MAXILLOFACIAL REHABILITATION IN PATIENT WITH NEOPLASMS USING
ZYGOMATIC IMPLANT-SUPPORTED PROSTHESES
Authors: Hovhannisyan Sergo , Mashinyan Karen , Khachatryan Levon , Karapetyan Edgar , Kharazyan Artavazd , Ordoyan Mikayel , Badalyan Aram 
Published: December 2023

Objective: The aim of this study was to report the clinical results of the use оf the zygomatic implants for prosthetic rehabilitation in patients with maxillectomy due to upper jaw tumors.
Materials and Methods: The study included 12 patients who underwent prosthetic rehabilitation using a zygomatic implant after maxillectomy for the treatment of upper jaw tumors in the period from 2021 to 2023. There were 8 male patients and 4 female patients with an average age of 53.2 years old. The type of tumors was determined by CT, MRT methods and histopathological examination. The distribution of lesions was the following: benign 4 and malignant 8,7 patients have undergone radiation therapy before or after implant placement. After the tumor was removed, immediate surgical obdurators were placed. Main prosthetic rehabilitation performed 6-12 months after tumor removal, but before that, a temporary obturator had made and used. 6-12 months after tumor resection, 1-4 zygomatic implants were inserted into the zygomatic bone
unilaterally or bilaterally. A total of 36 zygomatic implants were installed, 2 of which were unsuccessful and were removed in 1 patient. The implant systems used Zygoma TiUnite (Nobel Biocare, Zurich, Switzerland) and multi-unit abutments (MUA). The implants were
placed using the surgical guide, which was planned and prepared digitally. After which they loaded immediately using prefabricated complete dentures. They verified, adapted and screwed by titanium bases onto the zygomatic implants. The palatal part of these
prostheses is a separate unit, which attach to the main part of the prostheses with magnets. By detaching the palatal part of the prostheses, through the created opening, doctor or patient can keep track of the upper tissues, hygiene and antiseptic cleansing (irrigation, rinsing). Evaluation of functional efficiency of the treatment was assessed before and after prosthetic rehabilitation with zygomatic implants using
the Oral Health Impact Profile (OHIP-14) and the masticatory functional index. QOL was evaluated using the University of Washington Quality of Life version 4 (UW-QOLv4) questionnaire.
Results։ No postsurgical complications were seen, and the patients were discharged from the hospital after 7-10 days. The patients were able to return to a normal diet (hard) after just 7 days following surgery, with no further complaints regarding function or pain, apart from the residual swelling caused by the intervention. Patients' health-related quality of life (HR-QOL) before treatment was ≥48.3%.
HR-QOL and overall quality of life after rehabilitation increased to 76.8%, and assessed as good. The improvement of chewing function was also the most important goal for the patients (pre- 26,4% and post- 67,3%), masticatory function scores increased after prosthetic treatment with implants.
Conclusions: The use of prostheses fixed on zygomatic implants for patients with maxillary defects is an effective method of prosthodontic rehabilitation in complex clinical cases after maxillectomy