Eyebrow Anatomy

Chapter 5. Eyebrow Anatomy

Amr N. Rabie, MD; Samuel J. Lin, MD, FACS

GENERAL CONSIDERATIONS

The proper position and design of the eyebrow is relative and depends on a number of factors, including racial, cultural, and other factors. Measurements, marks, and parameters should only be used as a guide when planning for surgery, as they are not absolutely correct for every individual’s facial features. Nevertheless, it is widely regarded that the female brow is located above the superior orbital rim, is arched with its peak above the lateral limbus, and thins laterally, whereas the male brow is heavier in hair density, more inferiorly placed, and is more horizontal. With age, the brow will start to move below the rim, which will result in redundancy and folding of the skin of the upper eyelid, as well as narrowing of the space between the eyebrow hairs and the lashes, which leads to a frowning appearance. The skin of the eyebrow is hair-bearing, thick, and rich in sweat and sebaceous glands. The eyebrow fat pad lies between the periosteum and deep fascia, and enhances motility of the eyebrow. The fat pad extends inferiorly to the periorbital septal plane; through this fat pad, dense attachments secure the brow to the supraorbital ridge. It is very important during blepharoplasty procedures that the eyebrow fat pad be distinguished from the postseptal fat and the preaponeurotic fat. During rejuvenation procedures where the brow fat pad is manipulated, the surgeon must be careful not to give the female patient a masculine appearance, or, more commonly, give the male patient a feminine appearance. The eyebrow functions as an essential protective component for the eye; it keeps dust and sweat away from the eye and also acts as a stationary defense against eye injury through its overhang. The eyebrow also serves to portray facial mood and expression; a flat eyebrow indicates fatigue, elevation suggests surprise or sadness, a downward slant expresses anger, and a proper arch denotes happiness and attractiveness.

MUSCLES OF EYEBROW ANIMATION

The frontalis muscle is responsible for elevation of the eyebrow, it is the primary elevator of the eyebrow; hence, care should be taken to avoid injury during a brow lift procedure. It is a paired muscle that is a continuation of the occipitalis muscle and the galea aponeurotica. Its vertical fibers are inserted into the supraorbital dermis and its insertion does not go beyond the fusion line. The corrugator supercilii muscle is a paired muscle that arises from the periosteum of the superior orbital rim and is inserted via oblique fibers into the dermis of the medial eyebrow skin, and by way of lateral interdigitations into the medial portion of the orbicularis oculi muscle. Contraction of the corrugators will result in medial and inferior displacement of the eyebrow, as well as vertical oblique lines of the glabella.

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