Odontogenic And Nonodontogenic Cysts

Odontogenic And Nonodontogenic Cysts

Question 1. Classify the cysts of the jaw.
Answer:

Cysts of the jaw are broadly classified into:

1. Odontogenic cysts
2. Nonodontogenic cysts

World Health Organization Classification (1995) Further classifies cysts as follows:

• Developmental odontogenic cysts:
  • Primordial cyst
  • Gingival cyst
  • Eruption cyst
  • Dentigerous cyst

Read And Learn More: Oral Medicine and Radiology Question And Answers

• • Lateral periodontal cyst
  • Glandular odontogenic cyst
  • Sialo-odontogenic cyst
• Developmental nonodontogenic cysts:
  • Nasopalatine duct cyst
  • Globulomaxillary cyst
  • Median-palatine cyst

• Other cysts of the jaw:
  • Aneurysmal bone cyst
  • Traumatic bone cyst
  • Epithelial jaw cysts
• Other cysts of the oral region:
  • Dermoid cyst
  • Epidermoid cyst
  • Gingival cyst of newborn
  • Palatal cyst of newborn
  • Nasolabial cyst
  • Lymphoepithelial cyst.

Question 2. Describe residual cyst.
Answer:

• Residual cysts are inflammatory cysts arising as a result of incomplete surgical excision of odontogenic cysts, primarily radicular cysts.
• A residual cyst describes the radicular cysts that are retained after the tooth is extracted or cysts that are left following the incomplete enucleation of an odonto¬genic cyst.
• Residual cysts are commonly seen in edentulous areas of the mandible or maxilla.
• These cysts are asymptomatic.
• Long-standing cysts may become secondarily infected and turn symptomatic.
• They are diagnosed during routine radiographic examinations.
• Size may vary from a few mm to several cm.
• Do not cause any bone expansion.
• Treated by surgical curettage or marsupialization.

Question 3. Discuss periapical cyst
(or)
Radicular cyst.
Answer:

• The periapical cyst is the most frequently occurring type of odontogenic cyst. It is filled with fluid and lined by epithelium, hence a true cyst.
• It is an inflammatory cyst originating from the nonvital tooth with pulpal necrosis.

Periapical cyst Clinical Features:

• Mostly asymptomatic.
• Rarely undergo acute exacerbation and become painful.
• Commonly involve anterior teeth. Maxillary anterior teeth are more frequently affected than the mandibular anterior teeth.
• Root resorption and cortical bone expansion are rare.

Pathogenesis of Periapical Cyst:

Periapical cyst Radiographic Features:

• At the apical region of the involved tooth, a well-defined radiolucent lesion with a thin- radiopaque line at the periphery is characteristic.
• Radiopaque boundary indicates the bone reaction to the slowly expanding lesion.

Periapical cyst Treatment:

• Endodontic management with or without periapical surgery.
• Extraction of the involved tooth.

Question 4. Eruption cyst
(or)
Eruption hematoma.
Answer: It Is the cyst that develops around the crown of an erupting tooth which is at the level of the alveolar crest but not visible clinically.

Eruption cyst Pathogenesis:

• The collection of fluid or blood in the follicular space between the reduced enamel epithelium and crown of erupting teeth leads to cystic swelling.
• The presence of thick fibrous tissue in the overlying mucosa prevents the eruption.

Eruption cyst Clinical Features:

• Seen in childhood in the age group of 5-9 years.
• The cyst commonly occurs in association with the eruption of mandibular primary central incisors and permanent mandibular first molars.
• Seen as soft, fluctuant swelling of the alveolus about the emerging tooth and measures about 1-1.5 cm in size, asymptomatic.
• If the cystic cavity contains blood, it appeared purple and called as eruption hematoma.

Eruption cyst Radiographic Features: Soft tissue shadow over the crown of erupting tooth. No structural changes are evident.

Eruption cyst Treatment:

• In many cases, spontaneous rupture of the cyst is common.
• Surgically exposing the crown is needed in some cases to accelerate eruption.

