2.0 ANCC CE Contact Hours Understanding the Anatomy of the Upper Face When Providing Aesthetic Injection Treatments Tracey A. Hotta , BScN, RN, CPSN function when using a neuromodulator in this area. The Advanced rejuvenation procedures for the upper face are provider must assess for a functioning frontalis to deter- becoming increasingly popular for aesthetic providers mine whether a neurotoxin treatment is appropriate and but are considered a high-risk treatment area for dermal will achieve the desire aesthetic result. Treating a func- fi ller/contouring products. Risks may range from bruising, tional frontalis may result in a heaviness of the brow or which is manageable, to blindness, most often irrevers- brow ptosis. The provider may choose to treat the depres- ible. Detailed comprehension of the facial anatomy is sive action of the glabellar complex because the muscle imperative when performing aesthetic injections including fi bers are intertwined with the frontalis. This will result in neuromodulators and dermal fi ller/contouring products. relaxing the frontalis without actually treating it. Understanding the location and function of the muscles, The blood supply to the frontalis muscle comes from the as well as landmarking the blood vessels and nerves, will frontal branch of the superfi cial temporal artery, laterally, assist the aesthetic provider to perform safe, confi dent and the supratrochlear and supraorbital arteries medially. injection procedures. This article focuses on the upper The superfi cial temporal artery arises from the external face anatomy as identifi ed by the author's cadaveric dis- carotid at the area of the mandible, travels upward ap- sections and includes the treatment areas of the frontalis, proximately 1 cm in front of the ear in the preauricular temporalis, and glabellar complex. The author's next space, and travels across the zygomatic arch. As it crosses article for the Plastic Surgical Nursing journal will focus the zygomatic arch, it is known as the frontal branch of on the periorbital area. the superfi cial temporal artery ( Figure 2 ). The frontal branch is the terminal branch of the THE FRONTALIS MUSCLE superfi cial temporal artery and anastomoses with the The frontalis muscle is a large muscle that extends upward supraorbital arteries within the frontalis muscle. The su- and laterally across the forehead. Its function is to elevate pratrochlear and supraorbital vessels exit through a fora- the eyebrows, usually more centrally than laterally. It is men, or notch, located in the orbital rim. The supratroch- important to understand its origin and insertion points and lear neurovascular bundle is approximately 1.7 cm from how the frontalis is intertwined with the other periocu- the midline of the forehead, where the supraorbital bun- lar muscles. The origin of the frontalis is at the hairline, dle is approximately 2.7 cm from the midline ( Figure 3 ). known as the epicranium of the aponeurosis. Its insertion These blood vessels exit through the corrugator muscles is at the level of the eyebrows, where it is intertwined with and travel upward and insert into the frontalis approxi- the fi bers of the procerus, corrugator, depressor supercilii, mately 2 cm above the orbital rim ( Figure 4 ). and orbicularis oculi muscles. The directions of the muscle The frontalis is innervated by temporal branch of fi bers are vertical, which, with repeated movement, result the facial nerve. The nerve originates from beneath the in the appearance of horizontal lines across the forehead. parotid gland and travels upward across the zygomatic The frontalis terminates laterally at the temporal fusion arch. It is located in the loose areolar tissue just under the line, where it lies over the temporalis muscle ( Figure 1 ). temporoparietal fascia. The nerve changes its plane from Because the frontalis muscle is the only elevating deep to superfi cial as it enters on the undersurface of the muscle of the upper face, it is important to consider this frontalis muscle at the temporal fusion line. The frontal branch of the superfi cial temporal artery is superior to the nerve ( Figure 5 ). Tracey A. Hotta, BScN, RN, CPSN, is the owner of TH Medical Aesthetics and President of THMA Consult Inc. The author has not received any funding in writing this article. The author GLABELLAR COMPLEX declares no confl icts of interest. Address correspondence to Tracey A. Hotta, BScN, RN, CPSN, 75 Glabellar complex includes the procerus, corrugator Cricklewood Crescent, Thornhill, ON L3T 4T8, Canada (e-mail: tracey@ supercilii, and the depressor supercilii muscles ( Table 3 ). hotta.ca ). The corrugator supercilii muscle originates from the me- DOI: 10.1097/PSN.0000000000000149 dial supraorbital ridge of the frontal bone and