Cyst of Jaw - Classification Flashcards
What is a cyst?
A pathological cavity filled with fluid, semi-fluid or gaseous content and which is usually, but not always lined by epithelium
Can a cyst ever be filled with pus?
No - not created by accumulation of pus
If pus this would be abscess
What’s the most common cyst found in the jaw ?
Odontogenic cyst
How do odontogenic cyst arise?
From tooth forming tissue
What are different types of odontogenic cysts?
Inflammatory or developmental
Example of inflammatory odontogenic cysts?
RPR
Radicular
Residual
Paradental
Examples of developmental odontogenic cysts?
FLOCK GG
Folicular Lateral periodontal Orthokeratinised o.c Calcifying odontogenic odontogenic Keratocyst
Gingival cyst
Glandular odontogenic
Most common odontogenic jaw cyst?
Radicular - 65%
Second most common odontogenic jaw cyst?
Follicular
How does cyst grow?
Need a source of epithelium - give lining
Stimulus for proliferation and growth
Way resorb bone
Epithelial source for radicular cyst?
Remnants Hertwigs root sheath - remnants round PDL follow root shape
Epithelial source for follicular cyst?
Reduced enamel epithelium
Epithelial source for odontogenic keratocyst?
Remnant dental lamina
What is apical granuloma?
Ball of granulation tissue - lots of inflammatory cells and mediators
Can apical granuloma turn into cyst?
Yes can become radicular cyst - if acts upon epithelium will provoke proliferation
3 ways cysts can grow and expand?
- Osmosis and hydrostatic pressures
- Proliferation of lining
- Bone resorption
Where does dental lamina develop from?
Enamel organ
What does peridontal ligament contain?
Remnants of Hertwig’s root sheath - rest cells of malassez
What is radicular cyst?
Inflammatory odontogenic cyst which is associated w/ non-vital tooth
How does radicular cyst arise?
Arise from periodontal ligament from epithelial rests of Malassez as result of inflammation following death of pulp
Epidemiology of radicular cyst?
Male > female
Tend young- middle aged pt
Where most likely to see radicular cyst?
Anterior maxilla teeth most common
Always non-vital
3 types of radicular cyst?
- Apical - at apex of tooth associated w/ opening canal
- Lateral - at side associated w/ lateral branch of canal
- Residual
What is a residual cyst?
A radicular cyst which persist after extraction of tooth - left in alveolus
What expect to see radiograph radicular cyst?
Radiolucent lesion which is corticated
Continuity with PDL
Well defined
Pathogenesis of radicular cyst?
- Caries, extension bacteria into pulp = non-vital tooth
- Periapical granuloma - ongoing inflammation = tissue destruction = granulation tissue form
- Proliferation odontogenic epithelium
- Cyst form
Key features of radicular cyst on histology?
Cyst wall
Lining
Lumen cyst
Non-keratinised epithelium!
Why important to look at epithelium on histology radicular cyst?
Won’t be keratinised - differentiate from odontogenic keratocyst
What are some histological features could see in radicular cyst?
Keratin - very rare CIllia - like seen respiratory epitheium Hyaline bodies - Ruston bodies within epithelium Mucous cells - goblet cells Cholesterol/ cholesterol clefts
How to differentiate radicular cyst and apical granuloma?
Cysts tend to be larger, more radiolucent, well-defined, corticated and painlesss
What size would indicate apical granuloma or radicular cyst?
If less 1cm likely granuloma
If >1cm likely radicular cyst
Another word for paradental cyst?
Collateral cyst
What is a paradental cyst?
Inflammatory odontogenic cyst which develops alongside developing teeth
Definition of paradental cyst?
Cyst arise on lateral aspect of tooth as a result of inflammation in periodontal pocket