Periodontal fiber

Periodontal ligament
The tissues of the periodontium combine to form an active, dynamic group of tissues. The alveolar bone (C) is surrounded for the most part by the subepithelial connective tissue of the gingiva, which in turn is covered by the various characteristic gingival epithelia. The cementum overlaying the tooth root is attached to the adjacent cortical surface of the alveolar bone by the alveolar crest (I), horizontal (J) and oblique (K) fibers of the periodontal ligament.
Details
Precursor	dental follicle
Latin	fibra periodontalis
*Anatomical terminology* [edit on Wikidata]

The 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]

Development

Similar to the alveolar bone, the PDL develops from the dental sac of the tooth germ.^[2]

Features

Functions of PDL are supportive, sensory, nutritive, and remodeling.^[3]

The PDL substance has been estimated to be 70% water, which is thought to have a significant effect on the tooth's ability to withstand stress loads. The completeness and vitality of the PDL are essential for the functioning of the tooth.

The PDL ranges in width from 0.15 to 0.38mm with its thinnest part located in the middle third of the root.^[4]

The PDL is a part of the periodontium that provide for the attachment of the teeth to the surrounding alveolar bone by way of the cementum.

The PDL appears as the periodontal space of 0.4 to 1.5 mm on radiographs, a radiolucent area between the radiopaque lamina dura of the alveolar bone proper and the radioopaque cementum.

There are progenitor cells in the periodontal ligament that can differentiate into osteoblasts for the physiological maintenance of alveolar bone and, most likely, for its repair as well.^[5]

Structure

The PDL consist of cells, and extracellular compartment of fibers.^[5] The cells are fibroblast, epithelial cells, undifferentiated mesenchymal cells, bone and cementum cells. The epithelial rests of Malassez are also present; these groups of epithelial cells become located in the mature PDL after the disintegration of Hertwig epithelial root sheath during the formation of the root.^[2] The extracellular compartment consists of Type 1, 3, and 5 collagen fibers bundles embedded in intercellular substance. The PDL collagen fibers are categorized according to their orientation and location along the tooth.^[6]

Alveolodental ligament

The main principal fiber group is the alveolodental ligament, which consists of five fiber subgroups: alveolar crest, horizontal, oblique, apical, and interradicular on multirooted teeth. Principal fibers other than the alveolodental ligament are the transseptal fibers.

All these fibers help the tooth withstand the naturally substantial compressive forces which occur during chewing and remain embedded in the bone. The ends of the principal fibers that are within either cementum or alveolar bone proper are considered Sharpey fibers.

Alveolar crest fibers

Alveolar crest fibers (I)run from the cervical part of the root to the alveolar bone crest

Horizontal fibers

Horizontal fibers (J) 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 (K) are the most numerous fibers in the periodontal ligament, running from cementum in an oblique direction to insert into bone coronally.

Apical fibers

Apical fibers are found radiating from cementum around the apex of the root to the bone, forming base of the socket or alveolus.

Interradicular fibers

Interradicular fibers are only found between the roots of multirooted teeth, such as premolars and molars. They extend from radicular cementum to interradicular alveolar bone.

Transseptal fibers

Transseptal fibers (H) extend interproximally over the alveolar bone crest and are embedded in the cementum of adjacent teeth; they form an interdental ligament. These fibers keep all the teeth aligned. These fibers may be considered as belonging to the gingival tissue because they do not have an osseous attachment.^[7]

Pathology

Damage to the PDL may result in tooth ankylosis to the jawbone, making the tooth lose its continuous eruption ability. Dental trauma, such as subluxation, may cause tearing of the PDL and pain during function (eating).^[8]
The epithelial rests of Malassez can become cystic, usually forming nondiagnostic, radiolucent apical lesions that can be seen on radiographs. This occurs as a result of chronic periapical inflammation after pulpitis occurs and must be surgically removed.^[2]
The PDL also undergoes drastic changes with chronic periodontal disease that involves the deeper structures of the periodontium with periodontitis. The fibers of the PDL become disorganized, and their attachments to either the alveolar bone proper or cementum through Sharpey fibers are lost because of the resorption of these two hard dental tissue.^[2]
When traumatic forces of occlusion are placed on a tooth, the PDL widens to take the extra forces. Thus, early occlusal trauma can be viewed on radiographs as a widening of the periodontal ligament space. Thickening of the lamina dura in response is also possible. Clinically, occlusal trauma is noted by the late manifestation of increased mobility of the tooth and possibly the presence of pathological tooth migration.^[2]

External links

Max A. Listgarten, University of Pennsylvania and Temple University at http://www.dental.pitt.edu/informatics/periohistology/en/gu0401.htm
Structure of periodontal tissues in health and disease, Nanci and Bosshardt, Periodontology 2000, Vol. 40, 2006, 11–28 at http://www.nancicalcifiedtissuegroup.com/documents/Nanci%202006.pdf

