Scientific Abstract Presentations: Gender Surgery Session 4 Saturday, October 17 Sat, Oct 17 5:00-6:00 p.m. CDT

Purpose Evidence for facial masculinization surgery (FMS) remains limited relative to facial feminization. Testosterone influences soft tissues and hair but inconsistently alters craniofacial skeleton, yielding variable anatomy and non-standardized algorithms for procedural approach. Prior reviews mix cisgender cohorts with transgender patients, or frame techniques around cis male aesthetics, limiting applicability. We conducted a systematic review focused on transgender and nonbinary patients undergoing FMS and present an institutional case series to provide patient-level outcomes.

Methods Following PRISMA guidelines, PubMed, Embase, and Web of Science were queried through 2025. Inclusion: studies reporting FMS techniques and/or outcomes in transgender men or nonbinary patients; studies focused on cisgender men were excluded. Extracted variables included procedures, implant materials, follow-up, and complications, organized by facial thirds and subunits. Additionally, we performed a retrospective review of three institutional FMS patients (2022–2025).

Results 12 studies met inclusion; 7 provided primary patient data, totaling 16 transgender/nonbinary patients. Procedures were most frequent in the lower facial third (42.3%), followed by middle (30.8%) and upper (26.9%). Common lower-third techniques included sliding genioplasty and alloplastic chin implantation (83.3%) and mandibular angle implantation (75%). Reported materials for lower-third operations (by publication count) included porous polyethylene 33.3%, autologous bone grafts 25%, silicone 25%, hydroxyapatite granules 16.7%, titanium 8.3%, and polyamide 8.3%. Forehead augmentation appeared in 50.0% of articles, using porous polyethylene 33.3%, polyether-ether-ketone (PEEK) 25.0%, autologous bone 25.0%, and methyl-methacrylate 16.7%. Rhinoplasty techniques (41.7%) emphasized dorsal augmentation and wider tip profiles. Thyroid cartilage augmentation (41.7%) commonly used autologous cartilage to increase laryngeal prominence. Malar augmentation (41.7%) aimed to increase midface angularity and projection. Among studies with patient data, several reported no complications; one described a chin abscess requiring treatment. Satisfaction was generally high but measured narratively without validated FMS-specific PROMs; objective morphometrics were inconsistently reported, and follow-up was variable. Our institutional cohort consisted of 3 patients, with median age of 27 years (23-37). Procedures included advancement genioplasty (66.7%), chin implant with porous polyethylene (33.3%), porous polyethylene bilateral mandibular angular implants (100%), porous polyethylene zygoma implants (33.3%), and frontal implant using PEEK (33.3%). Notably, the senior author performed thyroid cartilage augmentation with a porous polyethylene implant – a novel technique that differs from previously described rib-cartilage techniques. Median operative time was 85 minutes (69-132). One patient required return to operating room for a mandibular abscess, necessitating implant removal and re-implantation; the others had no complication. Median follow-up was 13 months (12-20). Patient-reported satisfaction was positive in all cases (100%).

Conclusion Across published literature (n=16) and our early institutional experience (n=3), major complications appear uncommon and patient satisfaction is favorable, but small samples, heterogenous reporting, and variability in implant materials hinder comparison and material-specific benchmarking. For individuals undergoing FTM transition, a more scientific and mainstream understanding of FMS – grounded in standardized surgical and psychosocial outcomes – can enhance transgender visibility and safety and strengthen the evidence for insurance coverage. Limited FMS exposure within gender-affirming fellowships constrains provider capacity and outcomes data; adopting a consensus minimum dataset can expand evidence, inform training, and ultimately improve access.

Background: Facial feminization surgery has become a key component of the male to female transition, with popularity rising in recent years. Despite the increasing frequency among transgender patients, the primary identifiers of a feminine or masculine face across cultural and societal influences remain unclear. Although many studies have sought to analyze which facial features most strongly signify femininity, no research has surveyed the general population to identify which facial features are perceived as inherently more feminine or masculine across a broad scope of demographics. This study aims to determine which facial features are viewed as most masculine or feminine across biological sex and ethnicity.

