ortho

Question 1

What is the ideal amount of force for tooth movement?

Answer 1

Just greater than capillary pressure

Tension of the PDL causes osteoblast stimulation and bone deposition

compression side leads to osteoclast activity and bone resorption

Question 2

What type of force leads to quicker tooth movement, Light or heavy?

Answer 2

Light force leads to faster tooth movement

Question 3

What type of force in tooth movement leads to hyalinisation, Light or Heavy?

Answer 3

heavy force leads to the vascular supply being cut of and thus hyalinisation and sterile necrosis

Question 4

What are the risks of orthodontic treatment?

Answer 4

1) pain and discomfort
2) decalcification/gingivitis
3) root resorption
4) devitalisation
5) relapse
6) length of treatment

Question 5

Define anchorage

Answer 5

The resistance to unwanted toothmovement

Question 6

How can you create space?

Answer 6

1) extractions
2) headgear to move upper 6s distally
3) enamel stripping
4) use of leeway space
5) proclination/incisal inclination
6) expanding the maxilla

Question 7

Define in mm mild, moderate and severe crowding

Answer 7

mild : 1-4mm

moderate : 4-8mm

severe : >8mm

Question 8

Define the ‘centre of resistance”

Answer 8

the point on the tooth whereby a single force can bring about its translation along the line of action of the force

Question 9

What factors affect the centre of resistance of a tooth?

Answer 9

1) degree of alveolar bone loss
2) tooth root resorption
3) number of roots

Question 10

what are the three types of forces for tooth movement and which one requires the most and least force?

Answer 10

1) tipping
2) bodily movement (most force needed)
3) intrusion (least force needed)

Question 11

what should the visit interval length be to reactivate appliances and why?

Answer 11

minimum 4 week interval to allow repair mechanism for hyalinised areas

Question 12

give three type of appliances to apply force for tooth movement

Answer 12

archwires

intermaxillary eg elastics

removable appliances

Question 13

List two methods to achieve absolute anchorage

Answer 13

headgear

titanium screws

Question 14

In orthodontic treatment , why is thyroid supplementation indicated sometimes?

Answer 14

Patients with thyroid deficiency have a higher risk of severe generalised root resorption

Question 15

what three things are influenced by face height?

Answer 15

overbite

AP chin position

lip competency

Question 16

what treatment option is available for moderate class 2 div 1 for a patient in mixed dentition phase?

Answer 16

orthopaedic- functional appliance

Question 17

in regards to growth rotations of the mandible, what determines a long face?

Answer 17

backwards growth rotation

Question 18

what is the difference between a conical and tuberculate tooth?

Answer 18

conical: peg shaped, usually erupts and can either cause displacement or rotation of permanent teeth
tuberculate: barrel shaped, usually multiple cusps, usually doesn’t erupt and interferes with eruption of permanent dentition

Question 19

What three things accommodate for permanent anterior teeth?

Answer 19

• pre existing space
• proclination of permanent incisors
• growth - intercanine width increases

Question 20

what molar relationship is normal in primary/mixed dentition and not in adult dentition

Answer 20

e flush terminal plane

Question 21

what is leeway space? how is it significant?

Answer 21

the combined mesio-distal width between the c, d and e vs the 3, 4 and 5

upper arch 2mm
lower arch 4mm

the difference causes a mesial drift of the 6s, into the class 1 molar relationship

Question 22

true or false:

the lower gum pad at birth is wider than the upper

Answer 22

FALSE

upper gum pad is wider

Question 23

How does early loss of E’s impact the permanent dentition?

Answer 23

• loss of leeway space due to mesial shift of 6s = premolar crowding