Aesthetic lip surgery

Lips not only play an important functional role, such as when speaking or eating, but they are also an important aesthetic element of the face. Full lips are associated with youth, health, and strength. As society seeks these qualities, the number of lip surgeries has increased significantly. Cosmetic surgeons can now enlarge, reduce, renew, shorten, and lengthen lips to suit the patient's needs. This article provides an overview of the embryology, anatomy, aesthetics, and purposes of lip surgery. Finally, a variety of modern lip surgeries are described.

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Embryology and anatomy of the lips

Understanding the embryology of the lips is fundamental to understanding the principles of many modern surgical procedures on the lips. During fetal development, the upper lip is formed from two distinct pairs of structures, the lateral maxillary processes and the median nasal processes. These fuse together to form the upper lip. Thus, its characteristic contours are the result of the union of these structures. The lower lip is formed by the fusion of the paired mandibular processes, resulting in a simpler, less defined structure. Because of embryological differences, the functions of the upper and lower lips differ significantly. The upper lip has greater mobility than the lower lip.

The defining points of the upper lip are located in the central complex of the Cupid's bow, a line that defines the border between the skin and vermilion border of the upper lip. This complex is formed by the two highest points of the vermilion border, lying on the edges of the philtrum on each side, and a V-shaped notch between them. The most prominent points of the vermilion border of the lower lip are parallel to those of the upper lip, but there is no central notch. Another characteristic feature of the lips is the presence of the white line or ridge. This structure is a raised line of skin that separates the vermilion border of the lips from the cutaneous portion of the upper and lower lips. The function of the ridge is unknown; however, Giles hypothesized that it serves as a skin reservoir that allows the lip to perform such complex movements as wrinkling, smiling, speaking, and eating.

The skin of the lips contains hair follicles, sebaceous and sweat glands. The color of the red border of the lips is due to the absence of a layer of keratinized cells and a developed capillary plexus. The red border of the lips consists of dry and moist parts. The dry part contacts the air and, in general, is the visible part of the red border of the lips. In front, it borders on the skin part of the lip, and at the back it is separated from the moist part by a moist line.

The volume of the lip is formed by the orbicularis oris muscles. The red border of the lips and the adjacent skin are separated from the underlying muscle by a thin fascial layer. In the center of the upper lip, the fibers of the orbicularis oris muscle cross in a cross-shaped manner and are inserted into the edge of the subnasal groove on the opposite side. The commissures of the lips are complex areas where the fibers of the orbicularis oris muscle cross and the muscles that raise the lip, lower the lip, and the buccinator muscle unite.

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Lip aesthetics

There is no ideal standard for perfect lips. Everyone has their own opinion on what constitutes beautiful lips. Some like a fuller lower lip, while others prefer a more prominent upper lip. But despite individual preferences, there are fundamental proportions and anatomical characteristics that determine external attractiveness.

The distance from the menton (the lowest anthropometric point of the chin) to the subnasale (the point where the columella meets the upper lip) should be one-third the distance from the menton to the hairline on the forehead. If the patient has a high forehead, the first measurement should be the distance from the subnasale to the glabella (the most prominent point of the forehead). The upper lip should occupy one-third and the lower lip two-thirds of the length of the lower third of the face.

In profile, a line drawn from the subnasale to the soft tissue pogonion (the most prominent point of the chin) can be used to assess lip protrusion. Previously, some authors, Burstone, referred to these rules (i.e., "the upper lip should lie 3.5 mm anterior to this line, and the lower lip 2.2 mm). However, due to differences in individual aesthetic ideals, it is difficult to establish specific dimensions of lip protrusion. The determining factor in assessing lip protrusion is the position of the teeth. The lips cover the teeth, and therefore insufficient or excessive lip protrusion may reflect an incorrect position of the underlying teeth.

