,11,12,16-19 Temporal the facial nerve15 or temporal branch of each coronal strip. Above the zygomatic arch, the tem- nervus facialis branch,8,10,11,14,18,20,23-25 poroparietal fascia was composed of multiple (3-4) lay- (rami temporales)1 or frontotemporal ers (Figure 3 and Figure 4) that were integrated with branch9,14,21 thin fibrous septa immediately deep to the subcutaneous layer. The temporoparietal fascia could be easily dissected in posterior, middle, and anterior parts of specimens. Al- from the superficial layer of the deep temporal fascia above though this layer was thin (Ն2toϽ3 mm) in 36.3% of the zygomatic arch (Figures 5, 6, 7, and 8). Descend- posterior, 36.4% of middle, and 27.3% of anterior parts ing to the zygomatic arch, a discrete fatty layer called the of specimens, it was too thin (Ն1toϽ2 mm) in 27.3% superficial fat pad was encountered between the super- of posterior, 27.3% of middle, and 27.3% of anterior parts ficial layer of the deep temporal fascia and the temporo- of specimens, and was thick (Ն3toϽ4 mm) in 9.1% of parietal fascia (Figures 3 and 5). This fat pad disap- posterior, 36.3% of middle, and 36.3% of anterior parts peared below the middle level of the zygomatic arch. The of specimens. superficial fat pad was encountered in middle parts of The temporoparietal fascia had no attachment to the all specimens. However, this fatty layer was not visible zygomatic arch (Figures 3, 4, and 5). The temporopari- in 27.3% of posterior parts and 9.1% of anterior parts of etal fascia descending to the zygomatic arch lost its fas- specimens. The mean vertical lengths of the superficial cial layers and became a foamy tissue (Figures 3 and 6). temporal fat pad were 14, 20, and 25 mm, respectively, The level of change varied and was observed at approxi-

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DTF S

D-DTF TPF

S-DTF

IFP

SFP

DFP

MM SMAS

PMF B PG

Figure 2. Preferred names of the anatomic structures given in the Table. The asterisk marks where the deep layer of the deep temporal fascia (D-DTF) abuts the posterosuperior surface of the zygomatic arch (ZA) on 10 sides. The superficial layers and the deep layers of the deep temporal fascia (DTF) fuse at the anterosuperior surface of the ZA on 4 sides of the cadaveric heads. DFP indicates deep fat pad; IFP, intermediate fat pad; MM, masseter muscle; PG, parotid gland; PMF, parotideomasseterica fascia; S, skin; S-DTF, superficial layer of the DTF; SFP, superficial fat pad; SMAS, superficial musculoaponeurotic system; TM, temporal muscle; TPF, temporoparietal fascia. mately 1 cm above the zygomatic arch in 18% of specimens (6 of 33 sides of 11 specimens), in the upper level of the zygomatic arch in 64% (21 of 33 sides of 11 specimens), and in the middle of the zygomatic arch in 18% (6 of 33 sides of 11 specimens). The fascia continued as a superficial musculoaponeurotic system (SMAS) below the zygomatic arch (Figure 3 and Figure 9). Beginning from a level between the upper edge and the middle of the zygomatic arch, tight adhesions were observed between the temporoparietal fascia and the superficial layer of the deep temporal fascia, which covered the zygomatic arch, the mas- Figure 3. Coronal strips (A) and corresponding depictions (B) of the anterior seter muscle, and the parotid gland (Figure 9 and (right), middle (center), and posterior (left) thirds of the specimen. Figure 10). Below this level, the plane could only be found using sharp dissection between these layers (Figure 9). However, at the level of the parotid gland, fibrous inden- descended to the zygomatic arch, and a fibrofatty tissue tations were observed from the temporoparietal fascia into called the intermediate fat pad filled the space between the superficial layer of the deep temporal fascia covering these layers (Figures 3, 4, and 7 and Figure 11). The the parotid gland (Figure 6), and no dissection plane was deep layer of the deep temporal fascia could be easily dis- noted among the SMAS, the superficial layer of the deep sected from the intermediate fat pad (Figure 11). How- temporal fascia, and the parotid fascia (Figure 9). ever, dissection of the superficial layer of the deep tem- The deep temporal fascia lay under the superficial fat poral fascia from the intermediate fat pad was more pad and covered the temporal muscle. The thick single difficult because of extensions of a fibrous network of the layer of the upper part of the deep temporal fascia sepa- fat pad and arteriovenous perforators. In 10 specimens, rated into the superficial layer and the deep layer as it the layers of the deep temporal fascia did not fuse above

