CYSTS OF THE ORAL CAVITY

Cyst

-an abnormal cavity in hard or soft tissue, which contains fluid or semi-fluid and is often encapsulated and lined with epithelium.

Cyst of the Oral Cavity:

ODONTOGENIC CYST

NON-ODONTOGENIC CYST

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ODONTOGENIC CYST

(a) Periodontal/Radicular Cyst

(b) Dentigerous Cyst

(c) Lateral Periodontal Cyst

(d) Odontogenic Keratocyst

(e) Calcifying Odontogenic Cyst

ODONTOGENIC CYST

Periodontal/Radicular Cyst-most common type of cystic

lesion

Clinical Features:-painful condition at initial

stage of inflammation but eventually becomes asymptomatic

-associated tooth is non-vital-slow growing

Radiographic Features:

-well circumscribed radiolucency at the apex of the tooth involved

Histological Features:

- contents may be fluid or cheese- like material

-fluid contains inflammatory infiltrates

Treatment:

- enucleation following RCT or extraction of the tooth

ODONTOGENIC CYST

Dentigerous/Follicular cyst

-a cyst that produces an enlargement of the follicular space around the crown of a developing or unerupted tooth

Incidence:

-2nd most common type of odontogenic cyst

-Most prevalent among children and adults

-Affects late erupting teeth

3rd mandibular molars

Maxillary cuspids

Maxillary 3rd molars

Mandibular cuspids

Etiology: unknown

Clinical Features:

-Painless unless infection sets in

-May result to some degree of deformity or facial asymmetry

-As result of pressure the tooth involved may migrate to a considerable distance

-The cyst becomes very large before discovery

-Tooth is missing from the normal series of dentition

Radiographic findings:

-Well defined radiolucency associated with the crown of an impacted or unerupted tooth

-Generally unilocular

RADIOLOGICAL FEATURES:

• CENTRAL TYPE:

• LATERAL TYPE :

• CIRCUMFERENTIAL TYPE :

Radiographic Features:

Radiograph of two dentigerous cysts in the same patient. The cyst on the right is a lateral type; that on the left is a circumferential type

Radiographic Features:

A central type of dentigerous cyst. Note resorption of the root of the first mandibular molar

Treatment:

-Removal of associated tooth with enucleation

-If cystic lesion is very large, marsupialization may be done to allow decompression and subsequent shrinkage.

Gross specimen of a dentigerous cyst. Cyst encloses the crown of the tooth and is attached to its neck

ODONTOGENIC CYST

Lateral Periodontal Cyst

Clinical Features:

Age : 20 – 60 years, peak in 6th decade.

Sex : Male predilection.

Site : Lateral PDL regions of mandibularpremolars, followed by anterior maxilla

Signs and Symptoms:

• Usually asymptomatic as it occurs on the lateral aspect of root of tooth.

• Occasionally pain and swelling may occur.

• Associated teeth are vital, unless otherwise affected.

Radiographic Features:

• Round to ovoid ‘lucency with sclerotic margins.

• Cyst can be present anywhere between cervical margin to root apex.

• Radiographically, it can be confused with collateral OKC.

Radiograph of a lateral periodontal cyst lying between the mandibular premolar teeth. The margins are well corticated, indicative of slow enlargement.

Radiographic Features:

Lateral periodontal cyst. Radiolucent lesionbetween the roots of a vital mandibularcanine and first premolar.

Lateral periodontal cyst. A larger lesion causing root divergence.

Treatment:

-Surgical Enucleation

ODONTOGENIC CYST

Odontogenic Keratocyst

-it has the potential to grow a large cyst and has a very high recurrence rate.

Clinical features:

-usually involves the posterior portion of the mandible

-may be multilocular in larger lesions

-usually produces bone expansion

-may displace teeth but remains vital

Radiographic features:

-well circumscribed radiolucency with smooth margins and thin radiopaque border

Differential diagnosis:

-Ameloblastoma, dentigerous cyst, adenomatoidodontogenic cyst, tumor, ameloblastic fibroma

Treatment:

-Surgical excision with peripheral osseous curettage or ostectomy

ODONTOGENIC CYST• Calcifying Odontogenic Cyst

-Also called as Odontogenic ghost cell cyst or Gorlin cyst.

