Biomechanical evaluation of quad zygomatic, transnasal and subperiosteal implants in the rehabilitation of severely atrophic maxilla

ABSTRACT The study aims to compare the effects of different occlusal forces on quad zygoma, transnasal, and subperiosteal implants in patients with severely atrophic maxilla using finite element analysis. Using cone-beam computed tomography data from a patient with a severely atrophic maxilla, a three-dimensional finite-element analysis model was created. Three models were developed: Model 1, a quad zygoma model with four zygomatic implants placed using the extrasinus technique; Model 2, a combination of two zygomatic implants placed using the extrasinus technique and two transnasal implants; and Model 3, a subperiosteal implant model. Two different forces were applied: a 150 N vertical force at the first, second premolar, and first molar regions, and a functional force consisting of a 100 N vertical force combined with a 50 N horizontal force at the same locations. Stress values in the bone, implants, abutments, and prosthetic framework were evaluated. The subperiosteal implant model showed the lowest stress values for the bone implants, abutments, and prosthetic framework under both vertical and functional forces. The quad zygoma model exhibited the highest tensile and compressive stresses on the cortical bone under vertical and functional forces. According to stress analysis results from the three models, subperiosteal implants offer the greatest advantages for the rehabilitation of the severely atrophic maxilla. The quad zygoma implant model and the combination of zygomatic and transnasal implants exhibit similar stress values, with neither model demonstrating superiority over the other.