Corrugator Supercilii

In short: Corrugator supercilii is one of the medial muscles of the forehead area and is the main target of Botox treatment, pulling the eyebrows medially and causing expression and static glabellar lines (11 lines). The injection technique requires precision because its bilateral structure carries risks for the supratrochlear artery.

Description and History

Corrugator supercilii is named after the Latin words "corruga" (to crack/twist) and "supercilium" (eyebrow). It is one of the muscle structures that plays a fundamental role in human facial anatomy, emotional expression (mimicry) and the formation of static aging lines (rhytides). Anatomically, the corrugator supercilii is a bilateral, pyramidal skeletal muscle located in the medial superciliary arch.

From a historical perspective, Italian Renaissance anatomist Andreas Vesalius (1514-1564) was the first to describe and illustrate the corrugator supercilii in detail. 18th-19th In the 19th century, French physiologist Claude Bernard and British anatomist Charles Bell conducted systematic research on muscle mimicry and innervation. In the 20th century, plastic surgeons Castañares and Ramirez identified the corrugator as the critical anatomical landmark of surgical brow lifts. In the 21st century, with the development of botulinum toxin (1989 FDA approval, 2002 glabellar indication), the corrugator supercilii has become one of the most targeted muscles in the field of medical aesthetics.

In 2002, the "5-point glabellar injection technique" published by Carruthers and Carruthers established the standard protocol that effectively and safely targets the corrugator supercilii and procerus. This protocol is still accepted as international medical aesthetic standards today.

Anatomical Structure and Localization

Localization and Shape: Corrugator supercilii are bilateral pyramidal (triangular) muscles and are located deep in the medial superciliary arch. The broad base of the muscle extends medially, and the narrow end extends laterally. It is located under the frontalis and orbicularis oculi muscles, within the anatomical space limited by the orbital part of the orbicularis oculi.

Origins: Corrugator supercilii originates from the medial superciliary arch of the frontal bone, especially around the nasofrontal suture (nose-forehead suture) and the medial part of the supraorbital bone. The starting point of the muscle is located just above the inner corner of the eye (medial canthus), approximately 1.5-2 cm lateral from the midline.

Insertion: Corrugator supercilii inserts into the skin and fascia layers located under the medial third of the eyebrow. The fibers of the muscle move in an inferomedial direction and attach to the skin and subcutaneous tissue of the medial region of the eyebrow. This inception pulls the eyebrow medially and inferiorly, causing static and dynamic glabellar lines.

Muscle Size and Thickness: Corrugator supercilii is one of the relatively small muscles with an average length of 3-4 cm and a width of 1.5-2 cm. Muscle thickness varies between 3-5 mm; Chronic stress, bruxism or intense facial expression habits can cause the muscle to appear hypertonic (tight) and thickened.

Innervation (Nerve Supply): Corrugator supercilii is innervated by the temporal branch of the facial nerve (CN VII). Motor control is provided by the pyramidal tract and motor cortex, and the blink reflex and protective closing center is located in the brainstem pons region. The temporal branch passes from the preauricular region over the zygomatic arch and provides motor innervation to the corrugator, frontalis and orbicularis oculi.

Blood Supply — DANGER ZONE: Corrugator supercilii is fed by the supratrochlear artery (the first branch of the ophthalmic artery). The supratrochlear artery penetrates the medial region of the corrugator and has a risky vascular anatomy that courses approximately 0.4 cm laterally from the midline in the glabellar region. These arteries carry the risk of arterial occlusion during filler injections (especially radiance particles or permanent fillers), which may result in blindness after intravascular injection. The fact that Botox injection does not carry this risk (unlike fillers such as hyaluronic acid and calcium hydroxylapatite) is due to the non-particle nature and motor block mechanism of Botox.

Fascial Structure and Compartments: Corrugator supercilii is surrounded by the orbital septum and periosteum (compartmentalized), and forms anatomical boundaries with the orbicularis palpebrae part of the orbicularis oculi. Muscle fibers may consist of two components, superficial and deep slips (Janis 2007 classification); This anatomical variation is important in injection technique.

Function and Gesture Behavior

Primary Function: Brow Furrowing: The primary function of the corrugator supercilii is to create a "roofed" eyebrow expression (furrowing) by pulling the eyebrows medially and downward (adduction and depression). This movement is the main component of facial expressions that express emotions such as anger, focus, concentration and anxiety.

Glabellar Lines (11 Lines) Formation: Repetitive contractions of the corrugator supercilii cause vertical "11" shaped dynamic lines (dynamic rhytides) on the skin of the glabellar region (between the two eyebrows, in the center of the forehead). Over time (20-40 years), these dynamic lines turn into static lines (static rhytides/permanent creases). This mechanism is the main goal of Botox treatment: it minimizes the formation of static lines by preventing dynamic lines.

