Cysts of the jaw and other orofacial tissues

Question 1

what is the definition of a cyst?

Answer 1

a pathological epithelial lined cavity within tissue

Question 2

what do hard tissue (odontogenic) cysts have to arise from?

Answer 2

dental lamina, dental follicle, enamel organ or epithelial cell rests

Question 3

what are examples of odontogenic inflammatory cysts

Answer 3

radicular (periapical) or residual

Question 4

what are examples of odontogenic developmental cysts

Answer 4

dentigerous or keratocyst

Question 5

how do cysts usually present?

Answer 5

• usually asymptomatic
• usually incidental
• can cause some swelling
• can be associated with movement, migration or failure to erupt teeth
• can become infected and cause pain/swelling

Question 6

what can present if an infected CYST is close to the ID nerve?

Answer 6

can cause numbness in the distribution of the ID nerve

Question 7

how do cysts typically present radiographically?

Answer 7

well-defined, corticated

Question 8

what is the significance of cortication in cysts?

Answer 8

because they grow very slowly, they tend to push bone out of the way and as a result bone margins are very defined

Question 9

are cysts uni or multi locular?

Answer 9

they can be both

Question 10

why are cysts a problem?

Answer 10

• they grow!!!
• they can move/loosen or damage teeth
• they can become infected (if they get big enough and come to the surface)
• they can move or damage structures (ID nerve)
• they can weaken bone - leading to fracture

Question 11

what is the most common type of odontogenic cyst?

Answer 11

Periapical, radicular/inflammatory periapical cyst

Question 12

how do radicular (inflammatory) cysts arise?

Answer 12

from cell rests that are activated by inflammation

Question 13

explain how radicular cysts respond to inflammation

Answer 13

• tooth is carious, pulp dies off, chronic inflammation a the apex of the tooth causes PROLIFERATION of a number of cells around the apex (epithelial cells and cell rests), they expand to form a ball

Question 14

how can you distinguish between a periapical granuloma and periapical cyst?

Answer 14

pathologist

Question 15

when does a granuloma progress onto a cyst?

Answer 15

tooth is not treated = central liquefaction and necrosis of the cells leaving epithelial cells around the outside of the cyst cavity

Question 16

what are residual cysts?

Answer 16

present when you hava a periapical cyst and tooth is taken away but the cyst is left - it can persist as a residual cyst

Question 17

what is a dentigerous cyst always associated with?

Answer 17

UNERUPTED teeth

Question 18

where are dentigerous cysts typically seen?

Answer 18

around lower wisdom teeth or around premolars/canines

Question 19

how do dentigerous cysts arise?

Answer 19

from the dental follicle (as the crown of the tooth is formed and enamel is laid down, once the crown of the tooth is completed, the dental follicle is the remnant of the enamel organ. if the tooth doesn’t erupt, you can get some fluid caught between the enamel surface and the dental follicle - starts to expand = cyst

Question 20

what is a dental follicle?

Answer 20

made up of mesenchymal cells and fibres surrounding the enamel organ and dental papilla of a developing tooth.

Question 21

where do dentigerous cysts tend to be limited to and why?

Answer 21

the amelo-cemental junction because thats where the dental follicle is attached to

Question 22

why is it important to remove a dentigerous cyst with the associated unerupted tooth?

Answer 22

may cause resorption of other teeth / damage teeth

Question 23

what is a keratocyst?

Answer 23

arise from the dental lamina (can get them where there has been no tooth BUT also in association with unerupted teeth

Question 24

typically, do keratocysts give unilocular or multilocular appearance?

Answer 24

multilocular

Question 25

are keratocysts expansile and extensive?

Answer 25

yes! they tend to be V LONG and can cause expansion of the mandible

Question 26

why are keratocysts difficult to treat?

Answer 26

easy to miss out locules (and not take the whole cyst tissue and cyst lining tends to be very delicate

Question 27

where are keratocysts commonly found

Answer 27

angle of the mandible

Question 28

what syndrome are keratocysts associated with?

Answer 28

gorlin golts syndrome

Question 29

what syndrome is frontal bossing associated with?

Answer 29

gorlin goltz syndrome

Question 30

what are eruption cysts always associated with?

Answer 30

erupting teeth

Question 31

when does an eruption cyst disappear?

Answer 31

as soon as the tooth erupts

Question 32

what colour do eruption cysts tend to be?

Answer 32

blue-ish

Question 33

what radiolucency will an eruption cyst present as?

Answer 33

none! as outside the bone!!

Question 34

what are the management options for an eruption cyst?

