This document contains 20 multiple choice questions about orthodontic concepts and treatment planning. The questions cover topics like ideal occlusion percentages, treatment for cleft lip and palate, characteristics of hypothyroidism, force levels during mastication, importance of space maintainers, uses of chin caps, normal thumb sucking duration, reciprocal anchorage, extraction considerations, causes of overjet and Class II malocclusions, extraction alternatives, and contraindications for serial extraction. The father of modern orthodontics is identified as Edward H Angle.

1. Etiology , diagnosis and treatment planning ---- part I
1) The term over jet refer to:
a) Horizontal relationship between the maxillary and mandibular incisors (about 2 mm).
b) Vertical relationship between the maxillary and mandibular incisors (about 3-4 mm).
c) Horizontal relationship between the maxillary and mandibular incisors (about 8.5 mm).
d) Vertical overlap labially of the maxillary incisors and mandibular incisors (normal range 0-
33%).
2) Ideal occlusion normally constitute the following percentage:
a) 3-5%.
b) 80%.
c) 61.25%.
d) 43.75%.
3) Treatment of cleft lip and palate:
a) The treatment is usually started for lip closure at 2 months of age.
b) The surgical closure of the palate is started at around 18 months-2 years of age.
c) Orthodontic started usually after permanent teeth erupt and is of long duration.
d) All of the above.
4) Hypothyroidism is characterized by:
a) Constricted lower arch.
b) Short ramus and constricted maxillary arch.
c) Class III malocclusion and open bite.
d) B and c are true.
5) During mastication the force exerted on the teeth range from:
a) 400-700 pounds.
b) 150-500 pounds.
c) 50-150 pounds.
d) Up to 1000 pounds.
6) The term incompetent lips refers to:
a) Lip which do not seal when relaxed with the mandible in its rest position.
b) Lips against which tongue thrusts during swallowing.

2. c) Lips that contract during swallowing.
d) Lips which have some dryness.
7) Space maintainer after early loss of EE around 8-9 years of age:
a) Is not required.
b) Is of utmost importance.
c) Can cause impaction of 55 if not done.
d) Both a and c are true.
8) Chin caps are helpful in treatment of:
a) Class I malocclusion.
b) Class III malocclusion.
c) Class II div2 malocclusion.
d) Reverse over jet.
9) Thumb sucking is considered normal till
a) 2 years.
b) 2 months.
c) 3½ -4 years.
d) 6 years or till permanent teeth erupt.
10) Reciprocal anchorage is term applied to:
a) High level of force between molar and incisors teeth.
b) Reciprocal movement of two teeth with the same periodontal area.
c) A force differential between cortical and medullary bone.
d) None of above.
11) Incisors teeth should not extracted because :
a) There is tendency to develop open bite occlusion.
b) There is tenancy to develop an abnormally deep bite.
c) It interfere with the distal movement of the maxillary/mandiblar arch.
d) Arch form is difficult to maintain.
12) The 1st permanent molars should not be extracted if:
a) The 2nd molar in bucco-version.
b) If the molars are beyond repair.

3. c) The third molar are absent.
d) All the above.
13) The main cause of bruxisim is :
a) Physiological problem.
b) Periodontal problems.
c) Traumatic occlusion.
d) Psychological factors.
14) Extraction is not usually required in:
a) Open bite cases.
b) Calss II div.2 cases.
c) Class III cases.
d) Lip sucker.
15) The contraindication of 2nd permanent molar extraction includes:
a) Undersized 3rd molar.
b) Impacted 3rd molar.
c) Absence of third molar.
d) All of the above.
16) A large over jet may be caused by:
a) Maxillary proganthism.
b) Retrognathic mandible.
c) Lip biting.
d) All of the above.
17) When the SNA is large , it indicate:
a) Procumbency of maxillary incisors.
b) Procumbency of mandibular incisors.
c) Severe class II.
d) A large maxilla.
18) Second premolar may be extracted instead of first premolar if:
a) They are severely carious.
b) The case is of border line extraction.
c) If they are blocked out of alignment and would require extensive orthodontic tooth

4. movement.
d) All of the above.
19) The father of modern orthodontics:
a) Edward H Angle.
b) Norman kingsley.
c) George crozat.
d) Charles tweeds.
20) Serial extraction should not be undertaken if there is:
a) Severe crowding.
b) Presence of ectopic eruption.
c) Deep bite or open bite.
d) None of the above.