Cyst Radiology Limitations Quiz

Cysts of the Oral and Para-oral Region

Definition: A cyst is a pathological cavity lined with epithelium containing fluid or semi-solid material, found in hard or soft tissues. Some cysts lack an epithelial lining and are called pseudocysts. Cysts are more common in the jaws than other bones due to epithelial rests remaining after dental development.

Classification

Odontogenic Cysts: These cysts arise from odontogenic epithelial remnants associated with tooth development. They are further classified into inflammatory and developmental.
- Periodontal Cysts:
  - Inflammatory: Apical (radicular), lateral and residual, inflammatory collateral (paradental and mandibular buccal bifurcation).
  - Developmental: Lateral developmental cyst, Botryoid odontogenic cyst, Gingival cyst of adults, Gingival cyst of newborn (dental lamina cyst of newborn/Bohn's nodules).
- Dentigerous Cysts: (central, lateral, circumferential); cysts of eruption.
- Odontogenic Keratocysts
- Orthokeratinized Odontogenic cysts
- Calcifying odontogenic cyst (COC, Gorlin's cyst)
Non-Odontogenic Cysts: Cysts not arising from odontogenic epithelium.
- Cysts of vestigial ducts: Nasopalatine tract cysts (incisive canal cyst, cyst of palatine papilla).
- Fissural Cysts: Median cysts (median palatal cyst, median mandibular cyst), Globulomaxillary cyst, Nasolabial cyst.
Pseudocysts: Cavities without epithelial lining.
- Simple bone cyst
- Aneurysmal bone cyst
- Static bone cyst
Soft tissue cysts of the floor of mouth and neck: Dermoid and epidermoid cysts, thyroglossal tract cyst, cervical lymphoepithelial cyst (branchial cleft cyst), mucous retention, mucous extravasation cysts, and ranula.

Important Cyst Types

Apical (periapical/radicular) cyst: A common cyst originating from inflammatory hyperplasia of epithelial rests of Malassez in the periodontal ligament, frequently associated with a nonvital tooth, typically in adults. Characterized by a well-defined radiolucency near the apex of a tooth root.
- Treatment options: Enucleation of the cyst, apicectomy of the involved tooth, or removal of the tooth and enucleation of the cyst.
Inflammatory lateral periodontal cyst: Less common, developing on the lateral aspect of a tooth root, often related to pericoronitis and a history of long standing issues.
- Treatment options: Enucleation of the cyst.
Residual Cyst: A cyst that persists after the extraction of the offending tooth.
Dentigerous cyst: Associated with unerupted teeth, occurring most commonly in the second and third decades of life.
- Treatment: Removal of involved tooth and enucleation of the cyst.
Odontogenic Keratocysts: A relatively rare cyst, frequently found in the posterior mandible and maxilla, characterized by a keratinized lining.
- Treatment: Enucleation followed by curettage of the cyst cavity
Orthokeratinized odontogenic cyst: An odontogenic cyst lined by orthokeratinized stratified squamous epithelium.
- Treatment usually involves enucleation
Calcifying odontogenic cysts (COCs): These cysts are characterized by a mixture of calcifications, and are more involved in resorption and expansion of the bone that surrounds it.
- Treatment: Enucleation is the treatment of choice.
Developmental lateral periodontal cyst: A developmental cyst arising adjacent to or lateral to a vital tooth root. Usually asymptomatic, and is often discovered by radiographic examination. A well-defined radiolucent area around the tooth.
- Treatment includes enucleation of the cyst, and sometimes involves removal of the associated tooth.
Botryoid odontogenic cyst: A multicystic variant of the developmental lateral periodontal cyst, characterized by a grape-like appearance.
- Treatment often involves enucleation.
Gingival cyst of the newborn (Bohn’s nodules): Multiple, small, white nodules in the alveolar ridge of newborns, originating from dental lamina remnants. They usually resolve spontaneously.
- Treatment is not generally required.
Dermoid/Epidermoid Cysts: Soft tissue cysts of the floor of the mouth, origin from epithelial rests during the closure of mandibular arch during development. -Treatment: Surgical removal
Thyroglossal duct cyst: A common neck cyst, developing from remnants of the thyroglossal duct during embryonic development. -Treatment: Excision recommended
Cervical lymphoepithelial cyst (branchial cleft cyst): Originating from remnants of branchial clefts during development, and appears as a swelling along the lateral neck. -Treatment: Surgical excision
Mucous extravasation cyst (mucocele): A fairly common cyst often appearing in the lower lip from rupture of a minor salivary gland duct, which causes mucin to leak into the surrounding tissues. -Treatment: Surgical excision
Mucous retention cyst (salivary duct cyst): A cyst that develops from obstruction or dilation of a salivary gland duct, characterized by an accumulation of mucus in the soft tissues.
- Treatment: Surgical excision
Static bone cyst: Usually an asymptomatic, radiolucent lesion that appears as a well-demarcated, unilocular cavity, and is situated in the body and ramus of the mandible.
- Treatment: Typically a simple enucleation
Aneurysmal bone cyst Can be either primary or secondary, and is an intraosseous lesion characterized by blood-filled spaces and surrounded by a fibrous connective tissue.
- Treatment: Often involves curettage or enucleation.