The formation and maturation of dental tissues constitute an important process in craniofacial development. Genes coding the expression of growth factors, transcription factors and extracellular matrix molecules regulate this process. Tooth eruption through the dental follicle is a complex phenomenon. It involves osteoblastic and osteoclastic activity that contributes to form dentoalveolar bone. This bone formation and the development of dental occlusion, first for the deciduous, then for the succedaneous dentition, has a profound impact on the development of the lower part of the face. The mode of tooth eruption, guided by precise genetic control, is influenced by its neuromuscular environment and the response of the periodontal ligaments to the environment. Tooth positioning is altered by functional imbalance; as the periodontal ligament responds to forces and rapidly remodels the dentoalveolar complex in order to maintain the necessary physiological distance between the alveolar wall and the dental root.