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TPF TPF TM

TM TFA

DFP IFP ZA TB-FN

Figure 4. Dissection of the middle third of the coronal strip. The temporoparietal fascia (TPF) is composed of multiple layers. DFP indicates PG deep fat pad; IFP, intermediate fat pad; MM, masseter muscle; TM, temporal muscle; ZA, zygomatic arch.

Figure 6. Dissection of the posterior third of the coronal strip. There are fibrous indentations from the temporoparietal fascia (TPF) into the superficial layer of the deep temporal fascia (S-DTF) covering the parotid gland (PG). TB-FN indicates temporal branch of the facial nerve; TFA, transverse fascial artery; TM, temporal muscle; ZA, zygomatic arch. S-DTF

SFP

ZA TPF

PMF

TM TB-FN

D-DTF Figure 5. Dissection of the hemiface of a cadaver. The superficial layer of the S-DTF TPF deep temporal fascia (S-DTF) continues as the parotideomasseterica fascia (PMF). SFP indicates superficial fat pad; TB-FN, temporal branch of the facial nerve; TPF, temporoparietal fascia; ZA, zygomatic arch. TB-FN

the zygomatic arch. In these specimens, the deep layer IFP abutted the periosteum of the posterosuperior edge of the zygomatic arch (Figure 3), and the superficial layer descended through the anterior surface of the zygomatic DFP arch to form the parotideomasseterica fascia inferiorly (Figure 5). However, on 4 sides of the cadaveric heads, the superficial layer and the deep layer of the deep tem- ZA poral fascia fused at the anterosuperior edge of the zygomatic arch and continued inferiorly as a single layer to form the parotideomasseterica fascia (Figure 2). The mean vertical lengths of the intermediate fat pad were 23, 24, and 37 mm, respectively, in posterior, middle, and anterior parts of specimens. The intermediate fat layer Figure 7. The topographic relationship of the temporoparietal fascia (TPF) to the temporal branch of the facial nerve (TB-FN). The temporal branch twigs was divided into several lobules by a fibrous network of the facial nerve course within the TPF. D-DTF indicates deep layer of the (Figure 3). There were arteries (1-2 mm in diameter) and deep temporal fascia; DFP, deep fat pad; IFP, intermediate fat pad; veins (2-3 mm in diameter) in the fat pad (Figure 11). S-DTF, superficial layer of the DTF; TM, temporal muscle; Although small vessels were common, several larger ves- ZA, zygomatic arch. sels were also encountered in each coronal strip at 5 to 24 mm from the zygomatic arch. ral muscle. This layer (called the buccal fat pad) contin- Another fat pad (called the deep fat pad) was ob- ued between the masseter muscle and the temporal muscle served between the deep temporal fascia and the tempo- inferiorly (Figures 4, 7, and 11).

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S-DTF ZA

TB-FN

Figure 10. The topographic relationship of the temporal branch of the facial nerve (TB-FN) to the zygomatic arch (ZA). The distance between the ZA and the TB-FN piercing the fascia is 3 mm. The asterisk marks where the tissue was horizontally cut to show the relationship.