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The Aging Process

Thin, poorly defined lips can be either congenital or the result of trauma or the aging process. This process is a reflection of two separate factors. The first factor determining aging is largely related to hereditary programmed aging. The size of the lips increases until puberty due to hypertrophy of the muscular and glandular component, and then begins to gradually decrease. The second factor is due to external influences such as sun exposure and smoking, which can intensify the aging process. The aging evolution of the lips reflects changes not only in the skin, but also in the surrounding tissues (muscles, fat, teeth, bone). Over time, the clearly visible, raised white ridge surrounding the upper and lower lips begins to flatten. This, in turn, leads to smoothing of the Cupid's bow and a decrease in the visible part of the red border of the lips. Thinning of the subcutaneous layer and decreased muscle tone cause a decrease in the protrusion of the lips. These processes also lead to the drooping of the corners of the mouth. Due to the combination of reduced volume of supporting elements and loss of skin tone, wrinkles appear on the vermilion border and skin part of the lips. Thus, long, poorly defined lips with a small vermilion border and minimal protrusion are formed.

Goals of lip surgery

Many patients come to a plastic surgeon with very specific ideas about how to perform surgery. Others are less clear about their goals and have only a general idea. During the consultation, it is important to determine what patients expect from lip surgery. That is, are they concerned about the length of the lips, the definition of the Cupid's bow area, the size of the visible vermilion border, the degree of protrusion, the presence of wrinkles in the vermilion border and skin of the lips, the drooping of the corners of the mouth, or the possible loss of definition along the white ridges and edges of the philtrum? It is helpful to have the patient sit in front of a mirror and mark the areas of interest, thereby achieving mutual understanding with the patient.

The anamnesis should include all information about previous interventions on the lips, diseases and injuries. This concerns previously performed collagen injections, which can cause fibrosis in the lip area, as well as previous herpes infection, allergies and other important medical conditions.

The procedure for examining the lips is carried out with the patient’s face relaxed according to the following scheme.

• Bite assessment.
• Analysis of facial proportions: checking vertical thirds and measuring the length of the upper and lower lips.
• The degree of expression of the Cupid's bow.
• Prominence of the edges of the subnasal groove.
• The appearance of white ridges along the upper and lower lips.
• The size of the visible red border of the upper and lower lips.
• Visibility of teeth (in young patients, a few millimetres of the central teeth are visible, but as the lips lengthen with age, the teeth become less visible).
• Position of the corners of the mouth.
• The condition of the epithelium of the red border of the lips.
• The condition of the epithelium of the skin of the lips.
• Assessment of lip protrusion.
• Position of the chin (microgenia can make full lips appear even larger).

Following this scheme, the surgeon must identify the conditions underlying the patient's requests. Their correct diagnosis will be the cornerstone of a successful treatment outcome.

Photography

Photography plays a very important role in cosmetic surgery. In regards to lips, it allows the surgeon to identify and confirm asymmetry before surgery, for proper planning. It also allows patients to compare their pre-operative condition with the post-operative condition, to visualize the changes that have occurred. Any makeup must be removed before taking photographs. The boundaries of the target images should be: from above - the lower edge of the orbit, from below - the hyoid bone. Usually, images are taken in frontal, right and left oblique, right and left lateral projections at rest, as well as in the frontal projection of smiling and wrinkled lips.

Anesthesia

The area of the upper and lower lips can be very easily anesthetized by local blockade. 4% lidocaine jelly (Xylocaine) is applied to the mucous membrane of the upper and lower lips. Regional blockade of the mental nerves, infraorbital nerves and greater palatine branch is done through the oral mucosa with a mixture of equal volumes of 0.5% bupivacaine with epinephrine 1:200,000 mixed with an equal volume of 1% lidocaine with epinephrine 1:100,000. After this, 1% lidocaine with epinephrine 1:100,000 and hyaluronidase mixed in a ratio of 10 ml to 1 ml, respectively, can be locally injected into the lips. This mixture is injected along the lips in the plane of dissection. The volume of anesthetic should be limited so as not to cause distortion of the lip shape. When using dermal matrix grafts, the enzyme is not used to reduce the likelihood of its destruction. Depending on the patient's sensitivity and the plan for other surgeries, additional anesthesia may be used, ranging from 20 mg oral diazepam or hydrocodone bitartrate (Lortab) to general anesthesia.

