This book provides an insight to Regional Acceleratory Phenomenon (RAP) in Orthodontics. Clinical orthodontics is successful from patient perspective if it delivers perfect aesthetics with priority timing. Every orthodontic patient desires shortened treatment time. Surgical techniques, like alveolar decortication, traumatizing the cortical alveolar bone to causes a localized inflammatory response and thereby increases the regular bone turnover i.e. the regional accelerated phenomenon and increase the rate of tooth movement. RAP plays a pivotal role in the field of accelerated orthodontics. RAP was discovered by Harold Frost way back in 1983 and since then the principles to fasten tooth movement has remained but the methods have evolved. The prime objective of this book is to elucidate about RAP and its clinical implications to accelerate OTM.