A DTF B PG TPF

TM S-DTF

Figure 8. The temporal branch twigs of the facial nerve. The facial nerve D-DTF traverses along the zygomatic arch as multiple twigs. PG indicates parotid gland; S-DTF, superficial layer of the deep temporal fascia; TB-FN, temporal V branch of the facial nerve; TPF, temporoparietal fascia. A 3 2 IFP 1

SFP

SFP IFP DFP

TPF ZA

MM ZA

S-DTF Figure 11. Dissection of the layers of the deep temporal fascia (DTF) and schematic view of surgical approaches to reach the zygomatic arch (ZA) MM through the intermediate fat pad (IFP). A, The deep layer of the DTF (D-DTF) can be easily dissected from the IFP. B, Three possible approaches indicated SMAS by numbers 1, 2, and 3 (see the last paragraph of the “Comment” section for a discussion). The asterisk marks the subgaleal dissection plane. A indicates artery; DFP, deep fat pad; MM, masseter muscle; S-DTF, superficial layer of PG the DTF; SFP, superficial fat pad; TM, temporal muscle; TPF, temporoparietal fascia; V, vein.

Figure 9. Dissection of the middle third of the coronal strip in a fresh bers of temporal branch twigs passing over the zygo- cadaver specimen. The superficial layer of the deep temporal fascia (S-DTF) matic arch were 1 (14.3%), 2 (57.1%), 3 (14.3%), or 4 continues across the zygomatic arch (ZA) as the parotideomasseterica fascia. The temporoparietal fascia (TPF) continues as the superficial (14.3%) in the specimens (Figure 8). There was approxi- musculoaponeurotic system (SMAS). IFP indicates intermediate fat pad; mately 3 mm between the frontal nerve and the bone over MM, masseter muscle; PG, parotid gland; SFP, superficial fat pad. the zygomatic arch in the fresh cadaver specimens (Figure 10). Although the frontal nerve traversed inside TEMPORAL BRANCH OF THE FACIAL NERVE the deep layers of the SMAS and the temporoparietal fascia (Figure 7), no obvious dissection plane was encoun- Division of the temporal branch of the facial nerve oc- tered between the superficial layer of the deep temporal curred in the parotid gland. The temporal branch of the fascia and either the SMAS or the temporoparietal fascia facial nerve emerged from the parotid gland below the surrounding the temporal branch twigs over the zygo- zygomatic arch (Figures 6 and 10) and traversed inside matic arch. Above the zygomatic arch, a fat layer called the temporoparietal fascia over the zygomatic arch the superficial fat pad was observed between the tempo- (Figures 5 and 7) following the Pitanguay line. The num- roparietal fascia and the deep temporal fascia, and a thin

