Despite the cosmetic unit of the forehead appearing to be a convex arch, the frontal bone is not uniformly convex. There is a rounded elevation—the frontal eminence(tuber frontale)—on both sides of the forehead, approximately 3 cm above the supraorbital ridge.1The superciliary arches are located below the frontal eminence and separated from them by a concavity. They are more prominent medially, and are separated by the glabella and more visible in men than in women. Bone remodeling and atrophy of the subcutaneous tissue below the frontal eminence result in concavity above the eyebrows. Generally, restoring volume to this area between the frontal eminence and the superciliary arch is sufficient to rejuvenate the forehead. However, when looking to redefine the frontal contour, the entire forehead needs to be filled, as a wider, more convex, and smoother forehead is considered more feminine and attractive than a flat or concave one,2which is why some women seek this kind of procedure for projecting the entire region.
Anatomy
The subcutaneous tissue of the forehead comprises three fat pads: central, middle, and temporolateral.3
The fat pads are supplied by the supraorbital and supratrochlear arteries and by the frontal branch of the superficial temporal artery (STA). They are located in the subcutaneous tissue and also embedded in the frontal muscle. Motor innervation is supplied by the frontotemporal branch of the facial nerve (CN VII) and sensory innervation by the supraorbital and supratrochlear nerves (CN V).
The layers are: the skin, subcutaneous tissue, frontal muscle, and periosteum (Figs. 8.1–8.14,8.17,8.18, and8.24).
Technique
The filler injection technique used for the forehead comprises the following stages:
Before starting the procedure, block the the supraorbital and supratrochlear nerves for greater patient comfort.
Mark the area to be filled and the entry points for the cannula.
Perform an antegrade injection of the product into the supraperiosteal plane, below the frontal muscle. This application plane is safer and also reduces the risk of irregularities. Therefore, inject 2.5 cm above the eyebrow to avoid compressing the supraorbital/supratrochlear nerves and their respective arteries. To reduce pain after the procedure, avoid scraping the cannula on the periosteum and massage the area in order to achieve a uniform result. As is recommended for the temporal region, it is possible to dilute the hyaluronic acid (HA) according to Lambros’s technique4in order to guarantee that the product spreads uniformly.
When using a needle, inject small boluses of the product into the supraperiosteal plane, and then massage the area.
Technique with Cannula Superficial to the Muscular Layer
Edema and visualization of the local vessels are very common immediately after the procedure. These adverse effects are self-limiting and persist for up to 10 days. Nonetheless, asymmetry, irregularities, hematoma, and localized pain must be mentioned. Temporary ptosis of the eyebrow may last up to three hours due to the diffusion of lidocaine present in the filler. Intravascular injection of the filler can result in embolism, and because of the risk of retrograde flow, occlusion of the ophthalmic artery, resulting in amaurosis, cannot be ruled out.
References
1 Busso M, Howell DJ. Forehead recontouring using calcium hydro-xylapatite. Dermatol Surg 2010; 36(3, Suppl 3):1910–19132 Park DK, Song I, Lee JH, You YJ. Forehead augmentation with a methyl methacrylate onlay implant using an injection-molding technique. Arch Plast Surg 2013;40(5):597–6023 Rohrich RJ, Pessa JE. The fat compartments of the face: anatomy and clinical implications for cosmetic surgery. Plast Reconstr Surg 2007;119(7):2219–2227, discussion 2228–22314 Lambros V. A technique for filling the temples with highly diluted hyaluronic acid: the “dilution solution”. Aesthet Surg J 2011;31(1):89–94Fig. 8.1 A. 3D digital model of the left side of the face focusing on the forehead.B. Same region after removal of the skin, showing the superficial fat pad (SFP).C. Same region after removal of the skin and SFP, exposing the frontal muscle and orbicularis oculi muscle (OM).D. Same region after removal of the skin, SFP, and OM. Retroorbicularis oculi fat (ROOF) is visible.Fig. 8.2 A. 3D digital model of the left side of the forehead after removal of the skin, superficial fat pad (SFP), orbicularis oculi muscle (OM), and retroorbicularis oculi fat (ROOF). The frontal muscle is visible.B. Same region after removal of the skin, SFP, OM and frontal muscle. The corrugator muscle is visible.C. Bone structure of the aforementioned region.Fig. 8.3 Left side of the forehead.A. Corresponding vascularization and innervation.B. Corresponding arterial vascularization.C. Corresponding venous vascularization.D. Corresponding innervation.Fig. 8.4 A. Right profile view of a 3D digital model showing details of the forehead.B. Same region after removal of the skin, showing the superficial fat pad (SFP).C. Same region after removal of the skin and SFP, exposing the frontal muscle and orbicularis oculi muscle (OM). Retroorbicularis oculi fat (ROOF) is visible behind this.D. Bone structure of the aforementioned region.Fig. 8.5 Right profile view of the forehead.A. Corresponding vascularization and innervation.B. Corresponding arterial vascularization.C. Corresponding venous vascularization.D. Arterial and venous vascularization above the frontal muscle