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Skin interventions cube and red border

Wrinkles appear in the perioral area as a result of aging. This process is accelerated by insolation and smoking. Often, such changes reflect damage to both the dermis and the subcutaneous layer, with a loss of volume in the red border of the lips. Short-term correction of skin wrinkles is achieved by injecting collagen into the perioral lines. However, due to the mobility of this area, collagen can last up to 2 weeks. Longer-term correction is achieved by grinding the skin around the mouth. Initially, dermabrasion was performed specifically for perioral wrinkles. Modern grinding methods are represented by a wide range of methods - from hardware peeling for very superficial wrinkles to chemical peeling and CO2 laser grinding of deep wrinkles. The deepest wrinkles can often be treated with acetone followed by application of Baker's phenol-based chemical peeling solution with the wooden end of a cotton swab. This peeling solution can also be applied to the dry part of the red border of the lips. Then laser resurfacing is performed up to the vermilion border, including the areas of the previous spot peeling. This leads to softening of the lip wrinkles and an increase in the visible part of the vermilion border. Deep lines on the vermilion border are often a consequence of the loss of lip tissue, which is very similar to the decrease in the amount of air in a balloon. Wrinkles on the vermilion border can be smoothed out by restoring the volume of the lip with modern materials.

Lip augmentation surgeries

Increase

Upper and lower lip augmentation may involve the use of autologous materials such as dermis, fat, fascia, superficial musculoaponeurotic system, or materials such as AlloDerm (human acellular dermal scaffold grafts), Gore-Tex, collagen, silicone, Dermologin and many others.

The basic principles of augmentation are to either increase the vertical length of the lip or to increase lip protrusion. The former goal is attempted to be achieved by placing implants. When the goal is to lengthen the lip, the implant material is usually placed in the submucosa or in a tunnel along the lower aspect of the upper lip and the upper aspect of the lower lip. When an attempt is made to increase protrusion, the implant is placed either in the submucosa along the anterior aspect of the lip or in a tunnel along the anterior aspect. Because the lips are highly mobile, long-term retention of implanted material in the lip is challenging. Autologous materials are usually readily available; however, their use also involves a donor site and its associated problems. Fat retention has been found to be unpredictable, often resulting in an uneven lip surface. The success rate is increased by flushing the fat with lactated Ringer's solution to remove damaged and degraded fat cells as well as blood and serum. Dermal grafts and SMAS, due to the dense cellular nature of these materials, usually do not survive very long in the lips. The temporal fascia is usually very thin and does not provide significant volume gain in most patients.

Bovine collagen is flexible, which allows it to be injected into the white folds, along the philtrum and the vermilion border of the lips. To detect possible allergic reactions, skin testing of patients is necessary approximately 4 weeks before its use. Despite a negative result of a single skin test, some patients may experience allergic reactions to the material. In the lip area, collagen can be retained from 2 weeks to several months. It also helps to smooth out some of the fine wrinkles around the mouth. To reduce the likelihood of seals forming, patients should massage the injection areas.

