Odontogenic Cysts - radicular cysts Flashcards
What is a cyst?
Pathological cavity filled by a fluid or a semi-fluid which has not been created by pus accumulation
They jaws are the most common bones affected by cysts
What bone is the most affected by cysts?
Jaws
Cyst vs abscess?
Abscess has pus
Cysts has a fluid
Cysts of the jaws types/categories?
Epithelial cysts- odontogenic or non odontogenic
Non-epithelialized primary bone cysts
2 types of cysts?
Costs of the jaws
Soft tissue cysts
What are odontogenic cysts?
Cysts with an epithelial lining that originates from
residues of tooth forming enamel organ.
Origin of odontogenic cysts?
Rests of serres - remnants of dental lamina
Rests of malassez - remnants of hertwogs root sheath
Reduced enamel epithelium
2 types of odontogenic cysts?
Inflammatory
Developmental
Types of inflammatory odontogenic cysts?
Radicular
Paradental - not as common
Types of developmental cysts?
- Dentigerous cyst
- Eruption cyst
- Lateral periodontal cyst
- Gingival cyst
- Glandular odontogenic cyst
- Odontogenic keratocyst
What is the most common type of odontogenic cysts of the jaw?
Radicular
Types of Radicular cysts?
Apical Radicular cysts
Lateral Radicular cysts
Residual cysts
Rarest type of Radicular cysts?
Lateral Radicular
Most common type or Radicular cysts?
Apical Radicular cysts
What is shown here?
Radicular cysts
Differential diagnosis?
Periapical granuloma
Periapical abscess
Radicular cysts
What is shown here?
Lateral Radicular cysts
Margins of a lateral Radicular cysts?
Formation next to lateral root tooth
What is shown here?
Residual Radicular cysts
How do residual Radicular cysts differ from Radicular cysts?
Involved tooth has been extracted
Pathogens of Radicular cysts?
proliferation of rests of malassez within a periapical granuloma - develop into a cysts
- epithelium is not vascularised tissue - cells in centre have no blood supply so die/degeneration of central cells within a proliferating mass of epithelium = cavity lined with epithelium
epithelium start to proliferated due to neutrophils, GF, cytokines etc
Inflammatory stimuli
Bacterial endotoxins
Cytokines
GF
not all periapical granulomas develop into cysts
or degeneration of granulation tissues surrounded y proliferating epithelium
- area of necrosis leading to cysts formation
Radicular cysts arise from what?
Proliferation of rests of malassez within a periapical granuloma
Describe the lining of Radicular cysts?
Non-keratinised stratified squamous epithelial lining
Chronically inflamed fibrous tissue capsule
2 types of epithelial cysts?
odontogenic and non-odontogenic
What is the most common type of odontogenic cysts?
inflammatory - radicular
2 most common types of cysts?
radicular and dentigerous
Residual cysts?
cysts remains in jaw after tooth extracted
radiolucency
How do cysts appear on radiograph?
radiolucent lesions due to bone resorption
radiopaque due to margin
What type of tooth are radicular cysts associated with?
non-vital tooth
Why are radicular cysts rare in primary dentition?
the tooth is usually extracted before cysts formation
Clinical presentation of radicular cysts?
apical cysts associated with apices of non-vital teeth
symptomless if small
incidental findings on radiographs
alveolar bone expansion when they enlarge
may discharge through sinus
most cysts do not grow or very large dimensions
pain is rare unless superimposed by infection
When do radicular cysts cause alveolar bone expansion?
enlargement of cysts
How does the cysts cause bone expansion?
so much hydrostatic pressure in the cyts s
causes pressur eon the bien and osteoclast ion the bine are activated and causes bone resorption
also, bone make sup form it by firming layers of periosteum
rate of expansion is greater than bony deposition leading to eggshell cracking
eggshell crackling?
rate of expansion is greater than bony deposition
thinning of cortex
bone bulges into mucosa- appears as blue swelling
eggshell crackling also called what?
oil can bottling
What is the radiopaque margin of the radicular cysts continuous with?
lamina dura
What is the shape of a radicular cysts?
round to ovoid periapical radiolucency
Do all periapical granulomas develop into cysts?
no
Microcyst formation?
degeneration of central cells within a proliferating mass of epithelium
What is the origin of the epithelium of a cyst?
cell rests of malassez
epithelium regular or irregular?
irregular
as time goes by, it becomes more regular and uniform
What type of radicular cysts is this?
pocket cysts
Pocket cysts?
pocket cysts surround he root apex
more prone to heal after endodontic tx
What happens to the epithelium over time?
thinner stratified squamous epithelium and more regular
inflamed cause surrounding it
what happens to a radicular cysts over time?
the epithelial lining in established cysts is regular
even thickness
metaplasia gives rise to mucous cells
respiratory epithelium
cholesterol clefts, cant see fat in preparation- breakdown of red blood cells
What is this?
rushton bodies
hyaline eosinophilic bodies - can sometimes be found in radicular cysts.
with inflammation cells produce them
no clinical significance
With time if the inflammation is more contained, what are the features of the radicular cysts?
the capsule become more fibrous and less cellular with time - less inflamed
cholesterol clefts within the capsule
giant cells associated with them
What is the appearance of the cysts contents?
watery straw coloured fluid
semi solid brownish paste like consistency
shimmering appearance due to cholesterol crystals
What are the contents of the cysts?
breakdown products - epithelial, inflammatory and connective tissue cells
serum proteins
- high level immunoglobulins
water
electrolytes
cholesterol crystals
How would you describe the contents of the cysts?
hypertonic - highly concentrated
high osmolality of the cysts contents
How does hypertonic nature of the cysts affect expansion?
leads to expansion of the cysts due to osmosis
fluids move form the lower to higher conc of electrolytes
movement of fluids into the cysts lumen
cysts lining acts as a permeable membrane
Does the hydrostatic pressure of the radicular cyst cause bone resorption?
yes
water move in, cysts expands like a balloon (even on all sides)
pressure = osteoclast activation and bone resorption
is the cysts wall permeable or impermeable?
semi permeable
