User:Globalorthodontist/Orthodontic tooth movement

Orthodontic tooth movement is a general term that defines different ways a tooth can move.

Key Terms

 * Center of Resistance - It is a point of an object as force applied through center of mass which leads to an object moving in linear fashion or translation without any rotational movement. A center of resistance of a tooth can depend on its size of the root and the associated bone support of that tooth. The center resistance of each tooth is an arbitrary point that has been a point of discussion throughout orthodontic literature. Over the years several different definitions have been circulated in the literature such as
 * Center of Rotation - It is point of an object through which when a force is applied, leads to a rotational movement.
 * Moment (force) - This moment is produced when a line of force does not go through a center of resistance of an object. The moment due to force causes a rotational effect that is either clockwise or counterclockwise. The MF = F (force) x D (distance) is measured in g/mm. It is important to understand that when a force is applied in orthodontics to move teeth, the force acts on a bracket which does not lie in the same plane as a center of resistance of that tooth. Therefore, MF is produced in most cases.
 * Moment (couple) - A moment due to couple is created
 * Counter-moment -
 * Couple - A couple is a type of movement that is produced by two forces that are equal, opposite and parallel to each other.
 * Torque -
 * Tip -

M/F Ratios
The moment due to force ratios are determine the counterbalancing moment that is acting to oppose the net force being acted on a tooth. This counterbalacing moment always acts opposite to the moment due force.

Types of Orthodontic tooth movements
Orthodontic tooth movements can occur in 5 different ways as described below. In orthodontic literature, these movements are defined by the location of their center of rotation.
 * Translation Movement -
 * Rotational Movement - It is a pure rotation of a tooth as its center of rotation of is located at the center of resistance point.
 * Controlled Tipping
 * Uncontrolled Tipping
 * Root Movement - It is defined by movement of the root of a tooth only, without the crown moving. Some have also defined it as the center of rotation at the crown due to which the root moves.