L12 Radiology of cysts Flashcards
Name the causes of acquired pathological radiolucencies.
- Cyst (odontogenic or non-odontogenic)
- Infection
- Trauma
- Tumour (odontogenic or non-odontogenic)
- Allied lesion (giant cell lesion, bone cyst, fibro-osseus lesion etc.)
Describe the main features of radicular cysts.
- Found at the apex of a non-vital tooth
- Usually greater than 1.5cm in diameter (smaller more likely periapical granuloma)
- Round, unilocular
- Well defined, corticated outline continuous with the lamina dura of the non-vital tooth
- Uniformly radiolucent
- Cause buccal and lingual cortex expansion, displaces teeth
How is a radicular cyst managed?
- Small cysts may respond to RCT (may be periapical granuloma)
- Enucleation
Define enucleation.
Removal of the cyst lining from the bony cavity.
Define marsupialisation.
Decompression of the cyst by opening it into the oral cavity, allowing the gradual infilling of the bony cavity.
Generally used for very large cysts where there is a risk of jaw fracture.
Describe the main features of residual cysts.
- Radicular cyst left behind after extraction
- Site: apical region of edentulous part of the jaw
- Greater than 1.5cm diameter
- Well defined, corticated outline continuous with the lamina dura
- Uniformly radiolucent
- Cause teeth to be displaced and the expansion of buccal and lingual cortices
- Treatment: marsupialisation or enucleation
Describe the main features of inflammatory collateral/paradental cysts.
- Seen in children and adolescents usually affecting the 1st or 2nd molar, seen in people aged 20-40 usually affecting the 3rd molar
- Site: partially erupted teeth on the buccal aspect
- Size: variable, up to 3cm
- Unilocular
- Smooth, well defined and corticated border
- Uniformly radiolucent
- Does not cause tooth resorption, but can cause some displacement or tipping of teeth
What type of cyst is shown in these radiographs?
Paradental/inflammatory collateral.
What is the management for an inflammatory collateral cyst?
Enucleation +/- removal of the associated teeth – more commonly for 3rd molars, not so much for a child where the cyst is affecting the 1st or 2nd molar
Describe the main features of dentigerous cysts.
- Found surrounding the crown of an unerupted tooth
- Size: suspect if follicular space is greater than 3mm
- Round/oval, unilocular
- Well defined, corticated margins
- Uniformly radiolucent
- Displaces teeth, causes expansion of buccal/lingual bone
What radiograph can be used to see buccal/lingual expansion in the mandible?
90-degree occlusal view.
What radiograph can be used to see buccal/lingual expansion in the ramus/angle of the mandible.
PA mandbile.
(Posterior-anterior view)
What is the management for a dentigerous cyst?
- Enucleation of the cyst with extraction of the associated tooth
- Marsupialisation of the cyst in selected areas, particularly in children to allow the permanent tooth to erupt, or if the cyst is very large and there is a risk of jaw fracture
Describe the main features of odontogenic keratocysts.
- Most commonly found in the posterior mandible
- Variable size
- Oval, pseudolocular or multilocular
- Well defined, corticated outline
- Relative radiodensity
- Does not diaplce teeth, little/no expansion of bone
- Can grow very large before being clinically detected
- High recurrence rate (10-60%)
What view does this radiograph show?
Oblique lateral view of left mandible.
Shows an odontogenic keratocyst, pseudolocular as the septi are not passing all the way through the radiolucency.
Describe the main features of lateral periodontal cysts.
- Found on the lateral aspect of roots
- Approx. 1cm in diameter
- Round, unilocular
- Well defined corticated margins
- Uniformly radiolucent
- Displaces adjacent teeth, expansion of buccal/lingual bone if particularly large
What cyst is a variation of the lateral periodontal cyst?
Botryoid odontogenic cyst:
- Multilocular
What is a glandular odontogenic cyst?
- Aka. sialo-odontogenic cyst
- A developmental cyst with epithelial features that stimulate salivary gland tissue
- Present in 4th and 5th decades of life
- Unilocular or multilocular appearance
- Tend to be found in the anterior mandible
- May displace adjacent teeth but doen’t typically cause root resorption
- Rare
What is a calcifying odontogenic cyst?
- Most commonly found in the anterior mandible or maxilla
- Often associated with an unerupted tooth or odontome
- Radiolucent early on, becomes radiopaque as it calcifies
- As it matures calcified material becomes evident scattered throughout the lesion
- Rare
Describe the main features of nasopalatine duct/incisive canal cysts.
- Non-odontogenic inclusion cyst
- Seen most commonly in those aged 40-60
- Found at the midline of the anterior maxilla, posterior to the central incisors
- Variable size
- Round/oval shape, superimposition of anatomical structures may give it a heart shape
- Unilocular
- Well defined, corticated margin
- Uniformly radiolucent
- Displaces adjacent teeth, no root resorption
Describe the main features of a simple bone cyst.
- Aka. traumatic bone cyst or haemorrhagic bone cyst
- Non-odontogenic
- Seen in children and young adults
- Site: most commonly posterior mandible
- Variable size
- Unilocular, irregular margin, upper border arches up between teeth
- Lightly corticated, moderately well defined border
- Uniformly radiolucent
- Little/no effect on adjacent structures
Describe the main features of an aneursymal bone cyst.
- Non-odontogenic
- Rare expansile osteolytic lesion
- Seen mostly in adolescents
- Presents as painless swelling of the jaw, normally in the posterior region
- Blood-filled lesion
- Multilocular appearance
- Histological appearance: contains multiple giant cells
Summary of multilocular lesions (non-exhaustive).
Summary of lesions and their effects on adjacent structures/teeth.