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We show herein that the temporoparietal Despite many studies, controversy remains about the to- fascia is composed of multiple fascial layers that are in- pography of the temporoparietal fascia, which com- tegrated with thin fibrous septa. prises a fascial layer just under the subcutaneous tissue The deep temporal fascia is a dense uniform aponeu- in the temporal region extending to the parietal region.1 rotic layer covering the temporal muscle.1 There is agree- After description of the SMAS of the face by Mitz and Pey- ment that the deep temporal fascia is a single layer at- ronie,2 the temporoparietal fascia was recognized as im- tached along the length of the superotemporal line, where portant to the temporal branch of the facial nerve. These it blends with the periosteum14,15 and splits into the su- authors stated that the SMAS was a fibromuscular net- perficial and deep lamina above the level of the zygo- work located between the facial muscles and the der- matic arch.4,7,8,10,11,14,16-20 However, it is controversial where mis. According to their observations, the SMAS “crosses the deep temporal fascia splits and where and if its lay- in front of the zygomatic arch and belongs to the tem- ers abut the zygomatic arch or continue as the masse- porozygomatic SMAS”2(p85) and is independent of the pa- teric fascia over the zygomatic arch. Yas¸argil et al21 dem- rotid fascia. In 1988, Hing et al3 noted that the tempo- onstrated that the deep temporal fascia is divided into 2 roparietal fascia was attached to the zygomatic arch. In layers at the orbital level. According to them, the super- 1989, Stuzin et al4 demonstrated in cadaver dissections ficial layer and the deep layer of the fascia that are at- that the temporoparietal fascia continued as the SMAS tached to the lateral and medial borders of the zygo- across the zygomatic arch but was not in anatomic con- matic arch are separated by an intermediate fat layer. tinuity with the periosteum of the zygomatic arch. How- Stuzin et al4 subsequently showed that the deep tempo- ever, Gosain et al5 claimed that the SMAS was not in ana- ral fascia splits into 2 layers below the supero-orbital mar- tomic continuity with the temporoparietal fascia. Gassner gin. They documented that the superficial layer of the et al6 supported the finding by Gosain et al and stated deep temporal fascia is attached to the superior margin that the SMAS and the temporoparietal fascia were in cor- of the zygomatic arch, overlies the periosteum of the zy- responding anatomic layers but lost their anatomic con- gomatic arch, and blends with the parotideomasseterica tinuity when they fused with the zygomatic arch. In con- fascia. Salas et al9 argued that the deep layer of the deep trast, Campiglio and Candiani7 and Coscarella et al8 temporal fascia is attached to the posterosuperior mar- claimed that the temporoparietal fascia abutted the zy- gin of the zygomatic arch, continues along the deep sur- gomatic arch and comprised the parotideomasseterica fas- face of the zygomatic arch, and blends with the “pos- cia below the zygomatic arch. Our results agree with the teromasseteric fascia.” Ramirez et al19 found that the deep observation by Stuzin et al4 that the temporoparietal fas- layer and the superficial layer of the deep temporal fascia had no attachment to the zygomatic arch. Our find- cia fuse at 1 cm above the zygomatic arch and are at- ings are consistent with most studies4,9-11 in the litera- tached to the superficial surface of the zygomatic arch, ture reporting that the temporoparietal fascia continues blending with the attachment to the fascia of the masse- as the SMAS below the zygomatic arch. However, we dem- ter muscle. Ammirati et al20 reported that 2 layers of this onstrate herein that the temporoparietal fascia becomes fascia are attached to the anterior portion of the zygo- a foamy tissue between the upper level of the zygomatic matic arch and continue with the parotideomasseterica arch and approximately 1 cm above the zygomatic arch. fascia below the zygomatic arch. Campiglio and Candi- We also show that there are adhesions between the tem- ani7 noted that the temporal muscle fascia split into 2 poroparietal fascia and the superficial layer of the deep sheets at 5 cm above the zygomatic arch, with the su- temporal fascia between the upper and middle levels of perficial sheet abutting the anterior surface of the zygo- the zygomatic arch. Because of the fusion, elevation re- matic arch and the deep sheet abutting the posterior sur- quires sharp dissection between these layers; this could face of the zygomatic arch. These 2 fascial layers were endanger the temporal branch of the facial nerve, which fused in the anterior and posterior thirds of the zygo- is protected by only a thin layer of spongiosis-type tem- matic arch but were separated by a fat pad in the middle. poroparietal fascia or SMAS over the zygomatic arch. How- Similarly, Hwang and Kim22 demonstrated that the su- ever, we observed fibrous indentations from the SMAS perficial layer and the deep layer of the deep temporal into the superficial layer of the deep temporal fascia cov- fascia fused and abutted the superior margin of the zy- ering the parotid gland, which could reflect fusion of the gomatic arch in 18 dissections (56%) and abutted the su- SMAS and the parotid fascia to form a single layer. perolateral surface in 14 dissections (44%). Coscarella Telliog˘luetal12 reported that the temporoparietal fas- et al8 and Beheiry and Abdel-Hamid10 reported that the cia was composed of inner and outer parts. They stated fascia of the temporal muscle split into 2 layers at 1 to 2 that the outer layer extended as the SMAS below the zy- cm above the zygomatic arch or over the lower half of gomatic arch. The inner layer blended with the superfi- the temporal muscle, and the superficial fascia attached cial layer of the deep temporal fascia on the zygomatic to the lateral side of the zygomatic arch. The deep fascia arch and continued to the masseteric fascia. Hata13 dis- abutted the medial side of the zygomatic arch. In con- agreed with their findings, arguing that the outer layer trast, Accioli de Vasconcellos et al11 found that the deep

