1. Of the following most difficult impaction to extract isA. Mesioangular

B. Vertical
C. Distoangular
D. Horizontal
Ans. C

Distoangular impactions (mandibular molars) require more bone removal and may weaken the ramus and more prone for fracture.

2. Which of the following impactions of mandibular molats are easy to extract

A. Mesioangular
B. Vertical
C. Distoangular
D. Horizontal

Ans. A
Mesioangular is the most common and least difficult of all impactions

3. According to Pell & Gregory classification , if occlusal plane of impacted tooth is between occlusal plane and cervical line of 2nd molar, type of impaction is of

A. Class A
B. Class B
C. Class C
D. Class D
Ans. B

4. Bulls eye type of appearance in IOPA is seen in

A. Lingually placed mandibular III molar
B. Buccaly placed mandibular III molar
C. Inverted mandibular III molar
D. Disto angular impaction

Ans. A

5. An approach to an impacted mandibular molar is achieved by

A. Envelop flap
B. Bayonet flap
C. L shaped flap
D. All of the above
Ans. D

All these flaps are muco periosteal flaps. They have a posterior and an anterior limb without an intermediate limb. Wards incision is the other nane for the L shaped incision, which is most commonly practiced for removal of impacted teeth.

6. During extraction of lower impacted right molar bone is removed

A. To expose maximum dimension of tooth
B. Upto CE junction
C. Upto furcation area
D. Upto half of roots
Ans. A
2 ways of bone removal:

7. The complications of using aerotor at 30,000 rpm for impacted molar is

A. Necrosis of bone
B. Tissue laceration
C. Tissue necrosis
D. Emphysema

Ans. D
Bone removal with aeroter is usually contra indicated because of the danger of developing emphysema. Drying the root canal with air syringe is also contraindicated for the same reason.

8. Extraction of disto angular impaction of mandibular 3rd molar can cause

A. Slippage in lingual pouch
B. Fracture of ramus of mandible
C. Excessive haemorrhage
D. Dry socket

Ans. B
Distoangular impaction is difficult to remove beacause of its pathway of delivery into ascending ramus. Large amount of bone removal is required, which makes the ramus weak and more prone to fracture.

9. The advantage of lingual split technique for extraction of mandibular third molar impacted teeth is/are

A. Bone loss is minimal
B. Easy and quick method
C. Tissue trauma is minimal
D. All of the above

Ans. D
Usually buccal bone is removed during extraction of the mandibular 3rd molar. Lingual split technique was given by sir William Kelsey Fry. Kelsey Fry described the tooth division technique for removal of horizontal impaction to avpid excess bone removal.

10. Contributing factor to pericoronitis of an impacted mandibular third molar is

A. Trauma by opposing tooth
B. Previous radiation therapy
C. Systemic disease
D. Infected follicular cyst

Ans. A
Operculum covering the partially erupted third molar may be traumatized during normal bite by opposing teeth.