The Role of Components and Molecules of Periodontal Ligament in Orthodontic Tooth Movement

Orthodontic treatment requires moving and aligning the teeth into a favorable position aesthetically and functionally. To achieve that, the teeth are subjected to forces to push them to their new position. Loading of force on the crown causes tipping of tooth, subsequently the periodontal ligament is compressed adjacent to the alveolar bone on the side toward which the force is directed. On the opposite side of the root, the periodontal ligament is stretched and undergoing tension. Blood vessels are compressed and blood flow is decreased on the compression side, hence less oxygen supply is received on that side. Compression and tension are triggering specific signaling factors and mediators, which create local environment and gradients to regulate remodeling of the periodontal ligament and bone for tooth movement. In this review, we highlight the structures and mediators released in the very narrow zone periodontal ligament during orthodontic tooth loading.