The marginal mandibular nerve in rhytidectomy and liposuction surgery.

A concern in the current trend toward more aggressive undermining in rhytidectomy and liposuction surgery has been the potential for damage to the marginal mandibular nerve. This study was undertaken in an attempt to clarify the exact peripheral pathway of the marginal mandibular nerve. A series of 22 fresh cadaver heads were studied bilaterally by gross dissection and histologic studies. It was found that dissection superficial to the platysma up to a point 2 cm lateral to the lower lip can be done safely. Medial to this point, dissection is hazardous and is not indicated because the marginal mandibular nerve becomes more superficial as it travels to innervate its effector muscles. Additionally, dissection in this area is technically difficult because of the tight adherence of the skin to the underlying muscles. This adherence generally permits only the formation of fine superficial rhytids that are best treated by chemical peel or dermabrasion.