Methods: Four web-based survey instruments were used, displaying an image set of artificial intelligence-generated facial photos of a cis-man and a cis-woman from each of the following ethnicities - Black, Asian, Oceanic, South Asian, and White. Each survey evaluated the masculinity or femininity of specific facial components through various techniques to eliminate responder bias. Respondents voluntarily completed online consent forms and were randomly directed to one of the four survey instruments. Responses were de-identified to ensure anonymity. Faces were divided into 11 unique components, and were thus rated on a scale from 1 (most masculine) to 11 (most feminine).

Results: A total of 2,566 respondents completed the survey instruments. There was no significant difference in the ethnicity, gender, or socioeconomic status of respondents across each of the survey instruments. Across all facial images, respondents identified the lips as the most feminine facial feature (7.98–9.41, p<0.0001). Male respondents rated the lips as the most feminine feature for all faces (8.03–9.32, p<0.0001), except for the face of the Oceanic female, where the eyes were rated as the most feminine feature (8.03, p<0.0001). Female respondents found the lips to be the most feminine feature of all faces except those of the Black female and White male, where the eyes were rated as most feminine (8.09, 8.20, p<0.0001). Overall, the most masculine facial features were the mandibular angle (4.67), laryngeal prominence (4.81), chin (4.94), hairline (5.17), and forehead (5.35), while the most feminine features were the lips (8.50), eyes (7.84), orbits (6.74), cheeks (6.73), and nose (5.84), which were all statistically significant (p<0.05).

Conclusion: This study provides valuable insight into the public's perception of inherently masculine and feminine facial features across ethnicity and gender. Surgeons can use these findings to enhance patient satisfaction and use a patient-centric approach in the deliberation of a surgical plan.

Purpose: The inframammary fold (IMF) is a critical aesthetic and structural landmark influencing chest contour, scar position, and masculine chest proportions in reconstructive and gender-affirming surgery (1). In cisgender males, the IMF lies near the inferior border of the pectoralis major, producing a flat inferior chest contour with minimal shadowing, whereas in cisgender females the IMF typically sits lower due to breast weight and inferior pole projection (1,2). During double-incision mastectomy with free nipple grafts, the IMF is routinely released to eliminate lower pole memory and allow chest wall contouring (3). Anatomic and aesthetic studies demonstrate that scars aligned with the inferior pectoral border are perceived as more masculine and contribute to improved chest contour (2,4). This study aims to describe a reproducible technique for deliberate IMF elevation and to evaluate its aesthetic impact using blinded evaluation of standardized preoperative and postoperative photographs.

Methods: A retrospective review was performed of patients undergoing bilateral double-incision gender-affirming mastectomy with free nipple grafts between January 2019 to December 2024. Patients were categorized by IMF management: elevation versus preservation at the native level. In the raised-IMF cohort, the IMF was repositioned approximately 1-2 cm superior to the native crease along the inferior border of the pectoralis major. Mastectomy flaps were elevated, the native IMF was released, and the inferior flap was re-anchored to the chest wall fascia to establish a new fold.

A blinded survey study was conducted using preoperative and postoperative frontal chest photographs from 20 patients, including 10 with raised IMF placement and 10 with IMF preserved at the native level. Ten evaluators, consisting of plastic surgeons and plastic surgery residents, independently assessed postoperative results using a 9-point Likert scale evaluating overall aesthetic appearance, ideal post-operative IMF placement, and masculine chest contour. Mean patient-level scores were compared using Welch's unpaired two-tailed t-tests.

Results: A total of 162 patients underwent double-incision gender-affirming mastectomy, including 101 in the IMF elevation cohort and 61 in the IMF preservation cohort. Demographics and complication rates were similar between groups (p>0.05). Independent evaluation of standardized postoperative photographs demonstrated significantly improved aesthetic outcomes with raised IMF placement. The raised-IMF group demonstrated higher ratings for overall aesthetic appearance (7.31 vs 5.77, p=0.0004), ideal IMF placement (7.23 vs 6.14, p=0.0026), and masculine chest contour (7.53 vs 5.86, p<0.0001) compared to the control group.

Conclusion: Deliberate elevation of the inframammary fold during double-incision gender-affirming mastectomy is a safe, reproducible refinement that significantly improves masculine chest contour and aesthetic outcomes without increasing complication risk. This anatomy-based approach optimizes IMF position and scar placement along the inferior pectoral border, improving chest contour and addressing a critical but underrecognized determinant of masculine chest aesthetics.

