THE MECHANICAL ROLE OF THE PERIODONTAL LIGAMENT FOR DEVELOPING MATHEMATICAL MODELS IN ORTHODONTICS

Orthodontic treatment is based on the possibility to consciously move teeth within the alveolar bone by applying a force with appropriate magnitude and module. Histological studies confirmed that tooth movement is the result of bone remodeling, but the exact mechanism that transforms a quasistatic force into a signal that is able to initiate bone resorption and apposition is not fully known. Indeed, the clinical observation of the tooth movement phenomenon would suggest a bone response that seems to contradict the pivotal mechanostat theory of Frost. This apparent inconsistency could be explained by the presence of a soft, hyperelastic, viscoelastic, and anisotropic interface constituted by the periodontal ligament, a bundle of connective fibers anchoring and suspending the tooth to its alveolar bony socket. The landmarks and the gaps of the current knowledge are discussed, then some guidelines and perspectives to develop a mathematical model capable of predicting the mechanical behavior of the orthodontic force/periodontal ligament/alveolar bone interaction are provided.