Discussion
This program sought to determine whether imaging studies of maxillary defects are effective templates for developing 3D printed prosthetics and whether these prosthetics should be tested for future use in reconstruction of palatomaxillary defects. Our program illustrated that CTs served as feasible templates for developing hard palate prostheses for patients with palatomaxillary defects. It is important to note the CTs used were from a newer and more modern scanner and therefore yielded detailed palatal structures with higher accuracy more suitable for 3D modeling. Lower-quality CTs from the 4 patients excluded from the program were not suitable for 3D modeling. This suggests that with high-quality imaging, 3D printed prosthesis may be a viable strategy to help patients who struggle with their function following treatment for head and neck cancers.
3D printed prosthesis may also be a more patient centered and convenient option. In the traditional prosthesis creation workflow, the patient must physically bite down onto a resin (alginate or silicone) to make an impression, a very painful postoperative process that is irritating to the raw edges of the surgical bed.15,16 Prosthodontists then create a prosthetic minus the tumor and typically secure it with clips or glue.17 Many patients also experience changes in their anatomy over time requiring them to have a new protheses created. This is particularly important in veterans with palatomaxillary defects since many VA medical centers do not have a prosthodontist on staff, making accessibility to these specialists difficult. 3D printing provides a contactless prosthetic creation process. This convenience may reduce a patient’s pain and the number of visits for which they need a specialist.
Future Directions
Additional research is needed to determine the full potential of 3D printed prosthetics. 3D printed prostheses have been effectively used for patient education in areas of presurgical planning, prosthesis creation, and trainee education.24 This research represents an early step in the development of a new technology for use in otolaryngology. Specifically, many veterans with a history of head and neck cancers have sustained changes to their craniofacial anatomy following treatment. Using imaging to create 3D printed prosthetics could be very effective for these patients. Prosthetics could improve a patient’s quality of life by restoring/approximating their anatomy after cancer treatment.
Significant time and care must be taken by cancer and reconstructive surgeons to properly fit a prosthesis. Improperly fitting prosthetics leads to mucosal ulceration that then may lead to a need for fitting a new prosthetic. The advantage of 3D printed prosthetics is that they may more precisely fit the anatomy of each patient using CT results, thus potentially reducing the time needed to fit the prosthetic as well as the risk associated with an improperly fit prosthetic. 3D printed prosthesis could be used directly in the future, however, clinical trials are needed to verify its efficacy vs prosthodontic options.
Another consideration for potential future use of 3D printed prosthetics is cost. We estimated that the cost of the materials and labor of our 3D printed prosthetic to be about $150. Pricing of current molded prosthetics varies, but is often listed at several thousand dollars. Another consideration is the durability of 3D printed prosthetics vs standard prosthetics. Since we were unable to use the prosthetic in the patient, it was difficult to determine its durability. The significant cost of the 3D printer and software necessary for 3D printed prosthetics must also be considered and may be prohibitive. While many academic hospitals are considering the purchase of 3D printers and licenses, this may be challenging for resource-constrained institutions. 3D printing may also be difficult for groups without any prior experience in the field. Outsourcing to a third party is possible, though doing so adds more cost to the project. While we recognize there is a learning curve associated with adopting any new technology, it’s equally important to note that 3D printing is being rapidly integrated and has already made significant advancements in personalized medicine.8,25,26
Limitations
This program had several limitations. First, we only obtained CTs of sufficient quality from 1 patient to generate a 3D printed prosthesis. Further research with additional patients is necessary to validate this process. Second, we were unable to trial the prosthesis in the patient because we did not have FDA approval. Additionally, it is difficult to calculate a true cost estimate for this process as materials and software costs vary dramatically across institutions as well as over time.
Conclusions
The purpose of this study was to demonstrate the possibility to develop prosthetics for the hard palate for patients suffering from palatomaxillary defects. A 3D printed prosthetic was generated that matched the patient’s craniofacial anatomy. Future research should test the feasibility of these prosthetics in patient care against a traditional prosthodontic impression. Though this is a proof-of-concept study and no prosthetics were implanted as part of this investigation, we showcase the feasibility of printing prosthetics for palatomaxillary defects. The use of 3D printed prosthetics may be a more humane process, potentially lower cost, and be more accessible to veterans.
