Finite element analysis of stresses on the skull base caused by trauma during sinus lift with mallet and osteotome.

PURPOSE

This study aimed to investigate the stress accumulation on the skull base caused by the forces applied to fracture the bone at the sinus floor during the closed trans-alveolar technique of sinus elevation.

MATERIALS AND METHODS

This study was based on three-dimensional finite element analysis. Study models were determined as follows: Model 1, Model 2, and Model 3 (bone thickness at the sinus floor 1, 2, and 3 mm, respectively). The forces required for fracture of the bone at the base of the sinus were found to be 89,04 N, 138,88 N, and 210 N for Models 1, 2, and 3, respectively. The von Mises (VM), maximum principal (Pmax), and minimum principal (Pmin) stress values were examined at three different locations in the petrous part of the temporal bone. The highest stress values during the fracture process were recorded.

RESULTS

During fracture, VM, Pmax, and Pmin stress values were highest in Model 3 and lowest in Model 1. When the most critical levels were analyzed, it was seen that all stress values in Model 3 were more than twice the values in Model 1.

CONCLUSION

In closed trans-alveolar sinus lifting, as the forces applied to break the bone at the sinus floor increase, the stress accumulation at the petrous part of the temporal bone increases in direct proportion. This increase in cranial base stress may lead to an increased risk of benign paroxysmal positional vertigo which is a major complication of closed sinus lifting.