What gives a face its gender?

Evaluation of the beauty standards for forehead morphology in Black women: Implications in surgical and non-surgical forehead contouring

Owing to its importance in gender perception, forehead feminizing cranioplasty represents one of the most impactful components of facial feminization surgery. However, aesthetic standards for these procedures are informed largely by Caucasian beauty standards, which may not fully reflect those of other populations. This study evaluated the differences in forehead shape between conventionally beautiful Black and similarly identified Caucasian women. Two lists published by an independent publication (StyleCraze), "26 Most Beautiful African Women" and "52 Most Beautiful Women in the World," were used to identify Black and White women for comparison. Side profile images of the women were analyzed and compared using elliptical and piecewise linear models via multiple anatomic slope, angle, and eccentricity measurements. Black women were found to have a reduced forehead eccentricity (0.91 vs. 0.94, Cohen's d=0.88), indicating greater roundness of the forehead. In the piecewise linear model, there was a more acute angle of the inferior forehead in the Black women (160.72° vs. 170.01°, Cohen's d=1.57); this region, in particular, was responsible for the increased roundedness of the forehead in the Black models. Thus, the forehead shape in conventionally beautiful Black women has significant differences compared to similarly identified Caucasian women. Surgical planning for feminizing cranioplasty in this population should consider this underlying morphological variation for optimal cosmetic outcomes. Furthermore, we demonstrated a novel methodology using elliptical and piecewise linear models to approximate the curved surface of the forehead, which may provide a basis for future studies.

Effect of Facial Feminization Surgery (FFS) on Eyelid Anatomic Features

Facial feminization surgery (FFS) improves gender dysphoria. The brows and eyes are crucial in perceived gender, yet brow and eyelid surgeries are relatively underutilized. This study aimed to determine rates of brow and eyelid surgeries as part of FFS and characterize pre- and postoperative periocular features. We conducted a retrospective review to identify all patients with the diagnosis of gender dysphoria who underwent FFS at a single academic institution from 2019 to 2022. Thirty-four patients comprising 38 surgical cases were included. Twelve (35%) eyelid surgeries and 27 (79%) brow lifts were performed. Baseline eyelid measurements did not differ between brow lift and nonbrow lift cases. Those undergoing brow lift and eyelid surgery were older in age (p = 0.022), had a higher rate of negative canthal tilt (p = 0.050), and smaller baseline margin-reflex distance 1 (p = 0.014) than patients who had brow lift alone. Brow lift increased tarsal platform show (p ≤ 0.001) and lash-to-brow distance (p ≤ 0.001), and upper blepharoplasty increased tarsal platform show (p = 0.01). Rates of brow lift are high at our institution, and patients are appropriately selected for eyelid surgery in FFS. Brow lift and upper blepharoplasty can feminize anatomical features when using standards described for cisgender cohorts. The impact of periocular features on gender perception in transgender patients warrants further study.

Object recognition in primates: what can early visual areas contribute?

Introduction

If neuroscientists were asked which brain area is responsible for object recognition in primates, most would probably answer infero-temporal (IT) cortex. While IT is likely responsible for fine discriminations, and it is accordingly dominated by foveal visual inputs, there is more to object recognition than fine discrimination. Importantly, foveation of an object of interest usually requires recognizing, with reasonable confidence, its presence in the periphery. Arguably, IT plays a secondary role in such peripheral recognition, and other visual areas might instead be more critical.

Methods

To investigate how signals carried by early visual processing areas (such as LGN and V1) could be used for object recognition in the periphery, we focused here on the task of distinguishing faces from non-faces. We tested how sensitive various models were to nuisance parameters, such as changes in scale and orientation of the image, and the type of image background.

Results

We found that a model of V1 simple or complex cells could provide quite reliable information, resulting in performance better than 80% in realistic scenarios. An LGN model performed considerably worse.

Discussion

Because peripheral recognition is both crucial to enable fine recognition (by bringing an object of interest on the fovea), and probably sufficient to account for a considerable fraction of our daily recognition-guided behavior, we think that the current focus on area IT and foveal processing is too narrow. We propose that rather than a hierarchical system with IT-like properties as its primary aim, object recognition should be seen as a parallel process, with high-accuracy foveal modules operating in parallel with lower-accuracy and faster modules that can operate across the visual field.

Analysis of Cephalometric Differences of the Midface and Upper Face in Males and Females: A Radiographic Study

Gender affirmation facial surgery (GAFS) is an important component in treating gender dysphoria among transgender individuals by addressing gender incongruence of the face. There is a paucity of literature describing objective characterizations of the anatomic differences between male and female faces. In this study, cephalometric measurements were taken on routine CT imaging performed on cisgender patients between 2017 and 2020. Specifically defined cephalometric landmarks of the upper and midface were measured and compared between male and female cohorts. Thirty-eight patients, 19 male and 19 female, were identified for this study. Significant differences were identified in the frontal prominence, orbital size, malar height, bizygomatic width, nose, and upper lip, with moderate rates of specificity for each gender. Some important ratios are also presented. Differences in the malar region and the orbit highlight the importance of these areas as a point of focus for GAFS. These cephalometric findings provide objective evidence and parameters for perceived anatomic differences in male and female faces. In addition, they help both corroborate current surgical techniques as well as guide future approaches to GAFS.

The resolution of face perception varies systematically across the visual field

Visual abilities tend to vary predictably across the visual field-for simple low-level stimuli, visibility is better along the horizontal vs. vertical meridian and in the lower vs. upper visual field. In contrast, face perception abilities have been reported to show either distinct or entirely idiosyncratic patterns of variation in peripheral vision, suggesting a dissociation between the spatial properties of low- and higher-level vision. To assess this link more clearly, we extended methods used in low-level vision to develop an acuity test for face perception, measuring the smallest size at which facial gender can be reliably judged in peripheral vision. In 3 experiments, we show the characteristic inversion effect, with better acuity for upright faces than inverted, demonstrating the engagement of high-level face-selective processes in peripheral vision. We also observe a clear advantage for gender acuity on the horizontal vs. vertical meridian and a smaller-but-consistent lower- vs. upper-field advantage. These visual field variations match those of low-level vision, indicating that higher-level face processing abilities either inherit or actively maintain the characteristic patterns of spatial selectivity found in early vision. The commonality of these spatial variations throughout the visual hierarchy means that the location of faces in our visual field systematically influences our perception of them.

