cysts of the jaw bone

Definition Cyst is a pathological cavity lined by epithelium and filled with fluid or semisolid material.

Epithelial rests of dental tissue

1.Reduced enamel epithelium 2.epithelial rest of dental lamina 3.epithelial rest of malassez

Expansion of the cyst

1.Increase in hydrostatic pressure in side the cyst 2.Because of large number of osmotically active molecules in cyst fluid the cyst Contents are hypertonic (high osmotic Pressure) compared with serum 3.Cyst lining release bone resorbing factor Which stimulate osteoclastic activity Like prostaglandin E2&E3 and collagenase also released by the inflammatory cells of the capsule.

Classification

1.Epithelialized cysts 2.Non- Epithelialized cysts 3.Soft tissue cysts

Epithelialized cysts

1-Odontogenic cysts a. Developmental type b. Inflammatory type 2-Non- Odontogenic cysts

Odontogenic CystsDevelopmental type

Dentigerous cyst Odontogenic keratocyst Eruption cyst Glandular odontogenic cyst Gingival cyst ( neonatal type & adult type) Lateral periodontal cyst

Odontogenic CystsInflammatory types

Radicular cyst Apical type Lateral type Residual type Paradental cyst


Non-Odontogenic cyst
1.Nasopalatine duct cyst. 2.Nasolabial cyst (nasoalveolar cyst) 3.Globulomaxillary cyst. 4.Median palatine cyst. 5.Median mandibular cyst.

Non-Epithelialized cysts(Pseudocyst)

1.Solitary bone cyst (Traumatic bone cyst, Haemorrhagic bone cyst, Simple bone cyst)2.Aneurysmal bone cyst 3.Stafne’s idiopathic bone depression

Soft tissue cysts

1.Salivary mucoceles a. Mucus retention type b. Mucus extravasation type 2.Lymphoepithelial cyst a. Oral type b. Cervical type 3.Thyroglossal duct cyst 4.Dermoid & Epidermoid cysts

Key Features of Jaw Cysts

1.Form sharply-defined radiolucencies with smooth borders2.Fluid may be aspirated and thin –walled cysts may be transilluminated. 3.Grow slowly, displacing rather than resorbing teeth 4.Symptomless unless infected and are frequently chance radiographic finding. 5.Rarely large enough to cause pathological fracture 6.Form compressible and fluctuant swelling if extending Into soft tissue. 7.Appear bluish when close to the mucosal surface.

Incidence of the cystsof the jaw bone

90% are odontogenic cysts Radicular cyst are 65-75 % Detigerous cyst are 14-18% Odontogenic keratocyst are 3-11% Nasopalatine duct cyst 5% of jaw cysts.

Dentigerous cysts

Relatively common , always arise around the crown of an impacted tooth and it’s epithelial lining is derived from reduced enamel epithelium of the associated tooth.

Pathogenesis of Dentigerous cysts

Two hypothesis are suggested : 1.When the crown is fully formed. 2.Before the crown is fully formed.

Clinical features of  Dentigerous cyst

Always associated with impacted or unerupted tooth (most frequently lower wisdom ,upper canine or upper wisdom) or impacted supernumerary tooth or some time impacted odontome. but may occur at any site .may occur at any age but most common young adult. It’s slowly growing and asymptomatic unless it’s infected .

Radiographic features of Dentigerous cyst

Appear as well outlined unilocular or multilocular radiolucency and may cause displacement of the tooth .according to the relation of the cyst to the crown of the tooth it’s divided into : 1.Central type. 2.Lateral type. 3.Circumferential type.

Histological features of Dentigerous cyst

The cyst lined by non- keratinized epithelium (2 - 5 cell thick) of stratified squamous type also there may be mucus secreting cells ,Rushton bodies ,the C.T capsule is composed of fibrous tissue containing islands of odontogenic epithelium with no inflammatory cells.

Histopathological features of Dentigerous cyst

Complication & Treatment of Dentigerous cyst
Complication are: 1.Neoplastic transformation. 2.Recurrence.
Treatment by : 1.Enucleation . 2.Marsupialization.

Eruption cyst

Appear as soft translucent swelling in the gingival mucosa overlying the crown of an erupting deciduous or permanent tooth ,mostly in children younger than age 10 .most commonly associated with first permanent molar and maxillary incisors ,cyst may appear bluish –red due to collection of blood from trauma. No treatment is needed. otherwise ,simple excision of the roof of the cyst may facilitate the eruption of the tooth .


Odontogenic Keratocysts
Less common than dentigerous cyst but more serious because it show rapid growth of the lining epithelium ,arise from epithelial remnant of dental lamina. so in instead of a tooth there is cyst formation . the cyst show anterioposterior expansion

Clinical features ofOdontogenic Keratocyst

Occur most frequently in the mandible (in the area of lower wisdom) more than the maxilla ( in the area of upper canine or upper wisdom) ,some time associated with impacted tooth, occur more common in young adult, it’s slowly growing and asymptomatic but later may cause expansion of the bone and displacement of the teeth.

