The purpose of this study is to determine the efficacy of simultaneous innervation to prevent graft bone resorption in maxillofacial reconstruction. It may provide basis for future clinical trials and new strategies for improving the functional reconstruction of large jaw bone defects.

The use of autograft is still the main method for reconstructing large defects of jaw bones. However, the spontaneous resorption of the graft bone is still severe, and hinders the success of dental implant(s) and chewing function even after microsurgical vascularization. But till now, there is no effective prevention method for this major problem. Based on previous studies, the investigators pioneered a simultaneous innervated vascularized iliac bone graft method, through neurorrhaphy between the nerves innervating iliac bone and recipient site. A clinical retrospective study showed that this new method significantly decreases postoperative osteoporosis, and ensures the success of dental implants (Refer to our published article Wang L*, Wei J, Yang X, Yang Z, Sun M, Cheng X, Xu L, Lei D, Zhang C*. Preventing early-stage graft bone resorption by simultaneous innervation: innervated iliac bone flap for mandibular reconstruction. PlastIc Reconstructive Surgery, 2017, 139(5):1152e-1161e, Cover Featured Article).

The investigators intend to randomly divide the vascularized iliac bone graft cases into traditional group without innervation and simultaneous innervation group (through neurorrhaphy between the nerves innervating iliac bone flap and recipient site). The efficacy of simultaneously innervated maxillofacial reconstruction for preventing graft bone resorption will be assessed using bone mineral density test of grafted bone, as a blinded method. The innervation and sensation of the internal oblique abdominis muscle island will be tested using neuroelectrophysiological examination. The recipient nerve having the best effect on preventing bone resorption, will be determined using hierarchical comparison method.

Inclusion Criteria:

1. Patients between the age of 17 to 65 years (to avoid possible postmenopause osteoporosis), irrespective of gender.
2. Post resection segmental defect of mandible between 5-9 cm long.
3. Acceptable systemic conditions like nonmenopausal-related osteoporosis, Diabetes mellitus, in controlled normal range.
4. Patients agreeing to sign the informed consent form.

Exclusion Criteria:

1. Advanced malignant tumors.
2. Poor general condition, who can not tolerate vascularized bone flap reconstruction.
3. History of drugs affecting bone metabolism, like bisphosphonates, calcium agents or others.