Abstract :
Materials and methods: 3D finite element model of maxillary bone (both cortical and cancellous) and mini-screws were generated
on a computer to evaluate stress values at bone and mini-screw interface with varying the angle of insertion, length and diameter. Miniscrews
having diameter of 1.6 mm and 2 mm were used. The length of miniscrews was fixed at 8 mm, 10 mm and 12 mm. These were
inserted at 4 different insertion angles of 450, 600, 750 and 900.
Results: Comparison of the maximum von Mises stress in the cortical and cancellous bone showed that stress/strain field that
develops at the mini-screw and bone interface decreased with increase in diameter, length and insertion angle of the mini-screw.
Conclusion: Wider bi-cortical mini-screws should be preferred over mono-cortical mini-screws and should be placed as perpendicular
to the bone as possible for better and enhanced stability.
Keyword :
Mini-screw, Finite Element Analysis, Mono-cortical, Bi-cortical