This Book describes about extra-alveolar TADs(Temporary Anchorage Device) and its various biomechanics based on its anatomical insertion.This book also describes about efficieny and stability of tads and various literature reviews. One of the most revolutionary advancements in this field has been the introduction of Temporary Anchorage Devices (TADs). Among them, Extra-Alveolar TADs-such as the infrazygomatic crest (IZC) and buccal shelf (BS) screws-have significantly broadened the scope of orthodontic tooth movement by providing absolute anchorage from outside the dental alveolus. As Dr. John Lin aptly stated, "When anchorage is no longer a limitation, biomechanics becomes limitless." This quote resonates profoundly in the era of skeletal anchorage, where extra-alveolar TADs empower clinicians to execute complex movements without relying on patient compliance or compromising adjacent teeth. These devices, inserted in robust bone regions away from tooth roots, allow en-masse retraction, molar distalization, intrusion of posterior segments, and even skeletal open bite correction-all of which were once challenging using traditional techniques.