The gingiva, periodontal ligament, cementum and the alveolar bone form the investing tissues of the teeth called the periodontium. This is a book that unravels the mysteries of the developmental aspect of the Periodontium. Understanding the anatomy and its evolution from the embryo to a whole functional unit enables any clinician to base his diagnosis for the patient. Periodontology being the science of the smallest part of the body, this is an attempt to understand it.