Preoperative Evaluation in Aesthetic Head and Neck Surgery

Chapter 8. Preoperative Evaluation in Aesthetic Head and Neck Surgery

Kenneth B. Hughes, MD; Samuel J. Lin, MD, FACS

ANATOMIC NORMS

A general recognition of facial norms and proportions has great relevance for the plastic surgeon during the preoperative assessment of aesthetic surgery. The face can be divided into roughly equal thirds consisting of the trichion to nasal root, the nasal root to nasal base, and the nasal base to inferior mandibular midline (gnathion).

The forehead comprises the area from the trichion to highest point of the brow. The average height is 7 cm in men and 6 cm in women. An aesthetic eyebrow has its apogee at the lateral limbus with the lateral extent positioned 3 mm superior to the medial. In women, the eyebrow rests up to 3 mm above the supraorbital rim. Conversely, in males, the eyebrow should lie at the level of the rim. The intercanthal distance should be roughly 34 mm in men and 32 mm in women. The youthful eye should exhibit a positive vector, with the lateral canthus 2 mm above the medial. Scleral show should not be present superiorly or inferiorly.

The nose is composed of 3 sections: root (radix), dorsum, and soft nose. The nose can be divided further into 9 total subunits: nasal dorsum, tip, columella, paired ala, paired sidewalls, and paired soft triangles. The soft nose is comprised of the nasal tip, columella, and ala. The width of the ala should roughly equal the intercanthal distance. The angle between columella and upper lip (nasolabial angle) is 100 degrees in men and 105 in women.

The upper incisor shown at rest should be approximately 2 mm. On lateral view of the face, the chin and upper lip should have similar projection.

It is important to realize that these proportions can vary subtly or dramatically based upon ethnicity. These norms have largely been developed based upon Caucasian models. Every effort should be made to preserve ethnic identity for any aesthetic facial surgery contemplated.

PHYSICAL EXAMINATION

All facial assessment should include a thorough examination of the patient’s skin. The surgeon should note signs of poor skin elasticity, actinic damage, and deep facial wrinkles, as these factors can have dramatic implications upon any excisional or redraping procedure. Examinations of cranial nerves V and VII, in particular, should be performed and asymmetries noted. The relative amount of facial fat, as well as overall facial shape (eg, square or conical) should be documented. One should note the height of the trichion, the level of brow descent, and the amount of dermatochalasis. The surgeon should characterize the tear trough, the degree of malar fat pad descent, nasolabial fold prominence, degree of jowling, and relative laxity or banding of the platysma. A discussion of more specific anatomic considerations is addressed in specific chapters, but one should bear in mind general facial characteristics as no one feature exists in a vacuum. Operating on one aspect of the face inevitably alters perception of the remaining facial elements.