Alloderm

Human acellular dermal scaffold grafts were originally developed to cover large burn areas. However, they have also been successfully used as lip implants. The graft material is obtained from a certified tissue bank. After removing cells from the dermis, the material is freeze-dried. The result is an acellular scaffold that allows tissue ingrowth and cellular colonization of the scaffold (AlloDerm). As a result of the constant remodeling of the graft, by the end of the year AlloDerm is no longer present in the recipient's body, but is completely replaced by his tissue. This is an excellent sequence for installing a temporary scaffold that stimulates the growth of new tissue. AlloDerm is injected into the lips after regional anesthesia through incisions in the commissure of the corner of the mouth. Along the anterior or inferior edge of the lip, depending on the purpose of the operation, a submucosal tunnel is made with a tendon insertion instrument. After the instrument exits from the opposite side, a fragment of AlloDerm of the appropriate size is inserted into the pocket. When using this material, the surgeon must remember that after straightening, the rehydrated form will shrink in the recipient's body to a size close to the original size of the dry material. Therefore, the surgeon should determine the amount of augmentation desired by the dry fragment of AlloDerm, not by its rehydrated form. Typically, two-thirds of a 3 x 7 cm plate can be inserted into the upper lip and one-third of a 3 x 7 cm plate into the lower lip. However, it is often possible to insert a whole plate into each lip. The tunnel in the submucosa should be created deep enough so that the implant material does not show through the lip. If a small area of material is exposed after surgery in the corner of the mouth or on the edge of the vermilion border, it can be trimmed without consequences. An injectable form of AlloDerm is currently being tested. Preliminary results look promising. The same degree of lip augmentation can be achieved as with the plate, but the swelling will last only 2-3 days. Unlike bovine collagen, which is a dermal implant, the particle size of the AlloDerm injectable allows it to be used as a subcutaneous implant. A 25-gauge, 5-cm needle is inserted into the midline, puncturing the lip in the desired plane (the same plane as the AlloDerm insertion sheets). The finely ground AlloDerm is injected evenly into the tissue as the needle is withdrawn. Dermologin is a chemically dissolved acellular dermal matrix. The chemical dissolution is thought to remove various proteoglycans that would otherwise promote tissue ingrowth. Early observations of this material have been disappointing, as it does not last as long as bovine collagen.

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Porous polytetrafluoroethylene

Porous polytetrafluoroethylene (ePTFE, Gore-Tex) has been widely used for lip augmentation for many years. It is not resorbable. However, when inserted into the lip, it forms a capsule around it, which can tighten and tighten the lip. Another disadvantage of this material is that patients can feel the ePTFE in the lip. The complex movements of the upper lip make it very difficult to retain the implant inside it, and it is not uncommon for it to be squeezed out. Manufacturers try to increase the flexibility of large ePTFE fragments by creating a multi-strand structure of the implant. This works well on the lower lip, but in the author's experience is unacceptable on the upper lip.

Silicone

Microdrop silicone is a possible lip augmentation material that has been widely used in the past. However, due to the position of the U.S. Food and Drug Administration, it is not currently used by many physicians. Reactions to the microdrop injections can sometimes be observed, which is likely due to the lack of purity of the silicone itself.

VY plastic

VY advancement, or cheiloplasty augmentation, a technique that has been known for many years and was originally used to correct whistle-mouth deformity, involves suturing the mucosa according to the principle of translating a V into a Y. The entire mucosa can be advanced by making two adjacent V-shaped incisions (like a "W") and transforming them into a Y-shaped figure. The exact amount of augmentation may not be entirely predictable. To advance the lateral vermilion border, the W-plasty must be extended to the adhesions. Flaps are isolated and the incisions are closed according to the VY principle. Scarring is not significant and does not create any lumps that are felt by the patient.

Lip shortening surgeries

Moving the lips or moving the red border

The lip or vermilion border transfer was first described by Gilles and later refined by other surgeons. It is performed by removing an elliptical piece of skin adjacent to the vermilion border of either the upper or lower lip. In cases of a long upper lip with an indistinct Cupid's bow, this technique can be used to restore the central anchor points. It is often helpful to ask the patient to mark the shape and size they would like to achieve on the upper and lower lips with a marker. This can be done while seated in front of a mirror, allowing for a better understanding between the surgeon and patient of the surgical goals. Any existing tissue imbalances in the lip should be noted and discussed preoperatively. Once the areas have been marked, an additional 1 mm of tissue should be excised to compensate for the "rebound" of the lip. The ellipse is excised in the plane of the face, just beneath the skin, above the muscle. This will help to recreate the fullness of the white ridge adjacent to the vermilion border.

