Odontogenesis refers to the process of tooth formation, eruption and integration with its surrounding tissues. It encompasses primary and permanent dentition development. Odontogenesis involves the intra-oral molecular embryological process in which teeth are formed from specialised embryonic cells until their root formation and eruption are completed. Genetically complex processes regulate initial dental histological organisation, histodifferentiation, morphodifferentiation, spatial tooth arrangement, amelogenesis, dentinogenesis, cementogenesis, periodontal ligament formation and tooth eruption. A cascade of gene expression occurs to direct cells along the appropriate differentiation pathways. Signalling pathways involved in this cascade include (1) bone morphogenetic protein (BMP), (2) fibroblast growth factor (FGf), (3) sonic hedgehog (Shh), (4) Wingless-related integration site (Wnt) and (5) ectodysplasin A (EDA). Determining specific tooth types at their correct positions in the jaws is called patterning of the dentition.