Tooth Root Development and Homeostasis during Eruptive and Post-eruptive Movement.

Tooth eruption is the process whereby the developing tooth moves to its functional position in the occlusal plane and it occurs concomitantly with formation of the tooth root, which is a critical component of the tooth anchored to surrounding alveolar bone through the periodontal ligament. Post-eruptive tooth movement ensues that once occlusion is achieved, the teeth maintain their alignment within the alveolar bone to facilitate proper bite function through periodontium remodelling. Tooth overeruption presents a clinically significant issue, yet the precise mechanisms by which alterations in occlusal forces are translated into periodontal remodelling remain largely unexplored. In this review, the present authors aim to outline the latest progress on the potential mechanisms governing tooth root formation and homeostasis during tooth eruptive and post-eruptive movement. Based on recent findings using various mouse models, we provide an overview of the collaborative intercellular interaction during root formation, including Hertwig's epithelial root sheath, dental papilla and dental follicle. Moreover, we summarise the potential mechanism underlying post-eruptive movement mainly in view of the responses of periodontal tissues to vertical mechanical stimuli. In sum, the precise regulatory mechanisms during tooth eruption throughout life will shed light on disease treatment of tooth eruption defects and overeruption.