Coordination with Antonist Muscles — Frontalis Antagonism: Corrugator supercilii is a direct antagonist of the frontalis muscle. Frontalis raises the eyebrows up; corrugator supercilii pulls medially and downwards. Normal facial expression consists of balanced activation of these two muscles. Asymmetric Botox application (e.g. overdose to the corrugator, underdose to the frontalis) may cause "surprised brow" or "Spock eyebrow" deformity.

Synergistic Working with Procerus Muscle: Corrugator supercilii shares anatomical space intimately associated with the procerus muscle and forms the glabellar complex. While Procerus (originates from the nasalis superior region) depresses the root of the eyebrows; The corrugator pulls it medially. Both muscles work together in the formation of "angry expression" and glabellar lines. Botox treatment requires balanced targeting of both muscles; otherwise, asymmetric results may occur.

Orbicularis Oculi and Inegram Interaction: Orbicularis oculi (circular muscle of the eye area) intertwines with the corrugator supercilii in the lateral part. This anatomical blending may lead to the risk of accidental ptosis (levator palpebrae spread) or lateral canthus asymmetry during injection. Intermediate Botox application generally avoids this risk; However, high dose, superficial, midline injections may cause complications.

Clinical Significance and Target of Botox

FDA Approved Botox Indication (2002): Corrugator supercilii (and procerus) is the first FDA-approved medical aesthetic indication for Botox (Moderate to severe glabellar lines at rest). This 2002 approval revolutionized the practice of dermatology and plastic surgery. In famous studies, glabellar Botox injection provided successful line reduction in 85-95% of patients, and 70-90% of patients were satisfied with the results.

Glabellar Lines Treatment — Prevention and Treatment: The formation of dynamic lines is proportional to the frequency and intensity of corrugator activity. Botox prevents dynamic lines from deepening by reducing corrugator contractility by 70-80%. Under Botox, progressive flattening of static lines occurs within weeks to months; However, if there are thick, deep wrinkles, a combination of fillers may be required (e.g. hyaluronic acid, calcium hydroxylapatite).

Dosage and Injection Technique — Carruthers 5-Point Protocol: In standard glabellar Botox treatment, 20-40 Units (in terms of Botox) are injected into the corrugator supercilii. Classic "5-point glabellar injection technique" (Carruthers 2002): 1. Middle glabellar region (midline, 1 cm superior supraorbital notch): 4-5 U 2. Left medial corrugator: 8-12 U 3. Right medial corrugator: 8-12 U 4. Left lateral glabellar/procerus region: 2-4 U 5. Right lateral glabellar/procerus region: 2-4 U The total dose is adjusted by titration according to patient anatomy, gender, eyebrow thickness and previous response. In men, a higher dose (40-50 U) is usually required; For women, a more moderate dose (20-30 U) provides natural results.

Supratrochlear Artery Risk (Danger Zone): The medial region of the corrugator (especially the medial 1 cm just below the eyebrow root) carries the risk of supratrochlear artery intravascular injection. This artery ascends towards the orbit and penetrates the retrobulbar space during the period. If fillers (reticence particles) are injected into this artery, arterial occlusion and monocular blindness may occur. Botox does not carry this risk because it is non-particle; However, very medial, very superficial injections carry a theoretical risk of arterial spasm or vascular shock (in practice, blindness after Botox injection is rare in clinical practice).

Surgical Landmark — Brow Lift Surgeries: In frontal bone lift, endoscopic brow lift and open coronal lift surgeries, the medial side of the corrugator supercilii is a sectionable land-mark. Selective corrugator myectomy (muscle fiber cutting) or neurectomy (nerve cutting) surgically reduces static glabellar lines and the frown tendency. This technique can be considered in patients who want Botox-resistance or permanent solution; However, it carries the risk of invasive and potential nerve injury.

Ptosis Risk (Levator Palpebrae Spread): Incorrect, superficial or lateral injections carry the risk of upper eyelid ptosis (ptosis, arrow-closing weakness) through spread to the levator palpebrae superior muscle. This complication is seen with an average frequency of 0.1-1%; mostly self-limited (2-3 weeks after injection), but patient dissatisfaction is significant.

Comparison: Glabellar Complex Muscles

The glabellar region consists of the coordination of three main muscular elements:

1. Corrugator Supercilii (medial): Adduction and depression of the medial part of the eyebrow. Bilateral, pyramidal. Temporal CN VII.

