INTRODUCTION: The upper lip plays a significant role in facial animation and aesthetics. For that reason, reconstruction of defects involving the upper lip can be challenging. The purpose of this review is to analyze the mechanics of local flaps and provide a methodical approach for reconstruction of upper lip defects.
METHODS: A systematic review of the literature was performed using the PubMed database from 1978 -2017. Articles focused on the anatomy, histology and function of the upper lip, as well as reconstruction of defects with local flaps were included. Non-human studies and articles analyzing free flap reconstruction were excluded.
RESULTS: The primary role of upper lip is coverage of dentition and facial animation, while lower lip is critical for oral competence, speech and eating. In addition to the orbicularis oris, several muscles contribute to upper lip function. Elevation is executed by the coordinated action of the levator nasii septi, levator labii superioris alaeque nasi, levator labii superioris, zygomaticus major and minor, levator anguli oris and risorius. Eversion is performed solely by levator labii superioris. Anatomic studies have shown that animation muscles have various insertion points, including the upper lip dermis, orbicularis and modiolus. These findings are critical and should be taken into consideration when reconstructing upper lip wounds. From an aesthetic standpoint, attention should be especially focused on the philtrum, Cupid’s bow and vermilion border. Different reconstruction methods are available including primary closure, skin grafts and local flaps specific to the upper lip, such as the Abbe, Estlander, Karapandzic and Bernard-Burow flaps. An algorithmic approach of upper lip reconstruction is provided based on the size and location of the defect. Primary closure may be used to repair defects less than 1/3 of the upper lip. Defects larger than 1/3 usually require the use of a local flap. The Abbe flap is suitable for reconstruction of upper lip defects up to 2/3 involving the philtrum. The Estlander may be used for defects up to 2/3 involving the commissure. Central defects up to 2/3 can be reconstructed with a Karapandzic flap. Defects larger than 2/3 usually require utilization of the Bernard-Burrow flap or a different modified cheek flap or free tissue transfer.
CONCLUSION: Knowledge of the mechanics and special characteristics of available reconstructive options is crucial for optimal aesthetic and functional outcomes. A summary of all reconstruction methods is provided based on the ability to restore philtrum anatomy, upper lip animation and skin sensation.