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However, our findings demon- perficial fat pad for the intermediate fat pad and endan- strate that the point where the fascia splits differs at the gering the temporal branch of the facial nerve by interfacial anterior, middle, and posterior portions of the zygo- dissection and instead recommended deeper dissection matic arch because of the fat pad between the layers of to preserve the facial nerve. In contrast, Stuzin et al4 the fascia. We also show that the layers of the deep tem- claimed that a safe surgical plane is ensured by begin- poral fascia do not fuse above the zygomatic arch, but ning dissection in the superficial fat pad of the temporal the 2 layers could be seen as a single layer if a cross- region and by deepening the dissection at 2 cm above the section was obtained near the lateral orbital rim. In most zygomatic arch into the intermediate temporal fat pad of our specimens, the superficial layer continues as the to expose the zygomatic arch. Ramirez et al19 reported parotideomasseterica fascia, and the deep layer abuts the in 1991 that there was no structure between the perios- posterosuperior edge of the zygomatic arch. However, the teum of the zygomatic arch and the temporoparietal fas- superficial layer and the deep layer of the deep temporal cia. Therefore, they suggested that subgaleal dissection fascia continued together across the zygomatic arch as should be deepened through the layers of the deep tem- the parotideomasseterica fascia in 27% of specimens (9 poral fascia at about 3 cm above the zygomatic arch and of 33 sides of 11 specimens). that subperiosteal dissection should be performed at the Kim and Matic16 observed that a fibrous network di- level of and along the entire length of the zygomatic arch. vides the intermediate fat pad into lobules and that there In 2002, Ramirez25 described some changes in his sur- is a dual arterial supply to the intermediate fat pad from gical technique, noting that the zygomatic arch could be perforators originating from the middle and deep tem- entered at 2 to 3 mm above the superior border of the poral arteries, which pierce the superficial layer and the zygomatic arch. As part of their midface-lift technique, deep layer of the deep temporal fascia. Our study con- Quatela and Olney published the recommendation “to firms that the intermediate fat pad is divided into sev- elevate deep to the intermediate fat pad directly on the eral lobules by a fibrous network and that there are ves- deep layer of the deep temporal fascia and then deep to sels inside the fat pad, especially at 5 to 24 mm from the the periosteum.”17(p217) Krayenbühl et al14 suggested that zygomatic arch. We also show that perforators are more subgaleal fascia dissection can be performed up to the common between the intermediate fat pad and the su- adhesions between the temporoparietal fascia and the deep perficial layer and the deep layer of the deep temporal temporal fascia and that interfacial or interlaminar dis- fascia. section (between the 2 lamina of the deep temporal fas- Researchers have called attention to the number of tem- cia) or subfascial dissection could then be performed to poral branch twigs at the level of the zygomatic arch. Go- protect the facial nerve. sain et al23 demonstrated that 2 to 4 rami of the temporal In light of our findings and the results of the studies branch of the facial nerve cross the zygomatic arch. Zani reviewed herein, 3 approaches may be used to reach the et al24 noted that the temporal branch of the facial nerve zygomatic arch through the intermediate fat pad. The dis- is composed of 1 twig in 28% of cases, 2 twigs in 32% of section plane is incised down to the periosteum (sub- cases, 3 twigs in 16% of cases, and 4 twigs in 4% of cases periosteal) on the zygomatic arch in all 3 approaches at the level of the zygomatic arch. Ammirati et al20 showed (Figure 11). The first approach is a subgaleal dissection that the temporal branch of the facial nerve is divided into (superficial to the superficial layer of the deep temporal anterior, middle, and posterior rami after piercing the pa- fascia), deepening into the intermediate fat pad just above rotideomasseterica fascia. In our study, the temporal branch the zygomatic arch. Our study demonstrates that the tem- of the facial nerve traversed along the zygomatic arch as 1 poral branch of the facial nerve is covered by a thin layer twig in 14.3%, as 2 twigs in 57.1%, as 3 twigs in 14.3%, of the temporoparietal fascia above the zygomatic arch and as 4 twigs in 14.3% of specimens. and that there is a superficial fat pad between the tem- Various approaches have been described for a safe sur- poroparietal fascia and the superficial layer of the deep gical dissection around the temporal branch of the fa- temporal fascia. However, our study also shows that this cial nerve and the zygomatic arch. Researchers7,8,11,14,20 fat pad disappears and that adhesions are observed at the have observed that the temporal branch of the facial nerve dissection plane beyond the upper edge of the zygo- courses within the superficial fat pad. Because of this find- matic arch. Our findings suggest that continuous dissec- ing, Coscarella et al8 proposed submuscular dissection tion on the subgaleal plane to the upper edge of the zy- (deep to the temporal muscle) or subfascial dissection gomatic arch is safe and easy. Beyond this level, subgaleal (deep to the deep temporal fascia layer). In contrast, other dissection carries the risk of injury to the temporal branch authors4,9,12,18 have noted the temporal branch of the fa- of the facial nerve. Therefore, the surgeon will need to cial nerve in the deepest temporoparietal fascia above the continue deep dissection to at least a few millimeters above zygomatic arch. Beheiry and Abdel-Hamid10 reported that the zygomatic arch. The second approach begins with sub- the temporal branch of the facial nerve coursed first be- galeal dissection as in the first approach but deepens into tween the layers of the superficial lamina of the tempo- the intermediate fat pad at 1 to 2 cm above the zygo- roparietal fascia and then coursed between the deep layer matic arch. Our study shows that there are widespread and the superficial layer of the temporoparietal fascia. Con- vessels in the intermediate fat pad located 5 to 24 mm

