Various methods of reconstructing lower lip partial defects have been reported, for example those using the upper lip such as the Abbe and Estlander flap techniques. However, when a large defect of the lower lip with oral commissure is presented, the choice of reconstruction method is often difficult. For such cases, the Estlander flap technique is often used, although displacement of the oral commissure is one of the remaining problems. In the case of large defects of the lower lip with oral commissure, we opted for a reconstruction method in which the entire upper lip was incised and extended, a portion of which was reflected as a traditional Estlander flap. Four cases were treated using this method, and in all cases there were no complications such as venous return disturbance, and the site healed well. Sensation returned within 3 months, and contraction of the lips appeared within 6 months. The symmetry of oral commissures was maintained and the appearance was almost cosmetically satisfactory. Our technique is especially useful for reconstructing defects affecting 1/3-2/3 of the lower lip including the oral commissure. This technique is cosmetically and functionally successful and the symmetry of the oral commissure is maintained.