Effect of maxillary sinus morphology on the safety of hydraulic sinus floor elevation: a three-dimensional finite element analysis

To investigate the influence of sinus morphology on the safety of hydraulic sinus floor elevation surgery and provide a biomechanical basis for clinical treatment.

After approval by the Medical Ethics Committee of the institution, cone beam computed tomography imaging data from nine patients were collected. The sinus morphologies were classified into slope, flat and concave types. Three-dimensional finite element models of maxillary sinuses with the aforementioned morphologies were constructed using Mimics, Geomagic, Solidworks, and ANSYS software, followed by a simulation of the hydraulic elevation process. The sinus membrane elevation height was set at 1-6 mm. The pressure required for elevation and the equivalent, compressive, tensile, and shear stresses generated on the sinus membrane were recorded and analyzed. The equivalent stress distribution on the sinus membrane was visualized using contour plots.

The elevation pressure and the equivalent, compressive, tensile, and shear stresses generated on the sinus membrane increased along with the elevation height. When the sinus membrane was lifted to 6 mm, the elevation pressure was (301.17 ± 98.1) kPa, (151.85 ± 3.7) kPa, and (149.36 ± 10.31) kPa in the slope, flat and concave finite element analysis models, respectively. The equivalent stress was (1023.86 ± 201.99) kPa in the slope sinuses, comparing with (687.91 ± 69.08) kPa and (698.27 ± 96.09) kPa in the flat and concave sinuses. Higher elevation pressure and the equivalent stress, compressive stress and shear stress values were found in the slope sinus than in the flat and concave sinuses under the same elevation height (P < 0.05). Stress distribution analysis revealed that stress was uniformly distributed in the flat sinuses, followed by concave sinuses, but asymmetrically distributed in the slope sinuses.

The slope sinuses demonstrated inferior safety and efficiency compared with the flat and concave sinuses when performing hydraulic sinus floor elevation surgery.