(REPRINTED) ARCH FACIAL PLAST SURG/ VOL 12 (NO. 1), JAN/FEB 2010 WWW.ARCHFACIAL.COM 22 Downloaded from www.archfacial.com at Emory University, on March 15, 2010 ©2010 American Medical Association. All rights reserved. from the zygomatic arch. Although dissection using this anatomy of the SMAS: a reinvestigation. Plast Reconstr Surg. 1993;92(7): approach would be safer than the first approach, more 1254-1265. 6. Gassner HG, Rafii A, Young A, Murakami C, Moe KS, Larrabee WF Jr. Surgical bleeding may occur. The third approach is to dissect the anatomy of the face: implications for modern face-lift techniques. Arch Facial deep layer of the deep temporal fascia (deep to the in- Plast Surg. 2008;10(1):9-19. termediate fat pad) beginning from the division point of 7. Campiglio GL, Candiani P. Anatomical study on the temporal fascial layers and their the layers of the deep temporal fascia. Our study shows relationships with the facial nerve. Aesthetic Plast Surg. 1997;21(2):69-74. that the intermediate fat pad can be easily dissected from 8. Coscarella E, Vishteh AG, Spetzler RF, Seoane E, Zabramski JM. Subfascial and submuscular methods of temporal muscle dissection and their relationship to the deep layer of the deep temporal fascia and that only the frontal branch of the facial nerve: technical note. J Neurosurg. 2000;92 a few small vessels are encountered along the dissection (5):877-880. plane. Our results suggest that this approach is as safe 9. Salas E, Ziyal IM, Bejjani GK, Sekhar LN. Anatomy of the frontotemporal branch as the second approach in terms of injury to the tempo- of the facial nerve and indications for interfascial dissection. Neurosurgery. 1998; 43(3):563-569. ral branch of the facial nerve but that less bleeding and 10. Beheiry EE, Abdel-Hamid FA. An anatomical study of the temporal fascia and re- disruption of the fat pad occur compared with the sec- lated temporal pads of fat. Plast Reconstr Surg. 2007;119(1):136-144. ond approach. 11. Accioli de Vasconcellos JJ, Britto JA, Henin D, Vacher C. The fascial planes of the temple and face: an en-bloc anatomical study and a plea for consistency. Br Accepted for Publication: July 14, 2009. J Plast Surg. 2003;56(7):623-629. 12. Telliog˘lu AT, Tekdemir I, Erdemli EA, Tüccar E, Ulusoy G. Temporoparietal fas- Correspondence: Ozcan Cakmak, MD, Acibadem Uni- cia: an anatomic and histologic reinvestigation with new potential clinical versity, Department of Otorhinolaryngology, Acibadem applications. Plast Reconstr Surg. 2000;105(1):40-45. Kadikoy Hospital, Tekin Sokak, No. 8, Acibadem, Kadi- 13. Hata Y. Is it true that the temporoparietal fascia has two layered structures? Plast koy, Istanbul, Turkey 34718 (ozcan.cakmak@gmail Reconstr Surg. 2001;107(5):1309-1310. .com). 