BDS 10031 NGU Cyst PDF

BDS 10031 Cysts of the jaws: surgical management Overview • Definition:Cyst is an epithelial lined pathological cavity , containing fluid or semi fluid. • It is not formed due to pus accumulation. • Cyst is asymptomatic with no any signs and symptoms unless infected. • Usually discovered by routi...

BDS 10031 Cysts of the jaws: surgical management Overview • Definition:Cyst is an epithelial lined pathological cavity , containing fluid or semi fluid. • It is not formed due to pus accumulation. • Cyst is asymptomatic with no any signs and symptoms unless infected. • Usually discovered by routine radiographic examination. • It must be lined by an epithelial lining to be called a True cyst otherwise it is called Pseudocyst. Classification of the Cysts Radicular cyst • • • • • it is by far the most common type of cysts (55%) that may appear in the region of the jaws. it is also known as apical cyst, dental cyst or periapical cyst. it arises from the epithelial rests of Mallasez of a non vital tooth. it grows in size by the degeneration of the central cells of the cell masses followed by the osmosis of fluid from the surrounding areas . This is know as cystic degeneration. Clinical Features • The lesion grows slowly around the apex of a non vital tooth • It becomes gradually walled off by bone as a defense mechanisms causing its radiographic appearance as a radiolucency surrounded by a radiopaque margin. • It continuously grows in size and causes bony expansion and pushes all surrounding vital structures such as the inferior alveolar canal in the mandible • Its continuous increase in size may lead to the erosion of overlying bone and periosteum to form what is known as egg shell crackling bone sensation. • The cyst lining may become apparent as a bluish membrane. Diagnosis • • • • • • Cysts are usually asymptomatic and discovered accidentally unless infected. They usually expand the buccal bone except in the upper lateral incisor. The contents of the cyst are usually examined by aspiration. It reveals a straw like coloured fluid rich in cholesterol crystals. in very large cysts histopathological examination ,i.e, biopsy is to be made. In cases of an infected cyst , the aspirate contains pus + blood. Radiographic appearance • The cyst appears as a well defined radiolucency surrounded by a radiopaque margin. • It appears as a well corticated rounded or oval radiolucency related to the root apex of a non vital tooth. • In cases of infection it turns to a radiolucency with a hazy margin and becomes symptomatic. • 60% are found in the maxilla related to incisors and canines , they cause facial swelling except in case of lateral incisor they arise palatally due to root inclination. Treatment 1) Root canal treatment followed by apicectomy 2) Enucleation which means complete removal of cyst lining Done for medium and large sized cysts Done following root canal treatment of involved teeth and apicectomy 3) Marsupialization Cyst Enucleation Marsupialization • • • • • • as the name indicates it means to create a pouch. It is based on decompression of the cyst and thus decreasing its pressure on bone This stimulates new bone formation at its periphery it is indicated when the cyst is so large and encroaches a vital structure such as inferior dental canal, maxillary sinus or a natural tooth. Disadvantage : it requires a long follow up period and patient commitment till the cyst size shrinks and then enucleated. • In some cases a cyst may displace a tooth to the inferior border that enucleation may cause a fracture of the mandible. • In such a situation marsupialization is indicated Residual Cyst • A radicular cyst remains behind in the jaws after removal of the offending tooth or in cases of incomplete previous radicular cyst removal and this is referred to as residual cyst. • Radicular and residual cysts are by far the most common cystic lesions in the jaws, comprising 52.2% jaw cysts and 62% of odontogenic cysts. Clinical Picture • Many radicular cysts are symptomless and are discovered when periapical radiographs are taken of teeth with non vital pulps. • Painless unless infected. • Radiolucent with a radiopaque margin in the place of a previously extracted tooth (edentulous area) • The residual cysts are usually treated by enucleation Dentigerous cyst • • • • • • it appears related to impacted or unerupted teeth. it is very common with upper and lower wisdom teeth , upper canine , and supernumerary teeth. it arises from the Reduced enamel epithelium which forms the dental follicle surrounding unerupted teeth. Clinical Features : as the Radicular cysts Radiographic picture : a radiolucency surrounding the crown of an unerupted tooth It is discovered during routine radiographic examination , may reach very large sizes but once infected becomes painful and may be misled with ameloblastoma or odontogenic keratocyst Radiographic presentation types • Central Type • Lateral Type: • Circumferential Type Treatment • usually treated by cyst enucleation with extraction of the unerupted tooth. • UNLESS the size of the cyst reached very large sizes that may encroach a vital structure such as Inferior alveolar canal or Maxillary sinus >>> Marsupialization is to be done till it reaches a moderate size to be enucleated. Eruption Cyst • An eruption cyst is in essence a dentigerous cyst occurring in the soft tissues. • Whereas the dentigerous cyst develops around the crown of an unerupted tooth lying in the bone, • the eruption cyst occurs when a tooth is impeded in its eruption within the soft tissues overlying the bone. Clinical features • • • • • • The cysts are found in children of different ages, and occasionally in adults if there is delayed eruption. Deciduous and permanent teeth may be involved, most frequently anterior to the first permanent molar. The mandibular central primary incisors and first permanent molars were the teeth most frequently involved, and boys were affected twice as often as girls in their sample. The eruption cyst produces a smooth swelling over the erupting tooth, which may be either the colour of normal gingiva or blue. It is usually painless unless infected and is soft and fluctuant. Radiographic Picture • The cyst may throw a soft-tissue shadow, • but there is usually no bone involvement except • that the dilated and open crypt may be seen on the radiograph. Treatment • Eruption cysts are most