Cysts Flashcards
What is a cyst ?
A pathological cavity having fluid, semi-fluid or gaseous contents and which is not created by accumulation of pus.
What are some symptoms of cysts ?
Mobile teeth. Swelling. Discolouration. Pain or tenderness of teeth. Numbness. Loss of tooth vitality. Egg shell crackling. Failure of eruption.
Name 3 developmental odontogenic cysts.
Dentigerous cyst (or eruption cyst).
Odontogenic keratocyst.
Lateral periodontal cyst.
Name a development non-odontogenic cyst.
Nasopalatine duct cyst.
Name two other non-odontogenic cysts.
Aneurysmal bone cyst.
Solitary bone cyst.
What are the signs of a radicular cyst ?
Always associated with non-vital tooth.
Asymptomatic (if uninfected).
Slow growing with little expansion.
How to differentiate between radicular cyst and a PA granuloma ?
Cysts >15mm in size.
Granulomas <15mm in size.
Cannot differentiate otherwise radiographically.
When are radicular cysts more likely to occur ?
50-60 years old.
Describe the radiographic characteristics of a radicular cyst.
Well defined, round/oval radiolucency.
Corticated margin continuous with lamina dura of non-vital tooth.
Can displace adjacent structures.
Can cause external RR or contain dystrophic calcification.
Describe a radicular cyst histologically.
Incomplete hyperplastic epithelial lining.
Connective tissue capsule.
Inflammatory cells within.
Can have ulceration.
Define residual cyst - variant of radicular cyst.
When radicular cyst persists after loss of tooth or after tooth is successfully RCT’d.
Define lateral radicular cyst - variant of radicular cyst.
Associated with accessory canal.
Located at side of tooth instead of apex.
Define paradental cyst.
Typically occurs at distal aspect of partially-erupted mandibular third molar.
Describe a dentigerous cyst.
Developmental odontogenic cyst associated with crown of unerupted (and usually impacted) tooth.
Where cystic change occurs in dental follicle.
What teeth are dentigerous cysts most likely to affect ?
Mandibular third molars.
Maxillary canines.
When are dentigerous cysts most common ?
2-4th decades.
Describe the radiographic appearance of a dentigerous cyst.
Associated with unerupted tooth.
Corticated margins attached to ECJ.
Tends to expand symmetrically.
Variable bony expansion.
May displace tooth involved or anatomy.
Unilocular.
Describe the histological appearance of a dentigerous cyst.
Thin non-keratinised stratified squamous epithelium.
Variable inflammatory cells.
Hyaline/Rushton bodies.
Mucous metaplasia.
Cholesterol clefts.
At what measurement does a enlarged follicle become a dentigerous cyst ?
Widening >5mm be suspicious.
>10mm assume cyst.
What are the risks of leaving a dentigerous cyst untreated ?
Weakened bone - risk of mandibular fracture.
Compression of nerve - numbness of lip;.
What is the most common non-odontogenic cyst ?
Nasopalatine duct cyst.
What radiographs would you require to investigate a nasopalatine duct cyst ?
PA +/- anterior maxillary occlusal.
CBCT if surgical planning.
What diameter would you expect the incisive fossa to be ?
<6mm
6-10mm be suspicious and monitor, >10mm assume cyst.
Describe the radiographic appearance of a nasopalatine duct cyst.
Unilocular.
Well defined.
Corticated margins over roots of centrals.
Heart shaped due to superimposition of anterior nasal spine.
Describe the clinical presentation of nasopalatine duct cyst.
Asymptomatic.
Salty discharge.
Can displace teeth.
Can cause swelling on palate.
Always involve midline.
Not always symmetrical.
Describe the histological features of a nasopalatine duct cyst.
Non-keratinised stratified squamous epithelium OR modified respiratory epithelium.
Are solitary bone cysts more common in mandible or maxilla ?
Mandible.
Do solitary bone cysts require treatment/follow up ?
No treatment required usually.
Review and monitor every 3 months.
What are the radiographic characteristics of solitary bone cysts ?
Premolar/molar regions.
Non-tooth bearing areas.
Variable cortications.
Scalloped margins with pseudolocular appearance.
Projection between teeth.
What are the three histological samples you can take to assess and definitively diagnose a cyst ?
Aspiration biopsy.
Incisional biopsy.
Excisional biopsy.
What are the two surgical options for cysts ?
Enucleation.
Marsupulisation.
Describe marsupulisation.
Creation of surgical window in wall of cyst.
Remove contents of cyst.
Suture cyst wall to surrounding epithelium.
Leave open in oral cavity.
What is the aim of marsupulisation ?
Encourage cyst to decrease in size.
Sometimes prior to enucleation.
What are the indications for marsupulisation ?
Where enucleation would damage IAN.
Difficult access.
Can allow eruption of teeth.
Elderly/medically compromised.
Large cysts which would risk jaw fracture.
Combined with enucleation.
What are the advantages of marsupulisation ?
Easy to perform.
Can spare vital structures.
What is the disadvantages of marsupulisation ?
Opening can close and cause reformation of cyst.
Complete lining not available for histology.
Difficult to keep clean.
Long time for bone to fill void.
