Odontogenic cyst
Odontogenic cysts (from Greek : ὀδούς odous “the tooth” and γὲνεσις genesis “origin”) (cysts originating from the tooth) are cysts in the jaw area, the origin or formation of which goes back to teeth or dental organs . There are no comparable changes in any other region of the body.
requirements
The formation of odontogenic cysts requires epithelium in the depth of the tissue and requires a stimulus that promotes proliferation. They are surrounded by an independent wall that consists of connective tissue and is lined with epithelium . They contain liquid or pulpy contents. They grow purely expansively (displacingly), are benign structures and normally painless as long as they are not infected . They grow slowly, the mucous membrane over the cyst remains flexible.
diagnosis
Larger cysts can cause swellings in the oral vestibule or even externally in the corner of the jaw . Upon pressure, you may hear a parchment-like crackling sound when the often thin outer bone lamella breaks. Due to their slow growth, odontogenic cysts cause no symptoms for a long time and so often appear as "secondary findings" in X-rays . Due to their displacement, cysts can cause teeth to shift or tilt as they grow. Root resorptions can also occur, which in turn can lead to tooth loosening (up to and including tooth loss).
Classification of odontogenic cysts
Odontogenic cysts are divided into:
Radicular cysts
A radicular cyst (also called a tooth root cyst) develops in the vicinity of the tip of the root of a devitalized ( pulp-dead ) tooth.
Emergence
Valderhaug divided the pathogenesis of radicular cysts, which is based on inflammatory stimuli , into three phases.
First of all, as a result of chronic inflammation at the tip of the root ( periodontitis apicalis chronica ), epithelial cells , which originate from Malassez epithelial remnants, proliferate .
The inflammation in the apical area of a non-vital tooth or in a periapical granuloma is caused by bacterial endotoxins . Endotoxins act as mitogens for the epithelial cell and stimulate the production of cytokines . These are produced by activated cells of the immune system . Some important cytokines are interleukin ( IL-1 ) and interleukin ( IL-6 ), transforming growth factor ( TGF-β ), platelet derived growth factor (PDGF), and tumor necrosis factor (TNF).
From these proliferating epithelial strands, the wall of a cavity is formed simultaneously intra- and extraepithelially. This happens through the simultaneous disintegration of epithelium and granulation tissue and confluence of the cavities with subsequent epithelialization.
The cyst lumen (cavity) is filled with a yellowish liquid permeated with cholesterol crystals. A radicular cyst can remain and continue to grow after the tooth has been removed if the connective tissue cyst capsule (cyst follicle) is not carefully removed. The disintegration of epithelial cells and leukocytes and the accumulation of plasma exudate increase the osmolarity of the cyst fluid compared to that of the serum . As a result, the internal hydrostatic pressure becomes greater than the capillary pressure and tissue fluid diffuses into the interior of the cyst, which increases in size and displaces the bone. The cyst bellows act as a semipermeable membrane . Prostaglandins (PGE-2) are produced by odontogenic cysts and are responsible for bone resorption by the cyst.
If the contents of the cyst become infected with pus , an abscess can occur. On primary teeth radicular cysts occur only very rarely.
Follicular cysts
A follicular cyst is caused by a widening of the tooth sac in the crown area of an impacted (prevented from erupting) tooth, very often on lower wisdom teeth , upper canine teeth and surplus teeth.
Emergence
Two mechanisms are discussed for the development of the cysts, on the one hand an incorrect development of the enamel organ, on the other hand an inflammatory genesis. As with the radicular cyst, the follicular cyst is filled with a yellowish liquid permeated with cholesterol crystals.
Odontogenic keratocyst
An odontogenic keratocyst (KZOT, former designation keratocystic odontogenic tumor until 2017 or primordial cyst ) is causally in no contact with the tooth system, but comes from the epithelium of the tooth bud before it mineralizes.
Periodontal cysts
A periodontal cyst is not related to non-vital teeth or dental follicles. It is caused by pericoronal (around the tooth crown) pocket inflammation and thus develops next to the tooth, usually about the level of the tooth neck .
Gingival cysts
A gingival cyst is rare and occurs as a bluish-transparent solid nodule, preferentially in the area of the lower canines and premolars . The cause is probably remnants of the enamel-forming epithelium. In this respect, gingival cysts are close to primordial cysts, but are localized differently.
