Oral Med Cysts of the Oral Region

- an abnormal cavity, lined by epithelium, containing fluid or semi-solid material
- can be developmental and get larger in time
can be found in soft tissue as well as bone

- based on the source of the epithelium (odontogenic cyst, non-odontogenic cyst)
- based on their location (soft tissue, intrabony)

- a cyst which the lining of the lumen is derived from epithelium produced during tooth development
- can come from different parts of the odontogenic structures (Rests of Malassez, reduced enamel epithelium, dental lamina, etc)
- Also Classified on their location

- odontogenic cyst from the Rests of Malassez, this is one of the most common cysts
- located at the root apex of the tooth
- the tooth must be infected or inflammed which will extend to the apical area
- an odontogenic cyst of inflammatory origin that is preceeded by a chronic PA granuloma and stimulation of rests of Malassez

- PA cyst is always a radiolucency, but we cannot make a diagnosis based on the radiograph alone
- we cannot determine a cyst from a chronic inflammation (apical granuloma) without histological evaluation
- Failed RCT will lead to a PA cyst
- one requirement is having a necrotic/infected tooth (if the tooth is intact, this will be some other pathology)

- apical surgery is necessary to remove the cyst and then retrofill the lesion
- if the tooth is not salvagable, then we must remove the retained root and remove the cyst otherwise it will turn into a residual cyst
- note that histologically there are inflammatory cells and a capsule surrounding an epithelial layer with a lumen on the interior

- these are eiosinophilic bodie which result from degenerative changes in cells in some (not all) of the cystic lesions
- this is an indication of the longevity of a chronic lesion

- this develops from an untreated radicular cyst
- we must curate the lesion otherwise it will lead to a residual cyst

- this is an odontogenic cys (from the developmental structures of the tooth) which surrounds the crown of an impacted tooth
- caused by fluid accumulation between the reduced enamel epithelium and enamel surface resulting in a cyst
- this is a pericoronal cyst of an impacted tooth
- lined by non-keratinized epithelium (could be inflammed or not)

- this is an odontogenic cyst with the histologic features of a dentigerous cyst that surrounds a tooth's crown that has erupted through the bone but NOT the soft tissue
- clinically is visible as a soft fluctuant mass on the alveolar ridges
- found in children who are in the process of erupting their teeth
- possible to have a blue-ish color due to trauma and bleeding with pigments (hemosiderin)

- cyst derived from the remnants, rests of the dental lamina with a biologic behavior similar to a benign neoplasm
- distinct lining of 6-10 cells in thickness that exhibits a basal cell layer of palisaded cells and a surface of corrugated parakeratin
- they can be found anywhere in the mouth, when around the root of a tooth they can cause resorption of the bone

- this has histologically keratinized epithelium, thus if you look at the lumen of the OKC it will be filled with a cheezy material (keratin)
- have a uniform thickness with a flat basal membrane, no rete pegs, and a 7-8 cell layer
- not usually inflamed, not irritated
- also might see a micro-cyst or a daughter/satellite cyst in the cell wall of the OKC (leading to an increased probability of recurrence

- most of the OKC are single and thus if there are multiple present we must think of BCC syndrome
- also present with bifid ribs, pitting of the skin, CV problems, intracranial tumors
- complexity of the syndrome leads to a treatment of individual problems but not of the syndrome
- dentist is usually first to diagnose syndrome due to the presence of multiple OKC

- a slow-growing, non-expansive developmental odontogenic cyst derived from one or more rests of the dental lamina containing an embryonic lining of 1-3 cuboidal cells and distinctive focal thickenings (plaques)
- found between two adjacent teeth in the bone, common in the posterior mandible, rarely change shape and lined by NON-keratinized

- a type of lateral periodontal cyst that shows a multilocular growth pattern (looks grapelike)
- these are many cystic cavities which are lined by the same epithelium as the lateral periodontal cysts