Investigating the biomechanical properties of differentconcepts using zygomatic and pterygoid implants in an atrophic maxilla model by finite element analysis

Aim: The aim of this study is to investigate the outcomes of finite element stress analysis (FESA) in different rehabilitation concepts using zygomatic and pterygoid implants for atrophic maxilla, in order to guide future clinical studies. Material and Method: Using CBCT images of an atrophic maxilla, three different rehabilitation scenarios were created on a remodeled maxilla model. In model 1, four zygomatic implants were placed. models 2 and 3 involved a total of four implants, including two zygomatic and two pterygoid implants. Zygomatic implants were placed in the 12 and 22 regions in model 2, and in the 15 and 25 regions in model 3. A 150 N load was applied to both anterior and posterior regions via a spherical food bolus. Stresses in implants, abutments, prosthetic metal frameworks, and surrounding bone structures were analyzed using the finite element stress analysis method. Results: In terms of von Mises stress values on implants and abutments, Model 2 exhibited the lowest stress under anterior loading, while model 3 showed the highest. Under posterior loading, model 2 performed the worst, whereas model 1 had similar values. For the prosthetic metal framework, model 2 showed the best outcome under anterior loading, and model 3 showed the best under posterior loading. In cortical bone under anterior loading, model 1 showed the lowest Pmax value, and model 2 had the lowest Pmin value. Under posterior loading, model 3 had the best results for both Pmax and Pmin. In cancellous bone, model 2 showed the Pmax and Pmin values under anterior loading. Under posterior loading, model 1 had the best Pmax, and model 3 had the best Pmin. In the zygomatic bone under anterior loading, model 2 had the lowest Pmax, while model 3 had the lowest Pmin. Under posterior loading, both Pmax and Pmin were lowest in model 2. Conclusions: Based on the FESA results, the most favorable configuration appears to be model 2, which involves placement of zygomatic implants in regions 12 and 22 and pterygoid implants in regions 17 and 27. This model may serve as an alternative to the quad zygoma concept, minimizing surgical complications in zygomatic implant procedures, eliminating posterior cantilever effects, and avoiding the creation of new cantilever forces in the anterior region. Keywords: Atrophic Maxilla, Finite Elements, Pterygoid Implant, Zygomatic Implant