References: 1. Hudson (2024). The Role of the IMF in Aesthetic Surgery. ASP. https://doi.org/10.1007/s00266-023-03729-w 2. Nanigian, (2007). Inframammary crease: Positional relationship to pectoralis major origin. ASJ. https://doi.org/10.1016/j.asj.2007.06.002 3. Grabb and Smith's Plastic Surgery (9th-ed.). Chung, Llado-Farrulla, (2024). Chapter 114: Gender-affirming chest surgery. 4. Rahmani (2024). Understanding Public Perceptions of Nipple and Scar Characteristics After Masculinization Surgery. ASP, https://doi.org/10.1007/s00266-024-04172-1

Background: Patients seeking gender-affirming mastectomy frequently present with concurrent use of SSRIs, SNRIs, anti-anxiety medications, and/or chronic marijuana use (1,2). Under standard anesthesia protocols, this population often exhibits unprovoked intraoperative tachycardia. The typical response of periodic administration of additional beta-blockers and propofol boluses frequently results in oversedation, leading to significantly prolonged emergence and wake-up times (1). We present a case series utilizing a modified, multimodal anesthesia protocol designed to optimize intraoperative hemodynamics and facilitate rapid recovery in this specific patient population.

Methods: A modified anesthesia protocol was implemented for a series of transgender patients with chronic use of SSRIs, SNRIs, other anti-psychotic medications, or marijuana who underwent gender-affirming mastectomy. The regimen was designed to proactively manage heart rate without heavily relying on continuous deep sedation. The induction protocol included:

Standard induction medications (fentanyl, propofol, lidocaine, and rocuronium if utilizing endotracheal intubation). Esmolol (0.5 mg/kg). Ketamine (20–25 mg on induction, titrated up to a total of 50 mg during the first 1.5 hours of the case as needed). Maintenance anesthesia utilizing a propofol infusion initiated at a conservative rate of 75–100 mcg/kg/min.

Results: Implementation of the modified protocol successfully prevented the expected tachycardic response, maintaining stable intraoperative hemodynamics throughout the cases. By preemptively managing the heart rate with esmolol and utilizing ketamine's analgesic profile, the necessity for periodic intraoperative propofol boluses and escalating beta-blocker doses was eliminated. Overall consumption of both propofol and narcotic medications was markedly decreased compared to standard regimens. Consequently, patients experienced a smooth emergence with significantly reduced post-operative wake-up times, avoiding the prolonged sedation previously observed.

Conclusion: A targeted anesthesia protocol incorporating low-dose esmolol and ketamine on induction, combined with a conservative propofol maintenance infusion, safely and effectively manages intraoperative hemodynamics during gender-affirming mastectomy. For patients with chronic use of SSRIs, SNRIs, or marijuana, this tailored approach can help minimize excess propofol and narcotic administration, thereby optimizing post-surgical wake-up times and improving operating room efficiency.

References: 1. Baker, M. B., Binda, D. D., Nozari, A., Kennedy, J. M., Dienes, E., & Baker, W. E. (2025). Quantitative Analysis of Propofol Dosage in Cannabis Users: A Systematic Review and Meta-Analysis. Journal of clinical medicine, 14(3), 858. https://doi.org/10.3390/jcm14030858. 2. Fanelli, D., Weller, G., & Liu, H. (2021). New serotonin-norepinephrine reuptake inhibitors and their anesthetic and analgesic considerations. Neurology International, 13(4), 497–509. https://doi.org/10.3390/neurolint13040049.

Introduction: Breast augmentation remains one of the most frequently performed aesthetic procedures worldwide and is a cornerstone of gender-affirming care for transgender women. As the volume of gender-affirming breast augmentation continues to rise in the post–COVID-19 era, contemporary safety data comparing outcomes between cisgender and transgender patients remain limited. Given ongoing discussions regarding the perioperative risk profile of gender-affirming procedures, high-quality comparative data are needed to inform surgical counseling, risk stratification, and equitable access to care. This study evaluates 12-month postoperative complications following breast augmentation among cisgender and transgender adults in a large, multi-institutional database.

