The critical anatomy to understand is the makeup of the superficial musculoaponeurotic system (SMAS) or fascia, which is a thin fascia layer just deep to the subcutaneous fat. It is contiguous with the platysma muscle and is continuous to the inferior surface of the orbicularis oculi muscle.

There are retaining ligaments that are collagen attachments passing from the SMAS to the deeper tissues, which in the midface region are just lateral to the origin of the zygomaticus major muscle (the zygomatic retaining ligaments) and in the region of the superior most portion of the platysma muscle (masseteric retaining ligaments).

In the neck, the retaining ligaments or deep attachments are along the posterior border of the SMAS, just anterior to the greater auricular nerve, and run obliquely down the neck where they have attachments to the sternocleidomastoid muscle. There are also attachments in the region of the anteroinferior portion of the parotid gland.

For the SMAS to be completely mobile, all of these attachments must be divided.¹

Immediately underneath the SMAS are the branches to the facial nerve.

In the neck, the cervical branch comes out from the parotid and up into the platysma anterior to the retaining ligaments at the anteroinferior edge of the platysma and can be safely preserved while fully releasing the SMAS.¹

The marginal mandibular branch is well protected underneath the masseteric fascia.

The major buccal branch runs just above the Stensen duct and is underneath the very thin deep fascia overlying the buccal fat pad, which is more easily penetrated, meaning that nerve is less well protected but easily seen.

The zygomatic branch runs underneath the zygomaticus major muscle and thus is protected.

Finally, the frontal branch becomes more superficial above the zygomatic arch. Dividing the SMAS at the level of the arch protects the frontal branch while still allowing elevation of the malar fat pad with the SMAS if the dissection extends below the inferior edge of the orbicularis oculi muscle to preserve innervation to that muscle.

The aging process with relaxation of the SMAS and fat as well as overlying skin is progressive, with loss of collagen fibers and increasing viscoelasticity of the overlying skin.^2,3

However, the aging process is genetically highly variable. In patients of Asian background, for instance, the skin is somewhat thicker, and the retaining ligaments are stronger, and so development of jowls and malar descent is less pronounced with age.

In addition, there is loss of facial fat with age particularly around the mouth, and to a variable degree in the cheeks, so that facial rejuvenation usually includes some degree of volume restoration, particularly around the mouth.

Fat also accumulates in the submental region, and in some patients (small percentage), a true excess accumulates in the jowl region, which when combined with loss of fat in the prejowl perioral area accentuates the loss of a firm jawline.

The characteristic features of the aging face are development of jowls, malar descent, loss of facial fat, accumulation of submental fat, relaxation of the orbicularis muscle and overlying skin, and relaxation of the platysma muscle and overlying skin.

In many patients, the relaxation of tissues is more pronounced in one region than another.

Although nonoperative management of the aging face with fillers and fat, as well as noninvasive and minimally invasive techniques using laser, focused ultrasound, and radiofrequency, has increased greatly, there are limitations.

More advanced relaxation of the skin and deeper tissues can only be corrected with a face-lift.

The author performs a deep plane rhytidectomy in all patients who are candidates for face-lift, even those with changes limited to the neck and/or jowls, without significant changes in the midface.

What does vary is the extent of the dissection. In patients who are mainly concerned about the neck and jowls with
early aging changes, undermining and release of the SMAS in the midface can be quite limited without extending out to the masseteric and zygomatic retaining ligaments, but a deep plane dissection is still done in the neck.

The incisions can also be limited with a postauricular incision limited to the sulcus, and the preauricular retrotragal incision also limited. With a more limited dissection, the recovery period is accelerated.

Although the submental fat, including subplatysmal fat, and superficial release of skin attachments is always addressed with fine handheld cannulas through two or three 2-mm incisions, as the author’s experience has increased, a submental incision is never done except in the occasional patient 6 months postoperatively who is bothered by persistent platysmal bands in the postoperative period.

The main steps of the procedure are as follows: