FARKLI ŞEKİLLERDE YAPILAN MARJİNAL MANDİBULEKTOMİLERİN POSTOPERATİF KIRIK RİSKİ AÇISINDAN SONLU ELEMAN ANALİZİ İLE DEĞERLENDİRİLMESİ

OZET Amac: Calismamizin amaci, sonlu eleman analizi yontemini kullanarak marjinal mandibulektomiler sonrasi reziduel kemikte olusabilen kiriklari onlemek icin ideal bir rezeksiyon tasarimi ortaya cikarabilmektir. Bu amacla sikca kullanilan iki farkli tip tasarim karsilastirilmistir. Gerec ve yontem: Tomografi goruntulerinden uc boyutlu olarak elde edilen matematiksel mandibula modelleri uzerinde posterior korpus bolgesinde koseli ve egimli olmak uzere iki farkli tip marjinal mandibulektomi uygulanmistir. Elde edilen bu iki modelde isirma kuvvetleri altinda olusan stresler sonlu eleman analizi yontemiyle degerlendirilmistir. Bulgular: Modeller; minimum ve maksimum asal gerilimler (minimum ve maksimum principal stres), esdeger asal gerilim (Von Mises stres) ve yer degistirmeler acisindan degerlendirilmis ve karsilastirmalar yapilmistir. Her iki modelde de en yuksek stresler defektin postero-inferior koselerinde olusmustur. Benzer sekilde yer degistirme degerleri de her iki modelde arka koselerde daha yuksek bulunmustur. Koseli modelde tum bolgelerde egimli modele kiyasla daha yuksek stresler ve yer degistirmeler olustugu gorulmustur. Sonuc: Her iki modelin de defektin postero-inferior koselerinden kirilmaya daha yatkin oldugu ve koseli modelin de egimli modele gore daha yuksek postoperatif kirik riski tasidigi sonucuna varilmistir. Anahtar kelimeler: Marjinal mandibulektomi, postoperatif kirik, sonlu eleman analizi. THE EVALUATION OF DIFFERENT FORMS OF MARGINAL MANDIBULECTOMIES IN TERMS OF POSTOPERATIVE FRACTURE RISK WITH FINITE ELEMENT ANALYSIS ABSTRACT Purpose: The purpose of this study is to reveal an optimum marginal mandibulectomy design to prevent postoperative fractures. So then, two different common designs were compared with finite element analysis. Material and methods: Two types of marginal mandibulectomies (angular and curviliniear) were performed on the posterior corpus of a 3 dimensional mathematical mandible model which was created from the tomography images. Stresses which took place on those two models under bite forces, were evaluated with finite element analysis. Results: The models were evaluated and compared in terms of; minimum and maximum principal stresses, Von Mises stress and displacement magnitude. The highest stresses occured in the postero-inferior corners of the defects on both of the models. Similarly, the highest displacement magnitudes were measured in the posterior corners of both models. Higher stresses and displacement magnitudes were measured in all sites of the angular model compared to curvilinear one. Conclusion: We conclude that, both of the models' postero-inferior corners were more prone to be fractured and the angular model had more postoperative fracture risk in comparison with the curvilinear one. Key words: Finite element analysis, marginal mandibulectomy, postoperative fracture