Radiographic features of Odontogenic Keratocyst

Appear as well outlined multilocular radiolucency with displacement of the tooth in the area and root resorption of the adjacent teeth .

Radiographic features of Odontogenic Keratocyst

Histopathological features of Odontogenic Keratocyst
The histopathological feature is pathognomonic including: The surface epithelium is parakeratinized which is corrugated .the thickness of the epith. is 6-10 cell thick and it’s uniform in thickness. Basal cell layer is prominent with palisaded arrangement

The overall picture of the cyst is snaky.There is loose connection between the epith. and c. t. and C.T. capsule contain daughter or satellite cysts without inflammatory cells infiltration
Histopathological features of Odontogenic Keratocyst

Odontogenic Keratocyst

Odontogenic Keratocyst

Complication and treatment Odontogenic Keratocyst
Complication: 1.Rcurrence. 2.Neoplastic transformation.
Treatment: By enucleation.

Gorlin-Goltz syndromeOR Nevoid basal cell carcinoma syndrome

It’s an autosomal dominant condition the chief components are multiple basal cell carcinoma of the skin ,multiple odontogenic keratocyst ,intracranial calcification and rib and vertebral anomalies ,patients has a characteristic faces with frontal and temporoparietal bossing the eyes show hypertelorism and mild mandibular prognathism also patient has many other anomalies like : 1.Ophthalmic anomalies . 2.Neurological anomalies. 3.Sextual anomalies .

Gingival cyst of adult

It’s uncommon lesion ,derived from rest of dental lamina ,most frequently occur in the mandibular canine and premolar area and in the fifth and sixth decade of life and almost located on the buccal gingiva (in the attached or free gingiva or interdental papilla) as painless domelike swelling usually less than 0.5 cm in diameter the cyst treated by simple surgical excision .

Gingival cyst of newborn

These are small ,superficial keratin filled cysts that are found on the alveolar mucosa of infants. They arise from the rests of dental lamina the cysts are usually multiple whitish papules or pearls on the alveolar mucosa .maxillary alveolus is more commonly involved than the mandibular . No treatment is indicated because the lesion is spontaneously rupture and disappear.

Glandular odontogenic cyst

Also called sialo-odontogenic cyst . it’s recently recognized type of odontogenic cyst ,it’s similar to lateral periodontal cyst and arise from remnant of dental lamina. but it could show aggressive behavior .


Occur most frequently in middle –age patients and in the mandible most commonly in the anterior part of the mandible which may be small or large and the large cyst can cause expansion of the bone and may be painful . Clinical features ofGlandular odontogenic cyst


The lesion may appear as unilocular radiolucency but more commonly as multilocular radiolucency which is well outlined .
Radiographic features ofGlandular odontogenic cyst

Histopathological features of Glandular odontogenic cyst

The cyst lined by squamous epithelium of varying thickness .the superficial cells tend to be cuboidal to columnar and have some time papillary surface. Pools of mucinous material are often present within the epithelium ,cuboidal cell usually line these pools .mucous cell may or may not present within the epithelium.

Histopathological features of Glandular odontogenic cyst

Histopathological features of Glandular odontogenic cyst

Treatment of Glandular odontogenic cyst

This type of cysts treated by enucleation but some time show recurrence .because it has greater growth potential and tendency for recurrence some authors advocate en bloc resection for many of the lesions.

Apical radicular cyst

This cyst arise from epithelial rest of malassez present in the chronically inflamed periapical granulomas that always associated with the apices of non-vital teeth .but also may arise from crevicular epithelium or epithelium lining sinus tract.


Pathogenesis of Apical radicular cyst

Clinical features ofApical radicular cyst

Apical radicular cyst is slowly growing ,asymptomatic and may be discovered accidentally but when it’s infected it may cause swelling and pain .

Appear as well outlined round or ovoid radiolucency at the apex of the affected tooth ,may cause root resorption.
Radiographic features ofApical radicular cyst

Histopathological features of Apical radicular cyst

The cyst lined by stratified squamous epithelium which is non-keratinized ,on occasion ,the lining epith. May contain linear or arch-shaped calcification known as Rushton bodies and mucous secreting cells.

Histopathological features of Apical radicular cyst

The wall of the cyst consists of dense fibrous connective tissue ,often with an inflammatory infiltrate containing lymphocytes neutrophils ,plasma cells, histiocytes ,also multinucleated giant cell extravasated blood ,hemosiderin pigmentation .and cholesterol clefts

Histopathological features of Apical radicular cyst

Histopathological features of Apical radicular cyst

Histopathological features of Apical radicular cyst

Treatment ofApical radicular cyst cyst
1.Endodontic treatment. 2.Periapical surgery. 3.Extraction .

