Pretrichial Brow Lift

The brow lift operation aims to correct the loss of soft tissue elasticity in the upper third of the face, which may lead to ptosis of the brow and hypertonicity of the frontalis, corrugator supercilii, and procerus muscles with subsequent wrinkling of the forehead (see the image below). This confers a look often described as tired. Several techniques are available to correct this occurrence depending on the individual patient's needs and desires.[1]

The operative nomenclature describes the incision employed or the level of undermining necessary to achieve the result. Of course, it makes more sense to describe the operation using terms to define both the incision used and the level of undermining employed (eg, pretrichial subgaleal brow lift). For information on other brow lift techniques, see the Plastic Surgery Brow Lift section.

Pretrichial denotes an incision in front of the hairline. On a practical note, it is advisable to make the bevelled incision about 2 mm behind the hairline to induce hair growth through the scar and improve cosmesis. See the image below.

For expert viewpoints on skin procedures, see Medscape’s Aesthetic Medicine Resource Center.

Aesthetically, the face is divisible into 3 equal parts, of which the forehead (from the top of the eyebrow to the anterior hairline) occupies the upper third. In males, this area averages 7 cm; in females, it averages 5 cm. In Caucasians, in the ideal situation, the medial extent of the eyebrow lies over a line extrapolated upward from the nasal ala to the medial canthus. The lateral extent of the eyebrow lies over a similar line extrapolated upward from the nasal ala to the lateral canthus. The male eyebrow is less arched than the female eyebrow. Maximum arching of the eyebrow occurs in a vertical line with the lateral limbus. The male eyebrow lies at the level of the supraorbital rim; the female eyebrow lies above the rim. The top of the eyebrow lies approximately 2.5 cm from the mid pupil.[2] A lesser distance denotes eyebrow ptosis. With aging, these parameters may shift.

Loss of forehead skin elasticity from genetics, solar damage, and gravity causes eyebrow drooping, with resultant upper eyelid ptosis and visual embarrassment. This causes hypertonicity of the forehead elevator muscles. Aging causes depletion of the subcutaneous fat with resorption of the subjacent skull bone. This leads to forehead wrinkling, the direction of which depends upon the vector of action of the underlying muscle.

Clinical presentation

The patient may state that others describe him or her as having a tired, surprised, worried, or annoyed look. Younger patients may state that they are misconstrued as aged.

Clinical examination

The position of the hairline, eyebrow, and upper eyelids is carefully noted. The role of brow ptosis in causing pseudoblepharoptosis or in adding to blepharochalasis is examined. The examination is performed by manually locating the eyebrow to the ideal position and observing the effect on the upper eyelid. The presence of lagophthalmos is a contraindication to surgery. The sites of forehead wrinkles are recorded along with eyebrow asymmetry, which should be brought to the patient's attention. The patient is counseled on realistic results. If the patient questions the postoperative results, preoperative photodocumentation, apart from self-education, can help the physician demonstrate the results to the patient.

The pretrichial incision is indicated in individuals with a forehead section that is aesthetically larger than acceptable. Allowances must be made for impending or foreseeable receding male hairlines, which often require another approach.

Forehead region

The layers in the forehead and scalp region include the skin, subcutaneous fat layer, superficial musculoaponeurotic system (SMAS) equivalent termed the galea (which incorporates the paired frontalis muscles and continues laterally to become the temporoparietal fascia), a loose areolar layer, and the periosteum.

The frontalis muscle inserts at the medial supraorbital rim into the upper part of the orbicularis oculi muscle and overlying skin. The paired corrugator muscles, arising from the periosteum at the superomedial aspect of the orbital rim, lie deeper and insert with the frontalis and orbicularis oculi into the skin laterally. The supratrochlear nerves may penetrate the corrugator muscle to emerge on the deep surface of the frontalis muscle. Damage to the nerve may occur at this point during corrugator resection. The procerus muscle lies medial and ventral to the corrugator muscles, arising from the nasal bones and upper lateral cartilages and inserting into the skin between the eyebrows. The supraorbital nerve and vessels usually emerge from the supraorbital notch or canal and continue cephalad in the galea. Occasionally this neurovascular bundle may exit from a foramen cephalad to the orbital rim, demanding caution with blind subperiosteal dissection within 2 cm of the supraorbital rim.

Temporal region

The layers of the temporal region include the skin, subcutaneous fat, temporoparietal fascia (the equivalent of the SMAS layer), temporal fascia, and the temporalis muscle. See the image below.

The temporal fascia overlying the muscle splits into 2 layers that enclose the superficial fat pad before reuniting approximately 1 cm above the superior margin of the zygomatic arch and fusing with the parotidomasseteric fascia below. The deep fat pad is an extension of the masticatory fat pad of Bichat and lies deep to the deeper layer of temporal fascia. The frontal division of the temporal branches of the facial nerve lies in the temporoparietal fascia and is at risk during lateral undermining.

For more information about the relevant anatomy, see Forehead Anatomy.

Contraindications to surgery include general systemic instability and bleeding dyscrasias. The patient must discontinue use of aspirin and similar medications at least 2 weeks prior to surgery and for 2 weeks postoperatively. An absolute contraindication is the presence of lagophthalmos. Psychosocial deficiency is carefully assessed. Unrealistic expectations must be dealt with preoperatively.

