Continuing Education Activity

The etiologies of brow ptosis are numerous and include facial aging, facial nerve injury, and neuromuscular disorders, among others. It is the surgeon's responsibility to determine which of the myriad brow lift techniques is most suitable to meet the goals of the patient. This activity reviews the evaluation of brow ptosis and the technique of the pretrichial brow lift and its indications, contraindications, complications, and relevant anatomy while highlighting the role of the interprofessional team in evaluating and treating brow ptosis.

Objectives:

• Identify the anatomical structures involved in a pretrichial brow lift.
• Describe the equipment, personnel, preparation, and technique of the pretrichial brow lift.
• Review the potential complications of pretrichial brow lifting to ensure patients are sufficiently prepared for surgery.
• Discuss interprofessional team strategies for improving care coordination and communication to improve postoperative outcomes.

Introduction

Patients commonly present with chief complaints of "droopy eyes" or similar phrases, but "droopy eyes" often mean different things. In many cases, the anatomical issue in question is upper eyelid dermatochalasis. Sometimes, there may also be pseudoherniated fat in the upper eyelid or even lacrimal gland ptosis. Blepharoptosis commonly occurs with age as well, but what patients frequently overlook is the contribution of brow ptosis to the appearance of aging in the periorbital area and to upper visual field deficits. Therefore, it is incumbent upon the surgeon to evaluate the periorbital area thoroughly and to identify which patients are candidates for brow lifting, which may or may not be performed in conjunction with upper eyelid surgery, and then further to determine the optimal approach for brow lifting in the individual patient. In this article, we discuss the pretrichial brow lift approach, its benefits, and its limitations.

Since the first description of surgical brow lifting by Passot in 1919, myriad techniques have evolved to improve results. The traditional coronal approach was the first of the modern approaches developed in 1926 and was followed shortly thereafter by trichophytic and pretrichial variants.[1] Direct, midforehead, temporal, endoscopic, and transblepharoplasty approaches followed over the ensuing 70 years.[2][3][4][5]

As technology in facial plastic surgery has advanced and the focus has shifted towards minimally invasive procedures, endoscopic and transblepharoplasty techniques have gained popularity over open approaches. However, the coronal incision and its variants are still commonly employed in the following situations:

• Revision brow lifting after minimally invasive surgery that did not produce the desired result
• Advancing the frontal hairline while simultaneously performing a brow lift for aging face indications[6]
• Advancing the frontal hairline while providing access for frontal cranioplasty in gender affirmation surgery for transgender females[7][8]
• Accessing the frontal sinus, naso-orbito-ethmoid (NOE) region, brain, or anterior skull base for post-traumatic reconstruction or oncologic resection
• Accessing the frontal pericranium for the development of an osteoplastic flap

The choice of approach between coronal and pretrichial/trichophytic depends on whether any adjustment to the frontal hairline is necessary. A traditional coronal approach across the vertex of the scalp will elevate the hairline commensurately with the width of the scalp strip excised. Pretrichial/trichophytic approaches tend not to elevate the hairline and may even be used to lower it, if necessary. The choice between pretrichial and trichophytic approaches is generally based on surgeon and patient preference. The pretrichial approach places the incision directly anterior to the hairline, whereas the trichophytic approach runs a few millimeters posterior to the hairline in order to hide the scar. In some cases, such as for hairline adjustment, the incision may run partially anterior to the hairline and partially within it.

Anatomy and Physiology

Brow position: The concept of the ideal brow position is constantly evolving, in concert with changes in fashion and the popular perception of beauty. The male brow is generally described as full and roughly horizontal, lying at the level of the bony brow ridge. In contrast, the classical female brow position is at or just above the brow ridge with the peak located laterally, 20-25 mm above and between the lateral limbus and the lateral canthus.[9] That said, this classical description of the female brow should not be considered the sine qua non of periorbital feminity; many female actresses and models are well known for flatter or full brows and are considered highly attractive.

