Orthodontic Assessment 2

Question 1

Name 4 potential occlusal features of a sucking habit

Answer 1

proclination of upper anteriors
retroclination of lower anteriors
localised AOB or incomplete OB
narrow upper arch +/- unilateral cross bite

Question 2

incomplete anterior open bite

Answer 2

not quite a proper anterior open bite
to be considered proper must see space

Question 3

from what planes are the angulations of teeth measured

Answer 3

maxillary teeth measured against the frankfort plane
mandibular teeth against the mandibular plane

Question 4

what are the 6 types of bite

Answer 4

average - upper incisors cover 1/3 - 1/2 lower incisor crown
reduced - upper incisors cover less than 1/3 of lower incisor crown (nearing edge to edge)
anterior open bite
increased and complete , contacts tooth
increased and complete, contacts palate
increased and incomplete

Question 5

class I buccal segment relationship

Answer 5

mesial cusp of upper 6 lies in groove of lower 6

Question 6

class II buccal segment relationship

Answer 6

mesial cusp of upper 6 lies anterior to the lower 6 groove

Question 7

class III buccal segment relationship

Answer 7

mesial cusp of upper 6 lies posterior to lower 6 groove

Question 8

class I canine relationship

Answer 8

upper canine occludes buccal and distal to lower

Question 9

class II canine relationship

Answer 9

upper and lower canines occlude on top of one another

Question 10

class III canine relationship

Answer 10

upper canine occludes lingually to lower

Question 11

acronym for orthodontic laboratory prescription sheets

Answer 11

A - active components
R - retention
A - anchorage
B - base plate

Question 12

Active components

Answer 12

components that will be moving teeth via the application of force , usually springs or screws

Question 13

what size of wire are active components usually made with

Answer 13

0.5mm HSSW

Question 14

Retention

Answer 14

resistant to displacement forces
most removable appliances will have anterior and posterior retention

Question 15

name 5 displacement forces a URA may be subject to

Answer 15

tongue
mastication
speech
active components
gravity

Question 16

anchorage

Answer 16

resistance to unwanted tooth movement
as long as only 1 or two teeth are being moved at a time this wont be compromised and the baseplate will provide this

Question 17

what are removable appliance base plates normally made from

Answer 17

self cure PMMA
(heat cure has better properties but self cure is quicker to produce and is satisfactory)

Question 18

what is in stainless steel

Answer 18

72% iron
18% chromium
8% nickel
1.7% titanium
0.3% carbon

Question 19

what size of wire are retentive components usually made from

Answer 19

0.7mm

Question 20

advantages of removable orthodontics

Answer 20

good anchorage, cheaper than fixed, less time chairside than fixed, OH easier to maintain, no destruction to tooth surface, tipping of teeth

Question 21

disadvantages of removable orthodontics

Answer 21

less precise control of tooth movement than fixed, relies on patient compliance, can only move one or two teeth at a time

Question 22

how much tooth movement does orthodontics aim for per month

Answer 22

1mm tooth movement per month