Methods: A retrospective cohort study was conducted using the TriNetX Research Network (35 global healthcare organizations). Adult patients (≥18 years) who underwent implant-based breast augmentation between January 2021 and February 2025 were identified. Cisgender patients were captured using cosmetic indication CPT and ICD-10 codes, whereas transgender patients were identified using gender dysphoria and related ICD-10 codes. Patients with previously documented breast implant complications were excluded.

Propensity score matching (1:1) was performed to control for age, race, ethnicity, BMI, hypertension, diabetes, tobacco use, alcohol and opioid use disorders, anxiety disorders, dermatologic conditions, and pregnancy. Primary outcomes within 12 months included hematoma, seroma, wound dehiscence, infection, necrosis, hypertrophic scarring, and mechanical implant complications. Risk ratios (RR) with 95% confidence intervals (CIs) were calculated, and statistical significance was set at p < 0.05.

Results: After matching, 793 cisgender patients were compared with 793 transgender patients. Rates of hematoma, seroma, infection, wound dehiscence, necrosis, and hypertrophic scarring were statistically similar between cohorts (p > 0.05). However, cisgender patients demonstrated a significantly higher risk of mechanical breast implant complications compared with transgender patients (RR 2.30, p = 0.0024). No complications were observed to occur at a higher rate in the transgender cohort.

Conclusion: In this contemporary, propensity-matched analysis, breast augmentation demonstrated comparable short- to mid-term safety profiles in cisgender and transgender adults. Notably, transgender patients did not experience increased complication rates and had significantly lower risk of mechanical implant complications. These findings provide large-scale evidence supporting the perioperative safety of gender-affirming breast augmentation and may help guide evidence-based counseling while addressing misconceptions regarding surgical risk in transgender populations. Further investigation into implant selection, surgical technique, and long-term outcomes is warranted.

Introduction Facial feminization surgery (FFS) can reduce gender dysphoria in transfeminine patients. Brow position, hairline contour, and forehead projection contribute to a feminine appearance, often requiring a combination of craniomaxillofacial bone contouring techniques, including forehead reduction, orbital reconstruction, and frontal sinus setback. Using data from the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP), we compared inpatient and outpatient outcomes following these bone contouring procedures to determine if outpatient management increased perioperative risks or complications. Methods A retrospective cohort study was conducted using the ACS NSQIP database. To identify patients undergoing FFS involving craniomaxillofacial bone contouring, cases were queried using diagnostic and procedural codes. Inclusion criteria required a postoperative ICD-10 diagnosis of gender dysphoria (F64, F64.0, F64.8, or F64.9) and a primary or concurrent CPT code indicating facial bone contouring, reconstruction, or sinus setback (21137, 21138, 21139, 21172, 21209, or 21256). To isolate the perioperative risks of facial bone FFS and prevent confounding morbidity, patients undergoing concomitant non-facial surgeries were excluded. Following cohort identification, demographic characteristics and 30-day perioperative outcomes were compared between inpatient and outpatient surgical settings to evaluate the safety profile of outpatient FFS management. Results A total of 227 patients were included in the study (71 inpatient, 156 outpatient). Most of the cohort was between 18 and 34 years of age (63.9%). Patient age, body mass index, and median operative time (291.0 minutes) did not differ significantly between the inpatient and outpatient groups. However, there were significant differences in racial and ethnic distribution (p=0.0016), with African American patients comprised a larger proportion of the inpatient cohort (36.6% vs 13.5), whereas White patients comprised a larger proportion of the outpatient cohort (69.9% vs 45.1%). Additionally, the inpatient group had greater history of smoking than the outpatient group (19.7% vs 7.7%, p=0.0083). Regarding 30-day postoperative outcomes, there were no significant differences in complication rates between the surgical settings. The overall rate of superficial incisional surgical site infections (SSI) was 2.2% (n=5). While all five SSIs occurred in the outpatient group, this difference was not statistically significant (p=0.3283). Only one major infection (0.4%) was recorded across the entire cohort, also occurring in the outpatient group. There were zero recorded instances of wound dehiscence, unplanned readmissions, or unplanned reoperations in either setting. Furthermore, sub-analysis of patients who developed superficial incisional SSIs revealed no significant demographic, comorbid, or operative predictors (all p>0.05). Conclusions Outpatient management for craniomaxillofacial bone contouring during facial feminization surgery demonstrates a 30-day safety profile comparable to inpatient admission. There was no significant increase in perioperative complications between the two cohorts, including superficial incisional surgical site infections or major infections. These findings support the safety and feasibility of the outpatient surgical setting, offering a pathway to reduce patient burden and healthcare resource utilization without compromising surgical outcomes.

Introduction: Phalloplasty flap selection is guided by surgeon expertise, as well as patient anatomy and goals, yet comparative complication data across flap types remain limited. While radial forearm free flaps (RFFF) remain the predominant choice, emerging data suggest other flap types may offer comparable functional outcomes with improved complication profiles (1). This study aimed to describe complication profiles across five phalloplasty flap types and identify patient-level risk factors independently associated with adverse outcomes.

Methods: A retrospective review was performed of patients who underwent primary phalloplasty at a single urban center between June 2017 and October 2025 with ≥ 4 months follow-up. Patients were stratified by flap type: free musculocutaneous latissimus dorsi (MLD), RFFF, pedicled abdominal flaps, pedicled anterolateral thigh (ALT), and pedicled deep inferior epigastric perforator (DIEP) flaps. Demographics, comorbidities, and surgical complications were compared using Kruskal-Wallis tests for continuous variables and Fisher's exact tests for categorical variables. Primary outcomes were the incidence of any complication, hematoma, wound dehiscence, wound infection, delayed wound healing, partial flap necrosis, donor site complications, fistula, stricture, and urinary tract infection (UTI). Firth penalized logistic regression, adjusting for age, body mass index, hypertension, smoking status, and surgery stage, was used to evaluate independent predictors of complications. Significance was set at p<0.05.

Results: Among 64 primary phalloplasty patients, abdominal flaps were the most common (46.3%), followed by MLD flaps (32.8%), RFFF (9.0%), ALT flaps (5.9%), and DIEP flaps (5.9%). RFFF patients were younger (23.5 ± 2.6 years; p=0.027), abdominal flap patients had higher BMIs (29.4 ± 4.6; p=0.018), and DIEP flaps, often requiring prelamination, were performed at later surgical stages (2.8 ± 1.0 operations; p=0.020).

Overall complication rates were high across all flap types (73.3–83.3%) with no significant difference (p=0.992). Wound dehiscence was the most common complication in the abdominal group (43.3%), while MLD flaps had the highest rates of delayed wound healing (50.0%) and wound infection (45.0%). Fistula rates differed significantly across groups (p=0.003), driven by high incidence in ALT flaps (50.0% vs 0–16.7% in others).

On adjusted analysis, though flap type was not independently associated with overall complication incidence, ALT flaps demonstrated a markedly elevated adjusted odds of fistula (aOR 31.4, 95% CI 1.74–569.31; p=0.020). Across all flap types, current smoking was the strongest modifiable risk factor, significantly increasing odds of wound infection (aOR 9.44, 95% CI 1.32–67.57; p=0.025) and donor site complications (aOR 9.47, 95% CI 1.15–77.98; p=0.037). Importantly, phalloplasty in a later surgical stage independently predicted donor site complications (aOR 2.65, 95% CI 1.14–6.14; p=0.023).

Conclusion: Complication rates following phalloplasty are high across all flap types, but flap types may have differing complication profiles, with ALT flaps presenting the highest risk of fistula. Current smoking was the strongest modifiable predictor of complications across all flaps, associated with nearly 10-fold increased odds of wound infection and donor site complications, while phalloplasty in later surgical stages independently predicted donor site complications.

References: 1. Wang E, Cleff B, Basta A, et al. Flap Choice in Gender Affirming Phalloplasty Affects Postoperative Complication Rates. Microsurgery. 2026;46(1):e70154. doi:10.1002/micr.70154

