Background/Objectives: Mandibular reconstruction following trauma or oncologic resection is crucial for restoring function and aesthetics. While autologous bone grafting remains the gold standard, it presents challenges such as donor site morbidity and graft availability. Bone tissue engineering (BTE) offers an innovative alternative, integrating scaffolds, osteogenic cells, and bioactive factors to regenerate functional bone. This systematic review evaluates BTE strategies for mandibular reconstruction, focusing on critical-sized defects in large animal models and their translational potential for clinical applications. Methods: A systematic review was performed following PRISMA guidelines. Eligible studies involved large animal models and critical-sized mandibular defects treated with at least two BTE components (scaffold, osteogenic cells, or growth factors). Quality and bias assessments were conducted using ARRIVE guidelines and SYRCLE tools. Results: Of the 6088 studies screened, 27 met the inclusion criteria, focusing on critical-sized mandibular defects in large animal models such as pigs, sheep, and dogs. Common scaffolds included β-tricalcium phosphate (β-TCP), poly-lactic-co-glycolic acid (PLGA), and polycaprolactone (PCL), frequently combined with bone marrow-derived mesenchymal stem cells (BMSCs) and growth factors like recombinant human bone morphogenetic protein-2 (rhBMP-2). Preclinical outcomes demonstrated effective bone regeneration, vascularization, and biomechanical restoration. Advanced strategies, including in vivo bioreactors and 3D-printed scaffolds, further enhanced regeneration. However, challenges such as incomplete scaffold degradation, hypoxic conditions within constructs, and variability in growth factor efficacy and dose optimization were observed, emphasizing the need for further refinement to ensure consistent outcomes. Conclusions: BTE shows promise in mandibular reconstruction, achieving bone regeneration and functional restoration in preclinical models of critical-sized defects. However, challenges such as scaffold optimization, vascularization enhancement, and protocol standardization require further investigation to facilitate clinical translation. These findings emphasize the need for refinement to achieve consistent, scalable outcomes for clinical use.

Aesthetic limb lengthening (ALL) is a cosmetic procedure aimed at enhancing body symmetry and improving self-esteem through the gradual elongation of bones. Unlike functional limb lengthening, which addresses limb length discrepancies, ALL focuses on increasing limb length for aesthetic purposes. While functional limb lengthening has been extensively studied, a comprehensive analysis of ALL outcomes is needed. This systematic review evaluates the efficacy, complications, and patient satisfaction associated with different ALL techniques, including distraction osteogenesis and various external and internal fixation systems. A systematic search of PubMed, Embase, and Scopus was conducted up to July 2024 to identify relevant studies in English. Eligible studies included case series, cohort studies, and randomized controlled trials with at least 12 months of follow-up. Studies focusing on adult populations undergoing aesthetic limb lengthening were included. Data on limb lengthening achieved, bone healing rates, complications, and patient satisfaction were extracted and synthesized through narrative analysis. The methodological quality of studies was assessed using the MINORS criteria for non-randomized studies. A total of 12 studies involving 760 patients were included. Most patients were male (67%), with an average age of 24.75 years. Techniques employed included the Ilizarov method, motorized internal lengthening nails (MILN), and combined methods like Lengthening And Then Nailing (LATN). The lengthening achieved ranged from 62 mm to 87 mm, with an average of 67 mm. Patient satisfaction rates ranged from 88.8 to 98%. Psychological outcomes showed improvements in body image and self-esteem. Functionally, most patients resumed normal activities with minimal joint limitations. However, common complications included infections, bone healing issues, joint deformities, and material-related complications. ALL offers high patient satisfaction and psychological benefits, with patients reporting improved body image and self-esteem. Despite these positive outcomes, complications such as infections and bone healing issues remain significant. Further research with rigorous study designs is needed to improve the safety and efficacy of ALL procedures.

Critical-sized bone defects (CSBDs) are injuries that exceed the body’s natural capacity for repair and require external intervention. These defects are particularly challenging in the mandible, often resulting from trauma, tumor resection, or implant-related complications. Effective treatment involves scaffold designs that support vascularization, bone formation, and sufficient mechanical strength. This systematic review aims to assess whether ceramic-based scaffold properties, including porosity, pore size, and macroscopic characteristics, improve vascularization, bone formation, and the mechanical properties in the treatment of CSBDs in large animal models. A search of databases (PubMed, Embase, and Web of Science) identified 11 in vivo studies involving CSBDs (>2 cm), ceramic scaffolds, and histological analysis. Findings indicate that scaffolds with porosity exceeding 50% yield optimal outcomes by striking a balance between cell infiltration and mechanical stability. Pore sizes ranging from 300 μm to 700 μm are ideal for vascularization and bone ingrowth. Three-dimensional (3D) printing shows promise in creating scaffolds with precise and reproducible features. However, the studies varied significantly in their methodologies and outcomes, with no consensus on the optimal scaffold properties for mandibular CSBDs. Scaffold porosity and pore size play key roles in promoting vascularization and bone regeneration. Various animal models reinforce this finding, suggesting that scaffold architecture is crucial for biological integration and functional outcomes. This review highlights the importance of standardized research protocols and clear design criteria in enhancing the success of bone regeneration. Future research should investigate emerging biomaterials and new scaffold technologies to overcome current limitations in clinical applications.