3D-printed titanium surgical plates in head and neck reconstruction : from bedside to bench

Abstract

3D printing technology is revolutionizing the world. However, its application in surgery is limited. Considering the complexity and challenges of head and neck reconstruction, the application and benefits of 3D-printed titanium patient-specific surgical plates deserved to be investigated in a systematic manner. In the thesis, we aimed to explore the benefits and establish the workflow of applying 3D-printed patient-specific surgical plates in head and neck reconstruction.

There were a total of 12 chapters including bedside and bench studies. Chapters 1-5 identified the rationale for clinical research and provided the general basis for the study of computer-assisted mandibular reconstruction. On this basis, Chapters 6-10 were carried out at the bedside, to establish the workflow and confirm the feasibility and benefits of applying 3D-printed surgical plates in head and neck reconstruction. To address the issue of implant-associated infections and inflammation, Chapter 11 was conducted on bench, to develop a multifunctional coating for 3D-printed titanium implants, which killed bacteria and promoted osteogenesis. Chapter 12 included a summary and future perspectives.

In details, Chapter 1 introduced the current evidence and future directions in computer-assisted maxillary and mandibular reconstruction, highlighting the prospects of 3D-printed patient-specific surgical plates. Chapter 2 introduced the research rationale, hypotheses, objectives and framework of this thesis. Chapter 3 established a novel notation system—“Crabs”—for mandibular defects based on a 10-year case series of 591 patients. “Crabs” denoted marginal and segmental mandibular defects of the condyle, ramus, angle, body and symphysis in a simplified and scientific manner. Chapter 4 confirmed that computer-assisted surgery increased efficiency in mandibular reconstruction compared to conventional freehand surgery through systematic review and meta-analysis. Chapter 5 established the anatomical landmarks and measurements for spatial deviations of computer-assisted mandibular reconstruction. Chapter 6 proposed a novel “surgeon-dominated” approach to the design of 3D-printed patient-specific surgical plates in mandibular reconstruction, which was feasible and time-saving. Chapter 7 investigated the feasibility of using 3D-printed patient-specific surgical plates in head and neck reconstruction. The intraoperative success rate was 100% among 10 patients. Chapter 8 demonstrated a novel “one-piece” patient-specific reconstruction plate for double-barrel fibula-based mandibular reconstruction, confirming that 3D-printed plates facilitated complex surgery. Chapter 9 confirmed that 3D-printed patient-specific surgical plates increased accuracy of oncological head and neck reconstruction versus conventional surgical plates, based on a comparative study including 33 patients. Chapter 10 confirmed that 3D-printed patient-specific surgical plates increased spatial accuracy of temporomandibular joint after oncological mandibular reconstruction in 33 patients. Chapter 11 developed a multifunctional coating on 3D-printed patient-specific titanium implants assembling titanate nano-skeleton, 2-hydroxypropyltrimethyl ammonium nitrate chitosan, and silver nanoparticles, which killed bacteria and promoted osteogenesis effectively based on in vitro and ex vivo experiments. Chapter 12 mainly summarized the thesis and proposed the future perspectives of multifunctional titanium implants.

In conclusion, a series of studies were conducted that established the workflow and confirmed the benefits of 3D-printed titanium patient-specific surgical plates in addressing the complexity and challenges of head and neck reconstruction.