Teething cysts
A dentition cyst (also: eruption cyst ) forms (mostly in milk teeth) over a tooth that has not yet erupted. Since the growing tooth usually breaks through the eruption cyst itself, it is usually not necessary to remove the gingiva. Therapy with removal of the gingiva is only necessary in the case of inflammation, infection or pain.
Residual cysts
A residual cyst is a cyst that has remained and continues to grow after the extraction of a tooth with a radicular cyst (see above).
therapy
The aim of the therapy is to take the pressure out of the cavity (to prevent further growth) and to remove the cyst follicle including connective tissue and epithelium, or to expose the cyst cavity at least to the extent that the cyst epithelium can transform into oral mucosa . Depending on the location of the cyst, it can also be assigned to a different cavity (e.g. the oral or maxillary sinus ) as a "secondary indentation" .
Cystectomy
In a cystectomy (also called “ Partsch II operation”), the cyst is opened after a corresponding incision in the mucous membrane (Partsch arcuate incision), the bone is fenestrated and the cyst bellows and cyst epithelium are “peeled out” of the bone. In order to achieve primary wound healing , the wound is sutured so that the cavity can bleed completely. In the course of wound healing, capillaries grow into the resulting coagulum and it organizes itself into granulation tissue . After the removal of larger cysts, including those with larger bone defects, this primary wound healing can be disturbed. Since a large coagulum contracts more strongly (with the same percentage contraction - greater absolute contraction), it no longer has any contact with the bone walls and capillaries cannot grow in. Instead, the coagulum disintegrates - purulent (putride) / necrotic . In order to avoid the risk of this complication, in the case of large cysts, attempts can be made to stabilize the coagulum and reduce its contraction (autologous blood collection before the operation, mixing of this blood with antibiotics; or filling of the bone defect with granules of bone substitutes).
In the case of a radicular cyst, the cystectomy is usually combined with an apicectomy , whereby a root canal treatment can be carried out during the operation if this has not already been done.
Cystostomy
The cystostomy (read: cysto-stomy, not: cyst-os-tomia - from Greek στόμα ( stoma , stomatos ) "mouth", "throat", "mouth", "opening") (also "operation according to Partsch I" or " Marsupialization ") is available as an alternative for larger cysts in order to avoid the problems of an unstable blood clot. The cyst follicle is not completely removed, but rather to a side bay of a natural body cavity (mouth, nose or maxillary sinus ). Here, the cyst is opened over a large area, possibly sutured to the remaining cyst skin and initially tamponized. The wide opening of the cyst takes the pressure out of the cyst, it does not continue to grow, the cyst epithelium gradually transforms into mucosal epithelium and the cavity often re-forms - albeit slowly - as the bone regenerates from the bottom. A cystostomy is also recommended instead of a cystectomy if it can damage important anatomical structures in the immediate vicinity of the cyst.
Antrocystectomy
Individual evidence
- ↑ GEMOLL : Greek-German school and manual dictionary
- ^ A b c Walter Hoffmann-Axthelm : Lexicon of Dentistry , Quintessenz-Verlag, Berlin
- ^ J. Valderhaug: A histologic study of experimentally induced radicular cysts. In: International journal of oral surgery. Volume 1, Number 3, 1972, pp. 137-147, ISSN 0300-9785 . PMID 4199162 .
- ^ A b M. Harris, P. Toller: The pathogenesis of dental cysts. In: British medical bulletin. Volume 31, Number 2, May 1975, pp. 159-163, ISSN 0007-1420 . PMID 1100170 . (Review).
- ↑ M. Harris, MV Jenkins et al. a .: Prostaglandin production and bone resorption by the benign intraosseous dental cyst. In: Clinical science. Volume 44, Number 6, June 1973, pp. 24P-25P, ISSN 0009-9287 . PMID 4736580 .
- ↑ Joachim Gabka / Herbert Harnisch: Operationskurs for dentists , Georg Thieme Verlag, Stuttgart
- ↑ N. Jakse: Jaw cysts - differential diagnoses and therapy (PDF; 235 kB) Accessed July 1, 2011.