and orbicularis oculi muscle (OM).E. Same illustration asD after removal of the superficial temporal fascia and the frontal branch of the superficial temporal artery (STA). The corresponding arterial and venous vascularization is visible above the deep temporal fascia.F. Corresponding innervation.Fig. 8.6 A andB. Frontal view of a 3D digital model.C. Frontal view of a 3D digital model with markings indicating the region of the forehead to be filled.Fig. 8.7 A. Upper third of the left side of the face of a fresh cadaver specimen with the skin being pinched.B. Skin being folded back, revealing the frontal muscle and periosteum.C. Frontal muscle being pinched.D. Frontal muscle being folded back exposing the periosteum (blue arrow) and the frontal bone.Fig. 8.8 A. Left side of the face of a fresh cadaver with frontal muscle pinched and folded back.B. Periosteum being pinched (blue arrow).C. Exposure of the frontal bone. Note the bone depressions (blue arrows) where the superficial fat pads (SFPs) of the forehead are denser.Fig. 8.9 A. Right side of the face of a fresh cadaver with skin of the upper third being pinched.B. Skin of the upper third being folded back.C. Skin has been folded back to expose the temporal and frontal muscles, and superficial temporal artery (STA) (blue arrow) and its frontal branches (green arrows) .D. Frontal muscle being folded back to reveal the frontal bone. Note also the frontal branch of the STA (blue arrow) .E. Frontal muscle has been folded back to reveal the frontal bone.Fig. 8.10 A. Left side of the face of a fresh cadaver specimen with intact skin.B. Same region with the skin folded back to expose the frontal muscle (blue arrow).C. Frontal muscle being folded back exposing the periosteum and the frontal bone (blue arrow).D. Note the corrugator muscle (blue arrow) that was beneath the frontal muscle and has been folded back.E. The supraorbital foramen, the supraorbital nerve, and the vein and artery are visible beneath the corrugator muscle (blue arrow). Filler injections should not be performed close to the supraorbital or supratrochlear foramens. We suggest injecting the filler 2.5 cm above this region.Fig. 8.11 A. Right side of the face of a fresh cadaver showing the superficial temporal artery (STA) branches above the frontal muscle.B. Right side of the face of the sample showing the frontal branch of the STA, supraorbital and supratrochlear veins and, more medially, the supratrochlear artery (STrA). All the vessels described are located above the frontal muscle, embedded in the subcutaneous tissue.Fig. 8.12 Right side of the face of a fresh cadaver showing the frontal branch of the superficial temporal artery (STA), which anastomoses distally with the supraorbital artery. The supratrochlear and nasal dorsal arteries are visible medially, accompanied by their respective veinsin blue.Fig. 8.13 A. Right side of the face of a fresh cadaver with the skin and part of the subcutaneous tissue of the forehead folded back.B. Note the frontal branch of the superficial temporal artery (STA)in red, above the frontal muscle, which is being pinched.C. Frontal muscle being folded back together with the vessels that are above the muscle.D. Frontal bone exposed after the frontal muscle has been folded back. The supraorbital foramen is visible approximately 27 mm from the midline of the face, from which the supraorbital nerve, vein, and artery emerge.Fig. 8.14 Right side of the face of a fresh cadaver with the skin, subcutaneous tissue, and frontal muscle folded back. Note that there are no vessels posterior to the frontal muscle, which is why it is considered to be the safest plane for filler injections with needles.Fig. 8.15 A. Profile view of a model with markings showing the frontotemporal transition line(brown line) and further markings(in purple) showing the area of the forehead to be filled. A 25 Gx 40 mm cannula was inserted before the frontotemporal line in the supramuscular plane, where the product was injected with a retrograde injection technique.B. Profile of a patient with the frontotemporal transition linein green, and the area of the forehead to be filledin red. Note the raised outline of the 25 Gx 40 mm cannula inside the area circledin red. This is to show that the cannula is in the supramuscular injection plane, which is not advisable as this involves a greater risk of complications and emergence of the product due to overcorrection.Fig. 8.16 A. Right side of the face of a fresh cadaver with the skin folded back and a 25 GX 40 mm cannula inserted into the superficial fat pad of the forehead, in the supramuscular plane.B. The superficial fat pad is removed, and the 25 GX 40 mm cannula is visible above the frontal muscle, simulating the supramuscular application of the product.C. Supramuscular application ofgreen-colored hyaluronic acid (HA)(blue arrow).Fig. 8.17 The supratrochlear vein and artery are visible embedded in the subcutaneous tissue in the sagittal plane of the upper third of a fresh cadaver.Fig. 8.18 Right side of the face of a fresh cadaver where the supraorbital nerve, vein, and artery can be seen exiting the supraorbital foramen, after removal of the skin, the subcutaneous tissue and the frontal muscle. Note the absence of vessels above the frontal bone and medially from the supratrochlear vein and artery, in the subcutaneous tissue.Fig. 8.19 A. Upper third of a model with markings indicating the area of the forehead to be filled(in purple). A 25 GX 40 mm cannula was inserted into the submuscular plane, where the product was injected using a retrograde injection technique.B. Profile view of a patient with markings showing the frontotemporal transition line(in green) and further markings(in red) showing the area of the forehead to be filled marked. Note the 25 GX 40 mm cannula inside the area circledin red. As the raised outline noted inFig. 