This study investigates a comprehensive model of bone regeneration capacity of dypiridamole-loaded 3D-printed bioceramic (DIPY-3DPBC) scaffolds composed of 100% beta-tricalcium phosphate (β –TCP) in an immature rabbit model through the time of facial maturity. The efficacy of this construct was compared to autologous bone graft, the clinical standard of care in pediatric craniofacial reconstruction, with attention paid to volume of regenerated bone by 3D reconstruction, histologic and mechanical properties of regenerated bone, and long-term safety regarding potential craniofacial growth restriction. Additionally, long-term degradation of scaffold constructs was evaluated. At 24 weeks in vivo, DIPY-3DPBC scaffolds demonstrated volumetrically significant osteogenic regeneration of calvarial and alveolar defects comparable to autogenous bone graft with favorable biodegradation of the bioactive ceramic component in vivo. Characterization of regenerated bone reveals osteogenesis of organized, vascularized bone with histologic and mechanical characteristics comparable to native bone. Radiographic and histologic analyses were consistent with patent craniofacial sutures. Lastly, through application of 3D morphometric facial surface analysis, our results support that DIPY-3DPBC scaffolds do not cause premature closure of sutures and preserve normal craniofacial growth. Based on this novel evaluation model, this DIPY-3DPBC scaffold strategy is a promising candidate as a safe, efficacious pediatric bone tissue engineering strategy.

Introduction:Recombinant human bone morphogenetic protein-2 (rhBMP-2) is one of the most commonly used osteogenic agents in the craniofacial skeleton. This study reviews the safety and efficacy of rhBMP-2 as applied to craniofacial reconstruction and assesses the level of scientific evidence currently available.Methods:An extensive literature search was conducted. Randomized controlled trials (RCTs), case series and reports in the English language as well as Food and Drug Administration reports were reviewed. Studies were graded using the Oxford Center for Evidence-Based Medicine Levels of Evidence Scale. Data heterogeneity precluded quantitative analysis.Results:Seventeen RCTs (Levels of evidence: Ib-IIb) were identified evaluating the use of rhBMP-2 in maxillary sinus, alveolar ridge, alveolar cleft, or cranial defect reconstruction (sample size: 7–160; age: 8–75 years). Study designs varied in rigor, with follow-up ranging 3–36 months, and outcome assessment relying on clinical exam, radiology, and/or histology. There was wide variation in rhBMP-2 concentrations, carriers, and controls. Most studies evaluating rhBMP-2 for cranial defect closure, mandibular reconstruction, or distraction osteogenesis consisted of retrospective cohorts and case reports. The evidence fails to support RhBMP-2 use in maxillary sinus wall augmentation, calvarial reconstruction, mandibular reconstruction, or distraction osteogenesis. RhBMP-2 may be effective in alveolar reconstruction in adults, but is associated with increased postoperative edema.Conclusions:A risk–benefit ratio favoring rhBMP-2 over alternative substitutes remains to be demonstrated for most applications in plastic and reconstructive surgery. Long-term data on craniofacial growth is lacking, and using rhBMP-2 in patients younger than 18 years remains off-label.

Objective: This systematic review aims to evaluate nasoalveolar molding (NAM) in the context of burden of care defined as physical, psychosocial, or financial burden on caregivers. Search Methods: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, 5 databases were searched from inception through December 24, 2019, for keywords and subject headings pertaining to cleft lip and/or palate and NAM. Eligibility Criteria: Clinical studies on NAM with reference to physical (access to care, number of visits, distance traveled), psychosocial (caregiver perceptions, family interactions, breast milk feeding), and financial (direct and indirect costs) burden were included. Data Collection and Analysis: Study selection was performed by 2 independent reviewers. Results: The search identified 1107 articles and 114 articles remained for qualitative synthesis. Burden of care domains were discussed but not measured in 43% of articles and only 25% assessed burden of care through a primary outcome. Of these, 20 articles reported on physical, 8 articles on psychosocial, and 12 articles on financial burden. Quality of evidence is limited by study design and risk of bias. Conclusion: Nasoalveolar molding has been indiscriminately associated with burden of care in the literature. Although NAM may not be the ideal treatment option for all patients and families, the physical considerations are limited when accounting for the observed psychosocial advantages. Financial burden appears to be offset, but further research is required. Teams should directly assess the impact of this early intervention on the well-being of caregivers and advance strategies that improve access to care.

Background β-Tricalcium phosphate (β-TCP) is one of the most common synthetic bone grafting materials utilized in craniofacial reconstruction; however, it is limited by a slow degradation rate. The aim of this study was to leverage 3-dimensional (3D) printing in an effort to accelerate the degradation kinetics of β-TCP. Methods Twenty-two 1-month-old New Zealand white rabbits underwent creation of calvarial and alveolar defects, repaired with 3D-printed β-TCP scaffolds coated with 1000 μM of osteogenic agent dipyridamole. Rabbits were euthanized after 2, 6, and 18 months after surgical intervention. Bone regeneration, scaffold degradation, and bone mechanical properties were quantified. Results Histological analysis confirmed the generation of vascularized and organized bone. Microcomputed tomography analysis from 2 to 18 months demonstrated decreased scaffold volume within calvarial (23.6% ± 2.5%, 5.1% ± 2.2%; P < 0.001) and alveolar (21.5% ± 2.2%, 0.2% ± 1.9%; P < 0.001) defects, with degradation rates of 54.6%/year and 90.5%/year, respectively. Scaffold-inducted bone generation within the defect was volumetrically similar to native bone in the calvarium (55.7% ± 6.9% vs 46.7% ± 6.8%; P = 0.064) and alveolus (31.4% ± 7.1% vs 33.8% ± 3.7%; P = 0.337). Mechanical properties between regenerated and native bone were similar. Conclusions Our study demonstrates an improved degradation profile and replacement of absorbed β-TCP with vascularized, organized bone through 3D printing and addition of an osteogenic agent. This novel additive manufacturing and tissue engineering protocol has implications to the future of craniofacial skeletal reconstruction as a safe and efficacious bone tissue engineering method.