Design Guidelines for Custom Square Chin Implants for Men

While some men that request custom chin implants may not desire a more square chin appearance, many do.Here are some surgeon-experienced  guidelines for designing a custom square chin implant (male or masculinizing focus).

1. Aesthetic Objectives (Square ? Wide)

Primary goal: angularity and vertical definition, not excessive transverse width.

• Emphasize a flat or gently convex anterior face
• Create distinct inferolateral corners (boxy chin point)
• The width should not stick further out than the converging lines of the jawline
• Maintain harmony with:
  • Mandibular body width
  • Bigonial width
  • Lower lip–chin balance (avoid labiomental overprojection)

Common pitfall: over-widening the chin to achieve “square,” producing a boxy unnatural look.

2. Projection & Vertical Height

Projection

• Typical anterior projection: 5–12 mm. Determined by preoperative imaging.
• Men often tolerate slightly more projection than vertical height
• Avoid steep anterior convexity—think plateau, not button

Vertical lengthening

• Ideal increase: 3–6 mm if aesthetically tolerated
• Inferior lengthening improves squareness more reliably than width
• Maintain a flat inferior border, not pointed or teardrop-shaped

Rule of thumb:

A square chin is created more by inferior edge geometry than by frontal bulk.

3. Inferolateral Corner Design (Key Feature)

• Corners should be:
  • Sharp but blunted (not knife-edge)
  • Symmetric but not exaggerated
• Avoid wrapping corners too posteriorly—this encroaches on prejowl territory and risks asymmetry
• Ideal angle: ~95–105° between anterior and inferior surfaces

4. Width Control

• Lateral extension should usually stop:
  • Just medial to the mental foramen
  • Or at the vertical midline of each canine root
• Excessive width creates:
  • Masculinization beyond patient intent
  • Palpable implant edges
  • Mental nerve proximity issues

If width is requested:
consider combined chin + jawline strategy rather than chin alone.

5. Bone Interface & Fit

Posterior surface

• Full 3D bone conformity to the symphysis
• No point-loading zones
• Smooth transitions at all edges

Thickness

• Central thickness usually 4–7 mm
• Taper to <1mm at all margins
• Avoid abrupt transitions—these cause palpability

6. Mental Nerve & Soft Tissue Safety

• Maintain:
  • >5 mm clearance from mental foramen
  • Gentle lateral taper near nerve exits

7. Fixation Planning

• Screw locations do not need to be designed into the implant
• Their locations are determined intraoperatively
  • Typically 1 midline or 2 paramedian screws are needed
  • Any implant with over 5mms horizontal projection requires drilled screw placement

8. Material Selection

• Solid silicone (Silastic)
  • Preferred for square chins
  • Easier contouring, lower cost, reversible
• Porous polyethylene (Medpor)
  • Use cautiously
  • Higher rigidity, less forgiving for sharp angles

Avoid: overly rigid materials when sharp corners are designed.

9. Design Limitations

Avoid square chin implants alone if patient has:

• Weak jaw angles
• Narrow mandibular body
• Long lower face with lip incompetence

? Consider chin + jawline implants or genioplasty hybrid approach.

Dr. Barry Eppley

World-Renowned Plastic Surgeon