Cysts of the Oral RegionOdontogenic Cysts

Cysts-pathologic cavity, fluid filled, epithelium lined

Cysts of the Oral Region-majority of cysts found in within max and mand -generally are inflammatory in origin-some are developmental in origin-cysts may be defined as an epithelium lined pathologic cavity that may contain fluid or cellular debris-types:

1. True Cysts-has actual epithelium2. Pseudo Cysts-not epithelium lined

-the epithelial lining of these cysts originates from residues of the tooth forming organ-3 kinds of residue, responsible for the origin of a particular type of lesion

1. Epithelial Rests or Glands of Serres2. Reduced Enamel Epithelium3. Rest of Malassez

Cysts of the Oral Region-the epithelial rests or glands of serres derived from dental lamina give rise to the ff:

1. Odontogenic Cyst (now considered a tumor)2. Lateral Periodontal Cyst3. Gingival Cyst

-reduced enamel epithelium is derived from the enamel organ and covers fully formed crown of the unerupted tooth_____________________________-rests of malassez formed by fragmentation of the epithelial root sheath of Hertwig

--Radicular Cyst

Radicular (Periapical Cyst)-the most common cysts of the oral and perioral regions-also called Apical Periodontal Cyst

-an inflammatory cyst derives its epithelium from the proliferation of small odontogenic epithelial residues (rests of malassez) within the periodontal ligament

>Etiology-develops with a pre-existing periapical granuloma-periapical represents a discrete focus of chronically inflamed granulation tissue in bone or apex of the tooth-it develops in response to pulpal sheath and subsequent tissue necrosis

>pathogenesis-stimulation of the epithelial rests relates to the inflammatory process within the periapical granuloma-cystification occurs as epithelial elements proliferate ultimately forming a lining-remnants of cellular debris are found within cysts lumen-fluids ingress into the lumen ultimately results in outward growth of the cyst-outward growth is enhanced by the osteoclastic bone resorption

>clinical feat-most located in max, especially in anterior region followed by max post region, mand post region and finally man ant region-most cases are noted in males-occur at any age but reach its peak at 3rd-6th decades-most radicular cysts are _____________-often discovered during routine dental radiographic examination-most don’t produce bone expansion if present they tend to favor labial or buccal locations-presents in non-vital teeth (__________factor)-______________-the radiolucency is usually ovoid, with a narrow opaque margin that is contiguous with lamina dura of involved teeth

*biopsy-aspirational, yellow fluid means it’s a cyst

>differential dx__________

>tx

-extraction and curettage-endo therapy-apicoectomy

>prognosis-with _________ recurrence is unexpected-with incomplete removal, a residual cyst may develop from months to years after initial tx

Residual Cyst

Dentigerous Cyst-Follicular Cyst-2nd most common type of odontogenic cyst-associated with crown of an unerupted or developing tooth-dentigerous means containing teeth-cyst enclosing the crown of unerupted tooth-is attached to cervical region which helps differentiate this cyst from primordial cyst>etiology and pathogenesis-____________-expansion of dentigerous cyst is related to a secondary increase in cyst fluid osmolarity as a result of passage of inflammatory cells and desquamated epithelial cells into cyst lumen>clin feat-most common sites are 3rd molar regions of mand and max, max canine region-highest incidence during 2nd and 3rd decades-greater frequency in males with a ratio of 1.6-1-symptoms are generally absent with late frequent indicators of possible -________--radiographically_________-the development if crown is generally symmetric with occasional lateral radiolucencies-there is displacement of unerupted teeth-in mand it may extend to the ramus and or the body of mandible-in maxilla, it may extend into canine regions, max sinus, or to the _______

Paradental Cyst

-__________-these are found adjacent to buccal root surface of mand 3rd molar-radiographically appear well circumscribe radiolucencies over roots of 3rd molar ____>histopath--stroma is collagenous and its intervening ground substance is rich in acidic glycoprotein and _______>diff dx-ameloblastoma, especially when it occurs in post region of mand or max in _____ pxs>tx-removal of associated tooth with careful enucleation of soft tissue-if cyst affect ___

Eruption Cyst-separate form of dentigerous cyst-found in children-erupting teeth-epithelium lining this space is REE-a soft tissue cysts results from fluid _________

