Orthodontics

Question 1

ARAB definition

Answer 1

active component - exerting force to move teeth
retention - resistance to displacement forces
anchorage - resistance to unwanted tooth movement
baseplate - self cure PMMA

Question 2

what are the displacement forces

Answer 2

mastication, speech, tongue, gravity, active component

Question 3

what are the functions of the baseplate

Answer 3

connector, anchorage and retention

Question 4

what are 4 things to check on the URA

Answer 4

right appliance for right patient, right design you asked for, inspect surface for sharp edges that could cause trauma, check wire work - work hardening or damage

Question 5

what should you check when you insert appliance into patients mouth

Answer 5

soft tissues for blanching and areas of trauma, check posterior retention - flyover then arrowhead - check anterior retention in same manner

Question 6

what advice should you give to patient

Answer 6

will feel big and bulky initially, will cause excess salivation initially - will subside after 24 hours, will be uncomfortable - normal, it is working, may impede speech initially - practice speaking aloud

Question 7

what instructions should be given to patient

Answer 7

should be worn 24 hours a day - including meal time and sleep
should remove after meal and clean
should be removed for contact sports or activity and stored in container
avoid sticky foods that could damage appliance and be careful with hot foods
non compliance with appliance or appointments will significantly lengthen treatment time

Question 8

what are some advantages of a removable appliance

Answer 8

cheaper to make, easier to maintain hygiene as it can be removed, good anchorage, non-destructive to tooth surface

Question 9

what are some disadvantages of removable appliance

Answer 9

less precise control of movement, can only move in tipping/tilting, patient can remove so might not comply, can only move 1 or 2 teeth at a time

Question 10

what are the constituents of stainless steel

Answer 10

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

Question 11

what is the wire gauge for active components

Answer 11

0.5mm HSSW - buccal canine retractors and roberts retractor require 0.5mm ID tubing

Question 12

what is the wire gauge for retentive component

Answer 12

0.7mm HSSW, unless deciduous teeth - 0.6mm

Question 13

what is a local malocclusion

Answer 13

abnormality on either arch either with one two or several teeth, resulting in malocclusion

Question 14

what is 4 signs of digit sucking

Answer 14

anterior open bite, unilateral posterior cross bite, proclination of upper incisors, retroclined lower incisors

Question 15

what are 4 abnormalities of tooth number

Answer 15

supernumerary, hypodontia, retained primary teeth, early loss of primary teeth

Question 16

what are 4 types of supernumerary

Answer 16

conical, tuberculate, supplemental, odontome

Question 17

what are the aetiology of local cause of malocclusion

Answer 17

abnormal tooth number, abnormal tooth form, abnormal position, soft tissue and pathology

Question 18

when should canines be checked and how is this done

Answer 18

from age 9 onwards, visual assessment to see if they are present, palpate buccal sulcus to feel for them, inclination, colour and mobility of lateral incisor

Question 19

what are the risks of orthodontic treatment

Answer 19

decalcification, relapse and root resorption

Question 20

what is andrews 6 keys for ideal occlusion

Answer 20

molar relationship, crown inclination, crown angulation, no rotation, no spaces and flat occlusal plane

Question 21

what is andrews molar relationship

Answer 21

distobuccal cusp of upper first permanent molar should occlude with the mesiobuccal cusp of the second lower permanent molar

Question 22

what is angles classification on molar relationship

Answer 22

mesiobuccal cusp of upper first permanent molar should occlude with buccal fossa on the lower first permanent molar

Question 23

what is a canine classification 1

Answer 23

lower canine is anterior to upper canine

Question 24

what is BSI incisor relationship class 1

Answer 24

lower incisor edge lies on just below cingulum of upper incisor

Question 25

what is BSI incisor relationship class 2

Answer 25

lower incisor edge lies posterior to cingulum plateau of upper incisor. division 1 - proclination of upper incisors, often an over jet present. division 2 - retroclination of upper incisors, no overjet

Question 26

what is a BSI incisor relationship class 3

Answer 26

lower incisor edge lies anterior to upper incisor, reversed over jet present

Question 27

how is the skeletal relationship measured

Answer 27

antero-posterior, vertical or transverse

Question 28

how can the antero-posterior relationship be measured

Answer 28

visual assessment in frankfort plane, or palpate cranial base, or using lateral cephalometric

Question 29

what is looked at when assessing vertical relationship

Answer 29

frankfort plane, mandibular angle - frankfort mandibular plane angle

Question 30

how can the vertical relationship be measured

Answer 30

clinically - visual assessment

using lateral cephalometric

Question 31

what factors affect tooth movement

Answer 31

magnitude, duration, age and anatomy

Question 32

what amount of force is applied for different forces

Answer 32

tipping - 35-60grams
rotation - 35-60 grams
extrusion - 35-60 grams
intrusion - 10-20 grams
bodily movement - 150-200 grams
torque - 50-100 grams

Question 33

what are the different stages of eruption

Answer 33

pre-eruption
intra-osseous
mucosal penetration
pre-occlusal
post-occlusal

Question 34

when should the deciduous canine be extracted if the permanent is ectopic

Answer 34

when the root of permanent is one half to two thirds formed