Residual cyst

Apical radicular cyst that don’t resolved after extraction of the associated tooth called residual cyst although, most of the apical radicular cysts are spontaneously disappear after tooth extraction from lack of continued inflammatory stimulus, but minority of them may remain without clear explanation .

Residual cyst

Appear as round or ovoid radiolucency of variable size within the alveolar ridge at the site of previous tooth extraction.

Nasopalatine duct cystor Incisive canal cyst

Is the most common non-odontogenic cyst of the oral cavity ,it’s believed to arise from remnants of the nasopalatine duct

Clinical features ofNasopalatine duct cyst

More common in the fourth to sixth decade of life .male >female .many lesions are asymptomatic and discovered accidentally but may cause swelling of the anterior palate and pain just behined the upper two central incisors in the area of incisive papilla.



Radiographic features of Nasopalatine duct cyst
Well - circumscribed round or ovoid or inverted pear shape or heart shape radiolucency with sclerotic border in the midline of the anterior maxilla ,between and apical to the central incisor teeth .


The epithelial lining is variable ,it may be stratified squamous epithelium or pseudostratified columnar epith (with cilia and mucous cells)or cuboidal epith ,or any combination in the c.t. wall there may be nerves and vascular structure as normal content of the canal .

Histopathological features of Nasopalatine duct cyst

Histopathological features of Nasopalatine duct

Treatment of Nasopalatine duct cyst

the differentiate between apical radicular cyst and nasopalatine duct cyst done by : 1.Vitality test. 2.Radiograph. Treatment is by surgical enucleation.

Nasolabial cystor Nasoalveolar cyst

This is a rare developmental cyst .it’s pathogenesis is uncertain but there is a theory suggest that these cysts develop from misplaced epithelium of the nasolacrimal duct .this cyst appear as a swelling of the upper lip lateral to the midline ,resulting in elevation of the ala of the nose and obliterate the maxillary mucolabial fold .occur in old age patients and it’s asymptomatic unless it’s infected .

Globulomaxillary cyst

Current theory hold that most (if not all) cysts that developed in globulomaxillary area are of odontogenic origin. this cyst is developed between the maxillary lateral incisor and canine teeth .Radiographically appear as well-circumscribed unilocular radiolucency between and apical to the teeth resembling inverted pear causing divergence of the roots .


Median palatine cyst
This is a rare cyst occur in the midline of the palate behind the incisive papilla causing swelling of the palate but most of the cases are nasopalatine duct cyst that occur more posteriorlly in the palate

Median mandibular cyst

This cyst occur in the midline of the mandible. In the past it’s considered as fissural cyst but now they found that Most of the cases (if not all )are odontogenic cysts .

Traumatic bone cyst

The simple bone cyst is a benign lesion within the bone that is devoid of an epithelial lining .the cause is uncertain but several theories have been proposed like traumatic theory ,this theory suggests that trauma to the bone may result in an intraosseous hematoma. If the hematoma doesn’t undergo organization and repair,it may liquefy result in a cystic defect.

Clinical features ofTraumatic bone cyst

This cyst have been reported in every bone in the body but the majority involves the long bones .in the jaw bone this cyst occur most frequently between 10 – 20 years of age. Male > female .it’s essentially restricted to the mandible (mostly posterior part) but rarely occur in the maxilla .Usually it’s asymptomatic but may cause painless swelling .

Radiographic features ofTraumatic bone cyst

The lesion most frequently appear as well outlined radiolucency .the defect may range from 1 – 10 cm in diameter, when several teeth are involved in the lesion , the radiolucency extend between the roots in a scalloped pattern but the teeth that appear involved are vital .

Histopathological features ofTraumatic bone cyst

The walls of the defect may be lined by a thin band of vascular connective tissue that may be intermixed with bone trabeculae and giant cell reaction .

Treatment ofTraumatic bone cyst

For simple bone cyst of the jaw ,simple surgical exploration to establish the diagnosis is usually sufficient therapy for jaw lesions as it will induce bleeding and blood clot formation to establish the healing process.


Aneurysmal bone cyst
Aneurysmal bone cyst is an intraosseous accumulation of a variable – sized blood filled spaces surrounded by cellular fibrous connective tissue that often is admixed with trabeculae of reactive woven bone. The cause and pathogenesis of this cyst are poorly understood some authors suggests that this cyst may result from osseous haemodynamic disturbance when surgeon open the lesion a blood filled spaces with venouslike bleeding may be encountered that give a (blood soaked sponge) appearance.

