Pushes tooth further into the jaw bone, therefore impacts tooth

Etiology

• Impaction
• Delayed eruption

Common site

• Maxillary canine
• Premolars
• 3rd molars

Growth

• Regular
• Large
• Buccal expansion

Peak age

• 3-4th decade

Pathology

• Split develops between REE and enamel

Radiology

• Unilocular radiolucency surrounding crown

Histology

Cyst attached at amelocemental junction – surrounding crown of unerupted tooth

• Cyst wall:
  • Derived from dental follicle
  • Thin, delicate ‘myxoid’/mucinous appearance
• Epithelial lining:
  • Derived from REE
  • Mucous cells
  • Flat basement membrane – thin, uniform, non-keratinized, attached at amelocemental junction
  • No rete pegs
• Lumen:
  • Eosinophilic serous exudate
  • Cholesterol cleft

Management

• Surgical removal
• Marsupialization (large)
• Enucleation (small)

Recurrence

• Rare

Differential diagnosis

• Ameloblastoma
• Odontogenic myxoma
• Adenomatoid odontogenic tumor (AOT)
• Calcifying epithelial odontogenic tumor (CEOT)

Picture