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.
I. Cysts of the jawsA. Epithelial-lined cysts1. Developmental origin(a) Odontogenici. Gingival cyst of infantsii. Odontogenic keratocystiii. Dentigerous cystiv. Eruption cystv. Gingival cyst of adultsvi. Developmental lateral periodontal cystvii. Botryoid odontogenic cystviii. Glandular odontogenic cystix. Calcifying odontogenic cyst(b) Non-odontogenici. Midpalatal raphé cyst of infantsii. Nasopalatine duct cystiii. Nasolabial cyst2. Inflammatory origini. Radicular cyst, apical and lateralii. Residual cystiii. Paradental cyst and juvenile paradental cystiv. Inflammatory collateral cystB. Non-epithelial-lined cysts1. Solitary bone cyst2. Aneurysmal bone cystII. Cysts associated with the maxillary antrum1. Mucocele2. Retention cyst3. Pseudocyst4. Postoperative maxillary cystIII. Cysts of the soft tissues of the mouth, face and neck1. Dermoid and epidermoid cysts2. Lymphoepithelial (branchial) cyst3. Thyroglossal duct cyst4. Anterior median lingual cyst (intralingual cyst of foregut origin)5. Oral cysts with gastric or intestinal epithelium (oral alimentary tract cyst)6. Cystic hygroma7. Nasopharyngeal cyst8. Thymic cyst9. Cysts of the salivary glands: mucous extravasation cyst; mucous retention cyst; ranula; polycystic (dysgenetic) disease of the parotid10. Parasitic cysts: hydatid cyst; Cysticercus cellulosae; trichinosisBuccal bifurcation cystCalcifying odontogenic cystDentigerous cyst (associated with the crowns of non-erupted teeth)Glandular odontogenic cystKeratocyst (in the jaws, these can appear solitary or associated with the Gorlin-Goltz or Nevoid basal cell carcinoma syndrome. The latest World Health Organization classification considers Keratocysts as tumors rather than cysts)Paradental cystPeriapical 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 cystMost 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:
KeratocystCalcifying odotogenic cystAccording to the current (2005) classification of the World Health Organization, both (parakeratizied) odontogenic keratocyst and calcifying odotogenic cyst have neoplastic characteristics, thus renamed as Keratocystic odontogenic tumor and Calcifying odotogenic tumor, respectively.Cystic ameloblastomaLong 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.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.
