“Loop-Neurorrhaphy Technique for Preventing Bone Resorption and Preserving Lower Lip Sensation in Mandibular Reconstruction using Vascularized Iliac Bone Flap: A Single-Center Randomized Clinical Trial”

Abstract

Background: The aim of this study was to investigate whether using an innervated vascularized iliac bone flap could effectively prevent bone resorption and maintain sensory function in the lower lip. Methods: In the innervated group, the deep circumflex iliac artery and recipient vessels were anastomosed, with simultaneous microanastomosis of ilioinguinal nerve, mental nerve and inferior alveolar nerve. Conversely, the control group underwent solely vascular anastomosis. CT was utilized to assess bone quality. Sensory recovery of the lower lip was recorded using two-point discrimination and current perception threshold testing. Results: The study comprised a total of 40 subjects, with each group accounting for 20 participants, equally distributed in terms of gender. Hounsfield unit loss was significantly lower in the innervated group (13.26±8.65 %) as compared to the control group (37.98±8.60 %) (P < 0.001). Moreover, two-point discrimination values were lower in the innervated group (15.11±8.39 mm) when compared to the control group (21.44±7.24 mm) (P = 0.02). The current perception threshold values for the innervated group were 176.19 ± 31.89, 64.21 ± 19.23, and 42.29 ± 18.96 in 2kHz, 250Hz, and 5Hz respectively, while in the control group, the current perception threshold values were 204.47 ± 36.99, 82.26 ± 27.29, and 58.89 ± 25.38 in 2kHz, 250Hz, and 5Hz (P =0.02, 0.02, and 0.03, respectively). Conclusions: The innervated vascularized iliac bone flap represents a safe and effective novel approach to preserving lower lip sensation and preventing bone resorption through functional mandibular reconstruction.