Facial anatomy demands constant attention

Las Vegas

- To paraphrase English surgeon and anatomist Sir Ashley Paston Cooper, the best surgeon is the one who makes the fewest mistakes.

For dermatologic surgeons, minimizing mistakes means always being aware of underlying facial anatomy, says Hugh T. Greenway, M.D., chairman, Division of Procedural Dermatology, Scripps Clinic, La Jolla, California.

"The rest of our surgical colleagues in most specialties tend to identify things before operating. That’s probably something we as dermatologic surgeons need to pick up, rather than perhaps identifying structures after the fact," he says.

To that end, Dr. Greenway says, the facial region contains "a tremendous amount of material, located both superficially and deep. When you look at anatomy, it’s important to group things in terms of muscle groups or locations such as the scalp, as well as nerve, sensory and motor vessels and specialized structures such as the parotid and parotid gland."

In the facial area, superficial muscles surrounding the orbit and mouth merit special consideration, he says. More complex still is the facial neural network and blood supply.

When performing nerve blocks in the face, "You don’t necessarily have to hit the nerve. You just want to bathe it in the local anesthesia area and then give the anesthetic time to work," Dr. Greenway tells Dermatology Times.

More important is motor innervation of the face. The area on the side of the face anterior to the ear contains a reverse C-shaped region that carries the greatest risk. "The parotid gland covers the facial nerve. The problem is, there are no true definitions of the anterior border of the parotid gland. If we draw a line from the outer canthus straight down, anything midline to that probably is already divided, with the exception of the marginal mandibular," Dr. Greenway explains.

The scalp contains five varied skin layers: the epidermis/dermis, subcutaneous tissues (vessels, nerves, hair bulbs, fibrous bands), the aponeurosis, loose connective tissue and the periostium. Other anatomic considerations include respecting the scalp’s nerve and vascular supply, Dr. Greenway says. In particular, the scalp’s preponderance of blood vessels explains why this area bleeds profusely.

Similarly, structures at risk during superficial neck surgery include several nerves, blood vessels and glands. Also in the neck area, "Solid masses may well be metastatic tumor from the nose, mouth, larynx or pharynx," Dr. Greenway says. "Tumors within the parotid may appear extremely superficial, and any attempt to remove them may damage the facial nerve." DT

Disclosure: Dr. Greenway reports no relevant financial interests.