The safe face lift with bony anatomic landmarks to elevate the SMAS.
The risk for facial nerve injury has been reported to be increased with the inclusion of superficial musculoaponeurotic system (SMAS) elevation as compared with a skin-only face lift. The facial nerve courses through the parotid gland. The SMAS is elevated superficial to the parotid gland. However, in elevating the SMAS anterior to the parotid gland, the facial nerve is at risk of injury where its branches emerge from the anterior edge of the parotid gland. The purpose of this study was to identify bony anatomic landmarks to predict the location of the anterior edge of the parotid gland to avoid injury to the facial nerve branches as they exit the parotid gland. The authors dissected 20 cadaver face halves to determine bony landmarks-the masseteric tuberosity and the inferior lateral orbital rim-to predict the location of the anterior parotid edge. Then they measured the anterior edge of the parotid gland in relation to the vector formed between these two bony landmarks. They identified and measured the most anterior portion of the parotid gland in relation to this vector. Then the most posterior aspect of the parotid gland in relation to this vector was measured. In the 20 dissections, the authors found the most anterior portion of the parotid gland to be 2.7 +/- 1.0 mm anterior to the vector from the inferior lateral orbital rim to the masseteric tuberosity. The most posterior part of the anterior edge of the parotid gland in relation to this vector was found to be 1.0 +/- 1.5 mm posterior to this vector. The parotid gland measured an average of 38.8 +/- 3.5 mm in width from the tragus to the anterior parotid edge. In elevating the SMAS with a face lift, the facial nerve branches can be predicted to exit the anterior edge of the parotid gland, which can be located 38.8 mm anterior to the tragus and near the vector from the inferior lateral orbital wall to the masseteric tuberosity.
Wilhelmi
Bradon J
BJ
Plastic Surgery Institute, Southern Illinois University School of Medicine, Springfield 62974, USA. bwilhelmi@siumed.edu
Mowlavi
Arian
A
Neumeister
Michael W
MW
D002508:Cephalometry / Q000379:methods; D062109:Dermatologic Surgical Procedures; D005147:Facial Bones / Q000473:pathology; D005152:Facial Muscles / Q000473:pathology / Q000601:surgery; D005154:Facial Nerve / Q000473:pathology; D020220:Facial Nerve Injuries / Q000209:etiology / Q000517:prevention & control*; D006801:Humans; D010306:Parotid Gland / Q000473:pathology; D015361:Rhytidoplasty / Q000379:methods*