Orthodontics Flashcards
ARAB definition
active component - exerting force to move teeth
retention - resistance to displacement forces
anchorage - resistance to unwanted tooth movement
baseplate - self cure PMMA
what are the displacement forces
mastication, speech, tongue, gravity, active component
what are the functions of the baseplate
connector, anchorage and retention
what are 4 things to check on the URA
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
what should you check when you insert appliance into patients mouth
soft tissues for blanching and areas of trauma, check posterior retention - flyover then arrowhead - check anterior retention in same manner
what advice should you give to patient
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
what instructions should be given to patient
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
what are some advantages of a removable appliance
cheaper to make, easier to maintain hygiene as it can be removed, good anchorage, non-destructive to tooth surface
what are some disadvantages of removable appliance
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
what are the constituents of stainless steel
iron - 72%, chromium - 18%, nickel - 8%, titanium - 1.7%, carbon - 0.3%
what is the wire gauge for active components
0.5mm HSSW - buccal canine retractors and roberts retractor require 0.5mm ID tubing
what is the wire gauge for retentive component
0.7mm HSSW, unless deciduous teeth - 0.6mm
what is a local malocclusion
abnormality on either arch either with one two or several teeth, resulting in malocclusion
what is 4 signs of digit sucking
anterior open bite, unilateral posterior cross bite, proclination of upper incisors, retroclined lower incisors
what are 4 abnormalities of tooth number
supernumerary, hypodontia, retained primary teeth, early loss of primary teeth
what are 4 types of supernumerary
conical, tuberculate, supplemental, odontome
what are the aetiology of local cause of malocclusion
abnormal tooth number, abnormal tooth form, abnormal position, soft tissue and pathology
when should canines be checked and how is this done
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
what are the risks of orthodontic treatment
decalcification, relapse and root resorption
what is andrews 6 keys for ideal occlusion
molar relationship, crown inclination, crown angulation, no rotation, no spaces and flat occlusal plane
what is andrews molar relationship
distobuccal cusp of upper first permanent molar should occlude with the mesiobuccal cusp of the second lower permanent molar
what is angles classification on molar relationship
mesiobuccal cusp of upper first permanent molar should occlude with buccal fossa on the lower first permanent molar
what is a canine classification 1
lower canine is anterior to upper canine
what is BSI incisor relationship class 1
lower incisor edge lies on just below cingulum of upper incisor
what is BSI incisor relationship class 2
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
what is a BSI incisor relationship class 3
lower incisor edge lies anterior to upper incisor, reversed over jet present
how is the skeletal relationship measured
antero-posterior, vertical or transverse
how can the antero-posterior relationship be measured
visual assessment in frankfort plane, or palpate cranial base, or using lateral cephalometric
what is looked at when assessing vertical relationship
frankfort plane, mandibular angle - frankfort mandibular plane angle
how can the vertical relationship be measured
clinically - visual assessment
using lateral cephalometric
what factors affect tooth movement
magnitude, duration, age and anatomy
what amount of force is applied for different forces
tipping - 35-60grams rotation - 35-60 grams extrusion - 35-60 grams intrusion - 10-20 grams bodily movement - 150-200 grams torque - 50-100 grams
what are the different stages of eruption
pre-eruption intra-osseous mucosal penetration pre-occlusal post-occlusal
when should the deciduous canine be extracted if the permanent is ectopic
when the root of permanent is one half to two thirds formed
