Total lower lip reconstruction was performed in an 18-month-old boy following a dog bite. In order to obtain an optimal functional result and to avoid any additional facial scarring, a prefabricated gracilis muscle free flap was used in a two-stage procedure. Firstly, the muscle was delayed on its main pedicle, a 'tendinous' strip was inserted along its free border and a silicone sheet was slid under its predicted intraoral side. At the time of reconstruction, the neomucosal lining obtained in this way reconstituted the labial vestibule. Furthermore, the muscle, reinnervated by the mandibular branch of the facial nerve, was also put under minimal tension and suspended between the two modioli using the 'tendon' graft. This allowed both lip occlusion and normal speech development to be restored without any impairment of mandibular growth during a 4-year follow-up.