Cysts of the jaws

Question 1

What is the classification

Answer 1

Barnes 1. Odontogenic origin A. Development - Dentigerous cyst (eruption) REE - lateral periodontal cyst (botyoid) Maleez - orthokeratocyts (Nevoid BCC) series B. Inflammatory -periapical cyst (parentental, bufurcation, particular) - residual cyst 2. Non odontogenic origin A.developmental -Nasopalatine duct cyst -median palative cyst B. psuedocyts -stafne cyst -simple bone cyst (traumatic bone cyst)

Question 2

How do cysts form?

Answer 2

• lining proliferation due to epithelial growth factor etc, osteoclast activation and hydrostatic pressure. -epithelial rests condense then necroes as initial formation

Question 3

What are the Odontogenic Developmental lesions?

Answer 3

-dentigerous cyst -OKC -lateral periodontal cyst

Question 4

What is dentigerous cyst?

Answer 4

-REE, 10-30 years, unerupted often impacted teeth (supernumeraries, mand 8s, max 3s). -asymtptomatic unless secondary inflammation -displaces teeth, sometimes resorbs roots, does not erode cortical plate. -Radiographical: uniloc with sclerotic margins, right angle to CEJ, if >10cm may be pseudomultiloculated -does not have malignant transformation

Question 5

At what size is a follicle a potential cyst/

Answer 5

>3.5m (scholl, Avril)

Question 6

What are the histological findings of a dentigerous cyst?

Answer 6

SSE lining, with myxoid CT, sometimes cholesterol clefts, if inflamed will be hyperplastic.

Question 7

How do we treat Dentigerous cysts?

Answer 7

size dependant and vital structure dependant - decompress/marsuplise -enuleate and extract tooth - Coronectomy

Question 8

What is a lateral periodontal cyst?

Answer 8

• odontogenic development cyst -arises from rests of the dental lamina (serres)
• lateral of VITAL tooth.
• 40s, expands not eroded, displaces teeth, man canine/premolar -radiographically usually around 1cm, teardrop/oval-shaped well-circumscribed lesion with sclerosis of bone

Question 9

What is the histological presentation of a lateral periodontal cyst?

Answer 9

-1-5 cell thick SSE resembling REE with glycerol plaques. -hilanization (degradation into translucent substance) of surrounding CT

Question 10

How do we treat lateral periodontal cysts?

Answer 10

limited growth, monitor, enucleate if required 9may damage tooth/surrounding teeth).

Question 11

If there are multiple lateral periodontal cysts what condition can be suspected?

Answer 11

Botryoid variant. grape like clusters in anterior mandible. -high reoccurance

Question 12

What is an OKC

Answer 12

odontogenic developmental cyst of the jaw - forms from rests of serres (dental lamina). -SHH, PTCH gene pathway dysfunction -3-11% of odontogenic cysts, men, 20-30s -aggressive with high reoccurance -hydrostatic pressure not able to resorb cortical plate (M-D expansion) until very large -

Question 13

How do OKC’s present?

Answer 13

• 76% posterior mandible -Swelling, pain, M-D expansion before B asymmetry noticed. 2% paresthesia -straw coloured aspiration or cheese like masses

Question 14

How do OKCs present rdiographically?

Answer 14

unilocular well defined scalloped margined lesion -displaces teeth, looks multilocular at times as cyst lning grows faster than cavity

Question 15

What do OKCs look like histologically?

Answer 15

5-7 cell thick parakeratines SSE, no retes and budding seen in 50%, some have daughter cells (1/4)

Question 16

How are OKCs treated?

Answer 16

Biopsy, can have high reoccurance. enuleation with curratage, resection. 5 -15 year follow up

Question 17

What condition is suspected if multiple OKCs?

Answer 17

Nevoid BBC (PTCH)

Question 18

What are they types of inflammatory odontogenic cysts

Answer 18

-periapical (and variants) -residual

Question 19

What are tge features of a periapical cyst?

Answer 19

most common cystic lesion, -initiating factor pulpal irritation inducting cells rests of malessez. (dental progeinator cells - HPG - Mscs) - epithelia rests grow than break down into cystic lesion -40+, at apex. can cause root resorption -histological: non keratinsed SSE, hyperplastic CT, cholesterol clefts. fluid consists of necrotic cells, inflammatory excudate. -Tx; if under 20mm may resolve with RCT/exo on its own.

Question 20

What are the non odontogenic developmental cysts?

Answer 20

1. Medial palatine cyst 2. naso palatie Duct cyst

Question 21

What is a nasopalatine cyst?

Answer 21

remnant of the naso palatine duct from floor of nasal cavity. -contains neurovascular inclusions, possible salivary glands - 40-60years, males, midline -If on imaging duct appears more than 6-8mm suspect cyst -heart shaped lesion of squamous lining with columnar/cuboidal respiratory inclusions. Fibrous Ct with keratin containing fluid (inflam) TX: enuleation

Question 22

What is a medial palatine duct cyst?

Answer 22

Entrapped epithelium from palatal closure (5-10th week). -BMP -1-7% of cysts. -in midline, posterior to incisive canal, ovoid and does not contain nurovacular inclusions , may gete floor of nose elevation and swelling at palaal midline.

Question 23

What are the pseudocyst odontogenic cysts

Answer 23

1-Stafne Cyst 2-Simple bone cyst

Question 24

What is a simple bone cyst

Answer 24

-cavitation of the bone due to hemmorage and disorganized repair causing osteoclastic activation. -often empty or containing blood, single lesion, no infection, no lining, teeth should be vital and not displaced, no perf of cortical plate (does not expand) -<40, usually mandibular body tx: curettage, resection if very large - low reoccurance

Question 25

What is Stafne cyst?

Answer 25

Very distinct entitiy at lower angle of mandible (below IAN). well corticated or lytic usually with glandular inclusion. - error in formation of glandular tissue (4),

Question 26

Flow chart for Cysts?

Answer 26