PURPOSE: As demand for gender-affirming surgery (GAS) continues to rise, it has become an important component of comprehensive surgical care and training across multiple specialties, including plastic surgery and urology. However, residency programs vary widely in their availability of formalized exposure, institutional support, and training related to GAS and LGBTQ+ health. Little is known about how residency applicants perceive and prioritize GAS training and LGBTQ+ inclusion when evaluating residency programs. Understanding how applicants weigh these considerations is essential for residency programs seeking to align training environments with evolving trainee perspectives and can inform program development and recruitment strategies. METHODS: An anonymous cross-sectional survey was distributed to fourth year medical students who applied to plastic surgery and urology residency programs during the 2024-2025 application cycle. Survey domains included respondent demographics, perceived adequacy of institutional LGBTQ+ support resources, exposure to equity and inclusion education, importance of faculty and trainee composition, and perceived importance of exposure to both general and gender-affirming surgical procedures. Responses were measured using Likert scales. Descriptive statistics were used to summarize respondent characteristics and survey responses, with qualitative thematic analysis performed on free-response comments. RESULTS: A total of 119 applicants completed the survey, yielding an overall response rate of 21.4% (plastic surgery: 18.4%, n=70/380; urology: 27.8%, n=49/176). Respondents represented a broad geographic distribution across the United States and internationally and diverse backgrounds in age, income, race, ethnicity, gender, and sexuality. Across both plastic surgery and urology, respondents reported LGBTQ+ diversity, gender-affirming care training, in-state legislative trends restricting gender-affirming care, and exposure to specific gender-affirming surgical procedures were important factors in residency training and program ranking. Over 65% of respondents rated gender-affirming care training as somewhat or very important to their residency training. When broken down by specific surgeries, among plastic surgery applicants, facial feminization surgery (44.5%) and chest masculinization surgery (43.7%) were most frequently rated as important or very important. In contrast, vaginoplasty emerged as the most important procedure overall, across plastic surgery and urology applicants, rated as important or very important by 65.5% of respondents. Free-response comments highlighted appreciation for the study, personal stories related to LGBTQ+ identity, and concerns related to limited integration of LGBTQ+ medicine into their training. CONCLUSION: In this national survey of plastic surgery and urology residency applicants, gender-affirming surgery training and LGBTQ+ diversity emerged as salient considerations during program evaluation and ranking. The majority of respondents valued exposure to gender-affirming surgery during training, with strong emphasis on procedures such as vaginoplasty, facial feminization and chest masculinization surgery. Findings also suggested that institutional diversity and state-wide legislative context may be influential factors in training decisions. These findings suggest that applicants view gender-affirming care as an important component of contemporary surgical education. Residency programs may benefit from structured integration of gender-affirming surgical training to meet the evolving educational expectations of trainees and to enhance recruitment.

Background: Pain after multiprocedural facial feminization surgery (FFS) can be difficult to manage in the transgender population as there is higher incidence of drug use and misuse compared to the general population.(1),(2),(3) This study evaluates the effect of intraoperative methadone, a mu-opioid receptor agonist and N-methyl-D-aspartate (NMDA) receptor antagonist with selective serotonin reuptake inhibitor (SSRI) properties, on postoperative opioid requirements in patients who underwent FFS.

Methods: A retrospective review of patients who underwent multiprocedural FFS between June 2023 and September 2025 was conducted. All patients underwent full- or near-full FFS including at least two separate areas of the face (forehead, nose, and chin and/or mandibular angles). Patients received either 20mg of methadone or standard short-acting opioids intraoperatively. 24-hour postoperative opioid requirements were assessed as oral morphine milligram equivalents (OMME). Average OMME between the methadone and non-methadone cohorts were compared using a two-sample t-test.

Results: A total of 100 patients were included in this study. 50 patients received methadone and 50 patients received standard short-acting opioids intraoperatively. Postoperative OMME ranged from 0 to 91.5 in both groups. Average 24-hour postoperative OMME was significantly lower for the methadone cohort (mean 23.34, SD 23.04) than the non-methadone cohort (mean 39.33, SD 23.35) (p = 0.0008).

Conclusions: A single dose of intraoperative methadone during FFS provides analgesia intraoperatively and significantly lowers opioid use over the following 24 hours. Methadone may reduce the need for frequent redosing of short-acting opioids. These findings may help reduce the risk of opioid misuse in an at-risk population. Methadone should be considered as part of a multimodal regimen to treat pain in the transgender population.