Question 5. Nasolabial cyst.
Answer:

• It is a developmental, soft tissue cyst, known as klestadt’s cyst or nasoalveolar cyst.
• It arises as a result of the inclusion of epithelium along the fusion of the maxillary process, lateral nasal process, and globular process.

Nasolabial cyst Clinical Features:

• Frequently occurs in 4th or 5th decade of life with a female predilection.
• The swelling occurs at the ala of the nose over the maxilla with obliteration of the nasolabial fold and intraorally manifests at the labial vestibule.
• It is fluctuant and painless unless secondarily infected.
• A large infected cyst may cause referred pain in the anterior maxillary teeth.

Nasolabial cyst Radiographic Features:

As it is a soft tissue cyst, after aspirating the cystic fluid and injection of radiopaque dye into the cyst followed by taking a maxillary occlusal radiograph may reveal the spherically shaped cyst with a bracket-shaped line indicating the inferior margin of the anterior bony aperture of the nose.

Nasolabial cyst Treatment: Surgical excision.

Question 6. Nasopalatine duct cyst
(or)
Incisive canal cyst.
Answer:

• It is a developmental, nonodontogenic cyst, that arises due to the spontaneous degeneration of embryologic remnants of the nasopalatine duct.
• The cyst develops within the incisive canal in the palatine bone or in the soft tissue covering the incisive foramen.

Nasopalatine duct cyst Clinical Features:

• The cyst is characteristically seen at the center of the maxillary central incisor region.
• Usually asymptomatic at the initial stage.
• A salty taste fluid discharge and pain may manifest at later stages.
• Displacement of maxillary central incisors may also occur.

Nasopalatine duct cyst Radiographic Features:

• Well-defined, oval or inverted pear-shaped radiolucency located at the inter-radicular region between the apices of maxillary central incisors. The cyst is well-corticated unless secondarily infected.
• Radiographically, if the diameter of the incisive canal exceeds 6 mm, a nasopalatine cyst should be considered.

Nasopalatine duct cyst Treatment: Surgical enucleation.

Question 7. Globulomaxillary cyst.
Answer:

• The globulomaxllary cyst develops due to the entrapment of epithelium between the globular portion of the nasal process and the maxillary process.
• Clinically it appears between the lateral incisor and canine teeth. The cyst forms on the bony suture (incisive suture) between the maxilla and premaxilla, hence called premaxilla-maxillary cyst.

Globulomaxillary cyst Clinical Features:

• The majority of cases are reported during routine radiographic interpretation.
• Very rarely, it shows clinical manifestations. Local discomfort and pain are the symptoms in a secondarily infected cyst.
• Globulomaxillary cyst Radiographic Findings: Inverted peer-shaped radiolucency between the roots of the lateral incisor and canine teeth causing divergence of roots.

Globulomaxillary cyst Differential Diagnosis:

• Periapical cyst.
• Teeth associated with a globulomaxllary cyst are vital.

Globulomaxillary cyst  Treatment: Surgical Excision

Question 8. Traumatic bone cysts of the jaw.
Answer:

• This cyst is otherwise known as a hemorrhagic cyst, solitary bone cyst, unicameral bone cyst, and simple bone cyst.
• The traumatic bone cyst has no epithelial lining. Hence, it is a pseudocyst.

Jaw Etiology:

• Trauma-hemorrhage theory: Trauma leads to intraosseous bleeding and hematoma formation. Failure of the normal healing process causes liquefaction of clot by enzymatic action and leaves an empty cavity within the bone.
• The trauma may be mild and the time lapse between the traumatic incident and cyst formation may vary from months to years.
• Ischemic necrosis of fatty marrow.
• Result of low-grade infection.

Jaw Clinical Features:

• Commonly occurs in the second decade of life.
• The posterior mandible is more frequently involved than the anterior region.
• The associated teeth are vital.
• Swelling will be the complaint. Pain is rare.

Aspiration of Cystic Content: Straw-colored fluid or blood.

