Evaluating the distribution of force in maxillary defects according to the types and localizations of the implants by finite elements analysis method

In this study, in an implant-supported obturator made for an edentulous unilateral maxillary defect patient as a result of maxillary resection, when different types and localizations of the implants were used, the stress values and distribution areas in the bone were investigated by finite elements stress analysis methodIn the present study, zygomatic and dental implants were placed to the defected maxilla in 8 different ways and 8 different obturator were designed according to these ways. As a superstructure, ball attachments were preferred in models with two implants and bar attachments were preferred in the other models. 150 N vertical force was loaded by distributing it to the first premolar, second premolar and first molar teeth. Three different loadings were applied. First loading was applied to the defected area, second loading was applied to the undefected area and third one was applied to both areas. Maximum and minimum principle stresses in the cortical bone were investigated in the Algor (Fempro, USA) programmeFor all loadings, the highest stress values occured at the cortical bone around the neck of the implant. It was determined that for placing a zygomatic implant to the defected area decreased the stresses occured in the cortical bone dramatically for first loading. It was observed that in the models which have one zygomatic implant each side of maxilla with bar attachments, increasing the number of the implants in the undefected area has no possitive effect on the stress distribution. It was determined that in the models with two implants, the best stress distribution occured when both of the implants were zygomatic implants.Key words: Zygomatic implant, maxillary defect, obturator, finite elements stress analysis.