Gender Affirming Facial Surgery-Anatomy and Procedures for Facial Masculinization

For some patients, feminine facial features may cause significant gender dysphoria. Multiple nonsurgical and surgical techniques exist to masculinize facial features. Nonsurgical techniques include testosterone supplementation and dermal fillers. Surgical techniques include soft tissue manipulation, synthetic implants, regenerative scaffolding, or bony reconstruction. Many techniques are derived from experience with cisgender patients, but are adapted with special considerations to differing anatomy between cisgender and transgender men and women. Currently, facial masculinization is less commonly sought than feminization, but demand is likely to increase as techniques are refined and made available.

Facial Anthropometric Analysis of Gender-Related Characteristics in Computed Tomography

BACKGROUND

In recent years, facial feminization surgery (FFS) has gained increasing popularity because of increases in transgender individuals and the acceptance of diversity in gender identity. However, there is still a scarcity of anthropometric research to guide evidence-based practices for FFS in Taiwan.

AIM AND OBJECTIVES

The purpose of this study was to provide a reference for surgeons to achieve optimal outcomes for patients undergoing FFS. The anthropometric analysis could help surgeons meet patients' specific requirements and improve patients' alignment with their gender identity.

MATERIALS AND METHODS

The study group consisted of 100 patients (50 males and 50 females) who had undergone cranial computed tomography at Chang Gung Memorial Hospital in Taiwan because of the indication of blunt injuries to the head and face with suspected skull and facial fractures. The computed tomography images were imported into the OsiriX image software to conduct an anthropometric evaluation. The parameters used in the measurements included 2 aspects: bone and soft tissue anthropometric analysis.

RESULTS

Anthropometric data were obtained from 50 males (age 32.6 ± 11.4 years) and 50 females (age 33.7 ± 10.3 years). The results for bone measurements showed that both the forehead bossing length and nasal bone width in the male group were significantly greater. The frontal angle in both bone and soft tissue in the male group was significantly smaller. The chin height and bigonial width in both bone and soft tissue in the male group were significantly greater. Although the average gonial angle was greater in the female group, the difference was not significant. For the measurements of lip projection, the results showed that there was no significant difference. Although this group of Asian males had more acute nasolabial angles, the difference was not statistically significant. However, the average nasofrontal angle among females was significantly more obtuse than among males.

CONCLUSION

The results revealed that Asian males tend to have more prominent superior orbital rims, wider nasal bones, and wider and taller mandibles compared with Asian females. Despite showing some trends, the gonial angle and lip projections did not reveal any significant differences, which is likely because of a large amount of variation.

Quantitative Analysis of Morphometric Changes in Feminization Rhinoplasty Utilizing a Standardized Forehead-Rhinoplasty Technique

Background

Rhinoplasty is one of the most commonly performed facial gender-affirming surgeries (FGASs) for transgender females, but well-established morphometric parameters describing feminizing nasal changes do not exist.

Objectives

Describe the author's technique for feminization rhinoplasty, analyze the changes in 3-dimensional nasal anthropomorphic parameters, and describe patient-reported outcomes.

Methods

Three-dimensional photogrammetric evaluation was performed both preoperatively and postoperatively in transgender female patients who underwent FGAS. Measurements assessed included the nasofrontal angle, nasolabial angle, dorsal height, mid-dorsal width, alar width, nasal tip width, and tip projection. Patients were surveyed preoperatively and postoperatively using the FACE-Q Nose module. Paired t-tests were utilized to assess changes in postoperative measurements and FACE-Q Nose satisfaction scores.

Results

Twenty patients underwent FGAS during the study period. The average time between surgery and postoperative 3-dimensional images was 13.6 ± 6.8 months. The nasofrontal angle increased by 8.2° (148.0 ± 7.4° to 156.1 ± 6.7°, P < .001) and tip projection increased by 0.017 (0.58 ± 0.03 to 0.60 ± 0.04, P < .01). Dorsal height, mid-dorsal width, and tip width all decreased significantly (P < .05). There were significant improvements in patients' "Satisfaction with Nose," "Satisfaction with Facial Appearance Overall," "Psychological Function," and "Social Function" on FACE-Q. One revision rhinoplasty was performed, and no documented surgical complications were reported.

Conclusions

There were statistically significant changes in the nasofrontal angle, tip projection, dorsal height, mid-dorsal width, and tip width in patients receiving feminization rhinoplasty. These data may help surgeons with preoperative planning and intraoperative decision making.

Level of Evidence 4

Influence of colored face masks on judgments of facial attractiveness and gaze patterns

BACKGROUND

Facial aesthetics are of great importance in social interaction. With the widespread adoption of face masks in response to the Covid-19 pandemic, there is growing interest in understanding how wearing masks might impact perceptions of attractiveness, as they partially or completely conceal facial features that are typically associated with attractiveness.

OBJECTIVES

This study aimed to explore the impact of mask wearing on attractiveness and to investigate whether the color (red or blue) of the mask has any effect on the perception of a person's attractiveness, while also considering gender and age as contributing factors. Additionally, the study intended to evaluate gaze patterns, initial focus, and dwell time in response to masked and unmasked faces.

METHODS

30 AI-generated images of 15 female and 15 male faces were presented to 71 participants (35 male, 36 female) in 3 conditions: not wearing any mask, wearing a red surgical mask, and wearing a blue surgical mask. The perceived attractiveness was rated on an ordinal scale of 1-10 (10 being most attractive). Gaze behavior, dwell time and initial focus were recorded using a stationary eye-tracking system.

RESULTS

The study found that wearing masks had no significant effect on the attractiveness ratings of female faces (p = .084), but it did benefit the perceived attractiveness of male faces which were initially rated lower (p = .16). Gender and age also played a significant role, as both male and female participants rated female stimuli higher than male stimuli (p < .001), and younger participants rated both genders as less attractive than older participants (p < .01). However, there was no significant influence of the mask's color on attractiveness. During the eye-tracking analysis, the periorbital region was of greater interest while masked, with the time to first fixation for the eyes being lower than the non-masked stimulus (p < .001) and showed a longer dwell time (p < .001). The lower face was shown less interest while masked as the time to first fixation was higher (p < .001) and the fixation count was less (p < .001). Mask color did not influence the scan path and there was no difference in revisits to the mask area between red or blue masks (p = .202), nor was there a difference in time to first fixation (p = .660).

CONCLUSIONS

The study findings indicate that there is an interplay between the gender and age of the participant and the facial stimuli. The color red did have an effect on the perception attractiveness, however not in female faces. The results suggest that masks, especially red ones, might be more beneficial for male faces, which were perceived as less attractive without a mask. However, wearing a mask did not significantly impact already attractive faces. The eye-tracking results revealed that the periorbital region attracted more attention and was fixated on more quickly while wearing a mask, indicating the importance of eyes in social interaction and aesthetic perception.