Lateral Periodontal Cyst-a nonkeratinized, non-inflammatory developmental cyst occurring adjacent or lateral to the root of the tooth>etiology and patho-origin related to proliferation of rests of dental lamina within bone and _______>clin feat-majority occur in mand pm and cuspid region with ____ incisor area-distinct male predilection-radiographically, presents as a well delineated round or teardrop shaped radiolucency with an opaque margin along the lateral surface of tooth with no associated clinical symtpoms-area of involvement generally between adjacent roots with rare root development-radiographic lesion is most frequent monocystic-if polycystic/multiolocular botryoid ______>histopath-lined by a thin non keratinized epithelium-cluster of clear cells may be noted as modular thickening within cyst lining >diff diagnosis-cyst forming severe periodontitis-primordial cyst>tx and prognosis-local excision-little tendency for recurrence

Glandular Odontogenic Cyst-Sialo-odontogenic cyst-a combined features of both the botryoid odontogenic cyst and a mucus producing salivary gland lumen>clin feat-80% of cases noted in mand-when occurring in mand, most are found in ant region, often crossing the midline-when occurring __________-jaw expansion is possible in ________>radiographic feat-multiloculated-lesions exhibits a wide variation in size from some less than 1 cm to those involving most of the mand bilaterally

-radiographic margins are well defined and sclerotic>histopath-cystic lining consist of non keratinized epithelium with focal aggregated or nodular thickening within which the epithelial cells assume a swirled appearance-overall histomorphology is reminiscent of a low grade mucoepidermoid ____>tx-lesions should be considered locally aggressive-surgical tx-when adequate healthy bone remainperipheral curettage or marginal excision>prognosis-poor-long term follow up is essential given the local aggressiveness and recurrence potential

Gingival Cyst of the Newborn-Bohn’s Nodules-dental lamina cyst of newborn-appear typically as multiple nodules along the alveolar ridge in neonate-fragments of dental lamina that remain within alveolar ridge mucosa often tooth formation proliferate to form small keratinized cyst-in vast majority of cases, these cysts degenerate and involute or rupture into the oral cavity-histologically an intact cysts contain keratin debris and a thin epithelial linig (2-3 cell layers thick)>tx-similar in_______ cyst may occur along the midline of palate known as palatine cysts of newborn or epstein’s pearls-developmental in origin but didn’t derive from odontogenic epithelium-no tx necesary

Odontogenic Keratocyst (now considered a tumor)-any jaw cyst containing keratin-but many other cyst also contain keratin -distinctive entity that is worth of separation ______>etiology and pathogenesis-origin_______>clin feat

-2nd and 3rd decades-lesion found in children are often reflective of the multiple odontogenic keratocyst as a component of the _______ basal cell carcinoma syndrome-chief site-mand post portion of body and ramus-in max, usually occur in 3rd molar and canine region-radiographiclly with smooth margins and thin radiopaque borders-most lesion are unilocular adjacent to the crown of an unerupted teeth-multilocular _____-a significant percentage will produce buccal expansion>histopath-fibrous ct component of cyst wall is often _____ of an inflammatory cell infiltrate and is relatively thin-the lumen may contain large amounts of keratin debris or clear fluid similar to serum transudate-2 types

1. Parakeratotic (85-95%)2. Orthokeratinized (5-15%)

1. Parakeratotic-more aggressive-budding of basla layer of epithelium into supporting CT which may be slightly dysplastic and dyskeratotic-microcysts and satellite _______

2. Orthokeratinized-less aggressive-lower rate of occurrence-a prominent granular layer is found immediately below a _______ non-____ surface-basal cell layer is less _____-________

>diff dx-dentigerous cyst ameloblastoma-traumatic bone cyst, central giant cell granuloma, lat. Periodontal cyst

>tx-surgical excision with peripheral osseous _______ osteotomy-follow up is impt

>prognosis-high recurrence-poor

Calcifying Odontogenic Cyst-a development odontogenic cyst-odontogenic ghost cell tumor-occassional aggressive behavior (neoplastic)

>etiology and pathology-derived from odontogenic epithelial remnants within gingiva or within max and mand-char. Microscopic feat is the ghost cell _______

>clin feat-female predilection70% max-ant to 1st molar region-alveolar bone pressure resorption-radiographically, the central or intraosseous ____ present as an unilocular/multilocular radiolucency with discrete well dermacated margin-variable degrees of opacity-expansion of alveolar bone or soft tissue in 50% of cases-abssence of tenderness and pain are characteristic ____

>histopath-producing the ___ of a solid ____-epithelial layer irregular and ____ thickness-ghost cells =keratinized cells

>diff dx-early stages: dentigerous cyst, odontogenic k____, unicyst ameloblastoma-later stages:

>tx-simple enucleation>prognosis-little risk of recurrence