What is the intermediate plexus of PDL?
Intermediate between the bone and the cementum in actively erupting teeth (or orthodontic movements) the fibers of the periodontal ligament form a plexus of intermingling fibers (C). This plexus is called the intermediate plexus.
What are the structural elements of periodontal ligament?
The PDL consists of principal fibers, loose connective tissue, blast and clast cells, oxytalan fibers and Cell Rest of Malassez. The primary principal fiber group is the alveolodental ligament, which consists of five different fiber subgroups.
What is periodontium ligament?
The Periodontal Ligament (PDL) can be defined as a fibrous joint that anchors the root of the tooth to the alveolar bone socket. Made of fibrous connective tissue, it holds the tooth in sprung suspension enabling the tooth to take on the mechanical pressure during function.
What is the shape of periodontal ligament?
Introduction to periodontal ligament It is a complex, vascular, and highly cellular soft connective tissue interposed between roots of the teeth and the inner wall of the alveolar socket. It has the shape of an “hour glass” and is narrowest at the midroot level.
Where is the periodontal ligament located?
The periodontal ligament is only found between the tooth root and adjacent bone and does not support the outer gum tissues. The complex nature of the PDL tissue allows the tooth to properly function during chewing and to withstand the pressure from grinding or clenching.
What is the shape of PDL?
Introduction to periodontal ligament It has the shape of an “hour glass” and is narrowest at the midroot level. The PDL consists of a fibrous stroma in a gel of ground substance containing cells, blood vessels and nerves 202.
What causes widened PDL?
According to Auluck,5 widening of the PDL space is due to the involvement of the masticatory muscle, which becomes bulky, leading to an increased occlusal load and primary trauma from occlusion. Mehra6 suggested that an increase in the collagen synthesis in scleroderma may be the possible cause of PDL space widening.
What is dehiscence in perio?
PERIODONTAL DISEASES – PLAQUE, CALCULUS AND REGRESSIVE CHANGES (Page 4 of 4) Dehiscence and Fenestration (Fig. 18-8) A dehiscence is loss of alveolar bone on the facial (rarely lingual) aspect of a tooth that leaves a characteristic oval, root-exposed defect from the cementoenamel junction apically.
What is the width of periodontal ligament?
The normal width of the PDL ranges from 0.15 mm to 0.21 mm, which may decrease with age. 1,4 Widening of the PDL is one of the most important changes in the circumdental structures and may be related to different abnormalities.
How is the periodontal ligament formed?
The periodontal ligament is a unique specialised connective tissue between the cementum covering the tooth root and the alveolar bone. It is derived from the dental follicle region, which originates from the cranial neural crest cells .
What is intermediate plexus?
INTERMEDIATE PLEXUS Earlier it was believed that principal fibers follow a wavy course from cementum to bone and are joined in the mid region of the periodontal space giving rise to a zone of distinct appearance i.e the Intermediate plexus .
What are the principal fibers of periodontal ligament?
PERIODONTAL FIBERS Most important elements of periodontal ligament are the principal fibers which are collagenous & arranged in bundles & follow a wavy course when viewed in longitudinal section. Terminal portions of principal fibers are inserted into cementum called SHARPEY’S FIBERS.
What is the periodontal ligament (PDL)?
69. CONCLUSION • The periodontal ligament is a fibrous connective tissue forming important part of the Periodontium. • The PDL is a physically small, but functionally important tissue in tooth support, proprioception and regulation of alveolar bone volume.
How are periodontal ligaments compressed and stretched?
The periodontal ligament fibers are compressed in areas of pressure and stretched in area of tension. 143 141. VISCOELASTIC THEORY • According to it, the fluid movement largely controls the displacement of the tooth, with fibers playing a secondary role.