References

↑ Herbert F. Wolf; Klaus H. Rateitschak (2005). Periodontology. Thieme. pp. 12–. ISBN 978-0-86577-902-0. Retrieved 21 June 2011.
1 2 3 4 5 Illustrated Dental Embryology, Histology, and Anatomy, Bath-Balogh and Fehrenbach, Elsevier, 2011, page 184.
↑ Max A. Listgarten, University of Pennsylvania and Temple University at http://www.dental.pitt.edu/informatics/periohistology/en/gu0401.htm
↑ Ten Cate's Oral Histology, Nanci, Elsevier, 2013, page 220
1 2 Structure of periodontal tissues in health and disease, ANTONIO NANCI & DIETER D. BOSSHARDT, Periodontology 2000, Vol. 40, 2006, 11–28 at http://www.nancicalcifiedtissuegroup.com/documents/Nanci%202006.pdf
↑ Max A. Listgarten, University of Pennsylvania and Temple University, http://www.dental.pitt.edu/informatics/periohistology/en/gu0404.htm
↑ Ten Cate's Oral Histolog, Nanci, Elsevier, 2013, page 274
↑ Zadik Y (December 2008). "Algorithm of first-aid management of dental trauma for medics and corpsmen". Dent Traumatol 24 (6): 698–701. doi:10.1111/j.1600-9657.2008.00649.x. PMID 19021668.

Dentistry involving supporting structures of teeth (Periodontology)

Anatomy

Disease

Diagnoses	Chronic periodontitis Localized aggressive periodontitis Generalized aggressive periodontitis Periodontitis as a manifestation of systemic disease Periodontosis Necrotizing periodontal diseases Abscesses of the periodontium Combined periodontic-endodontic lesions

Infection	A. actinomycetemcomitans Capnocytophaga sp. F. nucleatum P. gingivalis P. intermedia T. forsythia T. denticola Red complex

Other	Calculus Clinical attachment loss Edentulism Fremitus Furcation defect Gingival enlargement Gingival pocket Gingival recession Gingivitis Horizontal bony defect Linear gingival erythema Occlusal trauma Periodontal pocket Periodontal disease Periodontitis Plaque Vertical bony defect

Treatment and prevention	Periodontal examination Ante's law Brushing Bleeding on probing Chlorhexidine gluconate Flossing Hydrogen peroxide Mouthwash Oral hygiene Tetracycline Triclosan Host modulatory therapy

Treatment

Conventional therapy	Debridement Scaling and root planing Full mouth disinfection Full mouth ultrasonic debridement

Surgery	Apically positioned flap Bone graft Coronally positioned flap Crown lengthening Open flap debridement Gingival graft Gingivectomy Guided bone regeneration Guided tissue regeneration Enamel matrix derivative Implant placement Lateral pedicle graft Pocket reduction surgery Socket preservation Sinus lift Subepithelial connective tissue graft Tools Curette Membrane Probe Scaler

Important personalities

Other specialties

Endodontology
Orthodontology
Prosthodontology

Fibrous joints of the human skull

Syndesmosis	Pterygospinous ligament Stylohyoid ligament

Sutures	Involving the frontal bone frontoethmoidal suture frontal suture coronal suture occipitomastoid lambdoid sagittal Involving the sphenoid bone sphenoethmoidal with frontal bone with parietal bone sphenosquamosal Involving the Petrous part of the temporal bone sphenopetrosal petrosquamous squamosal Facial: palatomaxillary suture Involving the zygomatic process with sphenoid bone with temporal bone with frontal bone

Mouth	Gomphosis Periodontal fiber Periodontium Dental alveolus Gingiva Cementum

Anatomy of the mouth

Lip	Upper Lower Vermilion border Frenulum of lower lip Labial commissure of mouth Philtrum

Cheek	Buccal fat pad

Roof	Hard palate Soft palate Palatine raphe Incisive papilla

Gums	Interdental papilla Gingival sulcus Gingival margin Gingival fibers Junctional epithelium Mucogingival junction Sulcular epithelium Stippling Periodontium Cementum Gingiva Periodontal ligament

Glands	Parotid gland duct Submandibular gland duct Sublingual gland duct

Teeth	see tooth anatomy

Tongue	Top Taste bud Median sulcus Terminal sulcus Foramen cecum Lingual tonsils Underside Frenulum Plica fimbriata Sublingual caruncle Glossoepiglottic folds Lingual septum

Back of mouth	Oropharynx fauces Plica semilunaris of the fauces Uvula Palatoglossal arch Palatopharyngeal arch Tonsillar fossa Palatine tonsil

This article is issued from Wikipedia - version of the Monday, March 14, 2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.