Soft Tissue Augmentation of Lip Lines

Background

Aging of the skin occurs via a multitude of offending processes that ultimately lead to cutaneous fine lines, deeper wrinkles, dyschromia, and laxity. Intrinsic factors such as inherent physiology and genetic makeup contribute only marginally to the aging process. On the other hand, extrinsic (environmental) influences including solar radiation and pollution account for the vast majority of factors that cause cutaneous aging and rhytid formation. Fine lines and wrinkles can affect almost any part of the face, and the perioral area is no exception. Lip lines can be especially bothersome and notoriously difficult to treat. In this chapter, we will discuss the anatomical basis of lip lines, proper counseling and approach to the problem, and safe and effective treatment guidelines.

Pathogenesis of Lip Lines

Perioral lines arise from a combination of repeated contraction of the orbicularis oris muscle and the natural epidermal and dermal atrophy, as well as collagen and elastin loss as a result of aging. The numerous muscle fibers of the orbicularis oris muscle originate from the medial aspect of the maxilla and mandible, perioral skin, and modiolus ( Fig. 26.1 ). The upper and lower portions of the muscle insert into the deep dermis of the lip mucosa. This intricate arrangement allows for closure of the mouth and puckering or pursing of the lips. The repeated dynamic contraction of this muscle group results in radial lines projecting vertically outward from the vermillion border of the upper and lower lip (perpendicular to the direction of muscle contraction). These lines are more prominent in individuals with marked photoaging due to other intrinsic and extrinsic factors and in those who frequently pucker their lips or forcibly exhale (smokers, certain woodwind instrumentalists, etc.).

There are other global changes that transpire in the face that can exacerbate the aged appearance of the lips and perioral area. Structural loss occurs due to bony resorption and subcutaneous fat atrophy, which results in flattening of the lower face and the appearance of the jowl and accentuation of the labiomandibular fold (marionette lines). The corners of the mouth, which are upturned in youth, begin to turn downward with age, creating the appearance of a resting frown and a chronically sad facial expression. This is exacerbated by the activity of the depressor anguli oris (DAO), which further depresses the corners of the mouth. Although outside the scope of this chapter, these are important factors that are prudent to address at the time of consultation for perioral lip lines, as a holistic approach yields the most aesthetically pleasing results.

Lip Lines: Does the Patient’s Sex Matter?

Historically, more women than men seek correction of perioral rhytids. This may be due partly to the fact that women seek cosmetic treatments more frequently than men do. However, histological studies have confirmed key anatomical differences between men and women that predispose the latter to more severe lip lines. In the perioral area, men exhibit a higher number of sebaceous glands and sweat glands, with a significantly higher sebaceous gland count per hair follicle, although the number of hair follicles do not differ. Men display more blood vessels, thicker epidermis, and more robust connective tissue in the dermis. Finally, the distance between the dermis and the orbicularis oris muscle was significantly larger in men; that is, the orbicularis oris muscle attaches closer to the dermis in women than it does in men. These anatomical differences seen on histology may explain why women express more severe perioral rhytids.

Consultation

Optimal patient selection helps to ensure satisfactory outcomes. While studies suggest that a grade of “3” or “moderate” on the Lemperle or Perioral Lines at Rest scale is appropriate to treat, this determination is based on the patient’s desire and the physician’s ability to improve the undesired findings. Although these validated tools are helpful, a practical consideration for patient assessment is (1) whether the patient has sufficient depth to the individual rhytid at rest (perhaps 1 mm or more), (2) the number of vertical rhytides in the area (to assess amount of product or limitations of treatment), and (3) the overall perioral anatomy, with particular focus on the upper cutaneous lip. Patients who have significantly elongated upper lip or with significant maxillary prognathism should be approached cautiously, as soft tissue augmentation of vertical lip lines could result in further imbalance in the overall facial harmony by adding volume to the upper portion of the mouth. Augmentation of lower facial structures such as the chin and jawline could be helpful in these patients who still desire treatment. Prior to any cosmetic intervention , discuss the goals of treatment and manage patient expectations. Clearly communicate that the goal is a softening of the perioral lines and not complete effacement. Discussing balance between softening the lines, maintaining a natural appearance, and avoiding excess filler placement that is not aesthetically pleasing and may cause functional impairment are essential. Patients who do not have realistic expectations are not ideal candidates for treatment. During the discussion, assess the patient’s availability for downtime and any contraindications that may preclude treatment. Bruising is common with filler injection in this area and should be noted. Finally, discuss cost of treatment as well as the need for maintenance treatment for optimal long-term results. The clinician and patient should work together to prioritize interventions based on budget, availability for downtime, and availability for repeat treatments if necessary.