The lips are not only a major aesthetic component of the face, but are also important for facial expression, speech and eating. Goals in lip reconstruction are to restore normal anatomy, oral competence and contour. These goals are easily attained following repair of small lip defects. However, restoring these characteristics of the lips in large defects remains a more arduous task. Although many different methods of lip reconstruction have been described in the literature, a few of the important and more commonly utilized methods are outlined in this chapter.
The surgical upper lip includes the entire area from one nasolabial fold to the other, and all structures down to the oral orifice. It extends intraorally to the upper gingivolabial sulcus. It is divided into the vermilion, one central and two lateral aesthetic subunits. The lower lip includes all structures superior to the labiomental fold including the vermilion and continuing intraorally to the inferior gingivolabial sulcus. Extending from the nasal base are bilateral philtral columns flanking the centrally located philtrum. The philtral columns extend downward to meet the vermilion-cutaneous junction (also known as the ‘white roll’) of the upper lip. Cupid’s bow is the portion of the vermilion-cutaneous junction located at the base of the philtrum. The tubercle is the fleshy middle part of the upper lip from which the vermilion extends bilaterally to meet the commissures. The vermilion of the lower lip is bisected by the central sulcus which is prominent in some individuals. The lower lip is considered less anatomically complex than the upper lip because it lacks a definitive central structure.
The vermilion is made of a modified mucosa with submucous tissue and orbicularis oris muscle underneath. The large number of sensory fibers per unit of vermilion is reflected in its comprising a disproportionately large part of the cerebral cortex. It has a high degree of sensitivity to temperature, light touch and pain. The natural lines of the vermilion are vertical, thus scars on the vermilion should be placed vertically if possible. The primary muscle responsible for oral competence is the orbicularis oris muscle. This muscle functions as a sphincter, puckering and compressing the lips. The fibers of the orbicularis oris muscle extend to both commissures and converge with other facial muscles just lateral to the commissures at the modiolus. The major elevators of the upper lip are the levator labii superioris, levator anguli oris and the zygomaticus major.
The mentalis muscle elevates and protrudes the middle portion of the lower lip. The major depressors of the lips are the depressor labii inferioris and depressor anguli oris. The risorius muscle pulls the commissures laterally. The blood supply to the lips comes from the superior and inferior labial arteries, which in turn are branches of the facial arteries. The paired superior and inferior labial arteries form a rich network of collateral blood vessels, thus providing a dual blood supply to each lip. These vessels lie between the orbicularis oris and the buccal mucosa near the transition from vermilion to buccal mucosa. There are no specific veins; instead there are several draining tributaries that eventually coalesce into the facial veins. The lymphatic channels of the upper lip and lateral lower lip drain into the submandibular nodes; whereas, the central lower lip lymphatics drain into the submental nodes. Motor innervation of the perioral muscles is from facial nerve branches. The buccal branches of this nerve supply motor input into the lip elevators; whereas, the marginal mandibular branches supply the lip depressors. The motor nerve enters each individual muscle on its posterior surface. Sensory supply to the upper lip comes from the infraorbital nerve (second trigeminal branch) and the lower lip is supplied by the mental nerve (third trigeminal branch).
Lip lesions are typically due to trauma, infection, or tumors. Defects less than one-fourth to one-third of the total lip length can be closed primarily. This involves the apposition of the lateral margins of the wound on both sides and direct layered closure. The muscle is approximated with interrupted deep absorbable sutures. The white roll is closely approximated and then the labial mucosa and vermilion are closed. Finally, the skin is closed with fine nonabsorbable sutures. Ideally, primary closure should cause minimal aesthetic and functional deformity; however, it can sometimes result in reduction of the oral aperture as well as asymmetry of the involved lip. Furthermore, primary closure in the upper lip can be problematic because opposing the edges of a large wound may create unfavorable distortion of the philtrum.
