Odontogenic Cysts Flashcards
Odontogenic Cysts Definition
Cysts lined by odontogenic epithelium
Inflammatory Cysts
Reactive, result or inflammation
Developmental Odontogenic Cysts
Unknown origin, although each type of cyst is thought to
arise from an aberration occurring at some point along the
continuum of normal tooth development
Classes of Inflammatory Cysts
- Periapical (radicular) cyst
- Residual periapical (radicular) cyst
- Buccal bifurcation cyst
Periapical Radicular Cysts basics
Always arises from a tooth with a necrotic pulp
• Often asymptomatic
Periapical cysts radiographic features
- Loss of lamina dura
- Relatively well-circumscribed radiolucency surrounding the apex/root
- May reach a large size
Periapical cysts v granuloma radiographically
radiographically identical
What is the difference
between a cyst and a
granuloma?
The periapical granuloma is an accumulation of chronically inflamed granulation tissue seen at the apex of a nonvital tooth. The radicular cyst is a lesion that develops over a prolonged period of time within an existing periapical granuloma. A cyst, by definition, has an epithelial lining.
Treatment of periapical cysts
endodontic therapy on
the involved tooth, or extraction of the tooth with curettage of
the cystic space. If the lesion does not resolve, seriously
consider biopsy. Don’t keep re-treating the tooth…
Residual Periapical Cyst
Radiographically appears as an oval or round lucency within the alveolar ridge at the site of a previous tooth extraction. Histology is similar to the periapical cyst… The clinical history and radiographic description that you provide are necessary to diagnose this
Buccal Bifurcation Cysts
Often develops on the buccal aspect of the
mandibular first permanent molars
• Usually seen in children from 5 to 11 years of age
• Complaints of tenderness, swelling, foul-tasting
discharge
• Buccal periodontal pocket may form
• One third of patients have bilateral involvement
Buccal Bifurcation Cyst Radiographical présentation
Radiographs reveal a well-circumscribed lucency involving the bifurcation and roots
Tx of Buccal Bifurcation Cysts
Treatment consists of enucleation of the cyst
without extraction of the tooth. Complete
healing is usually seen.
Developmental Odontogenic Cysts
- Dentigerous Cyst
- Eruption Cyst
- Odontogenic Keratocyst
- Orthokeratinized Odontogenic Cyst
- Gingival (alveolar) cyst of the newborn
- Gingival Cyst of the Adult
- Lateral Periodontal Cyst
- Calcifying Odontogenic Cyst
- Glandular Odontogenic Cyst
Dentigerous Cysts basics
Defined as a cyst originating from the separation of the follicle from around the crown of an unerupted tooth. Fluid accumulates between the reduced enamel epithelium and the crown. • Most common developmental odontogenic cyst, making up 20% of epithelial-lined gnathic cystic lesions
Clinical presentation of Dentigerous cysts
Most DC’s commonly involve mandibular third molars, followed by maxillary canines, maxillary third molars, and mandibular second premolars. • There is a slight male predilection. The DC is most often diagnosed between the ages of 10 and 30. • They are usually asymptomatic, and are discovered incidentally during radiographic exam.
Dentigerous cysts and bone expansion
Occasionally they may cause painless expansion of the bone upon
reaching a large size.
Dentigerous Cysts communicate with oral cavity
If a DC communicates with the oral cavity (partially erupted tooth
or adjacent periodontal defect), the cyst may become infected, with
subsequent pain and swelling experienced by the patient.
Dentigerous Cyst - Radiographic
• Usually unilocular radiolucency associated with the
crown of an unerupted tooth
• The cyst usually has a well-defined, thin, sclerotic
border
Radiographic presentation of an infected dentigerous cyst
• An infected cyst may show ill-defined borders
• Large lesions may appear multilocular due to persistence of bony
trabeculae
• Occasional tooth displacement, root resorption
Hyperplastic dental follicle v dentigerous cyst
Some clinicians allow 3-4 mm for a dental follicle. Anything bigger is
often a dentigerous cyst, but COULD also be an odontogenic
keratocyst, ameloblastoma, or another odontogenic entity. Biopsy
and histologic evaluation will provide the final diagnosis.
Dentigerous Cyst – Treatment and
Prognosis
• Removal of the unerupted tooth
• Enucleation of the cyst
• Large cysts may be marsupialized prior to
removal
• Excellent prognosis, low chance of recurrence
• Infrequent bad stuff: ameloblastoma, squamous
cell carcinoma, intraosseous mucoepidermoid
carcinoma
Eruption Cyst
• This is the soft tissue counterpart of the
dentigerous cyst. The associated tooth is only softtissue
impacted.
Eruption Cyst - Clinical
• This cyst is most often seen in children younger than age 10
• There is a soft, translucent swelling of gingiva located over the
crown of an erupting tooth.
• Blood may be present in the cyst fluid, giving a blue color to the
lesion.
• Eruption cysts usually involve permanent first molars or maxillary
incisors
Erruption cyst radiographically
Radiographically, the erupting tooth
appears normal. The soft tissue is seen
as a slightly radiopaque dome over the
involved tooth
Tx of eruption cysts
These cysts often rupture spontaneously with eruption of the tooth – treatment is usually not necessary
Odontogenic Keratocyst Basics
OKC’s arise from cell rests of the dental lamina
• It is thought that they do not enlarge by increased osmotic pressure
within the lumen, but from unknown factors inherent in the
epithelium or cyst wall
• Sporadic and syndromic cases are associated with a PTCH tumor
suppressor gene mutation on chromosome 9q22
• 3%-11% of all odontogenic cysts are keratocysts
Odontogenic Keratocyst (OKC/KCOT) - Clinical
• 60% diagnosed between age 10 and 40 years • Slight male predilection • Mandible, 60%-80% of cases; propensity for posterior mandibular body and ascending ramus • Usually asymptomatic • May grow large, tend to grow in an antero-posterior direction with no bony expansion