What Does the Periodontal Ligamen (PDL) Do?
The periodontal ligament does not support the outer gum tissues and is only found between the root part of the tooth and the adjacent bone. This complex tissue allows the tooth to function under the load of chewing and absorb excess pressure from clenching and grinding. The ligament is also involved in tooth movement and aids in the eruption of the tooth.
The PDL is also what makes orthodontic tooth movement possible. If the tooth were directly connected to the bone, the tooth would function similarly to a dental implant and not be able to move. Because the tooth is held in the socket by the periodontal ligament and not a direct bone-to-tooth interface, it can usually be extracted without removing any significant areas of the jawbone.
The periodontal ligament also allows the tooth to adapt to forces from tooth grinding (also known as bruxism) or other jaw clenching habits. The ligament can enlarge and allow the tooth to become loose. Once the excessive forces on the tooth are reduced, the PDL will heal, and tooth mobility will decrease.