A Systematic Review of Lower Lip Anatomy, Mechanics of Local Flaps, and Special Considerations for Lower Lip Reconstruction

Reconstruction of defects of the lower lip can be very challenging. The aim of this review is to analyze the unique characteristics of lower lip anatomy and provide a systematic approach for lower lip reconstruction. A review of current literature was performed using the PubMed database. Articles analyzing the anatomic and histologic characteristics of the lower lip, mechanics of local flaps, and different lower lip reconstruction techniques were included. Articles focused on lower lip reconstruction with free flaps were excluded. The orbicularis oris has been described as the main supportive mechanism, however, a number of other structures have been shown to provide mechanical support to the lower lip, including septations of connective tissue extending from the epithelium to the orbicularis oris, a fibroelastic meshwork located in the mentolabial sulcus, and subdermal muscular fibers with dermal terminations in the area of the modiolus. Depending on the location, size, and depth of the wound, a number of reconstruction options are available. Preservation of the competency of orbicularis oris, relationship of the modiolus with associated muscles, and sensation, are critical components of functional reconstruction. Primary closure and local flaps are assessed for these 3 components and analysis is provided. In conclusion, knowledge of the static and dynamic structural support of the lower lip, as well as the characteristics of different reconstructive options, is imperative for optimal functional and aesthetic outcomes.