Lip Reconstruction

The lip is a complex musculocutaneous structure that serves critical functions: oral competence (preventing drooling), articulation of speech, facial expression, and sensory perception. The upper lip extends from the base of the nose (nasal sill) to the vermilion border and is defined by the philtral columns, philtral dimple, Cupid's bow, and the paired peaked tubercles of the vermilion. The lower lip extends from the vermilion border to the labiomental crease. Key anatomic landmarks that must be precisely reconstructed include: the vermilion border (the white roll and vermilion-cutaneous junction), which is the single most conspicuous facial landmark and where even 1 mm of misalignment is immediately noticeable; the wet line (the junction between wet and dry vermilion on the mucosal surface); Cupid's bow (the double-curved border of the upper lip); the philtral columns (paired vertical ridges flanking the philtral dimple); and the oral commissures (the lateral junction points of the upper and lower lips). The muscular core of the lip is the orbicularis oris muscle, a circumferential sphincter that provides oral competence. The blood supply is the paired labial arteries (superior and inferior), which are branches of the facial artery and run within the substance of the orbicularis oris muscle, approximately 5-8 mm deep to the mucosal surface. Sensory innervation is provided by the mental nerve (lower lip, V3) and infraorbital nerve (upper lip, V2). Motor innervation to the orbicularis oris is from the buccal and marginal mandibular branches of the facial nerve (CN VII).

Lip reconstruction is guided primarily by the percentage of total lip width (not absolute size) that is lost. For defects involving less than one-third of the lip width, primary closure with a wedge or V-excision is usually achievable, provided the wound edges can be approximated without excessive tension on the commissures. For defects of one-third to two-thirds of the lip width, the Abbe cross-lip flap (from the opposite lip) is the standard approach. For defects exceeding two-thirds of the lip width, advancement-rotation techniques such as the Karapandzic neurovascular flap or the Bernard-Burow cheek advancement are required. The Estlander flap is specifically designed for defects involving the oral commissure. This algorithm applies to both upper and lower lip defects, although the aesthetic demands are generally greater for the upper lip due to the complexity of Cupid's bow and the philtral columns.

Primary closure is the simplest and often the best option for lip defects involving less than one-third of the total lip width. The defect is converted to a V-shaped or pentagonal (shield-shaped) wedge, and the lip is closed in layers. The layered closure proceeds from deep to superficial: first the oral mucosa (4-0 chromic or Vicryl), then the orbicularis oris muscle (4-0 Vicryl) to restore sphincter continuity, and finally the skin (5-0 or 6-0 nylon). The single most critical suture is the first cutaneous suture placed at the vermilion border. This must align the white roll with absolute precision. Even 1 mm of misalignment at this junction is immediately visible and uncorrectable without reopening the wound. Some surgeons place this key suture first (before the deep layers) to establish the landmark, then proceed with the layered closure from deep to superficial. A pentagonal modification of the wedge extends the excision lines slightly beyond the vermilion border on the cutaneous lip, distributing tension and preventing a notched vermilion. Mental nerve blocks (lower lip) or infraorbital nerve blocks (upper lip) are preferred over local infiltration to minimize tissue distortion near the vermilion border.

The Abbe flap is the workhorse technique for lip defects involving one-third to two-thirds of the lip width. It is a cross-lip (lip-switch) interpolation flap that transfers a full-thickness segment of one lip (including mucosa, orbicularis muscle, and skin) to reconstruct a defect on the opposite lip. The flap is designed with a width equal to 50% of the defect width, because the flap effectively halves the defect: it fills half the defect directly and closes the remaining half by advancing the native lip tissue on each side. The flap is based on the labial artery, which provides an axial blood supply through the muscular pedicle. The pedicle is positioned at one end of the flap (usually the end closest to the midline) and includes a cuff of orbicularis muscle through which the labial artery courses. At the first stage, the flap is elevated, rotated 180 degrees across the lip, and inset into the defect. The patient's mouth remains partially open during the bridging phase, with the pedicle maintaining the flap connection to the donor lip. At 2 to 3 weeks, the pedicle is divided, and the remaining flap edges are inset and refined. For upper lip defects, the Abbe flap is typically designed from the lower lip, centered on the midline to reconstruct the central tubercle and philtral dimple. The flap can incorporate a V-shaped skin island to recreate the Cupid's bow contour.

