Which of the following is the most common developmental cyst?

  # Which of the following is the most common developmental cyst?

A. Nasopalatine cyst

B. Nasoalveolar cyst

C. Globulomaxillary cyst

D. Median palatal cyst

The correct answer is A. Nasopalatine cyst.

Nasopalatine duct cyst/Nasopalatine canal cyst/ Incisive canal cyst is most common non-odontogenic cyst. Its location is peculiar and specific in that it affects the midline anterior maxilla. 

Option B nasoalveolar cyst is a rare fissural cyst that arise at the junction of globular process, the lateral nasal process and the maxillary process. 

Option C globulomaxillary cyst is found within the bone at the junction of the globular portion of the medial nasal process, maxillary process, the globule maxillary fissure, usually between the maxillary lateral incisor and cuspid teeth. 

Condyloma acuminatum is associated with:

  # Condyloma acuminatum is associated with:

A. HPV

B. HHV 8

C. CMV

D. EBV

The correct answer is A. HPV.

Approximately 90% of condylomata acuminata are related to HPV types 6 and 11. These 2 types are the least likely to have a neoplastic potential. It is characterised by transmissible, autoinoculable soft pink nodules which proliferate and coalesce rapidly to form diffuse papillomatous clusters or as papillomatous, bulbous masses of varying sizes. Topical podophyllin may be used or surgical excision may be needed to treat the lesion. 

The term poikilokaryosis refers to :

 # The term poikilokaryosis refers to :

A. Alteration of nuclear cytoplasmic ratio

B. large, prominent nucleii

C. division of nuclei without division of cytoplasm

D. loss of polarity and disorientation of cells

The correct answer is C. Division of nuclei without division of cytoplasm.

Criteria for diagnosis of epithelial dysplasia in carcinoma include: 

• Increased abnormal mitoses 

• Individual cell keratinisation 

• Epithelial pearls in the spinous layer 

• Alterations in nuclear Cytoplasmic ratio 

• Loss of polarity and disorientation of cells 

• Hyper chromatism 

• Large nucleoli 

• Dyskaryosis or nuclear atypism including giant nuclei. 

• Poikilokarynosis or division of nuclei without division of cytoplasm 

• Basilar hyperplasia Individual cell keratinisation and epithelial pearl formation is absent in carcinoma in situ or intra epithelial carcinoma. 

Which is a premalignant lesion?

 # Which is a premalignant lesion?

A. Oral submucous fibrosis

B. Syphilitic glossitis

C. Erythroplakia

D. Lichen planus

The correct answer is C. Erythroplakia.

Premalignant lesion according to WHO (1978) is defined as a morphologically altered tissue in which cancer is more likely to occur than its apparently normal counterpart. Examples include leukoplakia, erythroplakia, carcinoma in situ. 

Precancerous condition is a generalised state associated with a significantly increased risk of cancer. These include siderophenic dysphagia, submucous fibrosis, lichen planus, syphilitic glossitis. 

Anomaly of chromosome 8q12 with slow growing mass on the left cheek in front of ear lobule

 # A patient presents with a slow growing mass on the left cheek in front of ear lobule. A sample is sent for gene analysis and cytogenic analysis reveals anomaly of chromosome 8q12. What is the diagnosis?

A. Mucoepidermoid carcinoma

B. Adenoid cystic carcinoma

C. Acinic cell carcinoma

D. Pleomorphic adenoma

The correct answer is D. Pleomorphic adenoma.

The cytogenetic abnormality of chromosome 8q12 is clearly indicative of Pleomorphic adenoma. 

Pleiomorphic adenoma is most commonly seen in the Parotid gland. 

PLEOMORPHIC ADENOMA 

• Synonym: Mixed tumor. 

• Histogenesis: Following are the possible origins: - Myoepithelial cell - Intercalated duct reserve cell 

• It is the most common tumor of salivary gland cell. - Constitutes > 50% of all salivary gland tumors. - Constitutes 90% of all benign salivary gland tumors. 

• It contains cells of pleomorphic origin (can differentiate into epithelial- ductal/ non-ductal and mesenchymal cells-chondral, myxoid, osseous cells) 

• Genetics: PLAG1 (Pleomorphic Adenoma gene) mapped to chromosome 8q12 may be responsible for pleomorphic adenoma. 

• Clinical features: - Benign tumor; It is a mixed tumor i.e., composed of both ductal and myoepithelial cells (as against monomorphic adenomas that are composed of only one cell type). - Parotid is the most common site overall; intraorally, palate is the most common site.

Oral surgery retractor with V shaped notch is:

 # Oral surgery retractor with V shaped notch is:

A. Obwegeser retractor

B. Langenbeck retractor

C. Minnesota retractor

D. Austin retractor

The correct answer is A. Obwegeser retractor.

Obwegeser Coronoid/ Ramus Retractor: 

• The retractor is similar to the Langenbeck's retractor except that the edge of the retracting blade is forked, forming a 'V' shaped notch, so as to engage the anterior border of the ramus of the mandible and aid in good tissue retraction. 

• Uses: - To retract the soft tissues along the anterior border of the ramus during sagittal split or ramus osteotomy - To retract the tissues from the anterior border of the ramus during coronoidectomy procedures. 

Langenbeck's Retractor:

 It has a long handle and an 'L' shaped blade. This retractor is most commonly used in oral surgery. It is available in different sizes with various blade widths. The instrument can be single or double ended. It is used to retract the soft tissues, incision edges, to allow view of the deeper structures. 

Austin's Retractor: It is a short right-angled retractor used for retracting the cheek, tongue and the mucoperiosteal flaps. 

‘Choking off’ phenomenon takes place after application of:

 # ‘Choking off’ phenomenon takes place after application of:

A. APF

B. NaF

C. SnF2

D. Amine Fluoride

The correct answer is B. NaF.

Choking off phenomenon is seen with the application of sodium fluoride varnish.

Neutral Sodium Fluoride 

• Fluoride concentration = 9200 ppm 

• Formed by dissolving 20 gms NaF in 1 Litre of water in a plastic bottle 

• Knutson technique: used for NaF application - Clean and dry teeth and isolate the field - Apply 2% NaF over teeth with cotton bud/applicator. Allow the solution to dry for 3-4 minutes - Application is repeated at 2nd, 3rd and 4th week at an interval of 1 week each. These applications are not preceded by Scaling. - The four-visit procedure is recommended for age groups 3, 7, 11, 13 years coinciding with eruption of different dentitions 

• Mechanism of action - NaF applied to tooth surface reacts with tooth calcium to form CaF2 - As CaF2 develops, it impedes further penetration of fluoride into hydroxyapatite. This is called "Choking off" phenomenon. It is because of this phenomenon, repeated application of NaF should be done only after 4 minutes. - The CaF2 reacts with hydroxyapatite to slowly release fluoride and thus is caries inhibitory. 

• Advantages: 

- NaF is stable when kept in plastic containers. NaF reacts with glass 

- Taste is well acceptable by patient 

- Does not discolour tooth structure 

- Procedure indicated only at specific ages and not every year application 

• Disadvantages: - At the index age, 4 visits to the dentist are mandatory in that year.