Jaw Radiographic Features:

• A well-defined radiolucent area with/ without a sclerotic border.
• Extensive lesions may cause buccal cortical expansion.
• The cyst may extend between roots and produce scalloped margins.

Jaw Treatment: Surgical enucleation.

Question 9. Aneurysmal bone cyst.
Answer: Aneurysmal bone cyst arises as de novo in the bone because a definite pre-existing lesion cannot be demonstrated.

Aneurysmal bone cyst Clinical Features:

• The cyst occurs in young individuals, predominantly below 30 years of age.
• The cyst has a preference for long bones. Mandible is affected more than maxilla.
• Swelling will be firm and painful.

Aneurysmal bone cyst Pathogenesis:

• Initial osteolytic phase.
• Active growth phase: Increased rate of bone destruction and gives a subperiosteal blowout pattern.
• Mature stage: Also known as the stabilization stage. The formation of peripheral cortication and internal septa provides a soap bubble appearance.
• Healing phase: Gradual calcification and ossification.

Aneurysmal bone cyst Radiographic Findings: Well-defined, multilocular radiolucent cavity. In the mandible, the location of the aneurysmal bone cyst is above the inferior alveolar canal.

Aneurysmal bone cyst Treatment: Surgical excision.

Question 10. Stafne’s cyst.
Answer:

• It is an unusual form of aberrant salivary gland tissue found within or adjacent to the lingual surface of a body of the mandible forming a well-defined depression and therefore known as lingual mandibular salivary gland depression.
• It is a congenital defect, asymptomatic and detected during routine radiographic examination, hence called as a static bone cavity.

Stafne’s cyst Radiographic Findings: It is a well-defined, ovoid radiolucency, located below the inferior alveolar canal, between the inferior alveolar canal and the inferior border of the mandible.

Stafne’s cyst Complication: Salivary neoplasm may develop rarely.

Stafne’s cyst Treatment: It is a developmental anomaly hence, do not require any treatment.

Question 11. Dermoid cyst
(or)
Dermoid tumors.
Answer:

• Dermoid cysts are sequestration of skin and subsequent implantation at the line of fusion of the embryonic process.
• It is lined by epithelium and contains all skin appendages like hair follicles, sweat glands, and sebaceous glands.

Dermoid cyst Clinical Features: In the head and neck region, dermoid cysts develop as midline lesions at the scalp, face, neck, and floor of the mouth. Rare site includes lip, tongue, and uvula.

Dermoid cyst Subclasses:

• Epidermoid cysts: It is lined by epithelium and devoid of skin structures.
• Teratoid cysts: It is lined by epithelium and contains mesodermal components like muscle and bone.

Dermoid cyst Complications: Development of basal cell carcinoma and squamous cell carcinoma from epidermoid cyst are remote possibilities.

Question 12. Dentigerous cyst
(or)
Follicular cyst.
Answer:

• Dentigerous cysts are odontogenic cysts. They are formed around the crown of an impacted tooth or an impacted supernumerary tooth.
• The crown will be characteristically protruding into the cystic lumen. This cyst also develops from the odontome.

Dentigerous cyst Pathogenesis: The cyst is formed by the accumulation of fluid between the reduced enamel epithelium and enamel surface.

Dentigerous cyst Clinical Features:

• Common site: Mandibular or maxillary third molar region and maxillary canine region.
• Age group: 2nd and 3rd decades of life.
• This cyst is aggressive and causes rapid bone expansion, root resorption, and displacement of teeth. Mandibular expansion may extend up to the coronoid with hollowing out of the entire ramus and maxillary expansion is usually limited to the anterior region.
• No associated pain until get secondarily infected.
• Bilateral and multiple dentigerous cysts are present in cleidocranial dysplasia and Maroteaux-Lamy syndrome.
• Potential complication—Development of mural ameloblastoma.

Dentigerous cyst Radiographic Features:

Three types of presentation:

1. Central—Cyst symmetrically envelops crown.
2. Lateral—Cyst develops along the lateral aspect of the crown.
3. Circumferential—The cyst envelops the entire tooth.

