Rationalization of Mechanical Factors affecting Primary Stability of Orthodontic Miniscrew using Engineering Principles of Simple Machines

Miniscrews have become the regular components as an anchorage source in orthodontics. Stability and failure of miniscrew is materializing to be multifactorial with no consensus on causative factors. Factors that influence the load transfer at the bone-implant interface and miniscrew stability include host factors, biomechanical factors, sterilization protocol and hygiene. Biomechanical influences on bone structure play an important role in the longevity of bone. Incorrect loading or overloading as a result of ineffective implant geometries may lead to implant loss. Miniscrews are not an exception for following the mechanical behavior or engineering principles. More certainly, they are based on the simple machines, which is a mechanical device that changes the direction or magnitude of a force. This article produces an insight for rationalization of mechanical factors controlling the stability with principles of simple machines, namely (i) lever, (ii) wheel and axle, (iii) inclined plane, (iv) wedge and (v) screw.