Mandible / maxilla
Odontogenic cysts
Paradental cyst

Author: Annie Morrison, M.D. (see Authors page)
Editor: Kelly R. Magliocca, D.D.S., M.P.H.

Revised: 21 June 2018, last major update February 2014

Copyright: (c) 2004-2018, PathologyOutlines.com, Inc.

PubMed Search: Paradental cyst [title]

Cite this page: Morrison, A. Odontogenic cysts: paradental cyst. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/mandiblemaxillaparadental.html. Accessed December 17th, 2018.
Definition / general
  • Inflammatory odontogenic cyst occurring at the crown or root of a partially or fully erupted tooth
  • Is a term applied to a spectrum clinicoradiographic entities - see terminology
Terminology
  • Reduced enamel epithelium (REE): ameloblastic and epithelial cells from the outer enamel that overly an unerrupted tooth, as the REE degenerates the underlying tooth is exposed
  • Crevicular epithelium: epithelium lining the inner aspect of the gingival sulcus
  • Epithelial rests of Malassez: discrete clusters of residual cells from Hertwig epithelial root sheath
  • Inflammatory odontogenic cysts: distinguished from developmental odontogenic cysts by their association with inflammation
    • Clinicoradiographic variants include:
      • Apical radicular cyst
      • Lateral radicular cyst
      • Residual cyst
      • Paradental cyst
  • Buccal bifurcation cyst (BBC):
    • Aka paradental cyst, juvenile paradental cyst or mandibular infected buccal cyst
    • Occurs along the buccal root surface of partially erupted mandibular molar of children and young adults
    • Affected tooth is vital
  • Paradental cyst:
    • After excluding cysts occurring along the lateral / buccal surface of a partially impacted mandibular molar of a young individual, the term paradental cyst also refers to a variant of the dentigerous cyst with an inflammatory, rather than developmental pathogenesis
    • The two most common scenarios include vital (non-necrotic) teeth:
      • A dentigerous cyst that develops around the crown of an unerupted permanent tooth as a result of periapical inflammation from an overlying primary tooth
      • A partially erupted mandibular third molar that develops an inflamed cystlike lesion along the distal aspect associated with inflammation or recurrent pericoronitis
      • These are often called dentigerous cyst, as it is impossible to determine histopathologically whether the inflammatory component is primary or secondary in nature
Epidemiology
  • 1 - 5% of odontogenic cysts
Sites
  • Buccal >> Mesial surface
  • Erupted or partially erupted teeth
  • Molars >> premolars > cuspids
  • 3rd molar (wisdom teeth) >> 1st / 2nd molars
  • Mandibular teeth >> Maxillary teeth
  • ~24% of paradental cysts in 1st or 2nd molars are bilateral
Pathophysiology
  • Theorized to arise from one of the following, however, each can be debatable given the specified location of paradental cysts:
    • Reduced enamel epithelium
    • Epithelial rests of Malassez
    • Crevicular epithelium
    • Epithelial remnants of dental lamina
Clinical features
  • Recurring periodontal inflammatory process (pericoronitis)
  • Symptoms: discomfort, swelling, tenderness, pain
  • Often Asymptomatic
Diagnosis
  • Based on location, radiography, pathology, root vitality studies
Radiology description
  • Periosteal reaction common
  • Onion skin deposition of bone appears as parallel opaque layers
Radiology images

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Well defined semilunar shaped radiolucency

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Expansion of vestibular cortical bone

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Radiolucency in distal follicular space of first permanent molar

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Hypodense area in vestibular region

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Axial CT



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Expansion of vestibular bone

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Radiolucency demarcated by fine radiopaque line

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Well defined ovoid radiolucency

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Buccal bifurcation cyst

Prognostic factors
  • Good prognosis
  • No reports of recurrence to date
Case reports
Treatment
  • Curettage
Clinical images

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Intraoral preoperative view

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Intraoperative view of enucleation

Gross description
  • A cyst-like soft tissue (may or may not be intact) attached to the cementoenamel junction, or along the root of the tooth
Microscopic (histologic) description
  • The microscopic findings are not specific and cannot distinguish between the variants of inflammatory odontogenic cysts, or a markedly inflamed developmental dentigerous cyst
  • Clinical and radiographic correlation essential
  • Connective tissue wall
  • Heavy mononuclear inflammatory cell infiltrate
  • Hyperplastic nonkeratinizing stratified squamous epithelium
  • Often with hemosiderin pigment or cholesterol clefts
Microscopic (histologic) images

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Various images

Differential diagnosis