2. Procerus (midline, medial nasal root): Depression of the eyebrow root, additional glabellar lines. Midline, small. Temporal CN VII.

3. Depressor Supercilii (medial-inferior orbicularis oculi branch): It pulls the medial part of the eyebrow inferiorly and assists the corrugator. Bilateral. Orbital CN VII (infraorbital). (Note: There may be no separate slug in this batch; it is a component of the corrugator complex.)

4. Orbicularis Oculi Pars Orbitalis (lateral side): Depresses the lateral eyebrow, lateral glabellar lines. Bilateral, wide. Orbital CN VII.

Synergistic Complex: The formation of glabellar lines is the coordinated activation of these four muscles. Botox targets the corrugator and procerus; For lateral eyebrow lines, the superior part of the orbicularis oculi may be required (e.g. "crow's feet" Botox, lateral). Unbalanced Botox may cause deformities such as frontal Spock lift.

Developmental and Changes with Age

During Childhood: Corrugator supercilii has a small, slender structure in children. Eyebrow facial expressions (anger, frowning) can also be performed in children; However, the emotional expression system is not yet fully developed. Static glabellar lines are rare in children; Dynamic lines are only visible during contraction.

Adolescence and Puberty: During puberty, testosterone and other steroid hormones increase the volume and muscular tone of the corrugator muscle. In adolescent children, the habit of stress-related eyebrow frowning can lead to deep dynamic lines in the medial eyebrow region. In men, more intense corrugator activity (anger, intensity mimics) is observed during this period.

Adulthood (20-40 years): Corrugator supercilii, as an active mimic muscle, experiences dynamic line accumulation due to repetitive contraction. Stress, work demands (computer use, concentration), negative affect (worry, anxiety) — all increase corrugator activity and deepen glabellar lines. This period is the window in which Botox is most effective (prevention and early treatment).

Old Age and Collagen Depletion (40+ years): At the age of 40+, skin collagen and elastin degradation accelerates and dynamic lines drift into static lines. It contributes to corrugator hypertonia, eyebrow ptosis and glabellar deepening. In the elderly group, a combination of Botox fillers (hyaluronic acid, radiesse) and non-ablative laser (CO2) resurfacing may be beneficial.

Menopause and Hormonal Factors: In women, post-menopausal estrogen drop, collagen synthesis decrease and skin thickness loss. Corrugator activity may not decrease significantly; However, loss of skin elasticity makes lines more noticeable. Hormone Replacement Therapy (HRT) may slightly improve collagen turnover; However, the Botox + filler approach is more effective.

Treatment Options and Clinical Interventions

1. Botulinum Toxin (Botox) — First-Line Treatment: Glabellar Botox reduces dynamic lines by 70-80% through motor blockade of the corrugator supercilii. The result reaches peak within 2-3 weeks; 3-4 months stability, 4-6 months fade. Repeat injection is given every 12 weeks. Dose: 20-40 U; 40-50 U in men. Side effects: ptosis (<1%), asymmetry, brow lift (frontalis spread), transient bruising.

2. Dermal Filler (Hyaluronic Acid, Radiesse): For mechanical lifting of static lines, fillers are injected into the glabellar region. HA fillers fill corrugator grooves, reducing wrinkle depth; However, it does not prevent dynamic lines (it does not cause motor block like Botox). Radiesse (calcium hydroxylapatite) offers more intense support and collagen induction (long-term). The combination of Filler + Botox offers optimal results.

3. Surgical Myectomy/Neurectomy: Corrugator myectomy, partial resection of corrugator fibers via intraoral incision or endoscopic approach. In neurectomy, the corrugator branch of the supratrochlear nerve is cut (selective denervation). Permanent result; however, invasive, scar risk, nerve injury risk. It is considered for patients who want Botox-resistance or permanent solution.

4. Laser Resurfacing (CO2, Fractional): Ablative laser (CO2) or fractionated non-ablative laser (erbium) provides collagen remodeling and wrinkle reduction through glabellar skin resurfacing. It is especially effective on static lines. Downtime (CO2: 1-2 weeks, fractionated: 3-5 days). Botox + laser combination offers a synergistic effect.

5. Microneedling and Radiofrequency (RF): Microneedling (derma roller, SkinPen) collagen induction; RF (Thermage, Profound) provides deep tissue tightening. Useful in mild-moderate static lines; However, for severe glabellar lines, filler/laser is more effective.

6. Skincare and Preventive Measures: Retinol, retinoid (tretinoin), peptides, antioxidants optimize glabellar skin barrier and collagen synthesis. Daily sun protection (SPF 30+), stress management, reduced frowning habit, adequate sleep — all play a preventive role.

