Influence of Intruding Angle on Non-graft Osteotome Sinus Elevation

The contour of maxillary sinus matters in osteotome sinus elevation. So does the implant intruding angle between the axis of the implant and the tangent line of the sinus floor contour. The investigators have been engaged in studying the relationship between the outcome of bone formation and the intruding angle, which could guide our clinical decision-making.