Facial deformity, facial paralysis, and sensory loss are inevitable after some head and neck tumor resection and reconstruction, especially in high stage cancer. To overcome these obstacles, we present a case of T4a gum cancer patient (41‐year‐old) who received holistic reconstruction of the mandible defect via an osteo‐peroneal‐artery‐perforator combined flap for defect coverage and cross‐mental nerve graft for lower lip and chin sensation at the primary stage, followed by ipsilateral facial nerve (lower trunk) innervated gracilis functioning free muscle transplantation for facial reanimation and correction of the sunken face 3 years later. After 4.5 years of follow‐up, the patient was satisfied with his appearance, and obtained a spontaneous and symmetrical smile without sensory deficit. This experience showed a possible solution to the reconstruction for complicated head and neck cancer patients.