8.15 Bis not visible here, it can be assumed that the cannula is in the submuscular plane. This is the safest plane, as it avoids complications and emergence of the product due to overcorrection.C. A fresh cadaver with a 25 GX 40 mm cannula inserted into the submuscular plane.Fig. 8.20 A. A fresh cadaver with the frontal muscle being folded back and a 25 GX 40 mm cannula inserted into the submuscular plane(blue arrow).B. Frontal muscle being folded back and 25 GX 40 mm cannula in the submuscular plane, simulating an injection ofgreen-colored hyaluronic acid (HA)(blue arrow).C. Frontal muscle already folded back and a 25 GX 40 mm cannula in the submuscular plane, simulating an injection ofgreen-colored HA(blue arrow). This is the ideal plane for filler injections of HA in the forehead.Fig. 8.21 A. Injection ofblue-colored hyaluronic acid (HA), with cannula in the supraperiosteal plane, in the left side of the forehead of a fresh cadaver.B. Skin, subcutaneous tissue, and frontal muscle have been folded back.C. Note that the larger vessels were folded back, as they were between the subcutaneous tissue and the frontal muscle. See the small arteries (blue arrows) over the periosteum, whose only function is to nourish the periosteum. The supraperiosteal plane is therefore considered the safest site for filler injections in the forehead. Note the light blue-colored region (brown arrow); it is the site where the HA shown inA was deposited.Fig. 8.22 A. Profile of a model with markings showing the frontotemporal transition line(brown line) and further markings showing the area of the forehead to be filled(in purple). A 27 GX 13 mm needle was inserted into the marked area in the supraperiosteal plane, where the product is injected using a bolus technique.B, C, andD . Fig.A in different positions.E andF. Markings(in purple) showing the area of the forehead to be filled and insertion of a 27 GX 13 mm needle in the supraperiosteal plane, where the product is injected using a bolus technique, after aspiration.Fig. 8.23 A. Forehead of a fresh cadaver with a 27 GX 13 mm needle inserted into the supraperiosteal plane.B. Skin has been folded back, exposing the frontal fat pad and insertion of a 27 GX 13 mm needle into the supraperiosteal plane.C. Skin and fat pad of the forehead have been folded back, exposing the frontal bone. Note the 27 GX 13 mm needle in the supraperiosteal plane.D. Skin and fat pad of the forehead have been folded back, exposing the periosteum and frontal bone. Note the 27 GX 13 mm needle in the supraperiosteal plane where the product was injected(turquoise-colored), using a bolus technique.Fig. 8.24 A. Right side of the face of a fresh cadaver profile, exposing the frontal muscle. The left side of the face is covered by skin.B. Right side of the face showing the frontal muscle and the skin of the left side of the face being folded back, exposing the superficial fat pad of the forehead. Note how thin the skin that covers the left side of the face is.C. Skin of the left side of the face has already been folded back to completely expose the superficial fat pad of the forehead. The skin to be folded back is thin, measuring between 2 and 3 mm. The intradermal plane for injection is limited to this depth.Fig. 8.25 A. Upper third of the left side of the face of a fresh cadaver. Note the markings(in black) in the area of the forehead to be filled and the 27 GX 13 mm needle being inserted into the intradermal plane of this region.B. 27 GX 13 mm needle being inserted into the intradermal plane; note the raised outline it causes.C. 27 GX 13 mm needle has already been inserted into the intradermal plane. The raised outline indicates that the injection plane is quite superficial. This technique is indicated for correcting transverse wrinkles on the forehead as a complement to neuromodulators.Fig. 8.26 A. Upper third of a patient with indications for a filler injection of the forehead. See the shadows on the right side of the face, indicating atrophy of the fat pads (red arrows).B. Upper third of the same patient after application of a hyaluronic acid (HA) filler injection, in the supraperiosteal plane, with a 25 Gx 40 mm cannula complemented with a 27 Gx 13 mm needle. The shadows seen inA have been corrected on the right side of the face.Fig. 8.27 A. Upper third of another patient with indication of injection of the forehead and temporal hollows. Shadows are visible on the right side of the forehead and temples, caused by atrophy of the fat pads (red arrows).B. Upper third of the same patient after application of a hyaluronic acid (HA) filler injection in the supraperiosteal plane, with a 25 Gx 40 mm cannula complemented with a 27 Gx 13 mm needle. The shadows seen inA have been corrected on the right side of the forehead. The temporal region was also treated and corrected. In order to achieve a more harmonious result, we recommend treating the entire periorbital aesthetic unit.
Only gold members can continue reading. Log In or Register to continue
