Just a stab in the dark. Try selecting the object and then mesh>clean check all the boxes for non-manifold, laminar faces, faces with zero area and edges with zero length.

Also goto vert mode and select the entire model and be sure you do not have any floating verts

If that fails, if you don't mind sharing the model, compress it in a zip file and upload it and I will be happy to take a look at it to see whats causing the additional geo.