Function of Orofacial Stem Cells in Tooth Eruption: An Evolving Perspective

Tooth eruption is closely linked to the normal development of dentition and proper establishment of occlusion. Disturbances in tooth eruption may affect oral physiological functions, facial contour and aesthetics; it is therefore important to understand the eruption process. This process is a complex biological event involving dynamic changes at the tissue and cellular levels. It is guided by anatomical structures as well as biological and molecular factors that result in the movement of the tooth to its final functional position in the oral cavity. Evidence increasingly suggests that stem cells contribute to tooth development and eruption. Multiple stem cell populations have been discovered in teeth and in their supporting tissues, such as dental follicle precursor cells, orofacial bone-/bone marrow-derived mesenchymal stem cells, periodontal ligament stem cells, stem cells from the apical papilla and dental pulp stem cells. These stem cells exhibit distinct differentiation capacities and are closely linked to alveolar bone remodelling, periodontium development and root formation during the eruption process. The present review summarises the current knowledge of the characteristics and functions of orofacial stem cells in tooth eruption, with a particular focus on recent discoveries concerning their lineage allocation and regulatory mechanisms.