Fascial layers: Familiarity with facial anatomy from the level of the trichion down to the glabella and laterally to both lateral canthi is critical for pretrichial brow lifting, as dissection can be carried out in the subgaleal or subperiosteal planes.[10]

• At the level of the trichion in the central forehead, the soft tissue layers are (superficial to deep): skin, subcutaneous fat, galea aponeurotica, loose areolar tissue, and pericranium. 
• At the level of the lateral canthus in the temporal region, the layers include skin, subcutaneous fat, temporoparietal fascia (TPF, or superficial temporal fascia), superficial layer of the deep temporal fascia, superficial temporal fat pad, deep layer of the deep temporal fascia, temporalis muscle, and pericranium. Inferior to this, at the level of the zygomatic arch, the deep layer of the deep temporal fascia invests the deep temporal fat pad. Superior to the superficial temporal fat pad, there is only one layer of deep temporal fascia, which is synonymous with the temporalis muscle fascia.
• The conjoint tendon separates the central and lateral compartments described above. The conjoint tendon consists of a condensation of the superficial fascial layer (galea aponeurotica centrally and TPF laterally) and the deep fascial layers (pericranium centrally, and temporalis fascia and pericranium laterally). The tendon must be divided to provide adequate surgical exposure and mobilize the forehead sufficiently to elevate it.

Supratrochlear nerve: This is a branch of the ophthalmic division of the trigeminal nerve that provides sensation to the glabella and the medial forehead. This nerve exits the superior orbital rim through a shallow notch approximately 1.0-1.5 cm from the midline and travels superiorly in a deep to a superficial direction to provide sensory innervation to the central forehead. The nerve and its accompanying vessels traverse the corrugator supercilii muscle.

Supraorbital nerve: This nerve consists of medial and lateral branches, both of which originate from the ophthalmic division of the trigeminal nerve; they provide sensation to the lateral brow and the lateral forehead. The supraorbital nerve exits the skull lateral to the supratrochlear nerve - in the midpupillary line - and most commonly (72.4%) traverses a notch in the supraorbital rim, but it can pass through a true foramen 27.6% of the time.[11] If a notch is present, it limits the mobility of the soft tissue and puts the nerve at risk of traction injury when the forehead flap is reflected inferiorly. For this reason, an osteotomy can be performed to convert a foramen into a notch to improve mobilization. The presence of a notch on one side does not necessarily predict a notch on the other, as asymmetry in this regard is common.

The frontal branch of the facial nerve: This branch of the facial nerve is at risk during the lateral portion of the brow lift dissection because it courses along the undersurface or deep within the TPF. Pitanguy’s line, drawn between a point 0.5 cm below the tragus to a point 1.5 cm above the lateral margin of the brow, approximates the course of the nerve.[12] As a caveat, it is important to remember the nerve will branch as it proceeds distally, making an approximation of its course using a single line inaccurate, particularly because the position of the lateral aspect of the brow may vary based on grooming and prior surgery.[13] Generally, however, the nerve will not lie under the hair-bearing scalp, so operating in that area should be comparatively safe.

Facial Mimetic Muscles[14][15]

• Frontalis: This is the sole elevator of the brow; it is contiguous with the galea aponeurotica and inserts into the dermis of the brow. Contraction produces brow elevation and horizontal forehead rhytids.
• Corrugator supercillii: These paired muscles are situated along the supraorbital rims, originating from the superior aspect of the nasal bones and inserting into the dermis of the mid to lateral brow; they are responsible for vertical glabellar rhytids. 
• Procerus: This is a fan-shaped muscle that depresses the medial brow. It originates along with the nasal bones and projects superiorly towards the medial heads of the brows; it is located in the midline, superficial to the corrugator muscles, and produces horizontal glabellar rhytids.

Conjoint tendon: While not a true tendon, it is a confluence of the periosteum, galea, and temporalis fascia located along the temporal line and adherent to the calvarium. It must be released to mobilize and elevate the soft tissues of the forehead.

Arcus marginalis: This is a fascial condensation along the orbital rim where the pericranium, periorbita, and orbital septum meet. Much like the conjoint tendon, this needs to be divided to allow for mobilization and elevation of the skin and soft tissue.

