43 Odontoma

DEFINITION/OVERVIEW



  • Odontoma: oral mass that arises from odontogenic epithelial and mesenchymal origin

    • Ameloblastic fibro-odontoma (AFO) (formerly ameloblastic odontoma): radiolucent mass with osteolysis and varying amounts of intralesional mineralization
    • Complex odontoma: radiodense mass with fully differentiated dental components (more organized than AFO), but unorganized at the cellular level with no toothlike structures
    • Compound odontoma: mass with fully differentiated dental components resulting in the presence of denticles (toothlike structures; see “Clinical Features” section)

  • Hamartoma: proliferation of normal cellular components with an abnormal organization—not a true neoplasm (applicable to complex and compound odontoma types)

    • A definition to help delineate the three types of odontoma, not a type in itself

c43uf003ETIOLOGY/PATHOPHYSIOLOGY



  • Dogs/cats

    • AFO

      • Mixed odontogenic tumor with differentiation of odontoblasts, ameloblasts, and cementoblasts embedded in cellular mesenchymal tissue
      • Reciprocal inductive interaction of epithelial and mesenchymal tissues
      • World Health Organization (WHO) classification as a benign neoplasm with possible reoccurrence

    • Complex odontoma

      • Inductive processes resulting in dental components but not fully organized

    • Compound odontoma

      • Differentiation of dental components into varying levels of organization—denticles

c43uf004SIGNALMENT/HISTORY



  • Typically found in young animals
  • Oral swelling or mass (Fig. 43-1)
  • Delayed deciduous tooth exfoliation or delayed or abnormal tooth eruption at site


x25AA001rs Figure 43-1 Expansile mass on right mandible of dog with displacement of permanent teeth.


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c43uf005CLINICAL FEATURES



  • AFO

    • Most lesions are radiolucent with single or multiple (multilocular) expansile lesions of irregular configurations of dental components
    • Some lesions are associated with impacted teeth
    • Neoplastic mechanism: may recur (WHO—benign neoplasm)

  • Complex

    • Disorganized tissues within a thin, fibrous capsule
    • Radiographically, often a radial structure of hard tissue particles inside a radiolucent zone, embedded in the maxilla or mandible
    • Erupted teeth in that area may allow for communication between the odontoma and oral cavity, with a potential for bacterial contamination and infection

  • Compound

    • The presence of denticles is pathognomonic (Fig. 43-2)

      • Small, rudimentary teeth with crown formed, but the roots are often misshapen (dilacerated) (Fig. 43-3)
      • Denticles often associated with radiolucency
      • May be embedded or have some extent of eruption


x25AA001rs Figure 43-2 Presence of denticles between the right maxillary fourth premolar and first molar indicate the probability of compound odontoma.


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May 22, 2017 | Posted by in GENERAL | Comments Off on 43 Odontoma

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