Cysts of the Jaws

Question 1

what is a cyst

Answer 1

pathological cavity having fluid, semi-fluid or gaseous contents and which is not created by accumulation of pus

Question 2

when do cysts have pus

Answer 2

when they are infected

Question 3

what are the characteristics signs of a cyst

Answer 3

egg shell crackling sound
absence of tooth
swelling
cause loss of vitality
discolouration
increasing in size
numbness
tooth mobility

Question 4

what radiographs are initially taken for a cyst

Answer 4

periapical
occlusal
panoramic

Question 5

what radiographs are supplementally taken for a cyst

Answer 5

CBCT
facial radiographs (PA mandible/occipitomental)

Question 6

what are the features of a cyst we look at radiographically

Answer 6

location
shape
margins
locularity
multiplicity
effect on surrounding anatomy
inclusion of unerupted teeth

Question 7

what shapes do cysts take

Answer 7

spherical or egg shaped

Question 8

what are the margins of cysts like

Answer 8

well defined
corticated

Question 9

what can locularity of cysts be like

Answer 9

often unilocular
sometimes multilocular

Question 10

how can cysts affect the surrounding anatomy

Answer 10

displacement
root resorption with chronic cysts

Question 11

what happens if a cyst becomes secondarily infected

Answer 11

lose definition and cortication of margins

Question 12

how can cysts be classified

Answer 12

structure
origin
pathogenesis

Question 13

what are the 2 main categories of cysts

Answer 13

odontogenic
non-odontogenic

Question 14

where do odontogenic cysts occur

Answer 14

tooth bearing areas

Question 15

what is the most common cause of bony swelling sin the jaws

Answer 15

odontogenic cysts

Question 16

what are odontogenic cysts lined with

Answer 16

epithelium

Question 17

where do the sources of the epithelium for odontogenic cysts come from

Answer 17

rests of malassez
rests of serres
reduced enamel epithelium

Question 18

how are the rests of malassez activated to be part of a cyst

Answer 18

by infection or cytokines/idiopathic

Question 19

where is odontogenic epithelium located

Answer 19

above IAN canal

Question 20

what are the most common odontogenic cysts

Answer 20

radicular
dentigerous
odontogenic keratocyst

Question 21

what is a radicular cyst

Answer 21

inflammatory odontogenic cyst

Question 22

how do radicular cysts start

Answer 22

chronic inflammation at apex of tooth due to pulp necrosis

Question 23

what jaw is more common to get a radicular cyst in

Answer 23

maxilla

Question 24

how do radicular cysts present

Answer 24

asymptomatic but may become infected
slow growing with limited expansion

Question 25

how do you differentiate between a radicular cyst or a periapical granuloma on a radiograph

Answer 25

if the radiolucency diameter is larger than 15mm then most likely a cyst

Question 26

what is the pathway of disease to a radicular cyst

Answer 26

pulpal necrosis periapical periodontitis periapical granuloma radicular cyst

Question 27

what are the radiographic features of a radicular cyst

Answer 27

well-defined radiolucency corticated margin continuous with lamina dura of non-vital tooth may displace adjacent structures external root resorption sometimes

Question 28

what are the histological features of a radicular cyst

Answer 28

epithelial lining connective tissue capsule inflammation in capsule

Question 29

how does a granuloma turn into a radicular cyst

Answer 29

proliferating epithelium with central necrosis continues growing by osmotic effect with semi-permeable wall and cytokine mediated growth

Question 30

what cells are found in radicular cysts

Answer 30

inflammatory mucous metaplasia cholesterol clefts rushton bodies

Question 31

what are the causes of numbness of the lower lip

Answer 31

cyst tumours infection trauma

Question 32

what is a residual cyst

Answer 32

when a radicular cyst persists after loss of tooth/RCT

Question 33

what is a lateral radicular cyst

Answer 33

radicular cyst associated with an accessory canal located at the side of the tooth instead of apex

Question 34

what types of cyst does the term inflammatory collateral cyst cover

Answer 34

paradental cyst buccal bifurcation cyst

Question 35

what are inflammatory collateral cysts associated with

Answer 35

vital teeth

Question 36

what is a dentigerous cyst

Answer 36

developmental odontogenic cyst

Question 37

what is a dentigerous cyst associated with

Answer 37

crown of unerupted tooth

Question 38

where are dentigerous cysts more commonly found

Answer 38

mandible usually third molar

Question 39

what does a dentigerous cyst look like radiographically

Answer 39

corticated margins attached to ACJ of tooth may displace involved tooth tend to be symmetrical initially variable displacement of cortical bone

