periodontal ligament histology and anatomy

Periodontal Ligament Histology
The ligament which is present around the tooth area and acts as an anchor with alveolar bone having very important functions

1. Periodoantal ligament Dr Dinraj Kulkarni [BDS, MDS, PGDCR, PGDNT, FICD, PhD] Dr Dinraj Kulkarni, NEET PAI Dental wisdom Academy

2. Periodontium Periodontium – is a connective tissue organ , covered by epithelium that attaches the teeth to the bones of the jaws and provides a continually adapting apparatus for support of the teeth during function. It comprises of cementum, PDL, alveolar bone & part of gingiva facing the tooth ( dentogingival junction) Dr Dinraj Kulkarni, NEET PAI Dental wisdom Academy

3. Periodontal ligament The periodontal ligament is the dense fibrous connective tissue that occupies the periodontal space between the root of the tooth and the alveolus. Though it is a part of connective tissue consisting of epithelial cells in the form of “ R emnants of HERS cells (Cell rest of Malassez ” PDL occupies the space between cementum and periodontal surface of the alveolar bone known as “PDL space”. On radiograph it is about 0.4 to 1.5 mm. it is narrow in permanent than in deciduous dentition. Dr Dinraj Kulkarni, NEET PAI Dental wisdom Academy

4. PDL ranges in width from 0.15 to 0.38 mm. Thinnest around the middle third of the root at “fulcrum of rotation ” with an “Hour glass appearance”. Shows progressive decrease in thickness with age. Thickness of PDL – young adult (0.21 mm); mature adult (0.18 mm); older adult (0.15 mm). In mammals independent and tough suspension for the teeth is provided by PDL Dr Dinraj Kulkarni, NEET PAI Dental wisdom Academy

5. Dr Dinraj Kulkarni, NEET PAI Dental wisdom Academy

6. The most predominant connective tissue cell of PDL is – fibroblast. The main type collagen fibers in PDL – Type I (more than 70%) & III. Collagen biosynthesis occurs inside – Fibroblasts . PDL fibroblasts have special feature – presence of actin fibers which help for contraction and relaxation and also for shape change. Fibronectin is the part of glycoprotein that promotes the attachment of cells to the substratum especially collagen. Expressed strongly with cementum and PDL not with the bone. Dr Dinraj Kulkarni, NEET PAI Dental wisdom Academy

7. Dr Dinraj Kulkarni, NEET PAI Dental wisdom Academy

8. Sharpey’s fibers derived from Dental Follicle or sac Dr Dinraj Kulkarni, NEET PAI Dental wisdom Academy

9. Dr Dinraj Kulkarni, NEET PAI Dental wisdom Academy

10. The vascular supply of the PDL is – net like plexus that runs closer to the bone than to the cementum. Inferior and superior alveolar artery Nerve supply Dr Dinraj Kulkarni, NEET PAI Dental wisdom Academy

11. Functions Supportive Sensory Homeostatic Nutritive Eruptive Physical Dr Dinraj Kulkarni, NEET PAI Dental wisdom Academy

12. Narrowing of PDL in labially placed mandibular canine with age due to -- deposition of cementum and bone Dr Dinraj Kulkarni, NEET PAI Dental wisdom Academy

13. THANK YOU Dr Dinraj Kulkarni, NEET PAI Dental wisdom Academy