Dentigerous cyst Treatment: Surgical removal.

Question 13. Odontogenic keratocyst
(or)
keratocystic odontogenic tumor.
Answer:

• This cyst develops from the epithelial remnants of the dental lamina and resembles an odontogenic tumor.
• The cyst epithelium produces keratin that fills the cystic lumen. The epithelium is thin and has mitotic properties, hence grows like a neoplasm.

Odontogenic keratocyst Clinical Features:

• Age: 2nd and 3rd decade of life. Uncommon before 10 years of age.
• The mandible is more frequently affected than the maxilla. In mandible:
  • Ramus—Third molar area is involved more frequently than the first and second molar regions followed by the mandibular anterior region.
  • In the maxilla, the involvement of the third molar region and canine region are common in descending order of frequency.
• Soft tissue swelling, pain, expansion of bone, and paresthesia of the lip are the associated symptoms.
• If associated with nevoid basal cell carcinoma syndrome, this cyst will behave aggressively.
• It is locally destructive and has a high recurrence rate.

Odontogenic keratocyst Radiographic Features:

• Well-defined unilocular or multilocular radiolucency.
• Borders are scalloping due to the variation in growth patterns.
• Displacement of adjacent teeth is common
• Rarely produces root resorption

Odontogenic keratocyst Treatment: Surgical enucleation or marsupialization.

Question 14. Gorlin’s cyst
(or)
Calcifying epithelial odontogenic cyst.
Answer: A heterogeneous group of cysts showing a variable clinicopathological pattern and includes both non-neoplastic cysts and true neoplasms.

Cystic component:

1. Type 1—Typical Gorlin’s cyst. Unicystic type with/without calcified material.
2. Type 2—Unicystic odontome type.
3. Type 3—Unicystic ameloblastomatous proliferating type.

Neoplastic component: Odontogenic tumor with ghost cells.

Cystic Clinical Features:

• Slow-growing, painless, non-tender swelling.
• Prevalent in the second decade of life.
• The anterior region of the jaws are commonly affected, and maxillary canine region involvement is very common.
• Most commonly associated with the unerupted tooth.

Cystic Radiographic Features:

• The central part of the lesion is radiolucent that may contain foci of calcified material. Margins appear smooth and well-defined or irregular and poorly defined.
• The unilocular pattern is typical. It is associated with root resorption and lingual plate expansion.

Cystic Treatment: Surgical enucleation and curettage.

Question 15. Describe basal cell nevus syndrome.
Answer:

• It is an autosomal-dominant condition, comprising cleft lip or palate, frontal bossing, coarse facial features, and hypertelorism. It is also known as Gorlin-Goltz syndrome.
• The classic triad of this syndrome is multiple basal cell carcinomas, odontogenic kerato- cysts (OKC), and bifid ribs.
  • Odontogenic keratocyst may be the first indicative sign of this syndrome and start manifesting in the 1st and 2nd decades of life and continue to develop in the 3rd decade also.
  • The cysts are asymptomatic initially and later cause jaw expansion, pain, and facial asymmetry.

Cell nevus syndrome Clinical Significance:

• Ameloblastoma or squamous cell carcinoma may arise from these cysts.
• Other associated neoplasms include Hodgkin’s lymphoma, non-Hodgkin’s lymphoma, schwannoma, pleomorphic adenoma, tumor of adrenal glands, and salivary adenoid cystic carcinoma.

Cell nevus syndrome Management: A multidisciplinary approach including genetic counseling, chemoprevention (vitamin A supplementation) surgical care, and life-support measures like a routine examination in every 4 months to identify recurrent lesions is necessary.

Question 16. Describe the lateral periodontal cyst.
Answer:

• The lateral periodontal cyst is a developmental, non-inflammatory, and non-keratinized epithelial cyst presenting lateral to the root of a vital tooth.
• It is seen as a small swelling in the interdental papilla or slightly below the papilla on the labial aspect and is asymptomatic. Pulp vitality tests of adjacent teeth reveal normal responses.

