Lip reconstruction may be required after trauma or surgical excision. The lips are considered the beginning of the oral cavity and they are the most common site of oral cavity cancer. Any reconstruction of the lips must include both functional and cosmetic considerations. The lips are necessary for speech, facial expression and eating. Because of their prominent location on the face even small abnormalities can be apparent.

Superficial

The upper and lower lips include the vermilion border. This is the juncture between the lighter skin and the redder tissue (vermilion) that we commonly call the lip. This tissue is red because the skin is thin and there are many small blood vessels (capillaries) underneath it. The vermillion is different than oral mucosa because it maintains an outer layer of cells (stratum corneum) and it does not contain any salivary glands.

The pattern of the vermilion border defines the areas of the lip:

• Philtrum
  Philtrum
  The philtrum , is a medial cleft common to many mammals, extending from the nose to the upper lip, and, together with a glandular rhinarium and slit-like nostrils, is believed to constitute the primitive condition for mammals in general...
  
  -two vertical lines extending from the base of the nose to the central vermilion border, forming the bow of the central upper lip;
• Commissures-where the upper and lower lips meet laterally;
• Lateral upper lip-between philtrum and commissure.

Deep

The primary underlying muscle of the lips is the orbicularis oris. This circumferential muscle underlies the upper and lower lip. The muscle contracts the lips to allow for expression, speech, chewing and swallowing. It also maintains tone to prevent things from falling out of the mouth, this is called oral competence. Disruption of the circular nature of this muscle can have a significant effect on oral function.

In addition, there are other muscles both above and below the lips that attach either to the orbicularis oris or the fiberous bands that extend from the commissures.

Nerve supply

The muscles are supplied by two cranial nerves, the facial nerve

Facial nerve

The facial nerve is the seventh of twelve paired cranial nerves. It emerges from the brainstem between the pons and the medulla, and controls the muscles of facial expression, and functions in the conveyance of taste sensations from the anterior two-thirds of the tongue and oral cavity...

 and the trigeminal nerve

Trigeminal nerve

The trigeminal nerve contains both sensory and motor fibres. It is responsible for sensation in the face and certain motor functions such as biting, chewing, and swallowing. Sensory information from the face and body is processed by parallel pathways in the central nervous system...

.

Blood supply

The muscles and overlying skin are supplied by branches of the external carotid artery

External carotid artery

In human anatomy, the external carotid artery is a major artery of the head and neck. It arises from the common carotid artery when it bifurcates into the external and internal carotid artery.-Course:...

: the facial artery

Facial artery

The facial artery is a branch of the external carotid artery that supplies structures of the superficial face.-Structure:...

 and labial artery.

Principles of Reconstruction

• Preserve sensation of the lips
• Maintain oral competence
• Continuity of vermilion border
• Sufficient oral access (not too small, microstoma)
• Adequate lip appearance

Types of defects

Lip defects are classified by their depth and their size. Superficial defects involve the skin and vermilion, and leave the underlying muscles, nerves and arteries undisturbed. Deep/full thickness defects include the underlying muscles, primarily the orbicularis oris. The nerve and blood supply may also be affected if the defect is large. Regardless of the depth or size, a successful lip reconstruction considers the five principles and the effect that the reconstruction has on the surrounding tissue.

Superficial upper lip reconstruction

Successful reconstruction of the upper lip attempts to maintain the anatomic relationship of the philtrum (central portion of upper lip) and the base of the nose. Not distorting the commissure is also desirable for upper lip reconstruction.

Central lip

• Straight line closure-may cause a pulling up of the vermilion border as it heals
• Advancement flaps-these pull in skin from the sides and heal best when the defect is the full height of the upper lip, can come in from one or both sides (single or double advancement)

Lateral lip

• Straight line closure
• A-T closure-extends the defect up to the philtrum or down to the vermilion border to make the scar less noticeable.
• Single Advancement-incision along vermilion border to pull tissue in from the lateral aspect
• Rotation flaps-rotate in tissue from the cheek

Superficial lower lip reconstruction

The anatomic requirements are not as limiting for the lower lip because the surrounding anatomy is less complex. The considerations include maintaining a non-distorted vermillion border, hiding incisions in the horizontal crease of the chin, and not distorting the commissure.

Deep/full thickness lip reconstruction

Deeper and larger defects of the lip introduce greater reconstruction challenges, as they compromise the integrity of the orbicularis oris, its nerve and blood supply. Accordingly, there is a shift in emphasis toward the functional outcome of the reconstruction, and less focus on the appearance of the lip. All of the flaps described below can be used on the upper or lower lip.

Primary closure

Small defects of the upper and lower lip can be closed primarily. For the upper lip, defects of up to 1/4 (25%) of the lip may be closed primarily. For the lower lip, defects of up to 1/3 of the lip may be closed primarily. This means the edges of the defect are simply sutured together in three layers: oral mucosa, muscle, and skin. This closure has the best outcome because it re-establishes continuity of the orbicularis oris, which allows for oral competence, maximal preservation of sensation of the lip, continuity of vermilion border, and adequate size of the opening.

Abbe lip switch

If the defect is between 1/3 and 2/3 the length of the lip it can be closed by an Abbe flap. The flap was developed by the American plastic surgeon Robert Abbe

Robert Abbe

Robert Abbe was an American surgeon and pioneer radiologist in New York City. He was born in New York City and educated at the College of the City of New York and Columbia University ....

. It is based on a main artery of the orbicularis oris, the labial artery. A portion of the uninvolved lip (either upper or lower) is rotated across the mouth and into the defect of the involved lip while maintaining the blood supply from the labial artery. After 10–14 days, the blood supply of the flap has been established to the point where the artery can be divided. The Abbe flap has an excellent cosmetic result when it is used to replace the entire philtrum of the upper lip. The technique can also be used when the defect involves the commissure. This is called an Abbe-Estlander flap. This repair takes two surgeries and requires good planning to assure continuity of the vermilion border.

Gillies fan flap

This flap borrows tissue from the cheek and lip of the uninvolved side of lip with the defect. It restores lip continuity in a one stage procedure, but has some disadvantages, including an adverse effect on sensation, small size of mouth, and difficulty matching up the vermilion border of the central lip with the lateral lip.

Karapandzic flap

This flap borrows tissue from the sides of the defect, like the Gilles flap. The difference is that it maintains the nerve and blood supply of the orbicularis oris. The flap comes from both directions to meet in the middle of the defect. This is a one stage procedure that preserves sensation and oral competence. The main problem with this reconstruction is that it can create a very small mouth opening.

Total lip reconstruction

Whole lip reconstructed is a challenge. Tissue can be rotated in from the nasolabial or the cheek region bilaterally, but the results are limited by lack of sensation, small size, poor oral competency, and less than optimal appearance.

Complications of reconstruction

• Poor cosmetic result
• Lack of oral competence
• Small size of mouth
• Decreased sensation of lips or mouth
• Recurrent disease

Links

• Emedicine Lip Reconstruction article