Cysts of the jaw and other orofacial tissues Flashcards
what is the definition of a cyst?
a pathological epithelial lined cavity within tissue
what do hard tissue (odontogenic) cysts have to arise from?
dental lamina, dental follicle, enamel organ or epithelial cell rests
what are examples of odontogenic inflammatory cysts
radicular (periapical) or residual
what are examples of odontogenic developmental cysts
dentigerous or keratocyst
how do cysts usually present?
- 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
what can present if an infected CYST is close to the ID nerve?
can cause numbness in the distribution of the ID nerve
how do cysts typically present radiographically?
well-defined, corticated
what is the significance of cortication in cysts?
because they grow very slowly, they tend to push bone out of the way and as a result bone margins are very defined
are cysts uni or multi locular?
they can be both
why are cysts a problem?
- 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
what is the most common type of odontogenic cyst?
Periapical, radicular/inflammatory periapical cyst
how do radicular (inflammatory) cysts arise?
from cell rests that are activated by inflammation
explain how radicular cysts respond to inflammation
- 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
how can you distinguish between a periapical granuloma and periapical cyst?
pathologist
when does a granuloma progress onto a cyst?
tooth is not treated = central liquefaction and necrosis of the cells leaving epithelial cells around the outside of the cyst cavity
what are residual cysts?
present when you hava a periapical cyst and tooth is taken away but the cyst is left - it can persist as a residual cyst
what is a dentigerous cyst always associated with?
UNERUPTED teeth
where are dentigerous cysts typically seen?
around lower wisdom teeth or around premolars/canines
how do dentigerous cysts arise?
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
what is a dental follicle?
made up of mesenchymal cells and fibres surrounding the enamel organ and dental papilla of a developing tooth.
where do dentigerous cysts tend to be limited to and why?
the amelo-cemental junction because thats where the dental follicle is attached to
why is it important to remove a dentigerous cyst with the associated unerupted tooth?
may cause resorption of other teeth / damage teeth
what is a keratocyst?
arise from the dental lamina (can get them where there has been no tooth BUT also in association with unerupted teeth
typically, do keratocysts give unilocular or multilocular appearance?
multilocular
are keratocysts expansile and extensive?
yes! they tend to be V LONG and can cause expansion of the mandible
why are keratocysts difficult to treat?
easy to miss out locules (and not take the whole cyst tissue and cyst lining tends to be very delicate
where are keratocysts commonly found
angle of the mandible
what syndrome are keratocysts associated with?
gorlin golts syndrome
what syndrome is frontal bossing associated with?
gorlin goltz syndrome
what are eruption cysts always associated with?
erupting teeth
when does an eruption cyst disappear?
as soon as the tooth erupts
what colour do eruption cysts tend to be?
blue-ish
what radiolucency will an eruption cyst present as?
none! as outside the bone!!
what are the management options for an eruption cyst?
may require incision BUT mostly resolve/rupture spontaneously when the tooth erupts and becomes exposed
where do lateral periodontal cysts typically appear?
on the side of a tooth
where do lateral periodontal cysts originate from?
origin is uncertain - could be dental lamina or follice
what are the important distinctions of lateral periodontal cysts? (4)
- on the side of a tooth rather than apex
- associate with a vital tooth
- developmental NOT inflammatory
- tend to be pear shaped
what is the unusual variant of lateral periodontal cysts called? how do they appear?
botryoid variant - appear like a bunch of grapes - they are multilocular
what does a glandular odontogenic cyst have in it?
glandular epithelium
how does a calcifying odontogenic cyst differ from a glandular cyst
it contains areas of calcification
what are non-odontogenic hard tissue cysts usually associated with?
development/embryology of face NOT associated with teeth
what hard tissue structures fuse to form the face?
palatal plates and premaxilla
how do cysts form in non-odontogenic hard tissues?
lines of fusion between the structures - there is inclusion of epithelium which can go on to form a cyst
which is the most common type of non-odontogenic hard tissue cyst?
nasopalatine duct cyst
what cyst can arise between the line of fusion between the premaxilla and maxillary plates?
globulomaxillary cyst
what is staphnes idiopathic bone cavity?
normal submandibular gland tissue in the lingual aspect of the mandible
what treatment does staphnes idiopathic bone cavity require?
none!!!
where does it present radiographically? is it corticated?
under the ID canal, not corticated
what is a solitary bone cyst?
not lined by epithelium but tend to be lined by fibrous tissue or endothelial cells
what is an aneurysmal bone cyst?
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)
what is an aneurysmal bone cyst filled with?
filled with blood
what are soft tissue cysts categorised into?
developmental and non-developmental
how are soft tissue cysts formed?
fusion of the branchial arches and closure of the branchial cleft
what is the commonest developmental cyst in the head and neck?
dermoid cyst
how does a dermoid cyst arise?
caused by inclusion of material as the midline fuses (fusion of soft tissue - epithelium/epithelium structures get caught up in it)
where do dermoid cysts tend to present?
sublingually
what can branchial clefts also give rise to apart from cysts?
branchial sinuses
what is a thyroglossal duct cyst?
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
what do non-developmental cysts tend to be associated with?
salivary gland tissue
how are non-developmental cysts subdivided?
- mucous retention - saliva/mucous caught within the gland - blockage of saliva in the gland causes it to swell up
- 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
what is an example of a non-developmental cyst? what gland is it associated with?
ranula - usually associated with sublingual gland
what is a plunging ranula?
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
what is a lip mucoceles?
swellings in the lower lip
how is a lip mucocele caused?
- trauma?
- retention of saliva wihtin the salivary galnds
what is the treatment for lip mucocele?
- excision (works better)
- crytotherapy
what are the obvious risks involved with treatment of mucoceles?
scar, swelling, bleeding and bruising
