Fat Grafting for Forehead Contouring in Facial Feminization

Summary:

For gender-diverse individuals assigned male at birth, postpubertal estrogen and testosterone-lowering therapies alone are often inadequate to reverse the testosterone-related facial characteristics projecting a male sex identity. Facial feminization surgery significantly improves quality-of-life outcomes for gender-diverse patients by relieving this gender incongruence of the face. Because the shape of the forehead is so radically different between men and women, feminization of this area is critical for many individuals. Several techniques are typically used in combination, including hairline advancement, browlift, burring of the supraorbital rims, frontal bone contouring, and anterior table setback. This report describes the use of fat grafting as an adjuvant technique to forehead contouring as means to avoid frontal bone osteotomy, which carries a higher complication profile and often requires hardware placement.

Takeaways

Question: We review the utilization of fat grafting as an adjunct technique for forehead contouring in patients seeking gender-affirming facial feminization surgery.

Findings: This case series demonstrates that fat grafting to the forehead is a safe and effective adjunct technique for feminization of the upper third of the face. We present great postoperative results at 2-year follow-up.

Meaning: In carefully selected patients, fat grafting to the forehead may be offered as a less-invasive approach to help expand access to facial feminization surgery.

The forehead is one of the most essential features of the face conveying information about one’s sex.^1,2 Testosterone plays a key role in developing muscle strength leading to adaptive changes in the male forehead as the facial skeleton responds to increased pull of various muscle insertions.³ Key changes to forehead shape include frontal bossing, reduced nasofrontal angle, and lower-set eyebrows with a prominent supraorbital rim.⁴ Furthermore, testosterone increases skull cortical thickness, causing the slope of the forehead to the supraorbital notch to become more acute.^3,4 In contrast to individuals with high levels of testosterone exposure during puberty, estrogen exposure assumes a more convex appearance with a rounded shape.⁵ To address these phenotypical differences for transfeminine individuals, facial gender-affirming surgery (FGAS) often involves hairline advancement with forehead contouring to reduce frontal bossing.^5–8

Ousterhout classification is a standardized approach to managing frontal bone reduction.⁵ Group I includes patients with minimal to moderate forehead bossing, slight anterior projection of the supraorbital rim, and thick bone over the frontal sinus. These patients are managed by burring alone. Group II includes patients with slight anterior projection of the supraorbital rim and frontal bossing with thin bone over the frontal sinuses. These patients require burring with bone contouring while avoiding entering the frontal sinus. Group III includes patients with prominent supraorbital rim projection. These patients require burring, osteotomy of the anterior table, and frontal sinus setback.⁵

Roughly 90% of patients who undergo FGAS fall within group II and group III of the Ousterhout classification.⁵ Due to insufficient frontal bone over the frontal sinus, nearly all patients who undergo FGAS require osteotomy of the anterior table with frontal sinus setback. This requires craniofacial expertise and often necessitates the use of permanent hardware. Complications, including infection, hematoma, palpable hardware, and others, occur in roughly 5% of patients.^8,9 Although rare, there is potential for mucocele after any manipulation of the frontal sinus.

To avoid osteotomy, we propose a method of using fat grafting to camouflage the supraorbital ridge. This method may be used as an adjunct or alternative technique to help increase the availability of surgeons offering forehead contouring in appropriately selected patients. We acknowledge that fat grafting may not be an appropriate or equal replacement for frontal sinus setback for all patients. However, this is a well-described technique utilized elsewhere with promising results after 1-year follow-up.¹⁰

In this case series of six patients, we obtained preoperative maxillofacial computed tomographies to evaluate the location and thickness of the anterior wall of the frontal sinus. Average anterior table thickness was 2.02 mm with a range of 0.99–4.33 mm. Burring was performed in all cases. Hairline advancement was completed along with browlift in select patients. For these patients, endotines were used in a reversed position to secure the scalp and maintain hairline advancement. In all six patients, fat was harvested from the abdomen or flanks using the Coleman technique and transferred to the forehead through the incision site. A fanning technique with small aliquots was administered to give the forehead a more feminized, convex appearance. Between 11 and 20 mL of fat was added in the subcutaneous plane to improve contour. Fat was not placed submuscularly, as this is the plane of forehead flap dissection. Additionally, placement of a radix graft was utilized in three of the six patients with prominent glabellar ridges to further camouflage frontal bossing.

Figure 1A demonstrates the preoperative profile of the patient on the day of surgery. Figure 1B demonstrates the immediate postoperative forehead contour result achieved on the table after bone burring, fat grafting to forehead, thyroid cartilage shave, and scalp advancement with browlift. Figure 2A redemonstrates preoperative forehead contour. One-year postoperative results are shown in Figure 2B. There were no major or minor complications with this technique, including contour irregularities, infection, or vascular complications. Endotines were palpable to patients who underwent hairline advancement, and there was expected anterior scalp numbness with the raising of a forehead flap. No other palpable abnormalities or neurologic deficits were observed. Our longest follow-up time is 2 years with excellent forehead contour and symmetry. The patients in this case series have not required additional fat grafting. Overall, there is improved brow shape and forehead contour in all patients.

Fig. 1.

Preoperative and immediately postoperative photographs. A, A preoperative photograph demonstrating the steepness of slope from forehead to supraorbital notch. B, A photograph of immediate postoperative results achieved on the table following hairline advancement, forehead and orbital contouring with burring, and fat grafting to forehead.

Fig. 2.

Pre- and postoperative patient photographs. A, A preoperative photograph of the patient before forehead contouring with fat grafting. B, One-year postoperative results after forehead contouring with fat grafting.

DISCUSSION

In combination with frontal bone contouring and burring of the supraorbital rim, fat grafting is a safe and effective technique to further enhance anatomical convexity of the forehead. All patients with minimal frontal bossing and most patients with moderate frontal bossing may benefit from this technique. Fat is an excellent autologous option that we prefer over fillers and other exogenous substances. Though fat in the forehead does not have the same “feel” as underlying bony material, this palpable difference is discussed with patients preoperatively to establish expectations. Patients were also made aware that some bossing may be palpable postoperatively, even if not visible. No patients in our case series were concerned about the “feel” of their forehead postoperatively.

Predictability of outcome is a limitation compared with anterior table setback. Preoperatively, patients should be made aware that additional fat grafting sessions may be indicated. We estimate that fat absorption was roughly 30% after 1 year, and therefore, the “on-table” result is unlikely to be the final contour. Though no patients in this case series required additional fat grafting, we are limited by our 2-year follow-up time. Furthermore, although not observed in this study, fat grafting poses the additional risk of fat necrosis and tissue necrosis secondary to intravascular fat injection.

Overall, this technique avoids the morbidity with entering the frontal sinus and use of hardware to resecure the anterior table. As the upper third of the face conveys significant cues about one’s gender, safer techniques may be more widely adopted to improve access to FGAS for transfeminine individuals. We continue to offer this as an option to select patients where frontal osteotomy would otherwise be necessary.

DISCLOSURE

The authors have no financial interest to declare in relation to the content of this article.

PATIENT CONSENT

Patients provided written consent for the use of their images.