The lips are a vital organ for speech and eating, and have great esthetic importance. The lips are anchored in the upper and lower jaws, and continue into the cheeks. The lip muscle is found between the external skin layer and the internal mucous membrane, and this construction grants it a great deal of elasticity.
Reconstruction of the lips is required as a result of trauma or after the removal of tumors, primarily those that are malignant.
Partial reconstruction of the lips can involve different parts of the lip, such as skin, muscle, or mucous membrane, or, of course, a combination. Reconstruction of the partial defect of the lower or upper lip can be performed in many cases by making use of parts of the remaining lip. In this manner, one can deliberately rotate sections of the lip, which function as flaps of the different lip components, as is necessitated by the defect.
Reconstruction of the defect is performed by relying on the elasticity of the local tissue, and placing incisions in accordance with the esthetic sub-units that comprise the lip. It is possible to make use of flaps from the same lip on which the defect is to be reconstructed, or from a flap taken from the opposite lip. The advantage of these flaps lies in the fact that they reconstitute the muscle activity of the lip, and are therefore classified as dynamic reconstruction. In cases where the defect is larger than can be reconstructed from lip sections, it is possible to add flaps from the area of the cheeks or the chin. These flaps can include the muscle within them, but generally do not bring the lip back to full active use. These flaps are classified as a static reconstruction, and the remaining lip muscles generally attempt to compensate for the loss of activity in the flaps that were transferred.
In cases where the defect of the lip is too large to be easily reconstructed with the local tissues, it is possible to transfer free flaps with the blood vessels supplying them, and to attach them to local blood vessels using microsurgical techniques. These flaps do not include muscle, and enable reconstruction of the superficial skin or the internal mucous membrane, or both layers of the lip at the same time. The lip can be involved in a tumor of the oral cavity, in which case the reconstruction of a large oral cavity defect will require a complex reconstruction, which is optimally performed with a free flap. The flaps that are generally used for this purpose are free flaps from the forearm, the thigh, or a combination of a skin flap and the fibula bone, molded to fit the complex defect.