1. Occlusal development occurs in four periods: pre-dental, primary dentition, mixed dentition, and permanent dentition periods. 2. During the pre-dental period, gum pads are present with grooves that will guide tooth eruption. 3. The primary dentition erupts in a set sequence between 6-24 months and is characterized by spacing between incisors. 4. The mixed dentition period involves the eruption of both primary and permanent teeth between 6-12 years, with the potential for crowding as permanent teeth are larger. 5. During the permanent dentition period after age 12, teeth continue erupting through stages of pre-emerg