Etiology/Pathogenesis:

-derived from odontogenic epithelial remnants within the gingival

Pathognomonic Feature:

-ghost cell keratinization

Clinical Features:

-occurs more often in females >40 yrs. Old

-usually found in the Maxilla

-may be extraosseous in nature

Radiographic Features:• Intraosseous lesions produce

well defined lucency which is usually unilocular.

• Irregular calcified masses of varying sizes may be seen within the lucency.

• Displacement of root/roots with or without root resorption and expansion of cortical plates also seen-

• Within the radiolucent area there may be scattered irregularly sized calcifications producing variable degrees of opacity which may be seen as “salt and pepper” pattern

Radiograph of a calcifying odontogeniccyst of the maxilla. There is a well-demarcated margin and calcifications suggestive of tooth material.

Radiographic Features:

Radiograph of a calcifying odontogenic cyst with well-demarcated margins extending from the right to the left premolar regions of the mandible. Numerous calcifications are present, some suggestive of small denticles.

Histological Features:

Histological features of a calcifying odontogenic cyst with clusters of fusiform ghost cells and focal calcifications, lying in a stratified squamousepithelium.

- ghost cell keratinization-examination of ghost cells element will show individual cells or clusters with dystrophic mineralization

Treatment and Prognosis:

-simple enucleation is sufficient treatment with little risk of recurrence

NON-ODONTOGENIC CYSTIC LESIONS

(a) Globulomaxillary Cyst

(b) Nasolabial Cyst

(c) Nasopalatine Cyst

NON-ODONTOGENIC CYST Globulomaxillary Cyst

Clinical Features:

-well-defined radiolucency often producing divergence of the roots of the maxillary lateral incisor and the canine

-adjacent teeth are vital

-incidence rate is rare

-pear-shaped radiolucency

Treatment:

-enucleation

NON-ODONTOGENIC CYST

Nasolabial Cyst

Clinical Features:

-rare lesion found among 40-50 year old patients

-predilection for females

-seen as soft tissue swelling in the canine area

-teeth near the affected area are vital

Treatment:

-surgical excision

NON-ODONTOGENIC CYST

Nasopalatine Cyst

-also known as incisive canal cyst

Clinical Features:

-symmentric swelling in the anterior region of the palatal midline is characteristic of the lesion

-asymptomatic unless it reaches considerable size

-may produce divergence of the roots of Maxillary incisors

Radiographic Feature:

-heart-shaped radiolucency

Treatment:

-surgical incision

TREATMENT

Cysts of the jaws are treated in one of the following four basic methods:

(1) Enucleation,

(2) Marsupialization,

(3) A staged combination of the two procedures, and

(4) Enucleation with curettage.

ENUCLEATION

• Enucleation is the process by which the total removal of a cystic lesion is achieved.

• By definition, it means a shelling- out of the entire cystic lesion without rupture.

• Enucleation of cysts should be performed with care, in an attempt to remove the cyst in one piece without frag-mentation, which reduces the chances of recurrence by increasing the likelihood of total removal.

• However, maintenance of the cystic architecture is not always possible, and rupture of the cystic contents may occur during manipulation.

ENUCLEATION

TECHNIQUE :

• Aspiration Biopsy of Radiolucent Lesions

• Mucoperiosteal Flaps

• Osseous Window

• Removal of Specimen

ENUCLEATION

Aspiration Biopsy of Radiolucent Lesions :

• Any radiolucent lesion should be aspirated before surgical exploration.

• This provides the dentist with valuable diagnostic information regarding the nature of the lesion

Mucoperiosteal Flaps :

• Several varieties of mucoperiosteal flaps are available; the choice depends chiefly on the size and location of the lesion.

• Access may necessitate extension of the irmcoperiosteal flap. The location of the lesion dictates where the flap incisions are to be made.

