ura appliance design Flashcards
appliance design sheet
aim
ARAB
active components
retentive
anchorage
base plate
aim is
description of what the appliance design is aiming to achieve.
info: Retract canines, 1st Premolars extracted, 6mm Overjet (OJ)
Please construct a URA to retract 13 + 23
active components
the name of the component or components that will be moving teeth with the application of force
e.g. 13 + 23; Palatal finger springs + guards; 0.5mm HSSW
retentive
the resistance to displacement forces
e.g. 16 + 26; Adams clasps; 0.7mm HSSW
11 + 21; Southend clasp; 0.7mm HSSW
anchorage
resistance to unwanted tooth movement
e.g. moving only 2 teeth
baseplate
connects all the components together as a unit, provides anchorage and assists with retention
e.g. self cure PMMA
how do teeth move
Orthodontics is based on the principle that if prolonged force is applied to a tooth, tooth movement will occur.
The force exerted creates pressure this causes the bone around the tooth to remodel. Remodelling is a process where bone is selectively removed in some areas and added in others.
The remodelling of bone is controlled by the periodontal ligaments or fibres (PDL) the PDL is a collection of fibres surrounding the root which act as a buffer against shock
uses of orthodontic casts
treatment planning
diagnosis
fabrication of appliances
monitoring progress
patient education
teaching
case studies - research
record keeping - 11 years
advantages of removable ortho
Tipping of teeth
Excellent Anchorage
Generally cheaper than fixed
Shorter chairside time required
Oral hygiene is easier to maintain
Non- destructive to tooth surface
Less specialised training required to manage
Can be easily adapted for overbite reduction
Can achieve block movements
disadvantages
Less precise control of tooth movement
Can be easily removed by the patient
Generally only 1-2 teeth can be moved at one timeSpecialist technical staff required to construct the appliances
Rotations very difficult to correct
