Cysts of the Jaws

Cysts of the Jaws
Pathological cavity with fluid or semifluid content, lined by epithelium.

Growth : epithelial proliferation, internal hydraulic pressure, bone resorption.

WHO classification
1. Epithelial cysts:


 * Developmental odontogenic cysts: odontogenic keratocyst, follicular cyst, eruption cyst, gingival cyst.


 * Inflammatory odontogenic cysts: radicular cyst, residual cyst, periodontal cyst.


 * Non-odontogenic cyst: nasopalatine cyst, nasolabial cyst.

2. Non-epithelial cysts: solitary bone cyst, aneurismal bone cyst.

3. Other: benign mucosal cyst of max. antrum, post.op.max,cyst, dermoid cyst, cysts of salivary glands.

Odontogenic cysts: lined by epithelium derived from radicular cyst, odontogenic keratocyst; well defined round radiolucencies, well-defined margins; swelling, displacement of teeth, increased mobility of teeth;

Radicular cyst: apical dental cyst of inflammatory origin; well-defined round radiolucency associated with root apex, corrugated margin is continuous with lamina dura at root; cyst lumen lined with simple sq.ep and in parts may be replaced with granulation tissue.

Residual cyst: well-defined round radiolucency in edentulous area; occasional flecks of calcification; lining- simple sq.ep but mature.

Odontogenic keratocyst: well-defined radiolucency with dense corticated margins; multilocular; expansion limited; lining- continuous str.sq.ep with corrugated surface; enucleation, irrigation with chemical fixatives, excision to incl.bone margin around cyst.

Follicular cyst: pericoronal radiolucency >3-4mm; cyst attaches to tooth at amelocementl junction.

Eruption cyst: extrabony position soft tissue mass appears; marsupialialization-to expose erupting tooth.

Gingival cyst:
 * Neonates - white keratinous nodules (Epstein pearls); may open into oral cavity forming clefts that exude keratin.


 * Adults- found in buccal gingival in mandibular premolar - canine region; soft blue swelling with attached gingival, <5mm diameter.

Nasopalatine cyst: well defined round radiolucency in midline of anterior maxilla, heart-shaped, pseudostratified ciliate columnar epithelium.

Nasolabial cyst: soft tissue lesion so nothing seen on x-ray; lined by non-ciliated pseudostratified columnar ep.

Aneurysmal bone cyst: well defined radiolucency; multilocular; marked expansion curettage.

Solitary bone cyst: well defined non-corticated radiolucency; arches up between roots of teeth; cortical margins of canal may be lost.

Diagnosis

 * X-Ray

Treatment

 * Enucleation : one stage procedure- 3 side incision or semilunar incision; risk of damage to adjacent structures, leaves cavity prone to infection.


 * Marsupialization : one stage procedure; prolonged healing period; protects vitality of teeth and integrity of nerves; sup.part of cyst excised.

Differential Diagnosis

 * periapical abscess


 * ameloblastoma


 * malignant tumour