The operation is performed under monitored or general anesthesia. The hair is secured with rubber bands to expose the incision site; shaving is not necessary. A mixture of 1% Xylocaine and 1:100,000 adrenaline is injected along the incision site after appropriate cleaning and draping.

The scalpel incision follows 2 mm behind the hairline in the frontal region and extends into the hair in the temporal region. The lateral extension joins the upper extent of the facelift incision if a facelift is performed at the same time. The incision is beveled posteroanteriorly. Injudicious cautery use for hemostasis damages hair follicles with risk of alopecia.

The incision is deepened to the subgaleal plane in the frontal region. Undermining at this level in this region is relatively avascular. In the temporal region, the incision is deepened to the level of the deep temporal fascia and undermining is performed at this subtemporoparietal fascia/supra deep temporal fascia level. At or around the region of the anterior temporal hairline, transition is affected between the subgaleal plane anteriorly and the supra deep temporal fascial plane laterally. This affords maximum protection to the frontal division of the temporal branches of the facial nerve.

Anteroinferiorly, the supraorbital rim is identified along with the supratrochlear and supraorbital nerves. The former nerve may be hidden by the corrugator supercilii muscles, but gentle vertical spreading dissection with scissors displays its presence. The corrugator supercilii and procerus muscles are transected using bipolar electrocautery.

Some authors advise weakening the frontalis muscle. Exercise caution, as trauma may occur to both the motor and sensory nerves. Lateral to the supraorbital nerves, the periosteum may be incised and the dissection carried subperiosteally to expose the orbital fat. The rim periosteum is freed in this region to the level of the zygomaticofrontal suture. This allows better placement of the lateral hooding of the upper eyelid.

The entire flap is advanced posterocephalically and the excess trimmed to close without tension. The lateral eyebrow position is initially set with a single staple on each side. In the absence of excessive bleeding, no drains are used.

The incision is closed with 4-0 Dexon to the galea. For scalp skin, 6-0 Prolene sutures are used in the frontal region, and staples are used in the hair-bearing region. A light pressure dressing is applied.

A more conservative approach has been described by Aldo.[3]

Oral acetaminophen may be used for pain, which is usually minimal.

The wound is examined on the first postoperative day. Sutures are removed on the fifth postoperative day. Staples may be removed on the 10th postoperative day.

For excellent patient education resources, see eMedicineHealth's patient education article Black Eye.

No surgeon or operation is devoid of complications. Encountered complications specific to the brow lift operation may be enumerated as follows:

Hematoma formation

Minor or major hematomas may occur, usually within 12 hours of operation. Expanding ecchymosis, edema, and pain provoke suspicion. Neglected hematomas may cause skin necrosis and scarring. Minor hematomas may be dealt with by aspiration with an 18-gauge needle, while major hematomas may require flap re-elevation and exposure of the bleeder for appropriate action.

Infection

Because of the excellent blood supply, infection is rare. Appropriate antibiotic coverage is indicated should infection occur.

Facial nerve impairment

The frontal division of the temporal branches of the facial nerve provides motor innervation to the forehead. Unilateral trauma causes brow asymmetry at rest and aggravation of this asymmetry on volition. Immediate facial nerve palsy may be related to the local anesthesia. Neurapraxia may last several months, and aesthetic relief during this time may be provided by botulinum injection on the contralateral side. If recovery fails, a contralateral neurectomy may be considered after 18 months.

Sensory nerve impairment

The supratrochlear and supraorbital nerves, which are divided at the site of incision by necessity, provide sensory innervation. This causes numbness cephaloposterior to the incision, which tends to resolve in 3-6 months. Be aware of avoiding permanent damage to these nerves, particularly around the orbital rim, during surgery.

Alopecia

Alopecia may be temporary or permanent. Avoiding injudicious cautery to the incision edges and thus damage to the skin follicles may reduce permanent alopecia. Excessive skin tension closure also may contribute to this complication.

Eye complications

Postoperative lagophthalmos predisposing to corneal ulceration is a disaster. Careful preoperative assessment is necessary, especially if a concomitant upper lid blepharoplasty is planned.[4, 5] It is advisable to do the "brow before bleph" to plan exactly how much eyelid skin to excise without risk of ectropion.

Unsightly scarring

Undue tension on the incision leads to an unsightly scar that may need aesthetic correction.

Contour irregularities

Contour irregularities may arise from overzealous resection of soft tissue, particularly the frontalis muscle. Filler substances may correct the problem.

With appropriate patient selection, satisfactory outcomes are high. Failure to detect a patient with unrealistic expectations preoperatively results in an unhappy patient regardless of surgical results.

In a retrospective study of 31 patients who underwent forehead rejuvenation with either an endoscopic (17 patients) or pretrichial (14 patients) technique, Guyuron et al found that only the pretrichial method resulted in long-term hairline stability. Although there was no significant difference in hairline measurements between the endoscopic and pretrichial groups within 1 year postoperatively, examination of photographs 8 years or more postoperatively demonstrated significant hairline recession in the endoscopic patients, while those who underwent the pretrichial procedure showed a stable hairline position. Eleven control subjects (cosmetic surgery patients who did not undergo forehead rejuvenation) also showed long-term hairline recession.[6]

The endoscopic brow lift increases the vertical dimension of the forehead, thus is unlikely to compete for some time with the pretrichial brow lift operation in patients who insist on no alteration to this vertical height.