Indications

The primary indication for pretrichial brow lifting is the presence of clinically significant brow ptosis, generally brought to the attention of a surgeon by a patient who complains of drooping eyebrows or difficulty seeing things above eye level. Brow ptosis can be addressed with several different approaches, but the pretrichial incision is best suited for patients who are satisfied with their hairline position or who have high hairlines and want to have the hairline lowered or otherwise reshaped as in the case of facial feminization.[16]

Like other coronal-type approaches, the pretrichial incision also provides excellent access to the frontal calvarium and periosteum, frontal sinus, and NOE region; it also permits exposure and division of the corrugator muscles, which can alleviate the vertical glabellar rhytids known as "frown lines" or "number elevens." Lastly, the superior exposure provided by pretrichial brow lifting makes it a good approach for revision brow lifting, although the degree of lift expected from a pretrichial brow lift is equivalent to that achieved an endoscopic lift.[17][18]

Contraindications

Given the length of the pretrichial incision, primary contraindications to employing this approach involve the potential for an unsightly scar. Patients who have receding hairlines or whose hairlines are expected to recede should avoid the pretrichial approach. Similarly, patients with a history of poor scarring - or anyone focused on minimizing visible scars -  may prefer a different approach that uses shorter incisions or hides them in the hair-bearing portion of the scalp.

Because coronal approaches involve elevating the forehead as a unit, it is difficult to apply substantially more tension on one side relative to the other; for this reason, patients with significant brow asymmetry may be better served by a brow lift technique that addresses each brow separately, such as direct, temporal, or transblepharoplasty lifts. Finally, patients with low-lying hairlines may not be the best candidates for pretrichial brow lifting due to the potential to advance the hairline slightly during closure.

Equipment

• 1% lidocaine with 1:100,000 epinephrine
• #15 scalpel blade
• #3 Bard-Parker scalpel handle
• Freer elevator
• 10 mm Joseph double prong skin hooks
• 1/4 curved Daniel endoscopic forehead elevator
• Metzenbaum scissors
• Adson-Brown forceps
• 3 mm straight, unguarded osteotome and mallet (in case of a supraorbital notch)
• Monopolar and bipolar electrocautery
• Raney gun with extra clips
• 3-0 polyglactin suture
• 4-0 poliglecaprone suture
• 5-0 gut suture
• Suture scissors
• Antibiotic ointment
• Cotton gauze roll and compressive wrap for dressing

Personnel

• Surgeon
• Surgical assistant
• Surgical scrub technician
• Circulating nurse
• Anesthesia provider

Preparation

Prior to surgery, it is critical to discuss with the patient what results to expect from surgery, what to expect during the postoperative period, and what the risks of the procedure are. Appropriate expectation management will potentially improve the patient's perception of the surgical outcomes and decrease the frequency of postoperative phone calls to the surgeon's office. Additionally, these discussions strengthen the rapport between doctor and patient, which may be protective from litigation in the event of adverse surgical outcomes.

When patients undergo brow lifting and/or blepharoplasty for functional reasons, it is important to document visual field deficits for third-party payers.

Lastly, standard preoperative photography is essential. Images should include a frontal view in repose and with brow elevation, at a minimum. If blepharoplasty is planned, profile views of the eyes in neutral gaze, closed, and upward gaze may also be helpful. Preoperative photographs not only aid with surgical planning and provide medicolegal documentation when combined with postoperative images but should also be posted in the operating room during the procedure for reference.

Technique or Treatment

After the patient is prepped, marked, draped, and the consent document is signed, a local anesthetic (1% lidocaine with 1:100,000 epinephrine) is injected into the scalp from the temporal fossa across the entire forehead, up 1 to 2 cm into the frontal hairline, and into the contralateral temporal fossa. Centrally, the local anesthetic should be injected down to the bone and laterally down to the level of the temporalis muscle fascia. Alternatively, the tumescent solution may be used rather than undiluted lidocaine; this may be particularly useful if the patient is undergoing additional aging face procedures that will also require high doses of local anesthetics to minimize the likelihood of toxicity.

