Assessment of different treatment alternatives for patients with total maxillectomy.

Purpose: To assess the biomechanical advantages of combining zygoma and partial subperiosteal implants for maxillary reconstruction in severely atrophic maxillae, offering potential solutions to the challenges posed by traditional reconstruction methods.

Material and methods: A finite element analysis used a craniofacial model simulating a totally resected maxilla. Four treatment scenarios (SCs) were evaluated: SC-1, the quad zygoma approach; SC-2, two zygoma implants (ZIs) and a one-piece subperiosteal implant (SI); SC-3, two ZI and a two-piece SI; and SC-4, four ZI and a one-piece SI. Stress distributions on bone, implants, abutments, and metal frameworks were compared under occlusal forces.

Results: For the simulated bone regions under vertical and oblique forces, SC-4 values were higher than SC-1, while SC-2 and SC-3 values were comparable for p_max and p_min. In addition, SC-2 and SC-3 values were lower than those of SC-1 and SC-4. The most balanced von Mises stress values on the ZIsand were observed in SC-3 under vertical and oblique forces. Furthermore, lower von Mises stress values on the abutments were seen in SC-3 under oblique and vertical forces. Although the lower von Mises stress values on the metal frameworks at the lateral incisor and first premolar side were seen in SC-3, lower von Mises values were observed in SC-4 in the first molar region.

Conclusions: Overall, this study suggests that combining zygoma and partial subperiosteal implants may be a promising approach for reconstructing severely atrophic maxillae. These implants may offer improved biomechanical properties compared to ZIs alone.