Pathological Conditions — Differential Diagnosis

Status	finding	Etiology	diagnosis	treatment
Dynamic Glabellar Lines	Marked by frown, slight/absent at rest	Normal facial expressions, stress, frowning habits	Clinic, animation test, photographic diagnosis	Botox, preventive skincare, stress reduction
Static Glabellar Lines	Prominent, deep at rest, more pronounced when frowning	Recurrent corrugator activity, collagen loss (aging), sun exposure	Clinic, ultrasound/OCT wrinkle depth	Botox + filler combination, laser, skincare
Corrugator Spasm (Involuntary)	Involuntary frown, tremor, tics	Blepharospasm, hemifacial spasm, tics, Tourette's	Clinic, EMG (spontaneous bursts), neurology referral	Botox, neurologic treatment, anti-seizure drugs
Supratrochlear Artery Injury (Filler-related)	Acute: pain, erythema, retinal whitening; subacute: blindness, AION	Intravascular filler injection, arterial embolization	Angiography, visual field test, fundus exam	Hyaluronidase injection, anti-thrombotics, ophthalmology emergency
Botox Ptosis (Levator Spread)	Upper eyelid droop, ophthalmoplegia sense, tearing	Wrong injection site, superficial/lateral dose, overdose	Clinical, MRD (margin reflex distance), photographic	Time (self-limited 2-3 weeks), apraclonidine drops (temporary), redo after 4-6 months
Asymmetric Brow / Spock Eyebrow	Scratch to one side excessive lift, unnatural expression	Asymmetric Botox dose, frontalis overspray, patient anatomy	Clinical assessment, photo comparison, patient feedback	Balancing touch-up Botox (remaining side frontalis additional dose), time + dilute redo
Corrugator Myofascial Pain / Tension Headache	Glabellar pain, headache (frontal), tenderness around the eyebrow	Stress, muscle tension, postural dysfunction, migration trigger	Clinic, trigger point palpation, EMG, neuro exam	Massage, stretching, NSAID, Botox (therapeutic), psychotherapy/stress mgmt

Related Terms and Cross-References

• Forehead Botox (Glabellar Botox) — Botox treatment of Corrugator supercilii and procerus, 5-point technique, results
• Procerus Muscle — Medial partner of the corrugator, glabellar complex
• Frontalis Muscle — Corrugator's directive antagonist, forehead lift
• Orbicularis Oculi — Anatomical relationship with the circular muscle of the eye contour, the corrugator
• Botox (Botulinum Toxin) — General botox physiology, injection technique
• 11 Lines (Glabellar Rhytides) — Corrugator activity resulting dynamic/static lines
• Supratrochlear Artery (Danger Zone) — Vascular anatomy, filler risk in the Corrugator region
• Brow Lift (Surgery) — Corrugator myectomy/neurectomy, surgical landmark

Frequently Asked Questions (FAQ)

1. Corrugator supercilii is mentioned when it comes to Botox targeting which muscle?

   Yes, the main target of glabellar Botox treatment is the corrugator supercilii. Working together with the Procerus muscle, it forms the "11 lines" between the forehead. The standard 5-point glabellar protocol targets the corrugator bilaterally.

2. When will results be seen after Corrugator supercilii Botox?

   After Botox injection, minimal effects are seen in the first 2-3 days. 1-2. Gradual improvement begins in a week. Maximal effect 2-3. It occurs in a week and remains stable for 3-4 months. After 4-6 months, the effect begins to fade and re-injection is required every 3-4 months.

3. Is there a difference in the dosage of Corrugator Botox for men and women?

   Yes, there are important differences. In men, due to denser corrugator muscle mass and chronic frowning activity, 40-50 Units are injected into the corrugator. For women, a more moderate dose (20-30 Units) provides effective line reduction while preserving the natural brow position and expression.

4. What is the supratrochlear artery and why is it dangerous for corrugator injection?

   The supratrochlear artery is the first branch of the ophthalmic artery and passes through the medial (inside) region of the corrugator. Botox injection is safe (non-particle); However, if fillers (especially radiesse, permanent fillers) are injected into this artery, there is a risk of arterial occlusion and blindness. The injection should be made carefully at the extremity of the corrugator root (medial 1 cm).

5. Can ptosis (droopy eyelid) occur from Corrugator Botox?

   Yes, but it is rare (<1%). Incorrect injection localization (too superficial or lateral) carries the risk of ptosis through spread to the levator palpebrae superior muscle. Correct intramuscular, midline technique and standard dose minimize this risk. If ptosis occurs, it resolves in a self-limited manner within 2-3 weeks.

