Introduction

Although procedures in facial rejuvenation sometimes ignore the lower face, the perioral region – the center of emotional expression – is particularly susceptible to the effects of aging. Techniques aimed at improving fine lines around the lips, drooping mouth corners, pebbly or ptotic chins, and uneven jawlines have typically included more invasive procedures, such as surgery, deep chemical peels, dermabrasion, or ablative laser resurfacing. Augmentation with soft tissue filling agents can dramatically improve the appearance of the lower face, particularly with respect to the projection of the chin and definition of the jaw, which determines the shape of the face. Current concepts of facial aging embrace the importance of changes resulting from volume loss, as well as repetitive muscular activity over time. This is particularly important for injections in the perioral region, where repetitive movement tends to undermine the effects of a filling agent on its own. Optimal rejuvenation requires a multifaceted approach.

Anatomical considerations

The perioral region refers to the area of the face from the subnasal and nasolabial folds to the lower border of the soft tissue contour of the chin (the menton). The orbicularis oris – the sphincter muscle of the mouth – controls all movement, aided by other muscles involved in the elevation of the upper lips, such as the levator labii superioris, zygomaticus major, and levator anguli oris, and depression of the lower lip, such as the depressor labii inferioris and the depressor anguli oris (DAO).

Age-related changes are a result of a combination of factors, including loss of subcutaneous volume, thinning of the dermis, changes in bony structures, skin laxity due to loss of collagen and elastin, and downward gravitational shift of the skin and underlying tissues. Over the years, the entire perioral region begins to droop. The lips may deflate and flatten, vertical rhytides appear above and below the vermilion lips, the mandible rotates (downward and backward for women; forward for men), and oral commissures turn down emphasizing the drooping mouth and prominence of the marionette lines. Soft tissue atrophy and bone reduction in the region between the chin and jowl result in a groove termed the pre-jowl sulcus. Redistribution of overlying skin and subcutaneous tissues results in the underprojection of the chin and malar eminences. Loss of definition occurs around the mandible, and the mentalis area develops a pebbled ‘peau d’orange’ appearance owing to repetitive muscular activity in conjunction with volume loss in the chin (Fig. 19.1).

Figure 19.1 Aging in the lower face.

Ideal filling agents for perioral rejuvenation

Soft tissue augmenting agents fall into biodegradable (or non-permanent) and non-biodegradable (permanent) categories, and the choice of product will depend on several factors, including injector preference, area to be injected, and volume required. Permanent agents, such as polymethylmethacrylate (PMMA) and liquid injectable silicone, are associated with lumps and inflammatory reactions, as well as the rare occurrence of delayed reactions in individuals with normal immune systems, respectively, and should never be used for perioral rejuvenation. Bovine, porcine, or human collagen products have a long history of use in the face but are no longer utilized. Autologous fat transfer carries surgical risks, significant recovery periods, and inconsistent results.

With their malleability and high level of patient satisfaction and acceptance, non-permanent hyaluronic acid (HA) fillers have found a prominent place in the filler armamentarium, particularly for the lips and perioral region. There are a number of HA formulations available; the optimal filler for augmentation around the mouth is one that can be diluted with local anesthetic for patient comfort and to ‘construct’ individualized filler viscosity and flow characteristics appropriate for the different treatment areas (e.g. more diluted for the lips, more viscous for applications in the jaw and chin). Calcium hydroxylapatite (CaHA) can be used to delineate the jawline, chin, and cheeks, but the use of sturdy particles is not appropriate for the delicate skin of the lips.

Pain management

The perioral region is a sensitive area with extensive sensory innervations from multiple nerves; perioral nerve block should be strongly considered for optimal comfort. Other pain management strategies including adding lidocaine (10–20% by volume with 1 in 100 000 epinephrine) to the filler prior to injection and using topical anesthesia, the application of ice before and after the procedure, and massage. Selection of the smallest suitable needle, slow infiltration, and minimizing the number of needle punctures can also improve patient comfort.

Injection techniques

Like the choice of appropriate filling agent, injection techniques vary. Initial patient evaluation should include an overall assessment of the diffuse volume deficit, as well as the individual lines and depressions for a multifaceted treatment approach (Fig. 19.2). In some cases, rejuvenation of the lower face can be accomplished with filling agents alone using a conservative approach and follow-up visits to assess the need for additional treatment. Because of the dynamic nature of the perioral region, fillers often do not last as long as they do in less mobile locations. For this reason, restoration of volume in the lower face is often combined with movement control via botulinum toxin (BoNT). Indeed, combination therapy has been shown by numerous studies to work synergistically, providing optimal and longer lasting clinical benefits than with either modality alone. Some clinicians consider combination therapy the standard for rejuvenation in the lower face.

Figure 19.2 (A) Before and (B) after augmentation of the lower face.