Defects exceeding two-thirds of the lip width require advancement or rotation of the remaining lip and perioral tissues. The Karapandzic technique is a neurovascular advancement-rotation flap that circumferentially incises around the remaining lip tissue, releasing the orbicularis oris, buccinator, and perioral muscles from their insertions while meticulously preserving the neurovascular bundles (mental nerve, labial artery, buccal branch of facial nerve). This approach maintains functional innervation and blood supply to the advanced tissue, resulting in a competent oral sphincter despite the large tissue mobilization. The tissue is advanced from both sides to close the defect centrally. The primary limitation is microstomia (reduction of the oral aperture), which is proportional to the defect size but is partially mitigated by the elastic properties of the oral commissures and can be addressed with commissuroplasty if severe. The Bernard-Burow technique is an alternative for very large defects (subtotal or near-total lip loss). It advances cheek tissue medially through full-thickness incisions extending laterally from the commissures, with Burow triangles excised from the nasolabial fold and labiomental crease to accommodate the advancement. Unlike the Karapandzic, the Bernard-Burow sacrifices the neurovascular pedicles to the advanced tissue, resulting in a denervated, insensate lip segment. It provides bulk but not dynamic sphincter function. For this reason, the Karapandzic is generally preferred when innervated tissue can be preserved.

The Estlander flap is specifically designed for defects involving the oral commissure. The junction point of the upper and lower lips. Like the Abbe flap, it is a cross-lip interpolation flap based on the labial artery. The Estlander differs from the Abbe in that the flap rotates around the commissure rather than being transferred across the midline of the lip. The flap is designed on the adjacent lip (upper lip for a lower lip commissure defect, or vice versa), with the pivot point at the commissure. The flap is rotated 180 degrees around the commissural pivot to fill the defect, simultaneously reconstructing both the lip and the commissure. Because the pedicle is at the commissure (a single pivot point), the Estlander does not require a second-stage pedicle division. It is a single-stage procedure. The primary disadvantage is that the reconstructed commissure is typically rounded rather than possessing the natural angular contour, and the oral aperture is reduced. Secondary commissuroplasty can be performed at 3-6 months to refine the commissure angle and enlarge the aperture if needed.

Partial-thickness lip defects that cross the vermilion border present a specific challenge: the reconstruction must simultaneously address the cutaneous lip, the vermilion, and the transition between them while maintaining a crisp vermilion border. The double V-Y island pedicle technique (as described by Huilgol et al., 2014) addresses this with two vertically oriented V-to-Y advancement flaps, one designed above the defect on the cutaneous lip and one below the defect on the vermilion or mucosal surface. Each flap is elevated on its deep subcutaneous or submucosal pedicle and advanced toward the defect center. The critical technical point is the order of closure: the cutaneous defect above the vermilion border is closed FIRST. This initial closure aligns the vermilion border by bringing the native white roll together, establishing the most important aesthetic landmark before the flaps are inset. Once the vermilion border is aligned, the V-Y flaps are advanced and inset. A key anchoring suture. A buried 5-0 absorbable suture placed from the undersurface of the flap into the orbicularis oris muscle at the base of the defect. Provides deep fixation and prevents flap retraction. This technique is excellent for partial-thickness defects measuring 10 to 20 mm that cross the vermilion border, where a wedge excision would sacrifice too much lip tissue and an Abbe flap is unnecessarily complex.

Lip shave (vermilionectomy) is indicated for extensive actinic cheilitis or diffuse carcinoma in situ of the vermilion. The procedure removes the entire vermilion from commissure to commissure by excising the dry vermilion and a variable depth of underlying orbicularis oris muscle. The vermilion is reconstructed by advancing the labial mucosa (wet vermilion) anteriorly and suturing it to the cutaneous lip at the vermilion border. This mucosal advancement technique (lip advancement or mucosal flap) replaces the keratinized dry vermilion with non-keratinized oral mucosa, which gradually keratinizes over several weeks. The resulting "neo-vermilion" has a slightly different color and texture than the native vermilion but is generally well-accepted cosmetically. For focal areas of actinic cheilitis that do not require full vermilionectomy, localized excision with mucosal advancement or V-Y mucosal advancement can address the problem with less tissue sacrifice.