Children perceive illusory faces in objects as male more often than female

Face pareidolia is the experience of seeing illusory faces in inanimate objects. While children experience face pareidolia, it is unknown whether they perceive gender in illusory faces, as their face evaluation system is still developing in the first decade of life. In a sample of 412 children and adults from 4 to 80 years of age we found that like adults, children perceived many illusory faces in objects to have a gender and had a strong bias to see them as male rather than female, regardless of their own gender identification. These results provide evidence that the male bias for face pareidolia emerges early in life, even before the ability to discriminate gender from facial cues alone is fully developed. Further, the existence of a male bias in children suggests that any social context that elicits the cognitive bias to see faces as male has remained relatively consistent across generations.

Sex estimation from biometric face photos for forensic purposes

Sex estimation is an important parameter in cases where individuals need to be identified in forensic cases. Biometric photographs are a form of a passport photo with specific dimensions and features established by the International Civil Aviation Organization, which are read and digitally stored in appropriate devices, are used in travel documents, and are of high quality (at least 600 dpi). This study aims to reveal anthropometric data for estimating sex in Turkish adult population from facial images conforming to biometric photography criteria. Within the scope of this study, biometric facial images of a total of 334 participants, 146 female and 188 male, between the ages of 20 and 79 were used. The photos were taken using a Nikon D5100 and flat front lighting from a distance of 1 m. ImageJ 1.50i software was used to process these images. Statistical analysis was performed using descriptive statistics and discriminant analysis tests. Among the 11 variables on sex estimation, the highest accuracy rate of 78.1% was obtained with the measurement between Gonion points. However, sex estimation could be made with an accuracy of 80.5% by including all age groups and all variables, and when age-specific data were used, it was observed that these accuracy rates increased significantly in all three age groups (84.6%, 89.2%, 85.2%, respectively). Therefore, we are suggesting that using age-specific data generated for estimation in different age groups. Consequently, it has been shown that successful sex estimation can be done by formulas derived from biometric facial images in this study.

Contouring Plus: A Comprehensive Approach of the Lower Third of the Face with Calcium Hydroxylapatite and Hyaluronic Acid

A well-defined jawline is aesthetically pleasing, so that rejuvenation of the jawline is becoming part of routine aesthetic practice. Restoring balance to the lower face without surgical intervention requires a multiple treatment approach, among which the minimally invasive injectables play a central role. Nevertheless, amidst the plethora of different injectable products available, choosing the option that best suits the patient's need can be a challenge. A panel of experts sought to describe herein 4 clinical cases, illustrating the Contouring Plus technique, which provides a practical guidance for lower third assessment, choice of products, and treatment execution, especially among hyaluronic acid and calcium hydroxylapatite, aiming for immediate, as well as mid-to-long-term results.

Point of Care Virtual Surgical Planning and 3D Printing in Facial Feminization Surgery

The use of virtual surgical planning (VSP) and three-dimensional printing (3DP) technologies in the routine facial feminization surgery practice has gained a significant popularity over the past few years. The clinical applications of them are claimed to improve safety, accuracy, and efficiency of facial feminization surgeries. In this article, we review and discuss the current applications of VSP and 3DP in different facial feminization procedures.

Generating Deep Learning Model-Specific Explanations at the End User’s Side

End users who cannot afford to collect and label big data to train accurate deep learning (DL) models resort to Machine Learning as a Service (MLaaS) providers, who provide paid access to accurate DL models. However, the lack of transparency in how the providers’ models make predictions causes a problem of trust. A way to increase trust (and also to align with ethical regulations) is for predictions to be accompanied by explanations locally and independently generated by the end users (rather than by explanations offered by the model providers). Explanation methods using internal components of DL models (a.k.a. model-specific explanations) are more accurate and effective than those relying solely on the inputs and outputs (a.k.a. model-agnostic explanations). However, end users lack white-box access to the internal components of the providers’ models. To tackle this issue, we propose a novel approach allowing an end user to locally generate model-specific explanations for a DL classification model accessed via a provider’s API. First, we approximate the provider’s model with a local surrogate model. We then use the surrogate model’s components to locally generate model-specific explanations that approximate the explanations obtainable with white-box access to the provider’s DL model. Specifically, we leverage the surrogate model’s gradients to generate adversarial examples that counterfactually explain why an input example is classified into a specific class. Our approach only requires the end user to have unlabeled data of size [Formula: see text] of the provider’s training data and with a similar distribution; given the small size and unlabeled nature of these data, they can be assumed to be already available to the end user or even to be supplied by the provider to build trust in his model. We demonstrate the accuracy and effectiveness of our approach through extensive experiments on two ML tasks: image classification and tabular data classification. The locally generated explanations are consistent with those obtainable with white-box access to the provider’s model, thus giving end users an independent and reliable way to determine if the provider’s model is trustworthy.

Facial Gender-Affirming Surgery: Frontal Bossing Surgical Techniques, Outcomes and Safety

BACKGROUND

Facial gender-affirming surgery (FGAS) is described as a set of surgical procedures done to feminize the soft tissue and the facial skeleton, allowing for transfeminine individuals to be recognizable as women to others. It is established in the literature that the most significant facial area for determination of gender is the forehead (Spiegel in Laryngoscope 121:250-261, 2011). This article describes the author's three main surgical techniques used in forehead feminization and reports on the results.

METHODS

The type of surgery performed is based on the patient's anatomy. Type one FGAS consists of burring the anterior table of the frontal bone and is done when frontal bossing is very minimal. Type two FGAS includes burring and applying hydroxyapatite to contour the forehead and is done when frontal bossing is moderate. Type three surgery includes anterior table osteotomy, repositioning and fixation with a non-resorbable titanium plate and is performed for more severe frontal bossing.

RESULTS

We present three techniques to feminize the forehead based on patient anatomy, modifying Ousterhout's methods with the use of hydroxyapatite and titanium plates. Complications were rare and consisted of hematoma (1%), chronic sinusitis (1%), cicatricial alopecia (3%), hardware palpability (5%) and delayed wound healing (6%). Ninety-five percent of patients reported being satisfied/highly satisfied with their cosmetic outcome.

