Reconstructive plastic surgery procedures — cranioplasty in particular — are finding their way into the current dayto-day neurosurgery practices. A defect in the skull bones leads not only to cosmetic defects and related psychological problems, but can also cause neurological disorders. Reconstruction of skull defects is considered an important neurosurgical stage of craniocerebral injury victims’ recovery. Currently, there are no clear established algorithms or timing for cranioplasty. This paper presents data on the history and stages of the development of reconstructive neurosurgery. The efficiency of treatment of the syndrome of the trephinated with cranioplasty has been proven. The key materials used to close the skull bones defects are presented and the requirements for the material used for closing cranial defects are described. Advantages and disadvantages of materials currently used — autograft bone, allograft bone, reperen, polyetherketone, polymethylmethacrylate, titanium, hydroxyapatite — are presented in detail. A separate section of the article is devoted to the methods of transplant modelling — 3D printing and stereolithography. This is followed by the stipulation of the key principles of cranioplasty.

Introduction. Every year, there is an increase in the number of operations performed using personalized cranioplasts, which are made with additive 3D printing technologies. They allow surgical intervention, taking into account the characteristics of the shape of the patient's skull. This is especially important when closing large and complex defects extending from the cranial vault to the bones of the facial skeleton. One of the innovative applications of additive technologies in cranioplasty is the creation of implants, preformed based on individual 3D-printed models. However, no preliminary estimates of the results of treatment of patients using the traditional methods of cranial implants and individualized modeling methods were found in the available literary sources.The study objective is to compare the results of treatment using cranioplasts, preformed based on individual 3D-printed skull models and using traditional intraoperative modeling.Materials and methods. A study of 50 patients with post-craniotomy defects of the skull. All patients have undergone cranioplasty. Depending on the technique of individualization of the cranial implants, patients were divided into 2 groups: 1st - using individual 3D-printed models (n = 32), 2nd - traditional intraoperative modeling (n = 18).Results. Statistically, the groups differed significantly in terms of the duration of the intraoperative stage of cranioplasty, postoperative and total hospital stay, indicators of symmetry and financial costs. No differences were found in the duration of the preoperative hospital stay, the number of implant fixation points, the volume of intraoperative blood loss and the quality of life according to the SF-36. The first group (6.25 %) in comparison with the second (16.7 %) had a smaller number of postoperative complications.Conclusion. Modern 3D printing technologies recreate bone models based on patients' individual characteristics, thereby providing time for careful planning of the operation, even at the outpatient stage. The results of the study showed that the usage of cranioplasts preformed with 3D-printed models provides precise closure of post-craniotomy defects, better restoration of the skull contours, and a significant reduction in the duration of the cranioplasty stage. The use of the technology does not lead to a significant increase in the cost of treatment using traditional intraoperative modeling.