Periodontal Ligament Information
The periodontal fiber or periodontal ligament, commonly abbreviated as the PDL, is a group of specialized connective tissue fibers that essentially attach a tooth to the alveolar bone within which it sits.[1] These fibers help the tooth withstand the naturally substantial compressive forces which occur during chewing and remain embedded in the bone.
Functions of PDL are supportive, sensory, nutritive, homeostatic and eruptive.
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Structure of the PDL
It consist of cells, extracellular compartment of fibers. The cells are fibroblast, epithelial, undifferentiated mesenchymal cells, bone and cementum cells. The extracellular compartment consists of collagen fibers bundles embedded in ground substance. The PDL substance has been estimated to be 70% water and is thought to have a significant effect on the tooth's ability to withstand stress loads.
Types of fibers
A)The PDL collogen fibers are categorized according to their orientation and location along the tooth. They are:
Alveolar crest fibers
Alveolar crest fibers attach to the cementum just apical to the cementoenamel junction, run downward, and insert into the alveolar bone. They function to counterbalance occlusal forces on the more apical fibers and resist lateral movements.
Horizontal fibers
Horizontal fibers attach to the cementum apical to the alveolar crest fibers and run perpendicularly from the root of the tooth to the alveolar bone.
Oblique fibers
Oblique fibers are the most numerous fibers in the periodontal ligament, running from cementum in an oblique direction to insert into bone coronally.
Apical fibers
radiating from cementum around the apex of the root to the bone, forming base of the socket
Interradicular fibers
Interradicular fibers are only found between the roots of multi-rooted teeth, such as molars. They also attach from the cementum and insert to the nearby alveolar bone. B)Elastic fibrils: 1- Oxylatan 2- Elumine 3- Elastine
Pathology
The completeness and vitality of the PDL are essential for the functioning of the tooth. Damage to the PDL may result in ankylosis of the tooth to the jawbone, making the tooth loss its continuous eruption ability. Dental trauma, such as subluxation, may cause tearing of the PDL and pain during function (eating).[2]
References
- ^ Herbert F. Wolf; Klaus H. Rateitschak (2005). Periodontology. Thieme. pp. 12–. ISBN 9780865779020. http://books.google.com/books?id=LIQ_J5WzuKUC&pg=PA12. Retrieved 21 June 2011.
- ^ Zadik Y (December 2008). "Algorithm of first-aid management of dental trauma for medics and corpsmen". Dent Traumatol 24 (6): 698-701. PMID 19021668. http://onlinelibrary.wiley.com/doi/10.1111/j.1600-9657.2008.00649.x/abstract.
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Categories: Skull | Ligaments of the head and neck | Teeth
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