Cysts

Cysts

1. Epithelial = True Cysts

   • Odontogenic
     • Inflammatory
       • Radicular cyst
         • Non-vital tooth
         • Pulp necrosis -> Proliferation of Cells of Malassez -> Fluid accumulation
         • Most common = U2s
         • Most common cyst
         • Buccal expansion
         • If tooth removed --> can recur as Residual cyst
       • Paradental cyst
         • History of pericoronitis
         • Similar to Radicular cyst
         • Lower 8s - buccal/distal
     • Developmental
       • Dentigerous cyst
         • Unerupted tooth
         • Derivation = tooth follicle
         • Eruption cyst
           • Extra-alveolar dentigerous cyst
           • Often blood filled
           • Most common = 6s
           • Childen
         • Most common = L8s & U3s
         • Buccal expansion
       • Odontogenic Keratocyst
         • Vital teeth
         • No buccal expansion
         • Gorlin-Goltz syndrome
           • BCCs
         • Posterior mandible
         • High recurrence rate
         • Derivation = Dental lamina/Cell rests of Cerres/Enamel organ
         • Most aggressive cyst
         • Treatment = Enucleation + Carnoy's solution (modified)
       • Lateral periodontal cyst
         • Lateral to tooth
         • Rare
         • 3s, 4s, 5s
         • Small size
         • Vital teeth
         • Unknown deriavation
       • Gingival cyst
         • Rare in adults
           • Interdental papillae
         • Common in neonates
           • Spontaneously resolve
         • Derivation = Cell rests of Cerres
   • Non-odontogenic
     • Nasal Palatine duct cyst
       • Midline palate
       • Swelling +/- salty discharge, pain
       • Vital teeth
       • Heart-shaped
       • Derivation = remnants of naso-palatine duct
     • Naso-labial cyst
       • Swelling in nasolabial fold +/- pain, nasal obstruction
       • Derivation = embryonic nasolacrimal rod/duct

2. Primary Bone Cysts

   • Solitary bone cyst
     • Children
     • Premolar region, mandible
     • Fibrous tissue only
     • Gas or fluid filled
   • Aneurysmal bone cyst
     • Highly vascularised fibrous tissue, blood, osteoid, osteoblasts
     • Children, young adults
     • Angle of mandible
     • Multi-locular
   • Rare

3. Features

   • Well-defined, corticaled outline
   • Shape
     • Uni-locular
       • Lateral periodontal cyst
       • Radicular cyst
       • Paradental cyst
       • Dentigerous cyst
     • Multi-locular
       • Aneurysmal bone cyst
     • Either
       • Odontogenic keratocyst
   • Uniformly radiolucent
   • Tooth vitality
     • Non-vital
       • Radicular cyst
     • Vital
       • Odontogenic keratocyst
       • Nasal palatine duct cyst
       • Lateral periodontal cyst
   • Buccal expansion
     • Radicular cyst
     • Dentigerous cyst
   • Age
     • Adults
       • Radicular cyst
       • Dentigerous cyst
       • Lateral periodontal cyst
       • Nasal palatine duct cyst
     • Children
       • Primary Bone cysts
       • Eruption cyst
       • Gingival cyst
   • Site
     • Posterior mandible
       • Lower 8s
         • Dentigerous cyst (unerupted)
         • Paradental cyst
       • Odontogenic keratocyst
       • Aneurysmal bone cyst
     • Premolar mandible
       • Solitary bone cyst
     • Upper anterior
       • Radicular cyst (U2s)
       • Nasal palatine duct cyst (midline)

4. Treatment

   • Enucleation
     • Most common/definitive
   • Marsupialisation
     • Reduce cyst size
     • May allow tooth to erupt (Dentigerous cyst)
     • Shorter/avoid GA
   • Decompression
     • Reduce cyst size