Developmental defects of Enamel (DDE) are common dental problems that are commonly encountered by the dentist during routine dental practice. DDE result from the effects of genetic, environmental and nutritional factors that affects the enamel during its formation or development period. The effects may be on the laying of the enamel matrix or on the maturation of the enamel. The total result is an effect on on the patient of either the function, aesthetics or both. Many dentists experience difficulties in distinguishing one type of DDE from the other, hence the importance of writing this book. In this book, four types of DDE have been described and a suggestion made on the management regimes of each condition. It is hoped that the book will help many of these dentist to adequately understand and deal with DDE when they encounter them during their routine practice.