Mini implants as a means of absolute anchorage have travelled a long journey, crossing numerous obstacles to enjoy the success rate that it does today. The value of mini screw implants is in the prerequisite that, they remain relatively stationary in the bone, their ability to increase anchorage capacity, and the absence of adverse effects or complications that could endanger health or treatment outcome. Their clinical effectiveness lies in their ability to maintain close bone contact, thus resisting reactive orthodontic forces. Hence, it is wise to always consider the factors that influence its success to ensure making any undue errors that could have been avoided. This book contains the various factors effecting the primary stability of mini implants.