Orthodontic #1 – Unidontia

1. A 7 year old child has a badly carious deciduous mandibular first molar that needs removal. What space maintainer will you advise?

Nance button

Band and loop

Transpalatal arch

Distal shoe

2. 12 yr old patient comes with retained primary mandibular second molar and radiograph shows congenitally missing second premolar. Most conservative approach would be

Extraction of 2nd molar and giving a bridge

Retain the 2nd molar with minimum proximal contact stripping

Extraction of 2nd molar and Transplantation of third molar in its place.

Extraction of 11d molar and allowing the rest to migrate in its position

3. During intrusion, the center of rotation lies:

Inside the tooth at 1/3rd distance from apex

Outside the tooth

At infinity

At CEJ

4. Best method to retain a corrected maxillary canine rotation:

Long term removable retainer

Supracrestal fibrotomy

Permanent retention

Overcorrection

5. Branch of orthodontics concerned with management of teeth in mixed dentition period is called:

Preventive orthodontics

Corrective orthodontics

Interceptive orthodontics

Surgical orthodontics

6. Vertical height of face is measured by:

Boos gauge

Boyle gauge

All of the above

Will’s gauge

7. The two main conditions complicating the correction of a single tooth anterior crossbite are

lack of spacing and decreased overbite.

lack of spacing and increased overbite.

an increased overbite and a large labial frenum

a decreased overbite and a large labial frenum.

8. Angle’s classification of occlusion is based on

antero-posterior skeletal relationship of maxilla to mandible.

a full complement of teeth.

vertical relationships in the lower face.

antero-posterior relationship of maxillary and mandibular first permanent molars.

9. Two millimeters of maxillary incisor spacing in a 3 year old is indicative of a

persistent tongue thrusting.

normal pattern of development.

tooth size-arch size discrepancy.

maxillary Bolton deficiency.

10. Mesioangular ectopic eruption of a permanent mandibular first molar causing resorption of distal surfaces of the roots of the primary 2nd molar should be treated by:

Removing the soft tissue overlying the occlusal surface of permanent molar

Disking of the distal surface of the primary second molar

Use of a brass wire to move the permanent molar distally

Extracting the primary second molar

11. A patient, when in full intercuspation, shows a right side posterior crossbite and a lower midline that is deviated to the right. At initial contact there are bilateral posterior crossbites and coincident midlines. The most likely cause of this finding is

two ideal occlusions.

occlusal interference and functional shift.

true unilateral crossbite.

severe temporomandibular dysfunction.

12. A steep mandibular plane angle correlates with a:

Long anterior facial height and anterior deep bite malocclusion

Short anterior facial height and anterior deep bite malocclusion

Short anterior facial height dimensions and anterior open bite malocclusion

Long anterior facial height dimensions and anterior open bite malocclusion

13. Transverse cant of occlusal plane is seen in frontal plane examination. It occurs due to:

Alteration in pitch of dentition

Change in yaw of dentition

Alteration in roll of dentition

Alteration and abstraction of jaw

14. Thumb sucking in child leads to change in facial profile (dental and skeletal changes), if the child performs the habit at least for how much time:

2 hrs daily

Not related to duration

4 hrs daily

6 hrs daily

15. The best space maintainer to prevent the lingual collapse that often occurs following the early loss of a mandibular primary canine is a

band and loop space maintainer.

lingual arch.

distal shoe space maintainer.

Nance expansion arch.

16. Facial plane is measured from nasion to:

Gonion

Menton

Basion

Pogonion

17. Major site of growth of the mandible:

Coronoid

Condyle

Ramus

Body

18. Progressive malocclusion is:

Class I

Class III

Class II

A+C

19. In a case with Class II malocclusion in a growing child, why is deep bite corrected before overjet:

To achieve faster tooth movement

To aid in bonding brackets to lower anterior teeth

To remove mechanical obstruction in normal mandibular anterior shift

To reduce palatal trauma due to traumatic deep bite

20. Prior to the correction of a one tooth anterior crossbite, the principle factor to consider is the

sequence of eruption of the permanent dentition.

adequacy of mesio-distal space.

morphology of the anterior teeth.

developmental age of the patient.

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