CONCLUSIONS

FGAS plays an important role in the treatment for gender dysphoria, offering transfeminine individuals an improvement in their self-esteem and quality of life. In our series of 100 cases, we demonstrate good esthetic outcomes with a low complication rate.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Sex Differences in Adult Facial Three-Dimensional Morphology: Application to Gender-Affirming Facial Surgery

Background: Gender-affirming facial surgery (GFS) is pursued by transgender individuals who desire facial features that better reflect their gender identity. Currently, there are a few objective guidelines to justify and facilitate effective surgical decision making. Objective: To quantify the effect of sex on adult facial size and shape through an analysis of three-dimensional (3D) facial surface images. Materials and Methods: Facial measurements were obtained by registering an atlas facial surface to 3D surface scans of 545 males and 1028 females older than 20 years of age. The differences between male and female faces were analyzed and visualized for a set of predefined surgically relevant facial regions. Results: On average, male faces are 7.3% larger than female faces (Cohen's D = 2.17). Sex is associated with significant facial shape differences (p < 0.0001) in the entire face as well as in each sub-region considered in this study. The facial regions in which sex has the largest effect on shape are the brow, jaw, nose, and cheek. Conclusions: These findings provide biologic data-driven anatomic guidance and justification for GFS, particularly forehead contouring cranioplasty, mandible and chin alterations, rhinoplasty, and cheek modifications.

Asymmetric visual representation of sex from facial appearance

We efficiently infer others' traits from their faces, and these inferences powerfully shape our social behaviour. Here, we investigated how sex is represented in facial appearance. Based on previous findings from sex-judgment tasks, we hypothesized that the perceptual encoding of sex is not balanced but rather polarized: for the processes that generate a sex percept, the default output is "male," and the representation of female faces extends that of the male, engaging activity over unique detectors that are not activated by male faces. We tested this hypothesis with the logic of Treisman's studies of visual search asymmetries, predicting that observers should more readily detect the presence of female faces amongst male distractors than vice versa. Across three experiments (N = 32 each), each using different face stimuli, we confirmed this prediction in response time and sensitivity measures. We apply GIST analyses to the face stimuli to exclude that the search asymmetry is explained by differences in image homogeneity. These findings demonstrate a property of the coding that links facial appearance with a significant social trait: the female face is coded as an extension of a male default. We offer a mechanistic description of perceptual detectors to account for our findings and posit that the origins of this polarized coding scheme are an outcome of biased early developmental experience.

Dominance or Integration? Influence of Sexual Dimorphism and Clothing Color on Judgments of Male and Female Targets' Attractiveness, Warmth, and Competence

The face is an important source of information in social interactions. Prior studies exploring the mechanism of face perception were consistent with either dominance or integration theory. Studies have shown that both sexually dimorphic features and background cues play essential roles in the formation of impressions and the perception of facial attractiveness. In this study, we conducted two experiments to examine 539 participants' appraisal of attractiveness, warmth, and competence of the target faces of masculine and feminine men and women dressed in red, blue, or white. The results showed that: (1) feminized male/female faces were considered to have a higher degree of attractiveness, warmth, and competence, (2) people rated feminine faces wearing red higher in terms of attractiveness perception, while there was no significant effect of red on attractiveness perception of masculine faces, (3) when evaluating the warmth of targets, the promotion effect of red was found for feminine faces but not for masculine faces. This study, conducted in a pathogen disgust environment, provides direct evidence to support the integration theory over the dominance theory. Feminized red preference found in this study matches Chinese collectivism and the red cultural heritage, which has an important value for people's daily impression management and consumption decisions.

How sign language expertise can influence the effects of face masks on non-linguistic characteristics

Face masks occlude parts of the face which hinders social communication and emotion recognition. Since sign language users are known to process facial information not only perceptually but also linguistically, examining face processing in deaf signers may reveal how linguistic aspects add to perceptual information. In general, signers could be born deaf or acquire hearing loss later in life. For this study, we focused on signers who were born deaf. Specifically, we analyzed data from a sample of 59 signers who were born deaf and investigated the impacts of face masks on non-linguistic characteristics of the face. Signers rated still-image faces with and without face masks for the following characteristics: arousal and valence of three facial expressions (happy, neutral, sad), invariant characteristics (DV:sex, age), and trait-like characteristics (attractiveness, trustworthiness, approachability). Results indicated that, when compared to masked faces, signers rated no-masked faces with stronger valence intensity across all expressions. Masked faces also appeared older, albeit a tendency to look more approachable. This experiment was a repeat of a previous study conducted on hearing participants, and a post hoc comparison was performed to assess rating differences between signers and hearing people. From this comparison, signers exhibited a larger tendency to rate facial expressions more intensely than hearing people. This suggests that deaf people perceive more intense information from facial expressions and face masks are more inhibiting for deaf people than hearing people. We speculate that deaf people found face masks more approachable due to societal norms when interacting with people wearing masks. Other factors like age and face database’s legitimacy are discussed.

Sex-Related Characteristics of the Face

The face is central to individual identity and gender presentation. Sex-based differences are seen at nearly every component of the face, from craniofacial structure to skin and soft tissue distribution. This article provides a framework for identification and analysis of sex-based differences in facial anatomy. This can then be used to guide individualized approaches to surgical planning to create greater congruence between patients' existing physical features and goals for gender expression.

Relative tuning of holistic face processing towards the fovea

Humans quickly detect and gaze at faces in the world, which reflects their importance in cognition and may lead to tuning of face recognition toward the central visual field. Although sometimes reported, foveal selectivity in face processing is debated: brain imaging studies have found evidence for a central field bias specific to faces, but behavioral studies have found little foveal selectivity in face recognition. These conflicting results are difficult to reconcile, but they could arise from stimulus-specific differences. Recent studies, for example, suggest that individual faces vary in the degree to which they require holistic processing. Holistic processing is the perception of faces as a whole rather than as a set of separate features. We hypothesized that the dissociation between behavioral and neuroimaging studies arises because of this stimulus-specific dependence on holistic processing. Specifically, the central bias found in neuroimaging studies may be specific to holistic processing. Here, we tested whether the eccentricity-dependence of face perception is determined by the degree to which faces require holistic processing. We first measured the holistic-ness of individual Mooney faces (two-tone shadow images readily perceived as faces). In a group of independent observers, we then used a gender discrimination task to measured recognition of these Mooney faces as a function of their eccentricity. Face gender was recognized across the visual field, even at substantial eccentricities, replicating prior work. Importantly, however, holistic face gender recognition was relatively tuned-slightly, but reliably stronger in the central visual field. Our results may reconcile the debate on the eccentricity-dependance of face perception and reveal a spatial inhomogeneity specifically in the holistic representations of faces.

Illusory faces are more likely to be perceived as male than female

Face pareidolia is the phenomenon of perceiving illusory faces in inanimate objects. Here we show that illusory faces engage social perception beyond the detection of a face: they have a perceived age, gender, and emotional expression. Additionally, we report a striking bias in gender perception, with many more illusory faces perceived as male than female. As illusory faces do not have a biological sex, this bias is significant in revealing an asymmetry in our face evaluation system given minimal information. Our result demonstrates that the visual features that are sufficient for face detection are not generally sufficient for the perception of female. Instead, the perception of a nonhuman face as female requires additional features beyond that required for face detection.

Despite our fluency in reading human faces, sometimes we mistakenly perceive illusory faces in objects, a phenomenon known as face pareidolia. Although illusory faces share some neural mechanisms with real faces, it is unknown to what degree pareidolia engages higher-level social perception beyond the detection of a face. In a series of large-scale behavioral experiments (n_total = 3,815 adults), we found that illusory faces in inanimate objects are readily perceived to have a specific emotional expression, age, and gender. Most strikingly, we observed a strong bias to perceive illusory faces as male rather than female. This male bias could not be explained by preexisting semantic or visual gender associations with the objects, or by visual features in the images. Rather, this robust bias in the perception of gender for illusory faces reveals a cognitive bias arising from a broadly tuned face evaluation system in which minimally viable face percepts are more likely to be perceived as male.

Effects of face masks on the appearance of emotional expressions and invariant characteristics

Faces convey a lot of information about a person. However, the usage of face masks occludes important parts of the face. There is already information that face masks alter the processing of variable characteristics such as emotional expressions and the identity of a person. To investigate whether masks influenced the processing of facial information, we compared ratings of full faces and those covered by face masks. 196 participants completed one of two parallel versions of the experiment. The data demonstrated varying effects of face masks on various characteristics. First, we showed that the perceived intensity of emotional expressions was reduced when the face was covered by face masks. This can be regarded as conceptual replication and extension of the impairing effects of face masks on the recognition of emotional expressions. Next, by analyzing valence and arousal ratings, the data illustrated that emotional expressions were regressed toward neutrality for masked faces relative to no-masked faces. This effect was grossly pronounced for happy facial expressions, less for neutral expressions, and absent for sad expressions. The sex of masked faces was also less accurately identified. Finally, masked faces looked older and less attractive. Post hoc correlational analyses revealed correlation coefficient differences between no-masked and masked faces. The differences occurred in some characteristic pairs (e.g., Age and Attractiveness, Age and Trustworthiness) but not in others. This suggested that the ratings for some characteristics could be influenced by the presence of face masks. Similarly, the ratings of some characteristics could also be influenced by other characteristics, irrespective of face masks. We speculate that the amount of information available on a face could drive our perception of others during social communication. Future directions for research were discussed.

Face Masks Bolsters the Characteristics From Looking at a Face Even When Facial Expressions Are Impaired

Face masks impact social interactions because emotion recognition is difficult due to face occlusion. However, is this enough to conclude that face masks negatively impact social interactions? We investigated the impact of face masks on invariant characteristics (sex, age), trait-like characteristics (trustworthiness, attractiveness, and approachability), and emotional expressions (happiness and excitability). Participants completed an online survey and rated masked and no-masked faces. The same face remained masked or no-masked throughout the survey. Results revealed that, when compared to no-masked faces, masked happy faces appeared less happy. Face masks did not negatively impact the ratings of other characteristics. Participants were better at judging the sex of masked faces. Masked faces also appeared younger, more trustworthy, more attractive, and more approachable. Therefore, face masks did not always result in unfavorable ratings. An additional post hoc modeling revealed that trustworthiness and attractiveness ratings for masked faces predicted the same trait ratings for no-masked faces. However, approachability ratings for no-masked faces predicted the same trait ratings for masked faces. This hinted that information from masked/no-masked faces, such as from the eye and eye region, could aid in the understanding of others during social interaction. Future directions were proposed to expand the research.

Imaging of Facial Reconstruction and Face Transplantation

Pre- and postoperative imaging is increasingly used in plastic and reconstructive surgery for the evaluation of bony and soft tissue anatomy. Imaging plays an important role in preoperative planning. In the postoperative setting, imaging is used for the assessment of surgical positioning, bone healing and fusion, and for the assessment of early or delayed surgical complications. This article will focus on imaging performed for surgical reconstruction of the face, including orthognathic surgery, facial feminization procedures for gender dysphoria, and face transplantation.

Simultaneous Zygomatic Osteotomies with Reduction Mandibuloplasty - An Approach to Mid- and Lower-Facial Feminization in the Transfeminine Patient

BACKGROUND

Facial feminization surgery (FFS) is effective at treating gender dysphoria associated with anthropometrically masculine facial features. For many transgender women, FFS is a crucial component of the gender transition process. The purpose of this study is to report our experience with a pragmatic technique for simultaneous mid- and lower-face feminization by zygomatic osteotomy malarplasty and reduction mandibuloplasty.

METHODS

The technique to perform zygomatic osteotomy malarplasty and reduction mandibuloplasty is described, utilizing harvested bone from the mandible for bone grafting the zygomatic osteotomy gap. A retrospective chart review was performed for patients who underwent simultaneous middle and lower FFS using the described technique. Independent reviewers evaluated cropped preoperative and postoperative photographs of the mid and lower face and assigned each photograph a "femininity score."

RESULTS

Seventeen transgender women underwent simultaneous zygomatic osteotomy malarplasty and reduction mandibuloplasty over the study period with adequate follow-up (average 11.1 months). Transient nerve weaknesses were the primary complications noted. A statistically significant improvement in femininity score was reported in postoperative photographs, compared to preoperative photographs (P < 0.01).

CONCLUSIONS

The technique described in this study is an effective application of craniofacial approaches and techniques for feminizing the facial skeleton in transgender women by utilizing harvested mandibular bone for simultaneous malarplasty.

How facial aging affects perceived gender: Insights from maximum likelihood conjoint measurement

Conjoint measurement was used to investigate the joint influence of facial gender and facial age on perceived gender (Experiment 1) and perceived age (Experiment 2). A set of 25 faces was created, covarying independently five levels of gender (from feminine to masculine) and five levels of age (from young to old). Two independent groups of observers were presented with all possible pairs of faces from this set and compared which member of the pair appeared as more masculine (Experiment 1) or older (Experiment 2). Three nested models of the contribution of gender and age to judgment (i.e., independent, additive, and saturated) were fit to the data using maximum likelihood. The results showed that both gender and age contributed to the perceived gender and age of the faces according to a saturated observer model. In judgments of gender (Experiment 1), female faces were perceived as more masculine as they became older. In judgments of age (Experiment 2), young faces (age 20 and 30) were perceived as older as they became more masculine. Taken together, the results entail that: (a) observers integrate facial gender and age information when judging either of the dimensions, and that (b) cues for femininity and cues for aging are negatively correlated. This correlation exerts stronger influence on female faces, and can explain the success of cosmetics in concealing signs of aging and exaggerating sexually dimorphic features.

Social Perception of Facial Feminization Surgery Outcomes: Does Gender Identity Alter Gaze?

BACKGROUND

The evaluation of gender-affirming facial feminization surgery (FFS) outcomes can be highly subjective, which has resulted in a limited understanding of the social perception of favorable gender and aesthetic facial appearance following FFS. Eye-tracking technology has introduced an objective measure of viewer subconscious gaze.

OBJECTIVES

The aim of this study was to use eye-tracking technology to measure attention and perception of surgery-naive cisgender female and feminized transgender faces, based on viewer gender identity.

METHODS

Thirty-two participants (18 cisgender and 14 transgender) were enrolled and shown 5 photographs each of surgery-naive cisgender female and feminized transgender faces. Gaze was captured with a Tobii Pro X2-60 eye-tracking device (Tobii, Stockholm, Sweden) and participants rated the gender and aesthetic appearance of each face on Likert-type scales.

RESULTS

Total image gaze fixation time did not differ by participant gender identity (6.00 vs 6.04 seconds, P = 0.889); however, transgender participants spent more time evaluating the forehead/brow, buccal/mandibular regions, and chin (P < 0.001). Multivariate regression analysis showed significant associations between viewer gender identity, age, race, and education, and the time spent evaluating gender salient facial features. Feminized faces were rated as more masculine with poorer aesthetic appearance than surgery-naive cisgender female faces; however, there was no significant difference in the distribution of gender appearance ratings assigned to each photograph by cisgender and transgender participants.

CONCLUSIONS

These results demonstrate that gender identity influences subconscious attention and gaze on female faces. Nevertheless, differences in gaze distribution did not correspond to subjective rated gender appearance for either surgery-naive cisgender female or feminized transgender faces, further illustrating the complexity of evaluating social perception of favorable FFS outcomes.

Electrophysiological Chronometry of Graded Consciousness during the Attentional Blink

One of the ongoing debates about visual consciousness is whether it can be considered as an all-or-none or a graded phenomenon. While there is increasing evidence for the existence of graded states of conscious awareness based on paradigms such as visual masking, only little and mixed evidence is available for the attentional blink paradigm, specifically in regard to electrophysiological measures. Thereby, the all-or-none pattern reported in some attentional blink studies might have originated from specifics of the experimental design, suggesting the need to examine the generalizability of results. In the present event-related potential (ERP) study (N = 32), visual awareness of T2 face targets was assessed via subjective visibility ratings on a perceptual awareness scale in combination with ERPs time-locked to T2 onset (components P1, N1, N2, and P3). Furthermore, a classification task preceding visibility ratings allowed to track task performance. The behavioral results indicate a graded rather than an all-or-none pattern of visual awareness. Corresponding graded differences in the N1, N2, and P3 components were observed for the comparison of visibility levels. These findings suggest that conscious perception during the attentional blink can occur in a graded fashion.

Facial Hair Transplantation for Transgender Patients: A Literature Review and Guidelines for Practice

BACKGROUND

Facial hair transplantation has become an increasingly popular modality to create a more masculine appearance for transmasculine patients.

OBJECTIVES

This aim of this study was to review the current literature regarding facial hair transplantation and provide recommendations and best practices for transgender patients.

METHODS

A comprehensive literature search of the PubMed, MEDLINE, and Embase databases was conducted for studies published through April 2020 for publications discussing facial hair transplant in transmasculine patients, in addition to the nontransgender population. Data extracted include patient demographics, techniques, outcomes, complications, and patient satisfaction.

RESULTS

We identified 2 articles discussing facial hair transplantation in transmasculine patients. Due to the paucity of publications describing facial hair transplantation in transmasculine patients, data regarding facial hair transplant from the cisgender population were utilized to augment our review and recommendations.

CONCLUSIONS

Facial hair transplant is a safe and effective means of promoting a masculine appearance for transgender patients. Nevertheless, facial hair transplantation should be deferred until at least 1 year after the initiation of testosterone therapy to allow surgeons to more accurately identify regions that would benefit the most from transplantation. Additionally, providers should engage patients in discussions about any plans to undergo facial masculinization surgery because this can alter the position of transplanted hairs. Currently, follicular unit extraction from the occipital scalp is the preferred technique, with use of the temporal scalp if additional grafts are needed. Patients should be advised that a secondary grafting procedure may be needed a year after initial transplant to achieve desired density.

LEVEL OF EVIDENCE: 4

Predominance of eyes and surface information for face race categorization

Faces can be categorized in various ways, for example as male or female or as belonging to a specific biogeographic ancestry (race). Here we tested the importance of the main facial features for race perception. We exchanged inner facial features (eyes, mouth or nose), face contour (everything but those) or texture (surface information) between Asian and Caucasian faces. Features were exchanged one at a time, creating for each Asian/Caucasian face pair ten facial variations of the original face pair. German and Korean participants performed a race classification task on all faces presented in random order. The results show that eyes and texture are major determinants of perceived biogeographic ancestry for both groups of participants and for both face types. Inserting these features in a face of another race changed its perceived biogeographic ancestry. Contour, nose and mouth, in that order, had decreasing and much weaker influence on race perception for both participant groups. Exchanging those features did not induce a change of perceived biogeographic ancestry. In our study, all manipulated features were imbedded in natural looking faces, which were shown in an off-frontal view. Our findings confirm and extend previous studies investigating the importance of various facial features for race perception.

Facial Feminization Surgery: Key CT Findings for Preoperative Planning and Postoperative Evaluation

Facial feminization surgery is an increasingly performed component of gender affirmation surgery for transgender women. Preoperative facial CT is performed to plan the adjustment of the patient's masculine characteristics to feminine and to plan operative navigation around specific readily identifiable anatomic structures. In the upper face, surgery is performed to reduce the prominence of the brow and increase the nasofrontal angle; the radiology report should indicate the frontal sinus and supraorbital foramen anatomy. In the midface, rhinoplasty is performed to increase the nasofrontal and nasolabial angles; the radiology report should indicate the presence of a dorsal hump and septal deviation or spurring. In the lower face, the prominence of the chin and squareness of the jaw are adjusted via genioplasty and mandible contouring, respectively; the radiology report should describe the location and potential anatomic variations of the inferior alveolar nerve and mental foramina as well as the presence of dental abnormalities that directly inform the surgical approach. CT may also be performed if there is clinical suspicion for postoperative complications such as hardware fracture or osteotomy through the supraorbital or mental foramen. Familiarity with these findings will facilitate improved communication between radiologists and surgeons, thereby contributing to the care of transgender women.