The vermilion spans the entire length of the oral aperture, becoming increasingly narrow and tapering laterally as it approaches the commissure on both sides. It forms the transition zone between skin and mucosa of the inner mouth. Defects involving the vermilion can range from superficial, such as leukoplakia in which there is limited compromise of the integument, to significant, in which tissue deficit extends to deeper muscle and mucosal tissue. Although small defects of the vermilion can be primarily closed or left alone to heal by secondary intention, larger defects require reconstruction. Precise alignment of the vermilion-cutaneous margin on both sides ensures a curvilinear appearance of the border and avoids step-offs or lip notches after healing.
The traditional labial mucosal advancement flap can replace vermilion resections that span the entire length of the lower lip. The mucosa on the buccal surface of the lower lip is undermined and advanced to the previous mucocutaneous junction. Maximal use of blunt undermining helps to preserve sensory innervation of this vermilion-to-be. Additional advancement can be achieved using a transverse incision in the gingivobuccal sulcus and in the process creating a bipedicled mucosa flap based laterally. Extensive flap mobilization usually results in an insensate flap. A notched appearance of the vermilion can result from scar contractures or vermilion volume deficiency (due to previous surgery or trauma). Scar contractures can be released with a Z-plasty. This procedure recruits vermilion tissue on either side of the scar to functionally lengthen the scar in the antero-posterior and supero-inferior direction. A notched appearance due to volume deficiency can be corrected with a local musculomucosal V-Y advancement flap.
The next option of donor tissue is a flap from the ventral surface of the tongue but it is less than ideal because of color mismatch. Pribaz described the facial artery musculomucosal (FAMM) flap, which is a based on the facial artery and is used to reconstruct defects involving vermilion, lip, palate and a host of other oral structures. Labia minora grafts can also be used to reconstruct the vermilion.
Commissure deformities often result from electrical burns, trauma, or reconstructive lip surgery. For post-burn commissure contractures, splinting techniques have reduced the need for surgical correction. Nevertheless, repairing deformities that do not respond to conservative measures remains complex. The intricate network of adjoining perioral muscle fibers at the modiolus (which is crucial for oral competence and facial animation) is nearly impossible to reconstruct. Furthermore, the contralateral commissure is the gold standard of comparison when evaluating the results of a unilateral reconstruction, thus leaving little room for discrepancy. Various approaches attempt to repair mucosal defects involving the commissure including the simple rhomboid flap, in which intraoral mucosa is advanced to reconstruct the commissure angles after an incision is made to widen the commissure laterally. The tongue flap also may be used when the mucosal defect is thick in the region of the commissure. Despite many proposed techniques, commissure reconstruction remains a difficult task and attempts at reconstruction often yield poor results.
Upper Lip Reconstruction
Upper lip cancers are usually basal cell carcinomas that spare the vermilion. The central aesthetic subunit of the upper lip, the philtrum, makes upper lip reconstruction more challenging than lower lip reconstruction. Upper lip defects can be divided into partial-thickness and full-thickness defects.
Partial-thickness philtral defects can be allowed to heal by secondary intention or skin grafting. The triangular fossa skin-cartilage composite graft is well-described for reconstructing the philtrum in burn patients. Partial thickness defects of the lateral subunits can be repaired by a variety of means. For larger lateral subunit defects, an inferiorly-based nasolabial flap may be employed (sometimes to replace the entire lateral subunit). Upper lip defects that are next to the nasal ala may also be reconstructed with the nasolabial flap. This reconstructive method may not be ideal in men, however, because the nasolabial flap is not hair-bearing. Primary closure may be achieved for men by advancing adjacent lip and cheek tissue.
Full Thickness Defects
For full-thickness defects, the choice of reconstructive option depends on the size of the defect. Defects of one-quarter to one-third of the upper lip can be closed primarily. Larger defects of the upper lip require flaps from the lower lip or recruitment of adjacent cheek tissue. If these larger defects involve the central portion of the upper lip, perialar crescentic excisions may provide additional mobility if needed. Defects measuring one-third to two-thirds of the upper lip may be closed with the Abbe flap, the Karapandzic flap, or the Estlander flap. The Abbe and Karapandzic flaps are used for central defects whereas, the Estlander flap is used for lateral defects that involve the commissure. The Abbe flap may also be used for lateral defects that do not involve the commissure. Defects greater than two-thirds of the upper lip can be closed with the Bernard-Burow’s technique if sufficient cheek tissue is available. However, if sufficient cheek tissue is not available, most surgeons choose a free flap for reconstruction. The aforementioned reconstructive methods are described later in this chapter. Often, these methods can also be applied to closure of lower lip defects as well. Accordingly, for simplicity and ease of explanation, reference is often made to lower lip reconstruction.
Lower Lip Reconstruction
In contrast to the upper lip, lower lip reconstruction tends to be simpler. This advantage is due to the greater laxity of the soft tissues and lack of a separate central aesthetic unit. Since oral competence is mainly mediated by the lower lip, function and sensation tends to be more important than aesthetics.
Partial-thickness defects of the lower lip are treated differently based on whether the defect involves skin and subcutaneous tissue or vermilion. Skin and subcutaneous defects of the lower lip subunit can be left to heal by secondary intention or skin grafted. More commonly, however, a local advancement flap, rotation flap or transposition flap is employed for reconstruction. Careful planning and execution should allow the final scars to lie parallel to the natural skin tension lines. As previously mentioned, the white roll should be realigned as closely as possible.
Many of the reconstructive methods used for upper lip reconstruction can also be used for lower lip reconstruction. As in the upper lip, reconstructive options for full-thickness defects depend on the size of the defect. Defects up to one-third of the lower lip can be closed primarily as described earlier. Larger defects measuring one-third to two-thirds of the lower lip width may be closed with the Karapandzic, Abbe or Estlander flaps (see below).
If the commissure is involved, both the Karapandzic and Estlander flaps may be used; however, the Karapandzic is probably the better choice because it is better at maintaining oral competence. If the commissure is not involved, the Karapandzic or the Abbe flaps may be used. The Abbe flap is insensate; however it does provide a better cosmetic result. In the case of larger lower lip defects (more than two-thirds of the lip), if there is sufficient adjacent cheek tissue, the surgeon may employ the Karapandzic or the Bernard-Burow’s techniques. The Karapandzic flap may be used for defects up to three-fourths of the lower lip width whereas, the Bernard-Burow’s can be used to reconstruct the entire lower lip. If enough cheek tissue is not available, distant or free flaps may be used for reconstruction.
Application: Upper and lower lip reconstruction
Defect size: One-third to two-thirds of the lip width
Donor site: Opposite lip
Blood supply: Medial or lateral labial artery
Comments: Ideal for reconstruction of the philtrum; often used with other methods for reconstruction of large defects; insensate.
This flap is often the first option in reconstruction of medium-sized upper and lower lip defects that do not involve the commissures. A full-thickness mucomusculocutaneous flap based on the medial or lateral labial artery is transposed from the opposite lip into the defect. It may be used alone or in conjunction with other reconstructive measures such as perialar crescentic excisions. Typically done in two stages, the Abbe flap is set in place in the first stage and divided 14-21 days later in a second-stage procedure. One-fourth to one-third of the lower lip can be taken without significant loss of function. Studies have demonstrated evidence of muscle function in the transferred flap at its recipient site. Although this technique can be utilized for either lip, it is best for upper lip reconstruction because the lower lip has greater laxity and can contribute more tissue without disturbing a major central structure. Furthermore, the Abbe flap can be used to replace the entire philtral subunit. The Abbe flap does not recruit new lip tissue; it simply transplants tissue from the lower (or upper) lip to its counterpart. Thus, the size of the oral aperture remains the same as if the lip defect is closed primarily. The goal is to recruit enough unaffected lip tissue to balance the discrepancy in lip lengths after a medium-sized excision.
