Masculinisation vs Feminisation: Subtle Differences New Injectors Miss

An intermediate-level clinical guide for aesthetic injectors

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Introduction

One of the most consistent early clinical mistakes is not understanding the nuance between feminising treatments and facial masculinisation – then applying the same placement, volume, and target as for every patient regardless of whether that patient is male or female, or is aiming for more feminine or masculine features. The structural differences between male and female faces are not subtle at the population level; they are the result of consistent developmental dimorphism driven by sex hormones, skeletal growth patterns, and differential fat distribution. Understanding them is not advanced technique. It is foundational.

The clinical stakes are real. Perrett et al. (1998), in a landmark Nature study, demonstrated that subjects across UK and Japanese populations preferred feminised to average female faces, and feminised to masculinised male faces — but that enhancing masculine characteristics in male faces increased perceptions of dominance alongside negative attributions including coldness and dishonesty. Little, Jones and DeBruine (2011) confirm that sex-specific features are a consistent and meaningful component of facial attractiveness. A treatment that shifts a face toward the wrong end of the dimorphism spectrum does not merely fail to improve; it actively creates a result the patient will notice as wrong without being able to articulate why.

This blog outlines the key structural differences between male and female faces, the specific errors new injectors make, and the adjustments to assessment and technique that prevent them. For structured training on facial assessment and treatment planning, explore Acquisition Aesthetics courses.

Why Facial Sexual Dimorphism Exists

Facial dimorphism develops in response to sex hormone exposure during puberty. Testosterone drives mandibular growth, supraorbital ridge development, nasal projection, and the overall increase in facial skeleton size that characterises male development. Oestrogen contributes to midface and lip fullness, higher and more anterior malar positioning, and the retention of periorbital subcutaneous fat that gives female faces their characteristic periorbital fullness.

The resulting structural differences are documented across skeletal analysis (Mendelson & Wong, 2012), fat compartment anatomy (Cotofana et al., 2016), and mandibular morphology (Shaw et al., 2010).

Crucially, the evidence suggests that these dimorphic features are perceived, and that moving them in the wrong direction is noticed. Perrett et al. (1998) found that the preference for feminised female faces held across cultures, and that even feminised male faces were preferred over average male faces in attraction judgements in that study. What is most relevant clinically is the sensitivity of observers to directional shifts: faces that are moved toward the ‘wrong’ sex-typical direction, even subtly, register as discordant.

Region-by-Region Structural Dimorphism: Clinical Reference

The following table summarises the key anatomical differences and their direct clinical implications for injectable treatment.

Region	Female	Male	Clinical Implication
Forehead & brow	Smooth, rounded convexity; brow arched, sitting at or above the supraorbital rim; higher arch medially and laterally	More prominent supraorbital ridging; brow sits at the orbital rim or below; flatter, more horizontal	Neurotoxin-mediated lateral brow elevation feminises. In male patients, preserve the natural flat or slightly descending lateral brow
Orbital aperture	Larger apparent eye opening; rounder orbit; more defined superior sulcus	Smaller apparent aperture; heavier brow overhang; less pronounced sulcus	Filling the tear trough or orbital rim in males requires restraint — opening the eye creates a feminine result
Midface & cheeks	Higher, more anterior malar projection; smooth curved transition from orbital rim to cheek; rounder contour	Less pronounced anterior malar projection; more lateral zygomatic prominence; wider bizygomatic width	Anterior-superior cheek placement in males creates feminisation. Male midface filler targets the lateral cheek and supports the mandibular border
Nose	Smaller, more refined; more acute nasolabial angle (90–100°); softer dorsal profile; less projection	Wider base; more obtuse nasolabial angle (90–100° +); stronger dorsal profile; greater projection and length	Nasal filler goals differ significantly by sex. Elevation of the nasal tip in males should be approached cautiously
Lips	Fuller, more visible upper lip vermilion; defined Cupid’s bow; upper:lower ratio approaching 1:1.6; shorter philtrum	Longer philtrum; less visible upper lip vermilion; less defined Cupid’s bow; heavier lower lip relative to upper	Adding Cupid’s bow definition or increasing upper lip eversion in males produces an obviously feminised result
Chin	Narrower, more pointed, tapering to a rounded apex; shorter vertical height	Wider, squarer, more projecting; greater vertical height; broader mentum	Chin filler in females should preserve taper. Any squaring or widening of the female chin masculinises significantly
Jawline & mandible	Softer curve from chin to angle; less angular; more gradual taper	More defined inferior border; wider mandibular angle; stronger gonial angle	Jawline filler in males should emphasise definition and width. In females, aim for smoothness and taper rather than angularity

Developing the assessment framework to consistently perform this analysis is a core skill taught across Acquisition Aesthetics courses. Join our next free webinar to hear how our faculty approach facial assessment.

