Orthodontics Flashcards
Constituents of Stainless Steel (4)
- Primary iron
- Second most is chromium
- Nickel
- Titanium
Advantages of URAs (6)
- Excellent anchorage
- Cheaper than fixed
- Less chair side time
- OH easier to maintain
- Non destructive to tooth surface
- Can easily reduce overbite
Disadvantages of URAs (6)
- Less precise control of movement
- Teeth cannot be intruded or extruded
- Can be easily removed
- Only 1-2 teeth can be moved at a time
- Specialist technical staff required
- Rotations very difficult to correct
ARAB
Active Components
Retentive
Anchorage
Baseplate
HSSW
Hard Stainless Steel Wire
FABP
Flat Anterior Bite Plane
URAs - How many teeth can be moved at a time
1-2 teeth at a time
1mm per month
Increasing thickness of wire
Increasing force applied to teeth
Types of clasp for URAs (3)
Adams clasp
Southend clasp
Labial bow
URAs - Thickness of wire for retentive components
0.7mm permanent
0.6mm deciduous
URAs - Thickness of wire for active components
0.5mm
Types of active components for URAs (5)
- