Preventing Early-Stage Graft Bone Resorption by Simultaneous Innervation: Innervated Iliac Bone Flap for Mandibular Reconstruction.

BACKGROUND: Postoperative resorption of vascularized bone grafts jeopardizes the success of dental implant(s) and functional rehabilitation of the jaw. Recent evidence supports the crucial role of innervation in bone regeneration and turnover.

METHODS: This study reports a new technique for simultaneous innervation of vascularized iliac flaps in mandibular reconstruction, through neurorrhaphy between ilioinguinal nerves, which innervate iliac bone, and inferior alveolar nerves or great auricular nerves. Twenty-two patients (aged 50 to 69 years) with postoncologic continuity defects of the mandible underwent mandibular reconstruction (10 innervated flaps and 12 control flaps). Graft bone resorption was analyzed by computed tomographic scans at 6 and 12 months postoperatively, and bone quality was evaluated for dental implantation, with histologic and histomorphometric analyses for graft samples.

RESULTS: At 12-month follow-up, graft bone density loss in the control group was significantly higher than in the innervated group (p < 0.05). Bone quality evaluation indicated a suitable condition for dental implantation in all patients in the innervated group but in 41.7 percent of patients in the control group. Histologic and histomorphometric analyses showed successful innervation in the innervated group but not in the control group. Osteoclast activity was significantly higher in the control group than in the innervated group (p < 0.05).

CONCLUSIONS: Innervated iliac flaps may effectively prevent bone resorption of grafts in mandible reconstruction that otherwise jeopardize the success of dental implants. This new strategy of innervation of bone flaps appears clinically valuable and provides insights into the homeostasis of grafts for functional reconstruction.

CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.