The periodontal ligament (PDL) is a specialised connective tissue ligament that suspends each tooth root within its alveolar socket, connecting the root cementum to the alveolar bone via principal fibre bundles running in oblique directions to maximise force absorption. The PDL provides the remarkable ability to sense extremely small biting forces (as low as 1 gram) through its abundant mechanoreceptors, enabling the precise force modulation during chewing.
| Origin | Alveolar bone crest and alveolar socket walls |
|---|---|
| Insertion | Cementum covering the dental root |
| Actions | Suspends the tooth in the alveolar socket; absorbs and distributes masticatory forces; provides proprioceptive sensation of biting force |
|---|
Periodontal disease from bacterial plaque causes PDL destruction progressing from gingivitis to periodontitis with bone loss and eventual tooth loss. The PDL's fibre bundles between tooth and bone make orthodontic tooth movement possible — controlled force causes PDL compression on the pressure side (bone resorption) and PDL tension on the tension side (bone deposition), allowing tooth migration. Replanted avulsed teeth must be replanted within 30 minutes to allow PDL cell survival and successful reattachment.
Bacterial infection destroying the periodontal ligament and alveolar bone causing progressive tooth attachment loss and eventual tooth loss, managed with scaling, root planing, and surgical periodontal treatment.
