What are the recommended areas for injecting Botox (Botulinum toxin) for forehead wrinkles?

Recommended Areas for Botulinum Toxin Injection in the Forehead

For optimal treatment of forehead wrinkles with Botulinum toxin, injections should be administered in the glabellar region (5 points), horizontal forehead lines (5 points), and lateral canthal lines (3 points per side) using FDA-approved dosing guidelines.

Anatomical Injection Sites

Glabellar Lines (Frown Lines)

• Inject 4 Units into each of five sites: two in each corrugator muscle and one in the procerus muscle, for a maximum dose of 20 Units 1
• These injections target the procerus and corrugator muscles that create the "11" lines between the eyebrows 2

Horizontal Forehead Lines

• Inject 4 Units into each of five sites across the frontalis muscle, for a total of 20 Units 1
• Injection points should be at least 2 cm above the eyebrow to avoid brow ptosis 2, 3
• The pattern should be adjusted based on the patient's forehead width:
  • For wide foreheads (>70 mm glabella-hairline distance): arrange injections in three vertical lines 4
  • For narrow foreheads (<60 mm glabella-hairline distance): arrange injections in three horizontal lines 4

Lateral Canthal Lines (Crow's Feet)

• Inject 4 Units into each of three sites per side (six injection sites total), for a maximum of 12 Units per side (24 Units total) 1
• Injections should target the orbicularis oculi muscle lateral to the orbital rim 2

Dosing Considerations

Total Dosing

• When treating all three areas simultaneously (glabellar lines, horizontal forehead lines, and lateral canthal lines), the maximum recommended dose is 64 Units 1
• Retreatment should occur no more frequently than every three months 1

Personalized Approach Based on Frontalis Muscle Anatomy

• The frontalis muscle has four common anatomical variations that correspond to different horizontal wrinkle patterns 5
• Treatment should be tailored to the specific wrinkle pattern observed during muscle contraction 5, 6
• Injection depth should be intramuscular for optimal effect 3

Technique and Safety Considerations

Injection Technique

• Use a 30-32 gauge needle for minimal discomfort 2
• Inject perpendicular to the skin surface for consistent depth 3
• Avoid injecting too close to the eyebrow (maintain at least 2 cm distance) to prevent brow ptosis 2, 3

Common Complications to Avoid

• Brow ptosis: Avoid injecting too close to the eyebrow or using excessive doses 2
• Asymmetry: Mark injection points before administration and assess facial symmetry 5
• "Spock eyebrow" or "samurai eyebrow" deformity: Can occur if lateral frontalis is undertreated while medial frontalis is fully treated 3

Contraindications

• Infection at the proposed injection sites 1
• Known hypersensitivity to botulinum toxin or excipients 1
• Neuromuscular disorders such as myasthenia gravis 2
• Body dysmorphic disorder 2

Expected Outcomes

• Full effect typically develops within two weeks of injection 2
• Effects last approximately three to four months 2
• Dynamic wrinkles (visible during muscle contraction) show more dramatic improvement than static wrinkles (visible at rest) 2