Dentigerous Cyst

OVERVIEW

Cyst formation originating from tissue surrounding the crown of an unerupted tooth.

SIGNALMENT

Any breed that is at an increased risk for impaired eruption.
Boxers, bulldogs—mandibular first premolars, often bilateral.
Unerupted teeth at 6–7 months of age, but cystic development may not occur until much later, if at all.
SIGNS
Cystic changes may be initially unapparent without diagnostic imaging.
“Missing” tooth.
Formation of a soft swelling at the site of a missing tooth, often fluctuant with fluid.
Patients may present, with no previous indication of a problem, for a pathologic fracture of the mandible due to cystic destruction of the surrounding bone.

CAUSES & RISK FACTORS

Unerupted teeth

DIAGNOSIS

DIFFERENTIAL DIAGNOSIS

Odontogenic keratocyst—cysts of the jaw demonstrating aggressive expansion that may, or may not, be associated with unerupted teeth.
Primordial cyst—cystic degeneration of a tooth bud before enamel/dentin formation (cyst without a tooth).
Oral mass—odontoma. Tooth structures (complex or compound) sometimes contained within cystic structure, but with different levels of organization.
Transformation to ameloblastomas has been reported in humans; histologic evaluation of the cyst lining is highly recommended.

CBC/BIOCHEMISTRY/URINALYSIS

OTHER LABORATORY TESTS

N/A

IMAGING

Definitive diagnosis from radiography.
Radiographs are essential in any instance of missing or unerupted teeth.
Radiographically—radiolucent cyst originating from the remnant enamel organ at the neck of the tooth and encompassing the crown (a halo).

DIAGNOSTIC PROCEDURES

Histopathologic assessment if atypical.

TREATMENT

Appropriate preoperative antimicrobial and pain management therapy when indicated.
Appropriate patient monitoring and support during anesthetic procedures.
If cystic formation is present—surgical extraction, complete debridement of cyst lining, and histologic evaluation.
If an embedded tooth has been present in a mature animal—assess for any cystic structure or other pathologic changes involving the tooth; continued monitoring may be reasonable if surgical extraction would damage large amounts of bone.
If a non-strategic tooth can be easily extracted, it would be best to do so, even if cystic changes are not present.

MEDICATIONS

DRUG(S)

Postoperative analgesics, as necessary.

CONTRAINDICATIONS/POSSIBLE INTERACTIONS

N/A

FOLLOW-UP

POSSIBLE COMPLICATIONS

Pathologic fracture may occur if the dentigerous cyst is not diagnosed and treated.
Fracture of mandible at time of extraction, if compromised.

EXPECTED COURSE AND PROGNOSIS

Visit your veterinarian as early recognition, diagnosis, and treatment are essential.