frequently treated by marsupialization, • The dome of the cyst is excised, exposing the crown of the tooth which is allowed to erupt. Odontogenic Keratocyst • • • it is a type of cysts that arises from the epithelial rests of dental lamina. It shows a biological behaviour that is similar to a benign neoplasm it occurs more frequently in the mandible than the maxilla, especially in the region of the angle. • it appears in the 2nd and 3rd decade of life. • it is characterised with daughter / satellite cells thus increasing the chance for recurrence. Clinical Features • • • • • • • OKC grows in an un uniform fashion, resulting in appearance what is known as a multilocular appearance in radiographs. It spreads through the medullary bone spaces which results that no buccolingual expansion is apparent with the onset of the lesion. It is painless unless infected … but will not be infected till it reaches very large sizes to communicate with the oral cavity It causes displacement of teeth occasionally paraesthesia of lower lip Diagnosis • • • • it is diagnosed radiographically by a unilocular or multilocular radiolucency. it is approved by incisional biopsy for histopathological examination. by aspiration which gives a dirty white cheesy like keratin. In cases of very large cysts tilting of teeth , root resorption and buccolingual bony expansion with pain in cases of infection. Treatment • OKC in cases of being unilocular could be treated by enucleation with peripheral ostectomy and chemical cauterization using Carnoy’s solution. • • In cases of multilocular radiolucency , segmental resection is to be done with placement of reconstruction plate. • Some studies recommend in very large sized OKC marsupialization to be made to reduce in size prior to enucleation. • IT IS VERY IMPORTANT FOR FOLLOW UP TO BE MADE DUE TO THE HIGH RATE OF RECURRENCE • • • • • • • Carnoy’s Solution composition: Glacial acetic acid – 6ml Absolute alcohol -3 ml Chloroform – 3 ml Ferric chloride -1 gm Depth of penetration 1.5 – 1.8 mm. It is applied for 5 minutes after isolating all the surrounding tissues by Petroleum Jelly OKC Recurrence rate • • It has a high rate of recurrence up to 62% This is attributed to the presence of satellite or daughter cells which may be left behind after enucleation of the cyst. • in addition to the fibrous wall being thin and fragile especially in large sized cysts. • The presence of epithelial rests of Serres may be a reason for the recurrence of the OKC. • Studies suggest that there is a tendency for intrinsic growth of the epithelium which could be a reason for the high recurrence of the OKC. Gorlin-Gortz syndrome • Due to an autosomal dominant trait, patient may present with multiple skeletal as bifid ribs, CNS abnormalities and ocular abnormalities • multiple basal cell nevoid carcinoma of the skin. • and multiple Odontogenic keratocyst. • it is also called Nevoid Basal Cell carcinoma. Nasopalatine cyst • • • • • • • it is by far the most common type of fissural cysts that may appear in the region of the jaws. it is also known to arise from the remenants of nasopalatine duct. it arises from the palatal side and may cause separation of the roots of the central incisors.. it grows in size by cystic degeneration. It appears as heart shaped or inverted pear shaped radiolucency. It appears so similar to the radicular cyst but the teeth in this case are vital. It is treated by cyst enucleation from the palatal side never by marsupialization Nasopalatine cyst Nasolabial cyst • it is a fissural type of cyst that arises from the remenants of the nasolacrimal duct during embryonic development. • It arises in the soft tissues • when reaches large sizes it obliterates the nasolabial fold and causes saucerization of the facial bone surface and the lateral nasal wall. • It is confirmed by aspirating mucin and removed by surgical enucleation. Globulomaxillary cyst • • • • • it is a fissural type of cysts that appears from the remenant of fusion between the maxillary and the globular process. it appears as a radiolucency pear shaped between the lateral incisor and the canine. it may cause the deflection of the roots. it is treated by cyst enucleation. Some consider it as a radicular cyst arising from the lateral incisor. Solitary bone cyst • • it is also known as traumatic bone cyst , haemorrhagic bone cyst. it appears in the posterior side of the mandible as scalloped radiolucency in between the roots of the teeth.. • it is a pseudocyst, not a true cyst as it lacks an epithelial lining . • Treated by surgical exploration . Staphne’s idiopathic bone cyst • • • it is discovered by routine examination it is also known as static bone cyst, latent bone cyst. it arises from the of submandibular salivary gland tissues that got entrapped inside the body of the mandible. • it is static in size, contains salivary gland tissues. • Appears as a well defined radiolucency appearing under the inferior alveolar canal • It is not a true cyst , it just needs routine follow up. Aneurysmal Bone cyst • It is a pseudocyst due to its lack of epithelial lining. • It occurs in the mandible > maxilla • exact pathogenesis is unknown, it shows non endothelial lined blood filled spaces • it appears as a firm swelling in children and young adults. • Radiographically : could appear unilocular or as a soap bubble appearance. • Treatment : Currettage • En Bloc resection Unilocular Multilocular Summary • A cyst is true only if it has an epithelial lining, otherwise considered a pseudocyst. • Periapical cyst arises only from non vital teeth, therefore treatment should include root canal treatment to be made prior to the definitive treatment. • OKC is considered as one of the most aggressive types of odontogenic cysts due to its high rate of recurrence. • Aims: • The aim of this lecture is to provide an overview of the management of common cystic lesions of the jaws • Objectives: • On completion of this lecture, the student should be able to: • Understand the surgical management of residual, radicular, eruption and dentigerous cysts of the jaws • Have an awareness of the surgical management of other cystic lesions of the jaws Reading material • 1. Wray D et al; Textbook of General and Oral Surgery, Churchill Livingstone 2003 pp 229-237 • 2. Coulthard P et al, Oral and Maxillofacial Surgery, Radiology, Pathology and Oral Medicine, Churchill Livingstone 2003 pp155-157