References: 1 Bedar M, Dejam D, Caprini RM, Huang KX, Cronin BJ, Khetpal S, Morgan KBJ, Lee JC. An enhanced recovery after surgery protocol for facial feminization surgery reduces perioperative opioid usage, pain, and hospital stay. J Plast Reconstr Aesthet Surg. 2023 Oct;85:393-400. doi: 10.1016/j.bjps.2023.07.044. Epub 2023 Jul 23. PMID: 37572387. 2 Hughto JMW, Quinn EK, Dunbar MS, Rose AJ, Shireman TI, Jasuja GK. Prevalence and Co-occurrence of Alcohol, Nicotine, and Other Substance Use Disorder Diagnoses Among US Transgender and Cisgender Adults. JAMA Netw Open. 2021 Feb 1;4(2):e2036512. doi: 10.1001/jamanetworkopen.2020.36512. Erratum in: JAMA Netw Open. 2021 Mar 1;4(3):e213314. doi: 10.1001/jamanetworkopen.2021.3314. PMID: 33538824; PMCID: PMC7862992. 3 Kidd JD, Goetz TG, Shea EA, Bockting WO. Prevalence and minority-stress correlates of past 12-month prescription drug misuse in a national sample of transgender and gender nonbinary adults: Results from the U.S. Transgender Survey. Drug Alcohol Depend. 2021 Feb 1;219:108474. doi: 10.1016/j.drugalcdep.2020.108474. Epub 2020 Dec 21. PMID: 33360852; PMCID: PMC7856161.

Purpose: The Ousterhout forehead feminization classifies foreheads by prominence and frontal sinus size but overlooks sinus heterogeneity and asymmetry. This study investigates the relative contributions of the frontal sinus, frontal bone, and orbital characteristics to superomedial and superolateral supraorbital ridge prominence and proposes an algorithm for forehead feminization.

Methods: An IRB-approved review of maxillofacial CT scans was conducted on ethnicity- and age-matched groups of males and female (2003-2022). Three-dimensional reconstruction of the skulls and frontal sinuses was performed using Mimics and 3-matic software. Data collected included sex, age, ethnicity, orbit and frontal sinus dimensions, frontal sinus asymmetry index (smaller volume/larger volume*100), bi-temporal/bi-orbital widths, projection of supraorbital ridge and superolateral orbital rim, surface area of the frontal sinus and supraorbital prominence, nasofrontal angle, superolateral orbital angle, and anterior wall thickness. Moderate to severe asymmetry of the frontal sinus was defined as an asymmetry index below 60. To compare frontal sinus and orbital measurements between males and females, data normalization was performed using bi-temporal and bi-orbital distance, respectively, to account for the inherent skull size variation between the two sexes. Mann-Whitney test and Pearson correlation were performed to analyze associations between variables.

Results: 183 patients (106 males and 77 females) with a mean age of 50.9±20.3 years were included. Bilateral frontal sinus absent was found in 2.7%, unilateral absent in 8.2%, and 40.4% showed moderate/severe asymmetry. Areas of supraorbital prominence aligned fully with frontal sinus in 39.4%. Compared to females, males had larger sinuses (p<0.0001), thicker anterior walls (p=0.0004), steeper nasofrontal angles (p<0.0001), narrower superolateral orbital angles (p<0.0001), and more projected supraorbital (p<0.0001) and superolateral orbital ridge (p<0.0001). Orbit height (p=0.34) and width (p=0.26) were comparable. Supraorbital ridge projection correlated positively with surface areas of supraorbital prominence (r=0.45, p<0.0001) and frontal sinus (r=0.39, p<0.0001) and negatively with nasofrontal angle (r= -0.53, p<0.0001) and anterior wall thickness (r= -0.26, p=0.0005). A new algorithm was proposed: determine the primary contributor to supraorbital prominence - frontal bone only (FB), frontal sinus only (FS), or both (FBS). In FB only patients, burring of the frontal bone will flatten the forehead. In FS cases, if the anterior wall is thicker than the planned reduction, burring alone is sufficient. In patients with a thin anterior wall, anterior wall setback can correct mild prominence. However, when the prominence is moderate to severe, anterior wall intraosseous osteotomies are required to achieve a flat contour. In FBS cases, as the contribution of the frontal sinus to overall prominence increases and the severity worsens, the surgical intervention progresses from segmental anterior wall burring to segmental setback and intraosseous osteotomies.

Conclusions: Forehead feminization requires individualized sinus wall osteotomy, setback, and bone contouring given sinus asymmetry and variable bone-sinus contribution to forehead projection. Orbital rim contouring should target reducing superolateral orbital ridge projection and widening superolateral orbital angle rather than altering orbit width/ height.