Orthodontic Assessment 2 Flashcards
Name 4 potential occlusal features of a sucking habit
proclination of upper anteriors
retroclination of lower anteriors
localised AOB or incomplete OB
narrow upper arch +/- unilateral cross bite
incomplete anterior open bite
not quite a proper anterior open bite
to be considered proper must see space
from what planes are the angulations of teeth measured
maxillary teeth measured against the frankfort plane
mandibular teeth against the mandibular plane
what are the 6 types of bite
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
class I buccal segment relationship
mesial cusp of upper 6 lies in groove of lower 6
class II buccal segment relationship
mesial cusp of upper 6 lies anterior to the lower 6 groove
class III buccal segment relationship
mesial cusp of upper 6 lies posterior to lower 6 groove
class I canine relationship
upper canine occludes buccal and distal to lower
class II canine relationship
upper and lower canines occlude on top of one another
class III canine relationship
upper canine occludes lingually to lower
acronym for orthodontic laboratory prescription sheets
A - active components
R - retention
A - anchorage
B - base plate
Active components
components that will be moving teeth via the application of force , usually springs or screws
what size of wire are active components usually made with
0.5mm HSSW
Retention
resistant to displacement forces
most removable appliances will have anterior and posterior retention
name 5 displacement forces a URA may be subject to
tongue
mastication
speech
active components
gravity
anchorage
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
what are removable appliance base plates normally made from
self cure PMMA
(heat cure has better properties but self cure is quicker to produce and is satisfactory)
what is in stainless steel
72% iron
18% chromium
8% nickel
1.7% titanium
0.3% carbon
what size of wire are retentive components usually made from
0.7mm
advantages of removable orthodontics
good anchorage, cheaper than fixed, less time chairside than fixed, OH easier to maintain, no destruction to tooth surface, tipping of teeth
disadvantages of removable orthodontics
less precise control of tooth movement than fixed, relies on patient compliance, can only move one or two teeth at a time
how much tooth movement does orthodontics aim for per month
1mm tooth movement per month
