This document discusses growth spurts and their significance in orthodontics. It begins by defining growth and development, and describing the major developmental growth periods. It then discusses methods for studying growth, including longitudinal, cross-sectional, and semi-longitudinal studies. Key factors that influence growth and maturation are genetic, hormonal, nutritional, environmental and socioeconomic factors. The document explores concepts of growth including normality, growth rhythms, differential growth, and growth spurts. It concludes by noting the significance of growth spurts is important for orthodontic treatment planning.