A wedge-shaped pedicle flap is harvested from the opposite lip. At minimum the width of the flap should be one-half the size of the defect. The height of the flap should match the height of the defect, and the flap should be designed with sufficient tissue to permit a 180˚ arc of rotation into the defect. Because contralateral labial arteries form robust anastomotic connections in the midline, the flap can be based medially or laterally. Starting at the apex, an incision is made through skin, muscle and mucosa and is extended toward the vermilion border. As the vermilion border is approached, careful scissor dissection will avoid injury to the labial artery which can be found between the deep layers of orbicularis oris muscle and the mucosa approximately at the level of the vermilion border. Initial division of the nonpedicle side of the flap can locate the position of the labial artery and aid in its identification on the pedicle side. The pedicle should be at least 1 cm in width in order to maintain adequate venous drainage. The flap is rotated upon its pedicle, and a stay suture is placed after exact approximation of the vermilion border. The flap is secured with a three-layer closure approximating mucosa, muscle and skin, and the donor site is closed primarily or with the aid of crescentic excisions (labiomental or perialar depending on the donor site). The pedicle is usually divided 14-21 days later. The most common complication is flap loss due to inadequate blood supply. Careful dissecting technique, an adequate soft tissue envelope around the artery, and ample flap width minimize flap ischemia. Careful attention should be paid to the accurate approximation of the vermilion border of both donor and recipient sites before and after pedicle division. Since the lower lip vermilion can be significantly thicker than that of the upper lip, resection of the vermilion can be undertaken in a secondary procedure for improved aesthetic result.
Application: Upper and lower lip reconstruction
Defect size: One-third to two-thirds of lip width
Donor site: Cheek and lip advancement
Blood supply: Preserved labial arteries
Comments: A sensate and functional flap with poor aesthetic results; oral competence preserved at the expense of microstomia; ideal for reconstruction of large defects in the midline.
This is a sensate axial musculomucocutaneous flap based upon the superior and inferior labial arteries. It provides good oral competence and is useful for closing one-half to two-third defects of the upper lip and defects up to three-quarters of the lower lip. It is ideal in situations where no new lip tissue is required in central defects or lateral defects that involve the commissure. The blood supply is more robust than the Abbe flap, but the aesthetic outcome is inferior. Because new lip tissue is not recruited, microstomia may result after closure of larger defects. A semicircular incision of adequate length to close the defect is extended from the defect toward the commissures. The skin incisions are made with a scalpel, and careful mobilization of subcutaneous tissues is achieved using electrocautery. By
spreading the orbicularis oris muscle longitudinally along the line of the incision, or on a plane parallel to the fibers, separation from the adjacent musculature is attained while maintaining the nerves and vessels intact. Laterally, at the level of the commissures, the skin is incised only down to subcutaneous tissue. Careful dissection is needed to identify and preserve the labial arteries and buccal nerve branches. The flaps are rotated medially to close the defect, and a stay suture is placed after meticulous reapproximation of the vermilion border. The defect is closed in three-layers approximating mucosa, muscle and skin. Complications of this technique include microstomia and visible scarring. Secondary revision of the commissure is often indicated to prevent oral crippling in feeding, hygiene maintenance and denture placement. The circumoral scarring after this procedure is more noticeable because the scars do not lie in natural skin creases.
The Estlander Flap
Application: Upper and lower lip reconstruction
Defect size: One-third to two-thirds of lip width
Donor site: Opposite lip
Blood supply: Medial labial artery
Comments: Insensate but oral competence is preserved; one-step procedure that results in a rounded neo-commissure; frequently requires revision.
The Estlander flap is similar to the Abbe lip switch flap, but it is modified for use around the corner of the mouth. It is a one-step procedure but sometimes requires future revision to improve the commissure. Continuity of the orbicularis oris ensures adequate oral competence; however, the modiolus functional region is distorted leading to altered oral animation. This alteration is compounded by a rounded neo-commissure which lacks definition. The flap is designed to be about half the width of the defect to cover. It is based on the opposite lateral lip. The vascular pedicle is within the pivoting point, supplied by the contralateral labial artery. It is rotated into the defect, and the donor site is closed primarily.
