This article illustrates a new technique for repositioning the lip in the treatment of gummy smile. In particular, it introduces a formula to precisely calculate how much tissue should be eliminated to avoid the recurrence of gummy smile. The modified lip-repositioning technique (MLRT) also involves the microsurgical division of the tissue components (mucosa, periosteum, and bone) as well as the fixation of the surgically modified tissue to the periosteum component. The results of the technique are shown through case presentations of seven patients with follow-up of up to 3 years. Stable results were achieved with no recurrence of gummy smile.