[Evaluation of the effect of simultaneous neuralized iliac bone flap on the preservation of lower lip and chin sensation during mandibular reconstruction].

PURPOSE: To evaluate the effect of reconstructing inferior alveolar nerve and preserving the sensation of lower lip and chin in repairing mandibular defect by simultaneous neuralized iliac bone flap. METHODS: Patients with continuous mandibular defects requiring reconstruction were randomly assigned to the innervated(IN) group and the control(CO) group by random number table. In the IN group, the deep circumflex iliac artery and recipient vessels were anastomosed microscopically during mandible reconstruction, and the ilioinguinal nerve(IN), mental nerve(MN) and inferior alveolar nerve(IAN) were anastomosed at the same time. In the CO group, only vascular anastomosis was performed without nerve reconstruction. During the operation, the nerve electrical activity after nerve anastomosis was detected by nerve monitor, and the sensory recovery of lower lip was recorded by two-point discrimination(TPD), current perception threshold (CPT) and Touch test sensory evaluator(TTSE) test. SPSS 26.0 software package was used for data analysis. RESULTS: According to the inclusion and exclusion criteria, a total of 20 patients were included, with 10 patients in each group. All the flaps survived in both groups, and no serious complications such as flap crisis occurred, and no obvious complications occurred in the donor site. The results of TPD test, CPT test and TTSE test all indicated that the degree of postoperative hypoesthesia in the IN group was less(P＜0.05). CONCLUSIONS: Simultaneous nerve anastomosis vascularized iliac bone flap can effectively preserve the feeling of lower lip and improve the postoperative quality of life of patients. It is a safe and effective technique.

[Simultaneous innervation revitalizes bone marrow mesenchymal stem cells from postoperative iliac grafts].

PURPOSE：To compare the osteogenic potential of bone marrow mesenchymal stem cells (BMMSCs) from innervated iliac graft bone flap and traditional one for reconstructing mandibular defects. METHODS：Graft bone marrow samples were harvested 1 year after free vascularized iliac reconstruction of mandibular defects, with or without innervation through simultaneous nerve anastomosis. BMMSCs were isolated and cultured in vitro. Colony forming units-fibrosis observation, Brdu incorporation assay, population doubling, Alizarin red staining for in vitro calcified nodule formation and in vivo assay of subcutaneous osteogenesis in nude mice were used to detect BMMSCs proliferation, self-renewal and osteogenic differentiation capabilities, respectively. SPSS 24.0 software package was used for statistical analysis. RESULTS：Colony formation, proliferation, population doubling and osteogenic differentiation abilities of BMMSCs from innervated group were significantly higher than those from non-innervated group（P<0.05）. CONCLUSIONS：Simultaneous innervation of free vascularized iliac during reconstruction of mandibular defects may maintain self-renewal and osteogenic differentiation potentials of BMMSCs in graft bones, thereby maintaining bone homeostasis and reducing postoperative graft bone resorption.