Odontogenic cyst
Odontogenic cyst are a group of jaw cysts that are formed from tissues involved in odontogenesis (tooth development). Odontogenic cysts are closed sacs, and have a distinct membrane derived from rests of odontogenic epithelium. It may contain air, fluids, or semi-solid material. Intra-bony cysts are most common in the jaws, because the mandible and maxilla are the only bones with epithelial components. That odontogenic epithelium is critical in normal tooth development. However, epithelial rests may be the origin for the cyst lining later.
Not all oral cysts are odontogenic cyst. For example, mucous cyst of the oral mucosa and nasolabial duct cyst are not of odontogenic origin. 
In addition, there are several conditions with so-called (radiographic) pseudocystic appearance in jaws; ranging from anatomic variants such as Stafne static bone cyst, to the aggressive aneurysmal bone cyst.

Classification
I. Cysts of the jaws
A. Epithelial-lined cysts
1. Developmental origin
(a) Odontogenic
i. Gingival cyst of infants
ii. Odontogenic keratocyst
iii. Dentigerous cyst
iv. Eruption cyst
v. Gingival cyst of adults
vi. Developmental lateral periodontal cyst
vii. Botryoid odontogenic cyst
viii. Glandular odontogenic cyst
ix. Calcifying odontogenic cyst
(b) Non-odontogenic
i. Midpalatal raphé cyst of infants
ii. Nasopalatine duct cyst
iii. Nasolabial cyst
2. Inflammatory origin
i. Radicular cyst, apical and lateral
ii. Residual cyst
iii. Paradental cyst and juvenile paradental cyst
iv. Inflammatory collateral cyst
B. Non-epithelial-lined cysts
1. Solitary bone cyst
2. Aneurysmal bone cyst
II. Cysts associated with the maxillary antrum
1. Mucocele
2. Retention cyst
3. Pseudocyst
4. Postoperative maxillary cyst
III. Cysts of the soft tissues of the mouth, face and neck
1. Dermoid and epidermoid cysts
2. Lymphoepithelial (branchial) cyst
3. Thyroglossal duct cyst
4. Anterior median lingual cyst (intralingual cyst of foregut origin)
5. Oral cysts with gastric or intestinal epithelium (oral alimentary tract cyst)
6. Cystic hygroma
7. Nasopharyngeal cyst
8. Thymic cyst
9. Cysts of the salivary glands: mucous extravasation cyst; mucous retention cyst; ranula; polycystic (dysgenetic) disease of the parotid
10. Parasitic cysts: hydatid cyst; Cysticercus cellulosae; trichinosis
Buccal bifurcation cyst
Calcifying odontogenic cyst
Dentigerous cyst (associated with the crowns of non-erupted teeth)
Glandular odontogenic cyst
Keratocyst (in the jaws, these can appear solitary or associated with the Gorlin-Goltz or Nevoid basal cell carcinoma syndrome.
Paradental cyst
Periapical cyst (The periapical cyst, otherwise known as radicular cyst, is the most common odontogenic cyst.)
Radicular cyst (associated with the roots of non-vital teeth, also known as Periapical cyst)
Residual cyst

Cystic neoplasm
Most cysts in the body are benign (dysfunctional) tumors, the result of plugged ducts or other natural body outlets for secretions.  However, sometimes these masses are considered neoplasm:

Keratocyst
Calcifying odontogenic cyst
According to the current (2005) classification of the World Health Organization, both (parakeratizied) odontogenic keratocyst and calcifying odontogenic cyst have neoplastic characteristics, thus renamed as Keratocystic odontogenic tumor and Calcifying odontogenic tumor, respectively.
Cystic ameloblastoma
Long standing dentigerous cyst, odontogenic keratocyst, and residual cyst may have neoplastic potential converting into the locally aggressive ameloblastoma, or the malignant squamous cell carcinoma and mucoepidermoid carcinoma.

Diagnosis
On histopathology, cholesterol clefts indicate mainly a periapical (radicular) cyst or an inflamed dentigerous cyst.

Treatment
Treatment ranges from simple enucleation of the cyst to curettage to resection. For example, small radicular cyst may resolved after successful endodontic ("root-canal") treatment. Because of high recurrence potential and aggressive behaviour, curettage is recommended for keratocyst. However, the conservative enucleation is the treatment of choice for most odontogenic cysts. The removed cyst must be evaluated by pathologist to confirm the diagnosis, and to rule out other neoplastic lesions with similar clinical or radiographic features (e.g., cystic or solid ameloblastoma, central mucoepidermoid carcinoma). There are cysts, e.g. buccal bifurcation cyst with self-resolation nature, in which close observation can be employed unless the cyst is infected and symptomatic.

See also
Cyst
Mucous cyst of the oral mucosa


== References ==