The incision is then marked running from a point just superior to the root of the helix, up through the temporal hair tuft and meeting the hairline just as it makes a curve from the vertical temporal segment to the horizontal frontal segment. The exact location where the incision leaves the hair-bearing scalp to come out anterior to the hairline will vary depending on the preoperative contour of the hairline and any desired reshaping. The portion of the incision that follows just anterior to the central frontal hairline should have an irregular contour, just as the hairline is irregular to help camouflage the final scar. The incision then proceeds back into the contralateral temporal hair tuft and down towards the helical root.

Care should be taken to bevel the incision either parallel to the hair follicles or perpendicular to them; different surgeons have different preferences, but some feel that bevelling parallel to the follicles makes follicular injury less likely, and others feel that a perpendicular bevel allows the hairs to grow through the scar and better camouflage it. The incision is made with a #15 blade scalpel, and conservative hemostasis may be achieved with bipolar electrocautery or the application of Raney clips. Centrally - between the temporal lines - the incision should be carried down at least through the galea aponeurotica and potentially down through the periosteum as well, depending on the desired plane of dissection. Some surgeons prefer a subgaleal dissection that leaves the periosteum adherent to the calvarium, and some prefer a subperiosteal approach. In either case, leaving the periosteum intact will permit elevation of a pericranial flap, if necessary. Laterally, the incision should be carried down through the TPF and stop at the temporalis muscle fascia.

If a subgaleal plane is selected, blunt finger dissection will be sufficient to elevate the central forehead, although spreading with Metzenbaum scissors may be more comfortable. For a subperiosteal dissection, the elevation of the periosteum may begin with a Freer elevator and then proceed toward the supraorbital rims using a 1/4 curved Daniel forehead elevator. Elevation may proceed blindly until 1 to 2 cm superior to the supraorbital rims. If hairline adjustment is planned, 4-5 cm of back elevation posterior to the incision may be useful as well.

At this point, the lateral dissection should begin. The TPF should be incised and the temporalis muscle fascia exposed, after which the TPF should be elevated off the temporalis fascia from lateral to medial until the conjoint tendon is encountered. By carefully maintaining this plane, the surgeon ensures that the frontal branch of the facial nerve is elevated in the flap and remains intact, even though it is not likely to be visualized during the dissection. Once the conjoint tendon is identified, it should be perforated with a Freer elevator, from lateral to medial, 2 to 3 cm superior to the zygomaticofrontal suture. The Freer is then swept superiorly and inferiorly to avulse the conjoint tendon from the calvarium and create continuity of the central and lateral dissection compartments. The same technique is then employed contralaterally.

With this exposure, the forehead flap may be reflected inferiorly onto the nose; if the flap does not stay in this position unaided, an assistant may retract it with double prong skin hooks, taking care not to place them where the frontal branches of the facial nerves are located. The supraorbital rims and glabella should then be exposed under direct visualization. The supratrochlear neurovascular bundles may not be visualized, but in most cases, the supraorbital bundles will be encountered. The supraorbital neurovascular bundles should be released from their notches to permit full reflection of the forehead flap and exposure of the supraorbital rims; if foramina are present rather than notches, the inferior borders of the foramina may be osteotomized gently, laterally, and medially, with a 3 mm osteotome to release the bundles and permit flap reflection without neuropraxia. Regardless of the initial plane of dissection, the periosteum should be elevated at the level of the supraorbital rim itself and for approximately 1 cm superior and lateral to it. Exposure and periosteal elevation should run continuously from the level of the left lateral canthus all the way to the right. If the elevation was performed in a subglaeal plane and a pericranial flap was planned, the flap would need to be elevated at this juncture. If the dissection was performed in a subperiosteal plane and a pericranial flap was planned, the pericranial flap may be elevated off the undersurface of the forehead flap at any time.

After complete exposure of the supraorbital rim, the arcus marginalis should be divided sharply and spread aggressively to permit effective elevation of the brows. Failure to divide and spread the arcus marginalis is the primary reason for inadequate brow elevation. Any additional procedures, such as frontal cranioplasty, should be performed at this time.