Facial Feminization Surgery: Key CT Findings for Preoperative Planning and Postoperative Evaluation

Facial feminization surgery (FFS) is an increasingly performed component of gender affirmation surgery for transgender women. Preoperative facial CT is performed to plan the adjustment of the patient's masculine characteristics to feminine, and to plan operative navigation around specific readily identifiable anatomic structures. In the upper face, surgery is performed to reduce the prominence of the brow and increase the nasofrontal angle; the radiology report should indicate the frontal sinus and supraorbital foramen anatomy. In the midface, rhinoplasty is performed to increase the nasofrontal and nasolabial angles; the radiology report should indicate presence of a dorsal hump and septal deviation or spurring. In the lower face, prominence of the chin and squareness of the jaw are adjusted via genioplasty and mandible contouring, respectively; the radiology report should describe the location and potential anatomic variations of the inferior alveolar nerve and mental foramina, as well as presence of dental abnormalities that directly inform the surgical approach. CT may also be performed if there is clinical suspicion for postoperative complications such as hardware fraction or osteotomy through the supraorbital or mental foramen. Familiarity with these findings will facilitate improved communication between radiologists and surgeons, thereby contributing to the care of transgender women.

[Change of perception of aged male attractiveness by conventional or male facelift: 3D simulation study of a new facelift concept for men]

BACKGROUND

 Facelift is now the fourth most common aesthetic procedure in men. Facial ageing is very different in men and women. Therefore, individual techniques are used since a uniform concept for the surgical facelift in men does not exist. This study aims to evaluate a gender-specific facelift concept especially developed for men.

MATERIAL AND METHODS

 Women and men (n = 10 each) were subjected to a three-dimensional face scan and a subsequent simulation of a V-shaped lift vector (standard lift) and a new facelift concept especially for men in a double T shape (male lift). In an online survey with 262 participants, the simulated as well as the unchanged images were presented and the attributes masculinity, femininity, attractiveness and youthfulness were queried. Statistical models were used to identify attributes of lifting as well as other factors and differences between the simulations.

RESULTS

 Facelift changes are generally associated with a significant improvement in the attributes of youthfulness and attractiveness compared with unchanged control faces. As expected, a male lift leads to masculinisation, while a standard lift leads to feminisation, regardless of the sex of the subjects. The male lift led to higher values for the attribute attractiveness in male subjects, as did the standard lift in female subjects. The standard lift developed for women is indeed more suitable for women and is associated with a significantly higher probability for the attribute youthfulness, whereas this is not the case in the newly introduced male lift concept.

CONCLUSION

 The new facelift concept for male patients is significantly associated with masculinity and attractiveness, while the standard lift suitable for women is associated with significantly higher evaluations of femininity and youthfulness. The results of the SIMALIFT study are the first evidence of the need for a more differentiated, gender-specific approach to facelifting.

The Health Burden of Transfeminine Facial Gender Dysphoria: An Analysis of Public Perception

Objectives/Hypothesis: The face is a major communicator of gender identity. Transfeminine individuals report debilitating quality-of-life deficits as a result of their gender dysphoria, which may be addressed with feminizing therapies. We aimed to quantify the potential impact of facial gender dysphoria experienced by transfeminine patients, as well as associated treatments, including feminizing facial gender surgery, through validated health state utility measures. Methods: A transfeminine patient volunteer who underwent head and neck gender-affirming treatments was consented for research use of perioperative photographs. These media aided in the description of two transfeminine health states, pre- and postfacial feminization facial gender dysphoria. Monocular blindness and binocular blindness were two health state controls. General population adults rated these four health states through visual analog scale (VAS), standard gamble (SG), and time trade-off (TTO), which were used to calculate the quality-adjusted life years (QALYs). Results: Survey respondents totaled 206 with a mean (standard deviation [SD]) age of 35.8 (11.9) years. Mean (SD) health utility measures included 0.75 (0.22) QALYs for VAS, 0.82 (0.19) QALYS for SG, 0.79 (0.21) QALYS for TTO for pretreatment facial gender dysphoria, and 0.81 (0.21), 0.86 (0.19), 0.83 (0.20) QALYS for postgender-affirming treatments for facial gender dysphoria. The health utility scores for the postgender-affirming treatments for facial gender dysphoria (+0.06 VAS, p = 0.005) were significantly improved compared with the pretreatment state. Conclusions: To our knowledge, this study is the first to examine how the general population perceives the health burden of facial gender dysphoria experienced by transfeminine patients. Facial gender dysphoria is perceived to have a negative impact on health states, not dissimilar to monocular blindness in our sample. Feminizing facial gender surgery appears to significantly increase health utility measures.

Feasibility and Perception of Cross-sex Face Transplantation to Expand the Donor Pool

Background:

A major challenge in face transplantation (FT) is the limited donor allograft pool. This study aimed to investigate the feasibility of cross-sex FT (CSFT) for donor pool expansion by: (1) comparing craniomaxillofacial metrics following CSFT versus same-sex FT (SSFT); and (2) evaluating the public and medical professionals’ perception of CSFT.

Methods:

Seven cadaveric FTs were performed, resulting in both CSFT and SSFT. Precision of bony and soft tissue inset was evaluated by comparing pre- versus post-operative cephalometric and anthropometric measurements. Fidelity of the FT compared to the virtual plan was assessed by imaging overlay techniques. Surveys were administered to medical professionals, medical students, and general population to evaluate opinions regarding CSFT.

Results:

Five CSFTs and 2 SSFTs were performed. Comparison of recipients versus post-transplant outcomes showed that only the bigonial and medial intercanthal distances were statistically different between CSFT and SSFT (P = 0.012 and P = 0.010, respectively). Of the 213 survey participants, more were willing to donate for and undergo SSFT, compared with CSFT (donate: 59.6% versus 53.0%, P = 0.001; receive: 79.5% versus 52.3%, P < 0.001). If supported by research, willingness to receive a CSFT significantly increased to 65.6% (P < 0.001). On non-blinded and blinded assessments, 62.9% and 79% of responses rated the CSFT superior or equal to SSFT, respectively.

Conclusions:

Our study demonstrates similar anthropometric and cephalometric outcomes for CSFT and SSFT. Participants were more reticent to undergo CSFT, with increased willingness if supported by research. CSFT may represent a viable option for expansion of the donor pool in future patients prepared to undergo transplantation.