inserts into 104 www.psnjournalonline.com Volume 36 Number 3 July–September 2016 Copyright © 2016 American Society of Plastic Surgical Nurses. Unauthorized reproduction of this article is prohibited. FIGURE 1. Temporal fusion line. Cadaver preparation and dissection by Tracey Hotta. FIGURE 3. Landmarking the supratrochlear and supraorbital neuro- the medial eyebrow skin. The supratrochlear neurovas- vascular bundles. Cadaver preparation by Deborah Elias and Tracey cular bundle exits through the corrugator supercilii and Hotta. Dissection by Claudio DeLorenzi. supplies sensation and vascularity to the central forehead. The function of the corrugator supercilii is to cause medial The supratrochlear artery travels beneath the corruga- brow depression. tor and frontalis muscles, with the surface landmark be- Cadaveric dissections by Pessa and Rohrich (2012) ing the corrugator crease. As it courses upward through found that the glabellar complex has distinct compart- the frontalis muscle, the supratrochlear artery becomes ments of adipose tissue that creates the vertical lines or more superfi cial and is directly beneath the skin. It is this creases. These creases may be used as surface landmarks superfi cial position of the central forehead vessel that to identify the location of the supratrochlear artery and may contribute to reported complication risk of injections nerve. Contraction of the glabellar complex identifi es performed in the glabellar region due to the reduced these three distinct creases, which are the midline, cor- collateral blood supply. rugator, and supraorbital creases. Between these creases Because the supratrochlear and supraorbital arteries are fat compartments known as the medial and lateral are branches of the ophthalmic branch of the internal compartments. Cadaveric studies ( Pessa & Rohrich, 2012 ) carotid artery, landmarking for the corrugator and supra- show that the supratrochlear artery is situated within the orbital creases is important when a dermal fi ller is being corrugator crease and the supraorbital artery is situated used to augment these creases. Inadvertent injection into within the supraorbital crease. the supratrochlear artery may fl ow retrograde through the ophthalmic artery and lodge in the retinal artery, causing FIGURE 4. Pathway of the supratrochlear and supraorbital artery FIGURE 2. Location of the superfi cial temporal artery and the frontal through the corrugator supercilii and into the frontalis muscle. Cadaver branch of the superfi cial temporal artery. Cadaver preparation and dis- preparation by Deborah Elias and Tracey Hotta. Dissection by Tracey section by Deborah Elias. STA = superfi cial temporal artery. Hotta. Plastic Surgical Nursing www.psnjournalonline.com 105 Copyright © 2016 American Society of Plastic Surgical Nurses. Unauthorized reproduction of this article is prohibited. FIGURE 5. Pathway of the frontal branch of the superfi cial temporal FIGURE 7. Temporal fascia. Cadaver preparation by Deborah Elias artery entering the frontalis muscle at the temporal fusion line. and Tracey Hotta. Dissection by Claudio DeLorenzi. Cadaver preparation by Tracey Hotta. Dissection by Tracey Hotta. The temporal area consists of two fascial layers: deep potential blindness. Therefore, it is recommended that an and superfi cial. The deep temporal fascia is separated injection performed in this area should be superfi cial just from the superfi cial fascia by an avascular plane of loose under the dermis with a low hyaluronic acid concentra- areolar tissue. It is fi rmly attached to periosteum around tion product with low injection force. This will help re- the margin of the temporalis muscle but has no attach- duce the risk of bruising and inadvertent injury to the ment to the zygomatic arch. The cadaver dissection by the vessel ( Figure 6 ). author revealed that the fascial layer is tight to the muscle and has very little give, especially in younger clients. This anatomy must be considered when evaluating a client for TEMPORAL HOLLOWING temporal augmentation (Figure 7 ). The temporalis muscle is a large fan-shaped muscle that With age, the muscle under the temporal fascia at- is located at the side of the skull lateral to the orbital rophies, allowing more space for augmentation with a rim and above the zygomatic arch (Table 2 ). It is a mus- contouring product. There are two injection techniques cle of mastication and is intertwined with the masseter that may be used to treat temporal hollowing, and each muscle. The temporal hollow occurs from bony reabsorp- approach carries its own risks. The provider may choose tion, muscle atrophy, and defl ation of the fat pad over to do either a deep periosteal injection with a needle or the temporal area. This causes a depression at the lateral