Category:Teeth - Pathology

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Introduction

See anatomy and physiology of the teeth

Functional Anatomy

• The gingival crevice is an important site for disease processes in mouth to begin.

• In ruminants and rodents teeth may fail to oppose properly or to allow side to side movement of jaws. This produces uneven wear (especially in horse). Sharp edges are produced on the outside of the teeth in the upper jaw and inside of the teeth in the lower jaw, which causes painful feeding and inanition (not eating).
  • Approximately 75% of wasting horses have dental abnormalities.

• This is not a problem in carnivores as do they not use teeth for mastication.

• If a teeth is lost the opposing teeth may become very long and stop mouth closing properly.
  • Seen mostly in rodents - teeth may even penetrate through lip.

Proliferative Pathology

Hyperplastic

Focal fibrous hyperplasia

Neoplastic

Peripheral odontogenic fibroma^[1]

• aka: Fibromatous epulis of periodontal ligament origin
• 17% of cases.
• Proliferation of fibrous tissue with variety of osteoid, cementum or dentine-like material.
• Isolated strands or islands of odontogenic epithelium always present (ie: suggesting induction of connective tissue by the epithelial cells).
• The stroma contains neoplastic fibroblasts, with varying cellularity.
• The overlying epitheluim is normal.

With thanks to Andrew Jefferies (Cambridge) and Alun Williams (RVC) for providing access to their lecture materials

Peripheral ameloblastoma^[1]

• aka: basal cell carcinoma, acanthomatous ameloblastoma, acanthomatous epulis
• 18% of cases.
• Islands and sheets of mature odontogenic epithelium within a collagenous fibrous connective tissue stroma of low/moderate cellularity.
• Each of the islands bounded by a row of tall columnnar cells.
• These palisading cells exhibit polarisation away from the basement membrane and had cytoplasmic vacuolation.
• Central cells had a basaloid appearance.
• Often infiiltrating into the underlying bone.
• Synonymous with basal cell carcinoma.

With thanks to Andrew Jefferies (Cambridge) and Alun Williams (RVC) for providing access to their lecture materials

Central ameloblastoma^[1]

• Different from peripheral ameloblastoma - cystic changes and follicular arrangement of ameloblasts and stellate reticulum cells, resembling the basic structure of the enamel organ.

With thanks to Andrew Jefferies (Cambridge) and Alun Williams (RVC) for providing access to their lecture materials

Degenerative Pathology

Odontodystrophy

• Damage to ameloblasts (which form enamel) in utero upsets permanent incisor formation.
• Enamel is marked by pits, lines etc.

In ruminants:

• Damage to enamel formation most often caused by fluoride poisoning.
• Seen in cattle grazing on pasture contaminated by cement works effluent.
• Chalky mottling and yellow brown pitting of tooth.

In canines:

Very severe systemic disease early in life / or in utero may result in severe discoloration or pitting of teeth due to effect on enamel formation. (e.g. distemper in dog)

Metabolic Pathology

Nutritiona Pathology

Traumatic Pathology

Vascular Pathology

References

Learning Tools

Teeth Flashcards