In the anteroposterior bar major connector, the shape of the bars are:

  # In the anteroposterior bar major connector, the shape of the bars are:

A. Anterior bar – flat strap; posterior bar- half oval

B. Anterior bar – half pear shape; posterior bar- half pear shape

C. Anterior bar – half oval; posterior bar- flat strap

D. Anterior bar – flat strap; posterior bar- flat strap

The correct answer is A. Anterior bar – flat strap; posterior bar- half oval.

The anterior component is a flat strap located as far posteriorly as possible to avoid rugae coverage and tongue interference. The anterior border of this strap should be located just posterior to a rugae crest or in the valley between two crests. The posterior strap is thin, a minimum of 8 mm wide, and located

as far posteriorly as possible, yet entirely on the hard palate. It should be located at right angles to midline rather than diagonally.

Posterior palatal component: a strap of 22-gauge thickness, 8 to 10 mm wide (a half-oval form of approximately 6-gauge thickness and width) may also be used.

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The space maintainer which is contraindicated in a child suffering from subacute bacterial endocarditis is:

  # The space maintainer which is contraindicated in a child suffering from subacute bacterial endocarditis is:

A. Removable

B. Crown and loop

C. Band and loop

D. Distal shoe

The correct answer is D. Distal shoe.

A distal shoe space maintainer is indicated when the primary 2nd molar is lost before eruption of the permanent 1st molar. 

Distal shoe space maintainer is contraindicated in: 

• Patient with heart diseases 

• Patients with poor oral hygiene 

• Hemophilic patients 

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Middle concha of nose are a part of:

 # Middle concha of nose are a part of:

A. Nasal bone

B. Ethmoid

C. Vomer

D. Maxilla

The correct answer is B. Ethmoid.

The nasal conchae are curved bony projections directed downward and medially. 

The 3 conchae are:

 i) Inferior concha: It is an independent bone. 

ii) Middle concha: It is a projection from the medial surface of the ethmoidal labyrinth.

iii) Superior concha: It is also a projection from the medial surface of the ethmoidal labyrinth. This is the smallest concha situated just above the posterior part of middle concha. 

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Carboxylation reaction is related to:

 # Carboxylation reaction is related to:

A. Biotin

B. Vitamin B6

C. Vitamin C

D. Vitamin A

The correct answer is A. Biotin.

Biotin serves as a carrier of CO2 in carboxylation reactions. The reaction catalyzed by pyruvate carboxylase, converting pyruvate to oxaloacetate.

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Which bone reaches its adult size at birth?

 # Which bone reaches its adult size at birth?

A. Ear ossicles

B. Parietal bone

C. Mastoid process

D. Maxilla

The correct answer is A. Ear ossicles.

The bone that reaches its adult size at birth are ear ossicles. The tympanic cavity, mastoid antrum, auditory ossicles and structures of the internal ear are almost fully developed at birth and undergo little change after birth.

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Metopic suture fuses at:

 # Metopic suture fuses at:

A. 2.5 years

B. 6 years

C. 18 months

D. 9 months

The correct answer is D. 9 months.

The two frontal bones tend to fuse in the midline via the metopic or frontal suture. The timing of its closure is controversial. Fusion of metopic suture begins anteriorly at the bridge of the nose and progresses posteriorly. One-third of metopic sutures close at 3 months, and nearly 100% by 9 months. Although some may persist into 6 years and may not close until adulthood in up to 10% of patients. A premature fusion of the suture is termed metopic synostosis. This can result in trigonocephaly. It usually disappears by the age of 2 years but may even persist in a few individuals. 

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If access is made in gold crown for endodontic procedure and after completion of procedure

 # If access is made in gold crown for endodontic procedure and after completion of procedure hole is filled with amalgam, which is correct about subsequent possible event?

A.  Amalgam will act as anode to gold  

B. Amalgam will act as cathode to gold

C. Circuit will not be formed

D. All of the above

The correct answer is A. Amalgam will act as anode to gold.

If an amalgam is in direct contact with an adjacent metallic restoration such as a gold crown, the amalgam is the anode in the circuit. This type of electrochemical corrosion is called galvanic corrosion and is associated with the presence of macroscopically different electrode sites.

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