Bernard Burow’s Technique
Application: Lower lip (mainly) and upper lip reconstruction
Defect size: Two-thirds to full lip width
Donor site: Cheek
Blood supply: Labial and facial artery branches
Comments: Insensate but oral competence is preserved; one-step procedure that results in a rounded neo-commissure; frequently needs revision.
Although most commonly used in lower lip reconstruction, this technique can be useful in large defects of the upper lip as well. This is an advancement flap utilizing the remaining lip tissue and the cheeks for closure of the defect. For closure of very large defects this technique can be combined with an Abbe flap (from the opposite lip). Closure technique is different for upper lip and lower lip defects. For the upper lip, a perialar excision of skin and subcutaneous tissue is performed in the shape of a triangle (or crescent). Burow’s triangles are also excised lateral to the lower lip. Adequate mobilization of the flaps is achieved by making bilateral incisions in the gingivobuccal sulci being careful to leave sufficient gingival mucosa for subsequent closure of the mucosal layer. The tissue is advanced medially to close the defect and is sutured in three layers. The skin and subcutaneous tissue perialar incisions are closed in a single layer. Perialar crescentic excisions are more aesthetically pleasing but may not provide enough mobility. The vermilion is reconstructed using cheek buccal mucosa. The resulting insensate, nonfunctional upper lip does not usually lead to oral incompetence. This is because gravity charges the lower lip with the responsibility of oral competence. The most common complication of this procedure is microstomia, which can sometimes be improved by combining this technique with an Abbe flap. This technique can also cause some excessive tension on the upper lip and cheek resulting in distortion of the nasolabial fold.
In the Bernard-Burow’s technique for the lower lip, four Burow’s triangles are excised lateral to the nasolabial folds and in the labiomental groove to allow relief space for advancement of bilateral lower cheek flaps medially to fill the defect. Excision of these triangles avoids a typical tight lower lip and excess upper lip, and can vary in size as long as closure is achieved without tension. A minor modification in the originally proposed procedure preserves innervation and function by avoiding deep dissection through perioral muscles. Although a bulkier upper lip and poor anterior projection at the vermilion is common, this procedure remains a suitable option for reconstructing very large defects.
The emergence of microvascular free tissue transfers in the mid-1980s has considerably influenced methods used to repair massive facial defects involving the lips. Free flaps are often used in conjunction with an advancement flap from the remaining lip or adjacent cheek in order to meet the ideal reconstructive goals. Several methods of reconstruction using a wide variety of potential donor sites in the head and neck have been described. The radial forearm-palmaris longus tendon free flap has proven to be one of the preferred techniques for repairing substantial lip defects. A sensory component can be added by incorporating the lateral antebrachial cutaneous nerve. Recently, Lengele described a prefabricated gracilis muscle free flap for the lower lip that simultaneously reconstructs the labial muscular sling with mucosa, tendinous suspension and a skin cover. As with other reconstructive options, the selected method of free tissue transfer must address the soft tissue needs of each specific defect and the expressed goals of the individual patient.
Pearls and Pitfalls
Every lip reconstruction must be evaluated on a case by case basis. The lips of older patients tend to be more conducive to primary closure due to greater laxity. Reconstruction of facial defects in male patients may require the use of hair-bearing tissue. For women, when reconstructing the vermilion it is preferable to use tissue that will accept lipstick adequately, since application of lipstick can be helpful in camouflaging vermilion scars. Having considered the unique needs of each patient, the surgeon’s options can be divided into three main categories: those that employ remaining lip tissue including primary closure; methods using local flaps (such as from the cheek); and others techniques involving distant flaps. When performing lip reconstruction, the surgeon should adhere to a few key principles. Place incisions in relaxed skin tension lines whenever possible. In cases involving the vermilion border, mark the transition point before application of local anesthesia. Always align the markings of the white roll as the first step in closure. Finally, use deep absorbable sutures to oppose orbicularis oris fibers so that the closure scar does not widen or indent.