Answer 34

may require incision BUT mostly resolve/rupture spontaneously when the tooth erupts and becomes exposed

Question 35

where do lateral periodontal cysts typically appear?

Answer 35

on the side of a tooth

Question 36

where do lateral periodontal cysts originate from?

Answer 36

origin is uncertain - could be dental lamina or follice

Question 37

what are the important distinctions of lateral periodontal cysts? (4)

Answer 37

1. on the side of a tooth rather than apex 2. associate with a vital tooth 3. developmental NOT inflammatory 4. tend to be pear shaped

Question 38

what is the unusual variant of lateral periodontal cysts called? how do they appear?

Answer 38

botryoid variant - appear like a bunch of grapes - they are multilocular

Question 39

what does a glandular odontogenic cyst have in it?

Answer 39

glandular epithelium

Question 40

how does a calcifying odontogenic cyst differ from a glandular cyst

Answer 40

it contains areas of calcification

Question 41

what are non-odontogenic hard tissue cysts usually associated with?

Answer 41

development/embryology of face NOT associated with teeth

Question 42

what hard tissue structures fuse to form the face?

Answer 42

palatal plates and premaxilla

Question 43

how do cysts form in non-odontogenic hard tissues?

Answer 43

lines of fusion between the structures - there is inclusion of epithelium which can go on to form a cyst

Question 44

which is the most common type of non-odontogenic hard tissue cyst?

Answer 44

nasopalatine duct cyst

Question 45

what cyst can arise between the line of fusion between the premaxilla and maxillary plates?

Answer 45

globulomaxillary cyst

Question 46

what is staphnes idiopathic bone cavity?

Answer 46

normal submandibular gland tissue in the lingual aspect of the mandible

Question 47

what treatment does staphnes idiopathic bone cavity require?

Answer 47

none!!!

Question 48

where does it present radiographically? is it corticated?

Answer 48

under the ID canal, not corticated

Question 49

what is a solitary bone cyst?

Answer 49

not lined by epithelium but tend to be lined by fibrous tissue or endothelial cells

Question 50

what is an aneurysmal bone cyst?

Answer 50

not epithelial lined but tend to expand more than a solitary bone cyst (can get a bit of trabeculation within the cyst cavity = soap bubble appearance)

Question 51

what is an aneurysmal bone cyst filled with?

Answer 51

filled with blood

Question 52

what are soft tissue cysts categorised into?

Answer 52

developmental and non-developmental

Question 53

how are soft tissue cysts formed?

Answer 53

fusion of the branchial arches and closure of the branchial cleft

Question 54

what is the commonest developmental cyst in the head and neck?

Answer 54

dermoid cyst

Question 55

how does a dermoid cyst arise?

Answer 55

caused by inclusion of material as the midline fuses (fusion of soft tissue - epithelium/epithelium structures get caught up in it)

Question 56

where do dermoid cysts tend to present?

Answer 56

sublingually

Question 57

what can branchial clefts also give rise to apart from cysts?

Answer 57

branchial sinuses

Question 58

what is a thyroglossal duct cyst?

Answer 58

thyroid develops from tissue that originates in the foramen cecum (part of the posterior tongue) where the back of the anterior 2/3 of the tongue and junction with posterior 1/3 of the tongue - that migrates down into the neck to form the thyroid tissue (can get a little bit of tissue caught along the way which fails to move and can in later life form a thyroglossal cyst

Question 59

what do non-developmental cysts tend to be associated with?

Answer 59

salivary gland tissue

Question 60

how are non-developmental cysts subdivided?

Answer 60

1. mucous retention - saliva/mucous caught within the gland - blockage of saliva in the gland causes it to swell up 2. mucous extravasation - saliva has got out of the gland/duct it was supposed to be contained by - once it is in the tissues because of the nature of epithelium it can migrate around the bag of saliva and form an epithelial cyst lining

Question 61

what is an example of a non-developmental cyst? what gland is it associated with?

Answer 61

ranula - usually associated with sublingual gland

Question 62

what is a plunging ranula?

Answer 62

swelling in the floor of the mouth but also the neck because of a developmental defect in the mylohyoid muscle - whole cyst needs to be removed otherwise will reoccur

Question 63

what is a lip mucoceles?

Answer 63

swellings in the lower lip

Question 64

how is a lip mucocele caused?

Answer 64

- trauma? - retention of saliva wihtin the salivary galnds

Question 65

what is the treatment for lip mucocele?

Answer 65

1. excision (works better) 2. crytotherapy

Question 66

what are the obvious risks involved with treatment of mucoceles?

Answer 66

scar, swelling, bleeding and bruising