Ricostruzioni mandibolari: ampia meta-analisi e introduzione di un approccio su misura basato sul nuovo sostituto osseo SmartBone® = Mandibular reconstructions: extensive meta-analysis and introduction of custom-made approach based on new bone substitute SmartBone®

Bone reconstruction represents a challenging research field which has gained an increased interest among the scientific community in the last twenty years. Oral and maxillofacial surgery has a fundamental role in this field since its crucial outcome is the restoration of functional and aesthetic aspects of the maxillofacial region, which represents an imperative improvement in the quality of life of patients involved. This study focused on mandibular bone reconstructions, a high loaded anatomical region mostly affected by high recurrence-rate benign and malignant tumours which usually implicate an immediate resection and reconstruction of the compromised missing bone. The clinical practice relies on the autogenous bone grafting, the “gold standard” of mandibular reconstructions, based on the harvesting of the bone from the patient itself; disadvantages arising from this approach led to new proposed solutions which, nevertheless, still presents deficiency mostly in terms of osteointegration of the graft and restoration of biomechanics of the original bone. Through an inspection of the clinical approaches towards mandibular reconstructions, this study aims to identify common practices and possible improvements in order to achieve a successful reconstruction, introducing a new approach based on an innovative bone substitute produced by Biomedical Industries Insubri S.A. company (IBI-SA Mezzovico, Switzerland). This metanalysis was performed through an in-depth academic literature research focusing on the analysis of six main aspects of mandibular reconstructions: the evaluation of most common causes of reconstruction and defects of anatomical mandibular regions; the application of Computer-Aided Design and Computer-Aided Manufacturing technology; the crucial choice of the bone grafting material and analysis of alternatives to the autogenous grafting; the biomechanics of the reconstructed mandible and the restoration of the original stresses distribution; the fixation systems required as support to the bone substitute; and, finally, the software’s design strategies applied through the virtual planning of the new graft. For each aspect, advantages and disadvantages of common practice were evaluated in order to provide a clear view on actual mandibular reconstruction’s approaches. The results of this review showed that, although autogenous grafting provides good osteointegration, its main disadvantages, represented by complex and time-consuming surgery, high rate of infections and plate fractures and, most of all, donor site morbidity and patient’s discomfort, lead researchers to find new solutions represented by allogeneic, xenogeneic, alloplastic and synthetic materials. Tissue engineering strategy stands out for its promising outcomes coming from the combination of different materials’ properties. Nevertheless, these alternatives still didn’t achieve the main ideal goals of perfect osteointegration and long-lasting reconstruction. SmartBone®, the new bone substitute produced by IBI-SA, provides some excellent properties in terms of osteointegration and mimicking of the mandibular biomechanics and represents a promising bone graft material that should be introduced as a basis for a new approach towards mandibular reconstructions. The advantages introduced by this new possible approach are encouraging and the future purpose of this study will be the application of this approach to clinical cases in order to validate its efficacy.