There has been much debate over the appropriate treatment time as well as the most suitable methods concerning crowding diagnosed during the early mixed dentition period.This practical guide contains essential and latest information on clinical diagnosis & various non extraction methods of treating space discrepancies. Salient features includes : Different types of Space regainers ,Their Indications,Design & construction and latest introduced space regainers ; Basic concepts of expansion & Various Expansion devices (slow & rapid),their use in cleft lip & palate patients , Surgically assisted expansion. It is a definitive guide providing essential practical information for all dental undergraduates, practitioners & postgraduate trainees.