Do not go below the superficial plane of dissection, otherwise contraction and scarring may occur. The upper lip anchor points are brought together with vertical mattress sutures without undercutting the adjacent edges. Final wound closure is performed with a continuous subcuticular 5-0 Prolene suture, with additional reinforcement with absorbable sutures, if necessary.

Resection of the base of the nose

Base of nose resection is an excellent procedure for patients with a long upper lip, well-defined Cupid's bow, and base of nose areas. The ellipse of skin at the base of the nose should be gull-shaped and follow the contours of the base of the nose. Depending on the anatomical structure of the supporting ridge of the base of the nose, the incision may extend into this area. A line is drawn parallel to this ridge, creating an ellipse of skin to be excised. The skin is excised in the subcutaneous plane; the wound is sutured in two layers. Millard reported that the distance from the origin of the philtrum on the supporting ridge of the base of the nose to the vermilion border of the lips is up to 18 to 22 mm. If the lip exceeds this measurement or is longer than the relative proportions of the face, base of nose resection may be indicated for the patient.

Cheiloplasty

Cheiloplasty, or vermilion border reduction, can be accomplished by excising equal amounts of vermilion on each side of the wet line. The goal is to make an incision along the wet line or slightly posterior to it. Depending on the volume of the lip being reduced, the incision may extend beyond the mucosa. The incisions are then closed with absorbable sutures. Overcorrection is usually required to compensate for the postoperative lip retraction effect. Reduction cheiloplasty should address every component of the enlarged lip, including protrusion, vertical lip height, and the visible portion of the vermilion moist border. To reduce mucosal overcorrection, one side of the ellipse can be incised first, then the mucosa and hypertrophic glandular tissue can be undercut and the excess can be retracted posteriorly. The height of the lower lip should be maintained at the level of the lower incisors.

Additional improvements

The use of permanent cosmetic tattooing can help to emphasize the shape of the lips or perhaps even out post-operative asymmetry. This procedure can be performed on an outpatient basis under local anesthesia.

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Postoperative complications

Potential complications of any surgical procedure include infection and bleeding. Given the complex anatomy of the perioral region, it is important to identify asymmetries before surgery, as some may persist postoperatively. While some procedures are suitable for correcting minor asymmetries, other lip procedures will not correct these asymmetries and may even accentuate them. Significant postoperative asymmetries may be associated with local edema and should be treated with dilute steroid injections. Paresthesia of the lip may persist for up to 6 months.

Minor extrusion of the implanted material can be corrected by removing the exposed portion and treating the wound locally. Significant protrusion or infection of the implant usually requires its removal. The implant bed may then fill with scar tissue, which will result in a loss of lip elasticity. To minimize lip tightening, diluted triamcinolone is injected every one to two weeks. Patients are instructed to massage and stretch the lips 6-10 times daily. This is done for 10-12 weeks until the lips relax.

Lip surgeries are becoming increasingly popular. The cornerstone of a successful outcome, for both the patient and the surgeon, is a clear understanding of the goals and the initial situation. Once the surgeon has made the correct diagnosis, he only has to resort to a variety of means to achieve the desired result.

Postoperative period

After almost any lip surgery, patients report that their lips feel “tight” and unnatural when smiling for approximately 6-8 weeks. Although their lips may appear normal, patients feel discomfort during this period. Following surgery, patients are advised to relax their lips for 2 weeks. They are also advised to avoid smoking. Patients are usually given antiviral therapy if there is a history of herpes infection. Patients who have had augmentation surgery have to be careful if they have had eruption. Inflamed tissue is more friable and therefore more susceptible to implant eruption. Patients who have had surgeries more complex than collagen injections are usually given broad-spectrum antibiotics.