We present the successful reconstruction of a large mandibular defect with a severe maxillofacial deformity after malignant tumor resection and irradiation. The patient was a 16-year-old boy with a defect in the left mandible, which extended from the mandibular body to the condylar process and hypoplasia of the maxillozygomatic complex on the left side as a result of ablation and radiotherapy of a grown rhabdomyosarcoma in the left infratemporal fossa at the age of 10. We planned a two-stage reconstruction because of his wide mandibular defect and hypoplasia. LeFort I type osteotomy to correct the maxillary declination was combined with mandibular lengthening to decrease the width of the defect in the first stage. New bone formation was confirmed at the distraction site 4 months after surgery, and the second stage was performed. A free latissimus dorsi myocutaneous flap with a vascularized scapula and rib was transferred to reconstruct the ramus of the mandible, zygomatic arch, and soft tissues. This procedure resulted in satisfactory results. In conclusion, the combination of distraction osteogenesis and microsurgical bone transplantation facilitated the straightforward reconstruction of a three-dimensional deformity with huge bony defects. We think that this combined surgical procedure will become a favorable option in the treatment of severe maxillomandibular deformities with bone defects.