The forehead flap is then redraped and retracted superiorly with skin hooks until the desired brow height is reached. Some surgeons elect to secure the flap in its elevated position prior to closure, and several different methods can be employed, although the authors of this article prefer the use of resorbable polymer anchors. These anchors can be used not only to ensure the elevation of the brows by maintaining superiorly directed tension but can also be placed pointing the opposite direction to maintain anteriorly directed tension to ensure hairline advancement if it is required.

The closure is then begun by tacking the incision closed with sutures or staples and determining how much excess tissue can be removed and from where. In the case of most female aging face patients, this process will simply result in the removal of a long, elliptical strip of the scalp. However, in patients who desire hairline adjustment, the process can be slightly more nuanced, resulting in removing some non-hair-bearing skin laterally and some hair-bearing skin from the widow's peak area to reduce the M-shaped contour typical of a receding male hairline. This technique is particularly applicable to facial feminization. After the excess tissue has been removed, the remainder of the closure is performed, following appropriate hemostasis. The closure is accomplished in layers: galea aponeurotica/TPF, subdermis, and skin surface. Antibiotic ointment is applied over the sutures and/or staples. A drain may be placed, although it is not always necessary, and a pressure dressing may also be applied. However, if a pressure dressing is used, care is necessary to ensure that it applies pressure to the forehead without depressing the brows.

Complications

In addition to the standard complications of any soft tissue surgical procedure, such as pain, bleeding, infection, and unsatisfactory scarring, there are potential adverse outcomes, particularly with pretrichial brow lifting. These include but are not limited to numbness of part or all of the forehead due to supraorbital and/or supratrochlear nerve injury, weakness of brow elevation or brow ptosis due to injury to the frontal branch of the facial nerve, hematoma or seroma, brow asymmetry, insufficient brow elevation, over-elevation of the brow, hairline irregularities, and alopecia at the scar line. Additionally, patients should be informed that they will necessarily experience numbness of the scalp posterior to the incision, and this may not ever fully resolve.[19]

Clinical Significance

Despite the current focus on minimally-invasive approaches to facial aesthetic surgery, more traditional open techniques remain viable options for many patients. Pretrichial brow lifting is beneficial when patients require both brow elevation and adjustment of the frontal hairline; this approach is frequently employed for female transgender patients, who often desire elevation of the hair-bearing brow with concomitant reduction of the bony supraorbital ridges and reshaping of the hairline, all of which are easily performed through a pretrichial incision.

When neither the hairline nor the brow position is important, as, in cases of frontal sinus fractures, NOE fractures, and anterior skull base tumors, a pretrichial approach may still be preferable to a traditional coronal incision if the patient keeps his or her hair short and would prefer to avoid an obvious scar across the vertex of the scalp. Coronal-type brow lift approaches may be more time-consuming and more liable to leave a visible scar than minimally-invasive approaches, but they provide a similar degree of elevation and far better exposure of the fontal calvarium; pretrichial brow lifting, therefore, remains an important part of the facial surgeon's armamentarium.

Enhancing Healthcare Team Outcomes

During the perioperative period, the brow lifting patient will interact with multiple medical professionals of different disciplines. The surgeon's responsibility is to evaluate the patient preoperatively and determine the appropriate operative intervention if the patient meets candidacy criteria. The surgeon must also provide the patient an understanding of what to expect during and after surgery, set expectations, and discuss the recovery process. The patient's primary care provider may also be involved in the decision-making process and may help optimize any underlying medical conditions in preparation for surgery and general anesthesia.

Communication among all members of the operative team (surgeon, assistant, anesthesia provider, nurse, technologist) is critical for ensuring a safe and efficient procedure is performed. Postoperatively, outpatient nurses will play a major role in the patient's recovery, providing education regarding wound care, return to activity recommendations, and performing suture removal if needed. In addition, nurses are often the first to answer questions about potential complications, which is why they must have a thorough knowledge of normal and abnormal postoperative courses.

From start to finish, initial evaluation to suture removal, patients are cared for by clinicians, surgeons, nurses, and technologists, each of whom has the opportunity to improve the surgical outcome by honing their individual skills and by working as part of an interprofessional team.[Level 5]