title: Radiological assessment of bioengineered bone in a muscle flap for the reconstruction of critical-size mandibular defect.
abstract: This study presents a comprehensive radiographic evaluation of bone regeneration within a pedicled muscle flap for the reconstruction of critical size mandibular defect. The surgical defect (20 mm × 15 mm) was created in the mandible of ten experimental rabbits. The masseter muscle was adapted to fill the surgical defect, a combination of calcium sulphate/hydroxyapatite cement (CERAMENT™ |SPINE SUPPORT), BMP-7 and rabbit mesenchymal stromal cells (rMSCs) was injected inside the muscle tissue. Radiographic assessment was carried out on the day of surgery and at 4, 8, and 12 weeks postoperatively. At 12 weeks, the animals were sacrificed and cone beam computerized tomography (CBCT) scanning and micro-computed tomography (µ-CT) were carried out. Clinically, a clear layer of bone tissue was identified closely adherent to the border of the surgical defect. Sporadic radio-opaque areas within the surgical defect were detected radiographically. In comparison with the opposite non operated control side, the estimated quantitative scoring of the radio-opacity was 46.6% ± 15, the mean volume of the radio-opaque areas was 63.4% ± 20. Areas of a bone density higher than that of the mandibular bone (+35% ± 25%) were detected at the borders of the surgical defect. The micro-CT analysis revealed thinner trabeculae of the regenerated bone with a more condensed trabecular pattern than the surrounding native bone. These findings suggest a rapid deposition rate of the mineralised tissue and an active remodelling process of the newly regenerated bone within the muscle flap. The novel surgical model of this study has potential clinical application; the assessment of bone regeneration using the presented radiolographic protocol is descriptive and comprehensive. The findings of this research confirm the remarkable potential of local muscle flaps as local bioreactors to induce bone formation for reconstruction of maxillofacial bony defects.
authors.affiliation: University of Glasgow, Glasgow, United Kingdom.
authors.forename: Randa
authors.initials: R
authors.lastname: Al-Fotawei
authors.affiliation: University of Glasgow, Glasgow, United Kingdom.
authors.forename: Ashraf F
authors.initials: AF
authors.lastname: Ayoub
authors.affiliation: Oral & Maxillofacial Radiology, Glasgow University Dental Hospital & School, Glasgow, United Kingdom.
authors.forename: Neil
authors.initials: N
authors.lastname: Heath
authors.affiliation: Oral Surgery, Glasgow University Dental Hospital & School, Glasgow, United Kingdom.
authors.forename: Kurt B
authors.initials: KB
authors.lastname: Naudi
authors.affiliation: Biomedical Materials, School of Engineering, University of Glasgow, Glasgow, United Kingdom.
authors.forename: K Elizabeth
authors.initials: KE
authors.lastname: Tanner
authors.affiliation: Centre for Cell Engineering, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Dalby
authors.affiliation: Oral & Maxillofacial Surgery, Southern General Hospital, Glasgow, United Kingdom.
authors.forename: Jeremy
authors.initials: J
authors.lastname: McMahon
mesh_terms: D000818:Animals; D015519:Bone Density; D055419:Bone Morphogenetic Protein 7; D001861:Bone Regeneration; D054893:Cone-Beam Computed Tomography; D058752:Free Tissue Flaps; D048091:Guided Tissue Regeneration; D006801:Humans; D021621:Imaging, Three-Dimensional; D008334:Mandible / Q000002:abnormalities / Q000000981:diagnostic imaging* / Q000601:surgery*; D059630:Mesenchymal Stem Cells; D018482:Muscle, Skeletal / Q000637:transplantation*; D011817:Rabbits; D023822:Tissue Engineering; D054457:Tissue Scaffolds; D055114:X-Ray Microtomography
chemical_list: D055419:Bone Morphogenetic Protein 7