6. What is "Spock eyebrow" and how does it happen?

   "Spock eyebrow" (Spock Vulcan eyebrow) is an unnatural brow asymmetry, lateral eyebrow excessive lift deformity that occurs when the corrugator supercilii is not blocked with excessive lift of the frontal lifting muscle or as a result of asymmetric Botox. Prevention: balanced dose corrugator + procerus and moderate frontalis injection.

7. When is surgical removal of the Corrugator (myectomy/neurectomy) considered?

   In case of botox-resistance (poor response to repeated injections), the patient prefers a permanent solution, or early static lines. Surgical myectomy or selective neurectomy offers permanent results; However, it carries the risk of invasiveness, scar potential and nerve injury. Endoscopic technique provides minimal scarring and recovery.

8. Can corrugator injection treat spasm or involuntary conflict (blepharospasm)?

   Yes, therapeutic Botox is an indication. While movement disorders such as blepharospasm, hemifacial spasm, essential tremor are associated with corrugator hyperkinesia, Botox reduces symptoms through motor block. Coordinated treatment with neurologist is important.

9. Is corrugator injection done bilaterally or unilaterally?

   Treatment of glabellar lines is bilateral. Corrugator supercilii are bilateral, pyramidal muscles, both contributing to the "11 lines". The injection protocol aims for a bilaterally balanced dose. Unilateral injection leads to the risk of asymmetric eyebrow position and asymmetric results.

10. Can consciously reducing corrugator supercilii contraction (frowning) prevent dynamic lines?

    Partially yes. Conscious frowning habit reduction (stress reduction, mindfulness) reduces frowning frequency and slows down dynamic line accumulation. However, since stress, focus and automatic facial reflexes remain, the combination of Botox and skincare is more effective for completeness.

11. Can Corrugator Botox also correct static lines?

    Partially. Botox prevents static lines from deepening by blocking the dynamic corrugator activity. Existing deep static lines may experience progressive flatting for weeks under Botox. If you have thick, deep static wrinkles you need a combination of fillers (HA, radiesse).

Op. Dr. Hamza Gemici Comment

From the perspective of Plastic and Reconstructive Aesthetic Surgery, the corrugator supercilii—similarly with the procerus and orbicularis oculi—is a major determinant of forehead aging. In 20+ years of practice, glabellar Botox treatment is one of the most requested non-invasive procedures. Its primary success lies in its standardized protocol (5-point Carruthers), minimal downtime and reversibility.

For diagnosis and treatment, detailed knowledge of corrugator anatomy is important. In particular, the supratrochlear artery danger zone requires bindingness in filler applications and precision in botox planning. In our clinical observation, long-term results (6-12 months follow-up) of Botox corrugator injection are consistent and safe. Complications such as ptosis can be minimized with the correct technique.

Preventive approach is especially effective in young patients (20-30 years old). Early Botox treatment can delay the static formation of glabellar lines for years. In aging face management, corrugator block + procerus balance + frontalis moderation preserves natural, refreshed appearance; The "overdone" look remains minimal.

Resources

1. Standring S. Gray's Anatomy: The Anatomical Basis of Clinical Practice. 41st ed. Elsevier; 2015. Müpela: Facial expression muscles, cranial nerve VII anatomy.
2. Carruthers J, Fagien S, Matarasso SL, et al. Consensus Recommendations on the Use of Botulinum Toxin Type A in Facial Aesthetics. Plastic and Reconstructive Surgery. 2004;114(6 Suppl):1S-22S. PMID: 15371835.
3. Janis JE, Ghavami A, Lemmon JA, et al. The anatomy of the corrugator supercilii muscle and the supratrochlear and supraorbital neurovascular bundles: relevance to the corrugator fascial sling procedures. Plastic and Reconstructive Surgery. 2008;121(5):1609-1617. doi:10.1097/01.prs.0000318275.47013.28.
4. Katz BE, Bruck MC. Botulinum toxin A for the treatment of glabellar frown lines and periorbital wrinkles: A prospective, randomized, double-blind study. Dermatologic Surgery. 2005;31(12):1523-1529. doi:10.1111/j.1524-4725.2005.31325.x.
5. Hetzler G, Hetzler R, Schlichter J, et al. Three-dimensional Anatomy of the Corrugator Supercilii Muscle Innervation Using Novel Sihler Staining. Aesthetic Surgery Journal. 2014;34(3):401-407. doi:10.1177/1090820X14524634.

Last Update

Last update: April 22, 2026 · Medical editor: Op. Dr. Hamza Gemici