Oral Pathology: Odontogenic Cysts

Introduction

• Focus on lesions directly related to the teeth.
• Odontogenic cysts: Derived from cells associated with tooth formation.
  • "Odonto" = tooth
  • "Genic" = formation
• Residual odontogenic epithelium can undergo cystification.
• Cysts are cavities lined by epithelium.

Types of Odontogenic Cysts

Radicular Cysts (Periapical Cysts)

• Most common odontogenic cyst.
• Radiographically: Radiolucency at the apex of the root.
• Associated with a non-vital tooth and necrotic pulp causing periapical inflammation.
• Inflammation Types:
  • Acute: Leads to abscess.
  • Chronic: Leads to granuloma.
• Formation:
  • Epithelial rests of Malassez from Hertwig's epithelial root sheath encapsulate and form the cyst.
  • Origin from necrotic pulp.
• Treatment:
  • Root canal treatment.
  • Apicoectomy.
  • Extraction with curettage.

Dentigerous Cysts

• Second most common odontogenic cyst.
• Occurs over erupting tooth in children, called an eruption cyst.
• Radiolucency attached to CEJ (Cementoenamel junction).
• Common with canines and third molars.
• Accumulation of fluid between crown and reduced enamel epithelium.
• Treatment: Excision.

Lateral Periodontal Cyst

• Most common in mandibular premolar area.
• Associated with vital teeth.

Gingival Cyst of the Adult

• Soft tissue counterpart of the lateral periodontal cyst.
• Common in mandibular premolar area.
• No radiolucency since it’s in soft tissue.

Gingival Cysts of the Newborn

• Known as Bohn's nodules (lateral palate) and Epstein's pearls (midline palate).
• Origin from dental lamina.
• Treatment: None, as they involute with age.

Primordial Cysts

• Develops where a tooth should have formed.
• Common at mandibular third molar region.
• Treatment: Complete removal.

Keratocystic Odontogenic Tumor (KCOT)

• Also known as Odontogenic Keratocyst (OKC).
• Aggressive and recurrent.
• Common in posterior ascending ramus of mandible.
• Gorlin Syndrome:
  • Multiple KCOTs.
  • Multiple basal cell carcinomas.
  • Calcified falx cerebri.
  • Associated with brain.
• Treatment: Aggressive enucleation.

Calcifying Odontogenic Cyst (Gorlin Cyst)

• Rare and unpredictable.
• Involves "ghost cells" (nucleus absent, keratin-filled).
• Can undergo calcification, leading to radiopaque flecks.

Conclusion

• Important to distinguish between different types of odontogenic cysts.
• Each has specific characteristics and treatment methods.
• Understanding the origin and behavior of each cyst is crucial for effective diagnosis and treatment.

Note: Remember to review the characteristics and treatment options for each type of cyst, especially the items frequently tested, such as Gorlin Syndrome and its association with multiple basal cell carcinomas.