Review for the National Dental Hygiene Board Exams (NBDHE and NDHCE) Course Content Lessons Status 1 Embryology Overview 2 Preimplantation Period 3 Embryonic Period 4 Development of the Face 5 Stages of Tooth Development 6 Cleft Palate and Cleft Lip 7 Development of the Tooth Layers 8 Development of the Periodontium 9 Succedaneous and Non-Succedaneous Teeth 10 Oral Epithelium 11 Histology QuizzesStatus 1 Embryology and Histology (set 1) 2 Embryology and Histology (set 2)