Oral contraceptive failure occurs in a patient on Rifampicin because of:

 # Oral contraceptive failure occurs in a patient on Rifampicin because of:

A. Rifampicin induces the metabolism of contraceptive

B. Rifampicin stimulates gonadotropin release from the pituitary

C. Rifampicin decreases the secretion of progestin

D. Rifampicin antagonizes the action of oral contraceptives

Contraceptive failures can be minimized by using an oral contraceptive containing a higher dose of estrogen or by using an alternative method of contraception. Induction of liver enzymes means that concomitant drug treatment may be made less effective. Oral contraception will not be effective, so alternative birth-control methods should be used. 

Inter transitional stage refers to:

Inter transitional stage refers to:

A. Stage of eruption of first permanent molar to  4 to 5 years age

B. Stage of eruption of molars at 6 to 8 years of age

C. Stage where 12 primary and 12 permanent teeth are present in the oral cavity

D. Stage of eruption of permanent canine and premolars

The correct answer is C. Stage where 12 primary and 12 permanent teeth are present in the oral cavity

Mixed dentition period is classified into three phases:

1. First transitional period (6 to 8 years of age)

- emergence of first permanent molars

- exchange of deciduous incisors with permanent incisors

2. Inter transitional period (lasts for around 1.5 years)

- relatively stable phase with no changes occurring in the dentition

- teeth present are permanent incisors and first molars and deciduous canines and molars (so 12 primary and 12 permanent teeth are normally seen in this stage)

3. Second transitional period (9-10 year of age)

- Starts with shedding of posterior teeth

- Emergence of canines, premolars and second permanent molars

- correction of ugly duckling stage

Closed bite is seen in which type of malocclusion?

 # Closed bite is seen in which type of malocclusion?

A. Class I

B. Class II div 1

C. Class II div 2

D. Class III

The correct answer is C. Class II div 2.

Some children exhibit a skeletal vertical deficiency (short face), almost always in conjunction with an anterior deep bite and some degree of mandibular deficiency and often with a Class II division 2 malocclusion. The reduced face height is often accompanied by everted and prominent lips that would be normal if the face height were normal.

Ref: Proffit's Contemporary Orthodontics, 6th Edition

Salivary gland aplasia is seen in:

 # Salivary gland aplasia is seen in:

A. Hemifacial microsomia

B. LADD syndrome

C. Mandibulofacial dysostosis

D. All of the above

The correct answer is D. All of the above.

Aplasia occurs for unknown reasons as an isolated finding or in conjunction with other developmental defects such as hemifacial microsomia, the LADD syndrome and mandibulo-facial dysostosis (Treacher Collins). In the more severe cases, the ensuing xerostomia causes clinical problems. Salivary loss leads to increased caries, burning sensations, oral infections, taste aberrations and difficulty with denture retention.