Computer production of facial epitheses
Authors: Apresyan Samvel V. , Stepanov Alexander G. , Zrazhevskaya Anastasia P. , Suonio Valeria K. 
Published: July 2024

BACKGROUND: Patients with facial defects require urgent rehabilitation. In addition to the annual increase in the number of patients with cancer of the maxillofacial region, in recent years, the number of people with shrapnel and gunshot wounds to the face has increased as a result of local wars and conflicts.
Traditional methods of orthopedic rehabilitation of patients and the manufacture of facial epitheses are quite complex and lengthy. Postoperatively, the quality of life of these patients sharply decreases, basic body functions necessary for vital activity are impaired, and patients have poor social adaptation.
Direct application of facial prosthetics in the postoperative period is impossible owing to the lack of appropriate digital modeling technologies and structural materials for additive or subtractive production methods. Thus, the production of immediate facial epitheses using digital technologies is an urgent task to improve the social and functional living conditions of patients.
AIM: To develop three-dimensional (3D) modeling technology for additive manufacturing of immediate facial prostheses.
METHODS: The first task was to develop specialized 3D software for modeling defects in the facial area. The functionality of the program should allow virtual simulation of the missing parts of the face (ear, eye, nose, and orbit). Together with IT specialists, a digital platform was created using the following programming languages: C++ (for writing the software core and UI/UX interaction modules and interacting with the Windows operating system), C# (a complex assembly of the entire project), Python (for the automated assembly of virtual library modules), OpenGL HSLS (a shader language for graphical visualization of objects), and C ( creation of functions for interacting with shaders that require high speed).
RESULTS: A specialized computer program was developed for the 3D modeling of prostheses for patients with midface defects using combined facial scanning and computed tomography data (Computer program. Apresyan SV, Stepanov AG. A program for 3D modeling of facial epitheses. Registration number (certificate) 2023663490, Registration date: 07/04/2023).
Instead of obtaining analog impressions with plaster or silicone material, the developed technology uses a special 3D facial scanner, which greatly eases the suffering of patients. A virtual 3D database of ears, noses, orbits, and zygomatic bones of patients of various ages and sexes was integrated into the developed program. This allowed the specialist to select the most adaptive part of the face to make up for the defect. Built-in modeling tools allowed for the personalization of a 3D model of a part of the face based on the structural features of the maxillofacial region of a person. The finished 3D model of a part of the face can be exported in various formats.
CONCLUSION: The developed 3D program for modeling defects helps avoid invasive prosthetics approaches to coordinate the shape of future structures with the patient. The built-in library of structures with a database provides remote manufacturing of the prosthesis without the presence of the patient if replacement is needed. Among the undeniable advantages of the technology, prostheses can be made directly on the day of surgery for the removed part of the face, completely restoring lost functions and providing rapid social adaptation.