Clinical features of Aneurysmal bone cyst

Most commonly located in the long bones .in the jaw bone most cases arise in children and young adults (mean of age 20 years ) most cases occur in the mandible, mainly in the posterior part of the jaw. Cyst present as swelling which is usually rapid.

Radiographic features of Aneurysmal bone cyst

Appear as unilocular or multilocular radiolucency with marked cortical expansion and thinning .

Histopathological features of Aneurysmal bone cyst

The lesion consist of spaces of varying size , filled with blood surrounded by cellular fibroblastic tissue containing multinucleated giant cells and bone trabeculae .

Treatment of Aneurysmal bone cyst

Aneurysmal bone cyst of jaws are usually treated by curettage or enucleation. but recurrence may happen .

Stafne’s idiopathic bone depression This condition represents a focal concavity of the cortical bone on the lingual surface of the mandible .biopsy has revealed histologically normal salivary gland tissue, suggesting that these lesions represent developmental defects

Stafne’s idiopathic bone depression Radiographically appear as round or ovoid radiolucency below the mandibular canal in the posterior mandible between the molar teeth and the angle of the mandible. No treatment is needed.

Thyroglossal duct cyst

The thyroid gland begins it’s development at the embryonic life as a proliferation of endodermal cells between the anterior two third and posterior one third of the tongue (a point that later becomes the foramen cecum )this developing thyroid gland descends into the neck and reaches it’s definitive level below the thyroid cartilage, along this path of descend an epithelial tract or duct is formed .the thyroglossal duct epithelium normally undergoes atrophy and is obliterated .however, remnant of this epithelium may persist and give rise to cysts along this tract known as thyroglossal duct cyst

Clinical features ofThyroglossal duct cyst

Clinical features ofThyroglossal duct cyst
Thyroglossal duct cyst develop in the midline and may occur anywhere from the foramen cecum area of the tongue to the suprasternal notch .but most of the cases occur below the hyoid bone. this cyst may develop at any age but most commonly seen in the first and second decade of life as painless fluctuant movable swelling unless it’s infected. lesion that appear at the base of the tongue may cause dysphagia .

Oral lymphoepithelial cyst

It’s an uncommon lesion of the mouth that develop within oral lymphoid tissue .oral lymphoepithelial cyst may develop from the tosillar crypt that may fill up with keratin debris ,the tonsillar crypt may become obstructed producing keratin –filled cyst .or it also is possible that lymphoepithelial cyst may develop from salivary or surface mucosal epithelium that becomes entrapped in lymphoid tissue during embryogenesis.

Clinical features ofOral lymphoepithelial cyst

This cyst present as a small submucosal mass that is usually less than 1 cm in diameter ,the cyst may feel firm or soft to palpation and it’s white or yellow in color and it’s asymptomatic .the cyst may develop at any age but most common in young adult and most frequently occur in the floor of the mouth or on the ventral surface and posterior lateral border of the tongue or in the soft palate.

Cervical lymphoepithelial cyst(Branchial cleft cyst)

It’s a developmental cyst has a disputed pathogenesis .the classic theory says that the cyst develops from remnant of the branchial clefts .A second theory consider that it arises from cystic changes in parotid gland epithelium that becomes entrapped in the upper cervical lymph nodes during embryonic life .

Clinical features ofCervical lymphoepithelial cyst

this cyst most commonly occurs in the upper lateral neck along the anterior border of the sternocleidomastoid muscle ,most frequently affects young adults ,the cyst appear as soft ,fluctuant mass .pain may occur with secondary infection .


Dermoidand epidermoid cyst
The dermoid cyst is form of cystic teratoma derived principally from embryonic germinal epithelium , but in some instances may contain structures of other germinal layers. dermoid cyst occur in the head and neck mainly around the eyes and anterior upper neck .epidermoid cyst is also cyst of the skin but they may occur in the floor of the mouth.

Clinical features ofDermoid and epidermoid cysts

Occur in young adults when the lesion occur above the geniohyoid muscle it cause elevation of the tongue and difficulty in eating and appear as bulge in the floor of the mouth , it has daughlike feel to palpation or may be fluctuant and it’s bilateral

When the cyst occur deep below mylohyoid muscle it cause bulging in the submental region.the cyst is asymptomatic unless there is infection,and both types are treated by surgical removal.
Clinical features ofDermoid and epidermoid cysts

Epidermoid cyst composed of c.t. wall lined by a thin layer of st.sq.epith.usually is orthokeratinized and filled with keratin. Dermoid cyst in addition to the structure seens in the epidermoid cyst there are sebaceous gland and sweat glands ,hair follicles but some lesions may contain bone ,muscle and GIT derivatives represent complex teratoma
Histopathological features ofDermoid and epidermoid cysts

Dermoid cyst

Dermoid cyst

epidermoid cyst

epidermoid cyst