Question 40

what is on the histology of a dentigerous cyst

Answer 40

thin non-keratinised stratified squamous epithelium

Question 41

how do you decide if a lesion is a dentigerous cyst or an enlarged follicle

Answer 41

based on follicular space 5mm+ consider cyst cyst if radiolucency is asymmetrical

Question 42

what is the usual length of follicular space from crown to follicle edge

Answer 42

2-3mm

Question 43

what is an eruption cyst

Answer 43

variant of dentigerous cyst contained within soft tissue rather than bone

Question 44

where and in who do you normally get an eruption cyst

Answer 44

incisors children

Question 45

what is an odontogenic keratocyst

Answer 45

developmental odontogenic cyst

Question 46

where do odontogenic keratocysts usually occur

Answer 46

mandible posterior

Question 47

what are the radiographic features of odontogenic keratocyst

Answer 47

scalloped margins 25% mulitlocular often displacement of teeth enlarge in medullary bone space (along bone)

Question 48

what pre-operative diagnostic test is needed for odontogenic keratocysts

Answer 48

cyst aspirate biopsy

Question 49

what does an odontogenic keratocyst produce in a cyst aspirate biopsy

Answer 49

squames low soluble protein content

Question 50

what is the histology features of an odontogenic keratocyst

Answer 50

epithelial lining with keratin palisading daughter cysts no rete pegs

Question 51

why do odontogenic keratocysts recur

Answer 51

if any of the lining is left after surgery

Question 52

what condition may someone have if they present with multiple odontogenic keratocysts at a young age

Answer 52

basal cell naevus syndrome

Question 53

what are the 3 types of non-odontogenic cysts

Answer 53

nasopalatine duct cyst solitary bone cyst aneurysmal bone cyst

Question 54

what do nasopalatine duct cysts arise from

Answer 54

nasopalatine duct epithelial remnants

Question 55

how do nasopalatine duct cysts present

Answer 55

asymptomatic salty discharge can displace teeth or cause swelling in palate always involves midline

Question 56

what is the histology of a nasopalatine duct cysts

Answer 56

non-keratinised stratified squamous and modified respiratory epithelium

Question 57

what is seen on radiography of a nasopalatine duct cyst

Answer 57

corticated radiolucency between roots of central incisors unilocular

Question 58

how do you decide between a cyst or the incisive fossa

Answer 58

if >10mm definitely cyst if <6mm is incisive fossa if between 6-10mm monitor

Question 59

what is a solitary bone cyst and who does it occur in and where

Answer 59

non-odontogenic cyst without epithelial lining most common in teenagers mandible

Question 60

what is a stafne cavity

Answer 60

depression in bone in mandible only

Question 61

where do stafne cavities present making them easy to separate from a cyst

Answer 61

inferior to inferior alveolar canal

Question 62

what methods are used for obtaining material for histology

Answer 62

aspiration biopsy incisional biopsy excisional biopsy

Question 63

if there is blood with an aspiration biopsy what type of cyst is this

Answer 63

aneurysmal bone cyst

Question 64

what type of fluid is present in inflammatory or developmental cysts

Answer 64

clear straw coloured

Question 65

what type of fluid indicates keratocyst

Answer 65

white or cream semi-solid

Question 66

what is the purpose of an incisional biopsy

Answer 66

obtain a lining for histological analysis

Question 67

what are the surgical options for cysts

Answer 67

enucleation marsupialisation

Question 68

what are the advantages of enucleation

Answer 68

whole lining can be examined pathologically primary closure little aftercare

Question 69

what are the contraindications of enucleation

Answer 69

risk of mandibular fracture dentigerous cyst old age, ill health clot filled cavity can become infected incomplete removal = recurrence damage to adjacent structures

Question 70

what are the indications for marsupialisation

Answer 70

if enucleation would damage surrounding structures difficult to access area may allow eruption of tooth affected by dentigerous cyst elderly or medically compromised very large cysts risking jaw fracture

Question 71

what are the advantages of marsupialisation

Answer 71

simple can spare vital structures

Question 72

what are the contraindications/disadvantages for marsupialisation

Answer 72

opening may close and cyst reform complete complete lining not available for histology difficult to keep clean and lots of aftercare needed long time to fill in

Question 73

what is used to keep the window open after marsupialisation

Answer 73

obturator