Cysts of the Jaw

Question 1

Xrays for investigating cysts

Answer 1

PA/occlusal/OPT

CBCT
Pa mandible

Question 2

Important radiographic features to assess when looking at cysts

Answer 2

Location
Shape
Margins (well defined/corticated)
Locularity
Multiplicity
Effect on surrounding anatomy
Inclusion of UE teeth

Question 3

How are cysts classified

Answer 3

Structure (epithelium lined vs non epithelial lined)
Origin (odontogenic vs non-odontogenic)
Pathogenesis (development vs inflammatory)

Question 4

Classification of odontogenic cysts

Answer 4

Developmental:
Dentigerous, Eruption, OK, Lateral periodontal

Inflammatory:
Radicular, Residual, Inflammatory collateral cyst - Paradental/Buccal bifurcation

Question 5

Classification of non odontogenic cysts

Answer 5

Developmental:
Nasopalatine duct cyst

Other:
Solitary bone cyst
Aneurysmal bone cyst (no epithelial lining)

Question 6

Sources of epithelium for Odontogenic cysts

Answer 6

Rests of Malassez - Hertwigs Root Sheath
Rests of Serres - Remnants of dental lamina
REE - Remnants of enamel organ

Question 7

What is the most common odontogenic cyst

Answer 7

Radicular cyst (60%)

Question 8

Signs/symptoms of cysts

Answer 8

Mobility
Pain
Sensitivity
Spacing
TTP
Numbness
Failed eruption

Question 9

Classification of radicular cyst

Answer 9

Odontogic + inflammatory
Epithelial lined
Non vital tooth

Question 10

Incidence of radicular cyst

Answer 10

40s-50s
Maxilla>mandible

Question 11

Features of radicular cyst

Answer 11

Often asymptomatic
PA granuloma often at apex

Question 12

Radiographic features of radicular cyst

Answer 12

Well defined corticated margin continuous with lamina dura

Question 13

Histology of radicular cyst

Answer 13

Non keratinised stratified squamous
Connective tissue capsule

Question 14

Classification of residual cyst

Answer 14

Odontogenic + inflammatory
Epithelial lined

Question 15

Features of residual cyst

Answer 15

When radicular cyst persists after XLa/RCT of tooth

Question 16

Classification of inflammatory collateral cysts

Answer 16

Inflammatory + odontogenic
Epithelial lined
Vital tooth

2 types:
Buccal bifurcation - mandibular molars
Paradental - 38/48d

Question 17

Classification of eruption cyst

Answer 17

Developmental + odontogenic

Question 18

Features of eruption cyst

Answer 18

Around PE tooth
Exclusive to children

Question 19

Classification of dentigerous cyst

Answer 19

Developmental + odontogenic
Assoc with crown of UE mandibular 8s or max 3s

Question 20

Incidence of dentigerous cyst

Answer 20

20s-40s

Question 21

Radiographic features of dentigerous cyst

Answer 21

Large well defined corticated radiolucency around crown

Question 22

Histology of dentigerous cyst

Answer 22

Non keratinised stratified squamous epithelium
Fibrous capsule

Question 23

Classification of OK

Answer 23

Developmental + odontogenic

Question 24

Radiographic features of OK

Answer 24

Large radiolucency
Scalloped margins
Displacement of adjacent teeth
Characteristic expansion
25% multilocaular
Huge risk of pathological fracture

Question 25

Difficulties of treating OK

Answer 25

Recurrence rate - follow up 10yrs
Thin friable lining - difficult of surgery

Question 26

Tx options for removal of cysts

Answer 26

1. Enucleation
   - All cyst removed
   - Small cysts
   (Not for dentigerous cysts)
2. Marsupialisation
   - Negative pressure allows cyst to shrink
   - Enucleated at later date