Endoscopic browlift with internal fixation

CHAPTER 25 Endoscopic browlift with internal fixation





Physical evaluation




1. The sequelae of senescence in the upper third of the face range from subtle to dramatic. Glabellar and forehead rhytids, eyebrow ptosis/laxity, and forehead lengthening may appear in a range of severity. It is paramount to evaluate each of these factors in determining the best operative approach for the patient.


2. The artist’s canon of equal facial thirds. Symmetry of the facial thirds is considered attractive by most cultural standards. Conversely, an elongated upper facial third is deemed a sign of senescence. Evaluation of the hairline and the quality of the hair may also allow the clinician to determine patients at risk for visible scars and possible alopecia from scalp dissection.


3. The position of the eyebrow arch. In the ideal representation of the eyebrow, the medial brow is located at the level of the supraorbital rim and begins at a line perpendicular to the alar base. The arch then ascends slightly to the apex of the arch, located at a perpendicular line to the lateral limbus (at approximately the junction of the medial two-thirds and lateral one-third of the brow). The arch is slightly above the supraorbital rim in females and at the level of the supraorbital rim in males. The lateral extent of the brow is at a line extending from the alar base and the lateral canthus.


4. Further evaluation of the brow should include evaluation of brow symmetry. In cases of asymmetry, variable fixation of the two sides may result in a more even appearance to the brow arch. Discussion of preoperative asymmetry with the patient is important preoperatively and may minimize patient dissatisfaction if perfect symmetry is not achieved.


5. Eyelid ptosis. The etiology of the ptosis must include the differentiation of dermatochalasis versus true brow ptosis. In order to discern this difference, the examiner may have the patient tightly close their lids, then slowly open their eyes until they can see the examiner. This, in effect, negates the effect of the frontalis on the brow elevation. As the patient continues to open their eyes, the frontalis naturally compensates the brow position. Another method to deactivate the frontalis is to have the patient smile. Manual elevation of the brow to the desired level of fixation may also be utilized in order to assess the involvement of the lid in ptosis.


6. Evaluation of forehead rhytids. Transverse forehead rhytids result from continued frontalis contraction compensating for the lowered brow position. As brow descent increases, forehead rhytids become more evident.


7. Evaluation of glabellar rhytids. Both transverse and vertical glabellar rhytids occur as a result of brow descent and glabellar muscular activity. Concomitant with this may be displacement of the medial brow below the level of the supraorbital rim.



Anatomy


The basis of rhytids in the forehead and brow are directly translated into the frontalis and glabellar musculature. The frontalis originates and is contiguous with the galeal fascia of the scalp. It extends inferiorly and becomes more superficial, investing into the skin and subcutaneous tissues of the brow. Contraction of the frontalis results in a cranial force vector, thus elevating the brow and creating transverse forehead rhytids. Cephalic translation of the forehead and brow is limited by muscular and periosteal anchors. Laterally, the frontalis terminates at the superior temporal line. This tightly adherent confluence of superficial temporal fascia, galea, temporalis fascia and periosteum has been coined the temporal zone of fixation and is one regulator of cephalic translation (Knize, 1996). The orbital suspensory ligament also limits translation by indirectly attaching the lateral eyebrow skin to the lateral orbital rim at the level of the zygomaticofrontal suture (Knize, 1996). The arcus marginalis located across the supraorbital rim also limits cephalic translation of the brow. If these structures are not adequately released intraoperatively, optimal brow positioning may not be achieved.


The muscular central brow depressors include the corrugator supercilli, the procerus, the depressor supercilli, and the medial portion of the orbicularis oculi. The procerus originates from the nasal bones and inserts into the inferior forehead/glabellar dermis. Contraction of the procerus produces a caudal displacement of the medial brow as well as transverse glabellar rhytids. Contraction of the depressor supercilli musculature also have an effect on brow depression and result in primarily oblique glabellar rhytids. This muscle arises from the superomedial orbital rim and inserts into the medial eyebrow dermis.


The corrugator supercilli originates from the superomedial orbital rim, after which it penetrates the medial orbicularis oculi and inserts into the glabellar skin superior to the medial third of the eyebrow. Contraction of the transverse and oblique heads of the corrugator lead to an inferomedial vector, concomitant brow depression, and vertical glabellar rhytids.


The supratrochlear, supraorbital, and zygomaticotemporal nerves provide sensory innervation to the brow. Both the supraorbital and supratrochlear nerves are terminal branches of the ophthalmic division of the trigeminal nerve. The supratrochlear nerve exits the skull approximately 1.7 cm from midline, in the superomedial orbit. The nerve then penetrates into the corrugator and may divide into branches within the substance of the muscle before traversing the frontalis to its destination in the forehead. The supraorbital nerve exits from the supraorbital foramen/notch, approximately 2.7 cm from midline (2.0 to 4.9 cm). The nerve then divides into superficial and deep branches providing innervation to the lateral forehead and frontoparietal scalp. The zygomaticotemporal nerve innervates the temporal region of the forehead. Due to its location near the lateral orbital rim, this nerve is usually sacrificed during dissection of the lateral orbital rim and zygomatic arch. This is not typically a source for complaints from patients and is frequently purposely divided in migraine surgery if this is found to be a trigger point for migraine headaches.


Mar 4, 2016 | Posted by in Aesthetic plastic surgery | Comments Off on Endoscopic browlift with internal fixation
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