New Technologies in Bony Reconstruction of Complex Head and Neck Defects

Bone reconstruction using CAD/CAM technology in head and neck surgical oncology. A narrative review of state of the art and aesthetic-functional outcomes

Bone defects following resections for head and neck tumours can cause significant functional and aesthetic defects. The choice of the optimal reconstructive method depends on several factors such as the size of the defect, location of the tumour, patient’s health and surgeon’s experience. The reconstructive gold standard is today represented by revascularised osteo-myocutaneous or osteomuscular flaps with osteosynthesis using titanium plates. Commonly used donor sites are the fibula, iliac crest, and lateral scapula/scapular angle. In recent years, computer-aided design (CAD)/computer assisted manufacturing (CAM) systems have revolutionised the reconstructive field, with the introduction of stereolithographic models, followed by virtual planning software and 3D printing of plates and prostheses. This technology has demonstrated excellent reliability in terms of accuracy, precision and predictability, leading to better operative outcomes, reduced surgical times and decreased complication rates. Among the disadvantages are high costs, implementation times and poor planning adaptability. These problems are finding a partial solution in the development of “in house” laboratories for planning and 3D printing. Strong indications for the use of CAD/CAM technologies today are the reconstruction of total or subtotal mandibular or maxillary defects and secondary bone reconstructions.

The role of computer aided design/computer assisted manufacturing (CAD/CAM) and 3- dimensional printing in head and neck oncologic surgery: A review and future directions

Microvascular free flap reconstruction has remained the standard of care in reconstruction of large tissue defects following ablative head and neck oncologic surgery, especially for bony structures. Computer aided design/computer assisted manufacturing (CAD/CAM) and 3-dimensionally (3D) printed models and devices offer novel solutions for reconstruction of bony defects. Conventional free hand techniques have been enhanced using 3D printed anatomic models for reference and pre-bending of titanium reconstructive plates, which has dramatically improved intraoperative and microvascular ischemia times. Improvements led to current state of the art uses which include full virtual planning (VP), 3D printed osteotomy guides, and patient specific reconstructive plates, with advanced options incorporating dental rehabilitation and titanium bone replacements into the primary surgical plan through use of these tools. Limitations such as high costs and delays in device manufacturing may be mitigated with in house software and workflows. Future innovations still in development include printing custom prosthetics, 'bioprinting' of tissue engineered scaffolds, integration of therapeutic implants, and other possibilities as this technology continues to rapidly advance. This review summarizes the literature and serves as a summary guide to the historic, current, advanced, and future possibilities of 3D printing within head and neck oncologic surgery and bony reconstruction. This review serves as a summary guide to the historic, current, advanced, and future roles of CAD/CAM and 3D printing within the field of head and neck oncologic surgery and bony reconstruction.