14. Krayenbühl N, Isolan GR, Hafez A, Yas¸argil MG. The relationship of the frontotemporal branches of the facial nerve to the fascias of the temporal region: a lit- Author Contributions: All authors had full access to all erature review applied to practical anatomical dissection. Neurosurg Rev. 2007; the data in the study and take responsibility for the in- 30(1):8-15. tegrity of the data and the accuracy of the data analysis. 15. Standring S. Gray’s Anatomy: The Anatomical Basis of Clinical Practice. 39th ed. Study concept and design: Babakurban, Cakmak, and Qua- Edinburgh, Scotland: Elsevier Churchill Livingstone; 2008. tela. Acquisition of data: Babakurban, Cakmak, Kendir, 16. Kim S, Matic DB. The anatomy of temporal hollowing: the superficial temporal fat pad. J Craniofac Surg. 2005;16(5):760-763. and Elhan. Analysis and interpretation of data: Babakur- 17. Quatela VC, Olney DR. Management of the midface. Facial Plast Surg Clin North ban, Cakmak, Kendir, and Quatela. Drafting of the manu- Am. 2006;14(3):213-220. script: Babakurban, Cakmak, Kendir, and Elhan. Criti- 18. Sabini P, Wayne I, Quatela VC. Anatomical guides to precisely localize the fron- cal revision of the manuscript for important intellectual tal branch of the facial nerve. Arch Facial Plast Surg. 2003;5(2):150-152. 19. Ramirez OM, Maillard GF, Musolas A. The extended subperiosteal face lift: a de- content: Cakmak, Kendir, and Quatela. Statistical analy- finitive soft-tissue remodeling for facial rejuvenation. Plast Reconstr Surg. 1991; sis: Babakurban. Administrative, technical, and material sup- 88(2):227-238. port: Cakmak, Elhan, and Quatela. Study supervision: Cak- 20. Ammirati M, Spallone A, Ma J, Cheatham M, Becker D. An anatomicosurgical mak, Elhan, and Quatela. study of the temporal branch of the facial nerve. Neurosurgery. 1993;33(6): Financial Disclosure: None reported. 1038-1044. 21. Yas¸argil MG, Reichman MV, Kubik S. Preservation of the frontotemporal branch Previous Presentation: This study was presented and of the facial nerve using the interfascial temporalis flap for pterional craniotomy: awarded the best poster in the field of facial plastic sur- technical article. J Neurosurg. 1987;67(3):463-466. gery at the First Meeting of the European Academy of 22. Hwang K, Kim DJ. Attachment of the deep temporal fascia to the zygomatic arch: Otorhinolaryngology & Head and Neck Surgery in Col- an anatomic study. J Craniofac Surg. 1999;10(4):342-345. laboration With the European Federation of Oto-Rhino- 23. Gosain AK, Sewall SR, Yousif NJ. The temporal branch of the facial nerve: how reliably can we predict its path? Plast Reconstr Surg. 1997;99(5):1224-1236. Laryngological Societies; June, 28, 2009; Mannheim, Ger- 24. Zani R, Fadul R Jr, Da Rocha MA, Santos RA, Alves MC, Ferreira LM. 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