Intentional Gender Presentation: A Note on Trans and Non-Binary Patients

Some patients present with explicit goals to modify their gender presentation through aesthetic treatment. For example, women assigned male at birth seeking a more feminine appearance may request lateral brow elevation, anterior malar filling, upper lip vermilion eversion, and softer jaw definition. These are clinically coherent goals that should be treated with the same respect and precision as any other treatment goal.

The principle that matters here is patient-led goal setting: the injector’s role is to understand what the patient wants, assess whether it is achievable, discuss realistic outcomes, and execute with anatomical precision. The errors described in this blog are errors because they produce sex-shifted results the patient did not want or expect — not because sex-shifted results are inherently wrong. An injector who understands the anatomy of dimorphism can move the face in either direction deliberately and controllably. One who does not will produce shifts inadvertently.

Practical Assessment Framework

📋  Before Treating: Sex-Specific Assessment Checklist Identify the dominant brow position and shape. Is the lateral brow arched (feminine) or flat/descending (masculine)? Will neurotoxin placement affect this?Assess malar prominence direction: is it anterior (feminine) or lateral (masculine)? Where should filler project this patient’s cheek?Assess lip anatomy: what is the Cupid’s bow definition, philtrum length, and upper:lower lip ratio? What direction does any planned treatment move these?Assess chin: is it tapered (feminine), square (masculine), or somewhere between? Which direction does the patient need/want?Assess mandibular border: what is the width at the angle? Is definition the goal, or softening and taper?Assess the periorbital region: is it skeletonised or full? How much volume is appropriate without over-rounding the eye area?Confirm treatment goals explicitly with the patient, including what the treatment will and will not do to the overall gender presentation of the face

Summary for Injectors

• Facial sexual dimorphism is structural and consistent. It is driven by hormonal developmental effects on the skeleton, fat compartments, and soft tissue and is documented across every facial region (Mendelson & Wong, 2012; Cotofana et al., 2016; Shaw et al., 2010).
• Observers are sensitive to directional dimorphism shifts. Faces moved toward the ‘wrong’ sex-typical direction register as discordant even when the shift is subtle (Perrett et al., 1998; Little et al., 2011).
• The seven most common dimorphism errors are: brow lifting in male patients; anterior cheek placement in males; Cupid’s bow and upper lip eversion in males; squaring or widening the female chin; over-angulating the female jaw; over-filling the male periorbital region; and failing to assess before treating.
• For trans and non-binary patients seeking intentional gender presentation modification, these same anatomical principles apply — but the direction is guided by the patient’s goals, not their assigned sex.
• Sex-specific facial assessment is a prerequisite for safe, accurate treatment planning. It should precede technique selection, not follow it.

Train to Assess and Treat Every Face With Precision Understanding facial dimorphism is foundational to injectable practice. At Acquisition Aesthetics, facial assessment — including sex-specific structural analysis, goal-setting, and treatment planning — is embedded across all training levels from Foundation to Level 7 Diploma. ➤ Explore Our Courses and Book Your Place

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References

Cotofana S, Fratila AAM, Schenck TL, et al.. The anatomy of the aging face: a review.. Facial Plast Surg. 2016;32(3):253–260..

Little AC, Jones BC, DeBruine LM.. Facial attractiveness: evolutionary based research.. Philos Trans R Soc Lond B Biol Sci. 2011;366(1571):1638–1659..

Mendelson B, Wong CH.. Changes in the facial skeleton with aging: implications and clinical applications in facial rejuvenation.. Aesthetic Plast Surg. 2012;36(4):753–760..

Perrett DI, Lee KJ, Penton-Voak I, et al.. Effects of sexual dimorphism on facial attractiveness.. Nature. 1998;394(6696):884–887..

Shaw RB Jr, Katzel EB, Koltz PF, et al.. Aging of the mandible and its aesthetic implications.. Plast Reconstr Surg. 2010;125(1):332–342..