Asymmetric visual representation of sex from human body shape

We efficiently infer others' states and traits from their appearance, and these inferences powerfully shape our social behaviour. One key trait is sex, which is strongly cued by the appearance of the body. What are the visual representations that link body shape to sex? Previous studies of visual sex judgment tasks find observers have a bias to report "male", particularly for ambiguous stimuli. This finding implies a representational asymmetry - that for the processes that generate a sex percept, the default output is "male", and "female" is determined by the presence of additional perceptual evidence. That is, female body shapes are positively coded by reference to a male default shape. This perspective makes a novel prediction in line with Treisman's studies of visual search asymmetries: female body targets should be more readily detected amongst male distractors than vice versa. Across 10 experiments (N = 32 each) we confirmed this prediction and ruled out alternative low-level explanations. The asymmetry was found with profile and frontal body silhouettes, frontal photographs, and schematised icons. Low-level confounds were controlled by balancing silhouette images for size and homogeneity, and by matching physical properties of photographs. The female advantage was nulled for inverted icons, but intact for inverted photographs, suggesting reliance on distinct cues to sex for different body depictions. Together, these findings demonstrate a principle of the perceptual coding that links bodily appearance with a significant social trait: the female body shape is coded as an extension of a male default. We conclude by offering a visual experience account of how these asymmetric representations arise in the first place.

Prospective Quality-of-Life Outcomes after Facial Feminization Surgery: An International Multicenter Study

BACKGROUND

No data exist on the prospective outcomes of facial feminization surgery. This study set out to determine the effects of facial feminization surgery on quality-of-life outcomes for gender-diverse patients.

METHODS

A prospective, international, multicenter, cohort study with adult gender-diverse patients with gender dysphoria was undertaken. Facial feminization outcome score was calculated preoperatively and postoperatively (1-week to 1-month and >6 months). Photogrammetric cephalometries were measured at the same time points. Self-perceived preoperative masculinity and femininity were recorded. Externally rated gender appearance (scale of 1 to 5, with 1 being most feminine) and general aesthetics (scale of 1 to 10, with 10 being very good) for 10 facial feminization surgery patients were compared with those of five cisgender controls. Univariate linear regression analyses were used to predict outcomes from facial feminization surgery.

RESULTS

Sixty-six consecutive patients were enrolled. Patients noted that their brows, jaws, and chins were the most masculine aspects of their faces (54.5 percent, 33.3 percent, and 30.3 percent, respectively). Median facial feminization outcome score increased from 47.2 preoperatively to 80.6 at 6 months or more postoperatively (p < 0.0001). Mean satisfaction was excellent (3.0 at both 1-month and ≥6-month follow-up; p = 0.46). Cephalometric values were significantly more feminine after surgery. Gender appearance was feminine to very feminine (1.83 ± 0.96) and general aesthetics were good (6.09 ± 2.01) but different from those of cisgender women controls (1.25 ± 0.49 and 7.63 ± 1.82, respectively; p < 0.001 for each).

CONCLUSION

Facial feminization achieved improved quality of life, feminized cephalometries, feminine gender appearance, good overall aesthetics, and high satisfaction that were present at 1 month and stable at more than 6 months.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Assessing the presence of face biases by means of anorthoscopic perception

Anorthoscopy is a presentation mode in which an image is shown sliding behind a slit-shaped aperture, so that it is visible only part by part and never in its entirety. With the aims to assess (1) whether the processing of complex stimuli (faces) correctly occurs in anorthoscopy, and (2) whether the Own-Gender Bias (OGB: the better recognition of stimuli belonging to the same gender of the observer: faster and more accurate) and the Left-Face Bias (LFB: the preference to analyze the left half of the face) occur in such a part by part presentation, we presented female and male faces as whole stimuli (Experiment 1) and in anorthoscopy (Experiments 2 and 3), as well as female/male chimeric faces (Experiment 4), during a gender categorization task. Experiment 1 confirmed that participants correctly categorized the gender of faces, but the OGB was not found. In Experiments 2 and 3 we manipulated the direction (Experiment 2: upward/downward; Experiment 3: leftward/rightward), the speed (slow and fast) of the sliding faces, and the width of the aperture (small and large). Both tasks revealed that facial gender was correctly categorized in anorthoscopy. The OGB was found, but only for males/females in Experiments 2/3, respectively. In Experiment 4 the LFB emerged only in the tachistoscopic session, suggesting that this perceptual bias does not extend to anorthoscopy.

Setbacks in Forehead Feminization Cranioplasty: A Systematic Review of Complications and Patient-Reported Outcomes

IMPORTANCE

Forehead feminization cranioplasty (FFC) is an important component of gender-affirming surgery and has become increasingly popular in recent years. Little objective evidence exists for the procedure's safety and clinical impact via patient-reported outcome measures (PROMs).

OBJECTIVE

To determine what complications are observed following FFC, the relative frequency of complications by surgical technique, and what impact the procedure has on patient's quality of life.

DATA SOURCES

Database searches were performed in PubMed/MEDLINE, Scopus, CINAHL, Cochrane CENTRAL, Cochrane Database of Systematic Reviews, and PsycINFO. The search terms included variations of forehead setback/FFC. Both controlled vocabularies (i.e., MeSH and CINAHL's Suggested Subject Terms) and keywords in the title or abstract fields were searched.

STUDY SELECTION

Two independent reviewers screened the titles and abstracts of all articles. Two independent surgeon reviewers evaluated the full text of all included articles, and relevant data points were extracted.

MAIN OUTCOMES AND MEASURES

Complications and complication rate observed following FFC. Additional outcome measures were the approach utilized, concurrent procedures performed, and the use and findings of a PROM.

RESULTS

Ten articles describing FFC were included, encompassing 673 patients. The overall pooled complication rate was 1.3%. PROMs were used in half of studies, with no standardization among studies.

CONCLUSIONS AND RELEVANCE

Complications following FFC are rare and infrequently require reoperation. Further studies into standardized and validated PROMs in facial feminization patients are warranted.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

An ecological measure of rapid and automatic face-sex categorization

Sex categorization is essential for mate choice and social interactions in many animal species. In humans, sex categorization is readily performed from the face. However, clear neural markers of face-sex categorization, i.e., common responses to widely variable individuals from one sex, have not been identified so far in humans. To isolate a direct signature of rapid and automatic face-sex categorization generalized across a wide range of variable exemplars, we recorded scalp electroencephalogram (EEG) from 32 participants (16 females) while they were exposed to variable natural face images from one sex alternating at a rapid rate of 6 Hz (i.e., 6 images per second). Images from the other sex were inserted every 6th stimulus (i.e., at a 1-Hz rate). A robust categorization response to both sex contrasts emerged at 1 Hz and harmonics in the EEG frequency spectrum over the occipito-temporal cortex of most participants. The response was larger for female faces presented among male faces than the reverse, suggesting that the two sex categories are not equally homogenous. This asymmetrical response pattern disappeared for upside-down faces, ruling out the contribution of low-level physical variability across images. Overall, these observations demonstrate that sex categorization occurs automatically after a single glance at natural face images and can be objectively isolated and quantified in the human brain within a few minutes.