Mandible / maxilla
Odontogenic cysts
Dentigerous

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 October 2013

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

PubMed Search: Dentigerous cyst [title]

Cite this page: Morrison, A. Odontogenic cysts: dentigerous. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/mandiblemaxilladentigerous.html. Accessed August 16th, 2018.
Definition / general
  • Developmental odontogenic cyst that originates by separation of dental follicle from around the crown of an unerupted tooth
  • Diagnosis requires correlation with radiographs or knowledge of radiographic findings
Terminology
  • Dentigerous cyst also called follicular cyst
  • Ameloblasts: specialized epithelial cells that form tooth enamel
  • Reduced enamel epithelium:
    • Enamel is normally composed of two cell layers: inner layer of reduced or atrophied ameloblasts and external layer, probably stratum intermedium cells
    • Reduced enamel epithelium is normally found overlying an unerupted, otherwise developed tooth
  • Deciduous tooth: also called baby tooth or primary tooth; falls out during childhood
  • Succedaneous tooth: permanent tooth; also called adult tooth; replaces deciduous teeth; lasts throughout life under most normal circumstances
  • Eruption cyst: soft tissue counterpart to dentigerous cyst; involves an erupting tooth
Epidemiology
  • Second most common odontogenic cyst
  • Most common developmental odontogenic cyst
  • Multiple simultaneous dentigerous cysts uncommon
  • Represents 20% of epithelium lined jaw cysts (J Investig Clin Dent 2013 Jun 14 [Epub ahead of print])
  • Usually seen in teenagers / young adults, although can occur over a wide age range
Sites
  • By definition, a dentigerous cyst occurs in association with an unerupted tooth
  • Most commonly around permanent mandibular third molars (wisdom teeth)
  • Somewhat less common around permanent maxillary third molars, maxillary cuspids and mandibular second premolars but any tooth may be involved
  • Rarely involves supernumerary teeth and odontomas (Contemp Clin Dent 2011;2:215)
  • Distinctly rare to occur around unerupted primary teeth
Pathophysiology
  • Develops from accumulation of fluid (including glycosaminoglycans) between reduced enamel epithelium of dental follicle and crown of unerupted tooth
  • Vast majority are developmental odontogenic cysts; may have inflammatory pathogenesis:
    • Inflammation progressing from root apex of carious or necrotic deciduous tooth brings about development of dentigerous cyst around underlying, unerupted permanent tooth
  • Impossible to histologically distinguish inflamed developmental odontogenic dentigerous cyst from those induced by inflammation
Etiology
  • In normal tooth development, tooth enamel is produced by the enamel organ, an ectodermally derived specialized epithelium
  • After enamel formation is complete, the enamel organ epithelium atrophies
  • This reduced enamel epithelium eventually merges with the overlying mucosal epithelium to form the initial gingival crevicular epithelium of the newly erupted tooth
  • Dentigerous cysts form when fluid accumulates between the reduced enamel epithelium and the crown of the unerupted tooth
Clinical features
  • May be small / asymptomatic, identified on routine radiographs taken for unrelated reasons or for imaging to investigate delayed tooth eruption
  • Can grow large enough to produce a painless bony expansion, can displace the involved tooth, cause resorption of adjacent teeth
  • If secondarily infected, may be associated with pain
Diagnosis
  • Radiographic findings, in combination with clinical information, can support a histomorphologic diagnosis
Radiology description
  • Most commonly a well defined, unilocular radiolucency on X-ray
  • Often has sclerotic rim
  • Can cause resorption of adjacent teeth
  • Three different radiographic relationships between involved tooth and cyst described:
    • Central variety:
      • Most common radiographic relationship
      • Cyst develops around and surrounds the entire crown of tooth, thus tooth appears to be erupting into the cyst (see Clinical images)
    • Lateral variety:
      • Cyst develops at lateral tooth root and only partially surrounds crown (see Clinical images)
    • Circumferential:
      • Cyst develops around crown and extends down the root(s), thus roots also appear within the cyst
  • More aggressive odontogenic lesions such as odontogenic keratocyst, ameloblastoma, and other odontogenic tumors can have identical radiographic features
  • Bilateral dentigerous cysts are uncommon
  • Radiographic differential diagnosis for bilateral or multifocal 'cystic' lesions around impacted / partially impacted posterior teeth in a young person may include:
    • Odontogenic keratocyst (keratocystic odontogenic tumor)
    • Cherubism
    • Bilateral buccal bifurcation cysts
    • Enlarged dental follicles
    • Multiple hyperplastic calcifying follicles
    • Mucolipidosis Type III, or pseudo-Hurler polydystrophy
    • Maroteaux-Lamy syndrome, also known as mucopolysaccharidosis type VI
    • Amelogenesis imperfecta
    • Tuberous sclerosis or cleidocranial dysplasia
  • The radiographic distinction between an enlarged dental follicle and a small dentigerous cyst can be arbitrary
  • Generally, a pericoronal radiolucency that is larger than 3 to 4 mm in diameter is considered suggestive of cyst formation
Prognostic factors
  • Excellent prognosis, almost never recurs with complete enucleation, however follow up radiographic studies recommended
  • Recurrence may indicate incomplete excision or possibly incorrect original diagnosis
  • Tooth sparing marsupialization procedures may have higher risk of cyst recurrence / persistence
  • Rarely, second neoplasms can arise from dentigerous cysts, most commonly:
    • Ameloblastoma
    • Squamous cell carcinoma
    • Intraosseous mucoepidermoid carcinoma
Case reports
Treatment
  • Varies based on age, maturity, anatomic position and relative importance of tooth involved, size of cyst, presence of additional neoplasms; also patient preference, including cosmetic and functional considerations
  • Enucleation of entire cyst with extraction of the associated tooth is most common approach
  • Marsupialization:
Radiology images