Lateral periodontal cyst Radiographic Features:

• The unilocular radiolucent lesion appears between the roots of the mandibular canine and the first premolar or between premolars.
• Size is usually less than 1 cm but rarely larger size and polycystic appearance also present.
• The divergence of the roots may also be evident.

Lateral periodontal cyst Treatment: Cyst enucleation. Recurrence is unusual.

Odontogenic And Nonodontogenic Cysts Multiple Choice Questions

Question 1. Gorlin-Goltz syndrome is associated with

1. Multiple impacted teeth
2. Multiple odontogenic keratocyst
3. Failure of eruption
4. Delayed ossification

Answer: 2. Multiple odontogenic keratocyst

Question 2. Epstein pearls are present in the

1. Gingiva
2. Edentulous alveolar ridge
3. Mid-palatine raphe
4. Buccal mucosa
   (Note: Epstein pearls are keratin-filled nodules present along the mid-palatine raphe and originate from the epithelial remnants of fusion).

Answer: 3. Mid-palatine raphe

Question 3. Bohn’s nodules are derived from

1. Epithelial remnants
2. Palatine vessels
3. Nutrient canals
4. Minor salivary glands
   (Note: Bohn’s nodules are keratin-filled cysts, present at the junction of hard and soft palate, and derived from minor salivary glands).

Answer: 4. Minor salivary glands

Question 4. Dental lamina cysts of the newborn are seen on

1. Gingiva
2. Edentulous alveolar ridge
3. Mid-palatine raphe
4. Buccal mucosa
   (Note: Dental lamina cysts of the newborn are solitary, or multiple superficially raised nodules on the edentulous alveolar ridge).

Answer: 2. Edentulous alveolar ridge

Question 5. Dental lamina cysts of the newborn are

1. Interfere with feeding
2. Asymptomatic
3. Interrupting eruption
4. Severely tender

Answer: 2. Asymptomatic

Question 6. Dental lamina cysts of the newborn require

1. Excision
2. Incision and drainage
3. No treatment
4. Alveoloplasty
   (Note: Dental lamina cysts of the newborn require no treatment and disappear during the eruption of teeth).

Answer: 3. No treatment

Question 7. The lateral periodontal cyst is common in

1. Mandibular molar-ramus region
2. Mandibular premolar region
3. Maxillary canine region
4. Maxillary incisor region
   (Note: The lateral periodontal cyst is a deve¬lopmental cyst).

Answer: 2. Mandibular premolar region

Question 8. The multilocular pattern of lateral periodontal cyst is known as

1. Botryoid odontogenic cyst
2. Bay cyst
3. Aneurysmal cyst
4. Pilar cyst

Answer: 1. Botryoid odontogenic cyst

Question 9. Periapical granuloma with islands of squamous epithelium is known as

1. Botryoid odontogenic cyst
2. Bay cyst
3. Aneurysmal cyst
4. Pilar cyst

Answer: 2. Bay cyst

Question 10. Daughter cysts are characterized for

1. Odontogenic keratocyst
2. Ameloblastoma
3. Dentigerous cyst
4. Follicular cyst

Answer: 1. Odontogenic keratocyst

Question 11. Bohn’s nodules regress spontaneously within

1. 12-24 months of age
2. 12 years of age
3. 3-4 months of age
4. 4 years of age

Answer: 3. 3-4 months of age

Question 12. A single, homogeneous, highly radiopaque dome-shaped lesion with thin radiolucent air space outline in the maxillary sinus denotes

1. Mucoepidermoid tumor
2. Ciliated cyst of the antrum
3. Pneumatized sinus
4. Mucocele
   (Note: Mucocele or mucous retention cyst of the maxillary sinus).

Answer: 4. Mucocele

Odontogenic And Nonodontogenic Cysts Highlights

• Odontogenic and nonodontogenic cysts have some characteristic clinical patterns, but their diagnosis largely depends on radiographic interpretation and histopathological examination.
• This chapter summarizes the relevant clinical aspects of cysts and basic guidelines for accurate diagnosis.