21. CYSTS OF JAW ,DIFFERENTIAL ,TREATMENT

what are the epithelial lined cysts?

1. developmental origin

- odontogenic

- non-odontogenic

2. inflammatory origin

3. non-epithelial origin

list some odontogenic cysts?

gingival cyst of infants

odontogenic keratocysts

dentigerous cyst

eruption cyst

what are the non-odontogenic cysts?

mid palatal raphe cyst

nasopalatine duct cyst

nasolabial cyst

which are the cysts of inflammatory origin?

radicular cyst ( lateral + apical)

residual cyst

which are the cysts of non-epithelial origin?

solitary bone cyst

aneurysmal bone cyst

how do radicular cysts develop?

there are 3 main stages

1. initiation

2. formation of epithelial capsule

3. growth of the cyst

what occurs in the initiation of the radicular cyst?

arise from epithelial cells of Malassez

they start to proliferate because of pulp necrosis and released necrotic tissue

key pathogens are P.gingivalis and E.coli

key inflammatory cells are IgG, IgA, IgE and IgM

what are the theories about the epithelial capsule?

1. the epithelium is proliferating and starts to cover the connective tissue surface of the cavity

2. the cavity is formed as the epithelium proliferates in apical region through degneration and cells death . MMP13 is secreted from epithelial cells, fibroblasts and plasma cells

how does the cyst grow?

there is a higher pressure in the cyst compared to the local blood pressure

this is because of the fluid inside it

what are the clinical signs of radicular cyst?

bone expansion

swelling- soft, fluctuant, blue-ish colour

if aspiration performed cysts will give a straw colour fluid with cholesterol crystals

Differential diagnosis of radicular cyst

Odontogenic keratocyst

Amelloblastoma

what are dentigerous cysts (follicular)?

cyst that full/partially embrace the crown of unerupted tooth and accomplish contact in cej

types of dentigerous (follicular) cysts?

central - cysts encircles neck of tooth and crwon located within cystic cavity

lateral- cyst attached to small lateral section of crown or neck of tooth

eruptive - cystic sac beneath ginigiva

circumferential - cyst surround crown or neck of tooth but occlusal portion free allowing tooth to erupt

where are dentigerous cysts mostly found?

mandibular premolars in children

mandibular wisdom teeth in adults

maxillary canine

maxillary wisdom

what are the clinical signs of a dentigerous cyst?

swelling

tooth displacement

when over 2cm in size, cause sensitivity

what will the xray show for dentigerous cysts?

well defined radiolucency around an unerupted tooth- this is the sclerotic border

what are odontogenic keratocysts?

they arise from epithelial odontogenic rests

collagen breakdown occurs within the cyst

what is special about the cells in odontogenic keratocysts?

they have no nuclei- they are called ghost cells

What is Gorlin-Gotz syndrome ?

autosomal dominant inherited disorder with high penetration and is associated with maxillary keratocysts and cutaneous basal cell carcinomas

also includes skeletal neurologic and opthalmic abnormalities

what are the effects of odontogenic keratocysts?

they may displace teeth around them

if in the mandible they can displace the inferior alveolar nerve

what are the differential diagnoses for odontogenic keratocysts?

dentigerous cysts

ameloblastoma

what are nasoplatine duct cysts?

Epithelial cysts 

where are naso-palatine duct cysts found?

the connection between the incisive foramen to the nasopalatine infundibulum

the middle anterior maxilla

what is the etiology of a nasopalatine duct cyst?

trauma

infection

mucous retention

what are the clinical signs of naso-palatine duct cysts?

usually unilateral

swelling

may be asympotomatic with lesion seen on xray

nasopalatine duct cyst radiographic appearance

well circumscribed lesion in midline of maxilla

lesion apical to central incisors

radiolucency has a heart shape