A Dentigerous cyst also called as follicular cyst.Dentigerous cyst can be defined as an odontogenic cyst that surrounds the crown of an impacted tooth, caused by fluid accumulation between the reduced enamel epithelium and the enamel surface, resulting in a cyst in which the crown is located within the lumen.
This is one of the most common types of developmental odontogenic cyst. They form over the top of an unerupted tooth, or partially erupted tooth. The dentigerous cyst nearly always involves or in associated with the crown of a normal permanent tooth. This cyst is commonly associated with unerupted third molars, first and second premolars and canines. It is reported to be present more in males than in females. Dentigerous cyst may remain symptom less and may be diagnosed on routine radiographs or patients may give history of slowly enlarging swelling. Pain may be present only when they are secondarily infected.
- This cyst is always associated initially with the crown of an impacted, embedded or unerupted tooth.
- A dentigerous cyst may also be found enclosing a complex compound odontoma or involving a supernumerary tooth
- The most common sites of this cyst are the mandibular and maxillary third molar and maxillary cuspid areas, since these are the most commonly impacted teeth
- Most dentigerous cysts are solitary. Bilateral or multiple cysts are usually found in association with syndromes such as cleidocranial dysplasia and Maroteaux-Lamy syndrome.
- Itis potentially capable of becoming an aggressive lesion.
- Expansion of bone with subsequent facial asymmetry, extreme displacement of teeth, severe root resorption of adjacent teeth and pain are all possible sequelae brought about by continued enlargement of the cyst.
- Custic involvement of an unerupted mandibular third molar may result in a hollowing out of the entire Ramos extending up to the coronoid process and condole as well as in expansion of the cortical plate due to the pressure exerted by the lesion.
- In the case of a cyst associated with a maxillary cuspid, expansion of the anterior maxilla often occurs and may superficially resemble an acute sinusitis or cellulitis. There is usually no pain or discomfort associated with the cyst unless it becomes secondarily infected.
Radiographic examination of jaw involved by a dentigerous cyst will reveal a radiolucent area associated with an unerupted tooth crown. The impacted or unerupted tooth crown may be surrounded symmetrically by this radiolucency. A dentigerous cyst can be suspected when the follicular space is more than 5mm.
The dentigerous cyst is usually a smooth unilocular lesion but occasionally one with multilocular appearance may occur. In actuality, the various ompart ents are all united by the continuous cystic membrane. Sometimes the radiolucent area is surrounded by a thin sclerotic line representing bony reaction.
Three radiological variations of the dentigerous cyst may be observed.
- In the central variety, the crown is enveloped symmetrically. In these instances, pressure is applied to the crown of the tooth and may push it away from its direction of eruption. In this way, mandibular thrid molars may be found at the lower border of the mandible or in the ascending Remus and a maxillary canine may be forced into the maxillary sinus as far as the floor of the orbit.
- The lateral type of dentigerous cyst is a radio graphic appearance which results from the dilatation of the follicle on one aspect of the crown. This type is commonly seen when an impacted third molar is partially erupted so that it’s superi aspect is exposed.
- Circumferential dentigerous cyst results when the follicle expands in a manner in which the entire tooth appears to be envelopedby cyst.
There are no characteristic microscopic features which can be used reliably to distinguish the dentigerous cyst from the other types of odontogenic cysts. It is usually composed of a thin connective tissue wall with a thin layer of stratified squamous epithelium lining the lumen.
Rete peg formation is generally absent except in case that are secondarily infected. Islands of odontogenic epithelium is seen. An additional finding, especially in cysts which exhibit inflammation, is the presence of Rushton Bodies within the lining epithelium.
The treatment of dentigerous cyst usually dictated by the size of the lesion. Smaller lesions can be surgically removed in their entirety with little difficultly. The larger cysts which involve serious loss of bone and thi the bone dangerously are often treated by insertion of a surgical drain or marsupilization. Such a procedure is often necessary because of the potential danger of fracturing the jaw if complete surgical removal wer attempted. Recurrence is relatively uncommon.
Several relatively serpotential complications exist stemming from the dentigerous cyst, besides simply the possibility of recurrence following incomplete surgical removal. These include
- The development of an ameloblastoma either from the lining epithelium or from rests of odontogenic epitheliumin the wall of the cyst
- The development of epidermoid carcinoma from the lining epithelium or odontogenic epithelium.
- The development of a mucoepidermoid carcinoma, basically a malignant salivary gland tutor, from the lining epithelium of the dentigerous cyst.