• the flap design should provide 4 to 5 mm of sound bone around the anticipated surgical margins

• mucoperiosteal flaps for biopsies in or on the jaws she be full thickness and incised through mucosa, submucosa, and periosteum

ENUCLEATION

Osseous Window :

• once the flap has been elevated, a rotating bur should be used to remove an osseous window

• The size of the window depends on the size of the lesion and the proximity of the window to normal anatomic structures such as roots and neurovascular bundles.

ENUCLEATION

Technique :

• A dental curette is used to peel the connective tissues wall of the specimen from surrounding bone.

• The concave surface of the instrument should always be kept in contact with the osseous surfaces of the bone cavity

• The bony cavity is inspected after irrigation with sterile saline

• Any residual fragments of soft tissue within the cavity should be removed with curettes.

• Once the cavity is devoid of residual pathologic tissue, it is irrigated and the flap is replaced and sutured in its proper location.

ENUCLEATION OF CYST

MARSUPIALIZATION

• Marsupialization, decompression, and the Partsch operation all refer to creating a surgical window in the wall of the cyst, evacuating the contents of the cyst, and maintaining continuity between the cyst and the oral cavity, maxillary sinus, or nasal cavity.

• The only portion of the cyst that is removed is the piece removed to produce the window. The remaining cystic lining is left in situ.

• This process decreases intracystic pressure and promotes shrinkage of the cyst and bone fill. Marsupialtzatron can be used as the sole therapy for a cyst or as a preliminary step in management, with enucleation deferred until later.

INDICATIONS:

1. Amount of tissue injury : Proximity of a cyst to vital structures can mean unnecessary sacrifice of tissue if enucleation is used.

2. Surgical access : If access to all portions of the cyst is difficult, portions of the cystic wall may be left behind, which could result in recurrence.

3. Assistance in eruption of teeth : If an unerupted tooth that is needed in the dental arch is involved with the cyst (i.e., a dentigerous cyst), marsupialization may allow its continued eruption into the oral cavity

4. Extent of surgery : Marsupialization is a reasonable alternative to enucleation, because it is simple and may be less stressful for the patient

5. Size of cyst : In very large cysts, a risk of jaw fracture during enucleation is possible. It may be better to marsupialize the cyst and defer enucleationuntil after considerable bone fill has occurred.

MARSUPIALIZATION

Advantages :

• It is a simple procedure to perform. Marsupiaiization also spare vital

structures from damage should immediate enucleation be attempted.

Disadvantages :

• Pathologic tissue is left in situ, without thorough histologicexamination.

• Patient is inconvenienced in several respects

• The cystic cavity must be kept clean to prevent infection, because the cavity frequently traps food debris.

• In most instances this means that the patient must irrigate the cavity several times every day with a syringe

TECHNIQUE OF MARSUPIALIZATION

1) Anaesthesia

2) Aspiration

3) Incision

Circular, oval or elliptic. Inverted U shaped incision with broad base to the buccal sulcus. Mucoperioteum is reflected in this case.

4) Removal of bone

5) Removal of cystic lining specimen

6) Visual examination of residual cystic lining

7) Irrigation of cystic cavity

8) Suturing

Cystic lining sutured with the edge of oral mucosa.

In U shaped incision the mucoperiosteal flap can be turned into cystic cavity covering the margin. The remaining is sutured to oral mucosa.

9) Packing-- Prevents food contamination & covers wound margins.

Done with ribbon gauze soaked with WHITEHEAD VARNISH.

COMPOSTION:

Benzoin – 10g

Iodoform – 10g

Storax - 7.5g

Balsam of Tolu – 5g

Solvent ether to 100ml

Pack removed after 2 weeks.

10) Maintenance of cystic cavity

Instruct the patient to clean and irrigate the cavity regularly with oral antiseptic rinse with a disposable syringe.

11) Use of plug

Prevents contamination. Preserves patency of cyst orifice.

Plug should be stable, retentive and safe design.

Should be made of resilient material ( avoid irritation) like acrylic.

12) Healing

Cavity may or may not obliterate totally. Depression remains in the alveolar process.