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Central variety

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Lateral variety

Multiple radiopaque masses with thin radiolucent rim

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Expansion and thinning of the bony sinus wall


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Unerupted maxillary canine

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Lesion extension

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Lesion pushing inferior wall of sinus

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Orthopantomograph

Clinical images

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Swelling of right maxilla and left mandibular region

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Swelling of right cheek

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Intraoral involvement of maxillary right quadrant

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Surgical exposure of lesional site

Gross description
  • Relationship of tooth and cyst usually disrupted during surgery
  • If cyst contains any nodularity, these areas should be sampled to rule out neoplastic change
Gross images

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Hard and soft tissues with impacted lateral incisor

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Enucleated specimen with embedded canine

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Cystic lesion

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Tan-colored thickenings in wall of cystic lesion

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Maxillary right quadrant


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Mandibular left quadrant

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Wisdom tooth with preserved dentiginous cyst orientation

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Dentigerous cyst remnants with tooth

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Extracted tooth and pathologic lining

Microscopic (histologic) description
  • Microscopic features are influenced by presence of inflammation
  • Inflamed Dentigerous Cyst:
    • Fibrous connective tissue
    • Hyperplastic non-keratinized epithelium, sometimes elongated interconnecting rete ridges
    • Chronic inflammatory cells
    • Cholesterol clefts, possibly formation of cholesterol granuloma
    • Rushton bodies
    • Scattered mucous, or ciliated or sebaceous cells uncommon but possible
    • Occasional dystrophic calcifications
    • Odontogenic epithelial rests, small, inactive appearing

  • Non-inflamed Dentigerous Cyst:
    • Fibrous to fibromyxoid connective tissue
    • No rete ridges, flat interface
    • Lining epithelium, 2 - 4 layers of cuboidal epithelium, devoid of superficial keratinization
    • Occasional mucous cells; rare ciliated cells
    • Occasional dystrophic calcifications
    • Odontogenic epithelial rests, small, inactive appearing
    • Some lesions submitted as dentigerous cysts are partially lined with a thin, fragmented layer of eosinophilic columnar cells / low cuboidal epithelium representing the postfunctional ameloblastic layer of the reduced enamel epithelium
      • Many of these lesions probably do not technically represent true cysts but just hyperplastic connective tissue dental follicles
Microscopic (histologic) images

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Cystic lumen

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Reduced enamel epithelium

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Dentigerous cysts

Differential diagnosis
  • Most significant and most common lesions to distinguish from dentigerous cyst:
    • Cystic ameloblastoma
      • Columnar basal cells with hyperchromatic nuclei
      • Usually but not always exhibit reverse polarization of nuclei (away from basement membrane)
    • Odontogenic keratocyst / keratocystic odontogenic tumor
      • Uniform epithelium
      • 4 - 8 cell layers in thickness
      • Hyperchromatic basilar palisading of cuboidal to columnar cells
      • Characteristic wavy / corrugated surface parakaratosis
      • +/- keratin flakes within cyst lumen
    • Differential greatly influenced by
      • Radiographic features (relationship or lack thereof with impacted tooth / teeth, lytic vs. opaque imaging characteristics, size of lesion, number of radiographic lesions, precise tooth involved)
      • Amount and features of epithelium available for evaluation
      • Degree of inflammation
      • Clinical history of new diagnosis vs recurrent disease also essential

    • Radiographic features unknown / unavailable, markedly inflamed squamous epithelial lining
      • Radicular / periapical cyst
      • Paradental cyst
        • Terminology used inconsistently
        • For some, this term is used to characterize a dentigerous cyst suspected to be induced by inflammation rather than a developmental odontogenic cyst
        • Others use the term paradental cyst synonymously with buccal bifurcation cyst
      • Odontogenic keratocyst / keratocystic odontogenic tumor, markedly inflamed
      • Dental follicle, inflamed
      • Eruption cyst
      • Plexiform variant ameloblastoma, inflamed
      • Unicystic ameloblastoma, inflamed

    • Radiographic features unknown / unavailable, limited cystic epithelium present for evaluation (ie: incisional biopsy of cystic lesion), however, basal palisading of the squamous epithelium present:
      • Calcifying odontogenic cyst / Gorlin cyst
      • Ameloblastoma with cystic features
      • Unicystic ameloblastoma
      • Odontogenic keratocyst / keratocystic odontogenic tumor
      • Dentigerous cyst (uncommon to have basal palisading and if present, is focal)
      • Odontogenic cyst or cystic odontogenic tumor, NOS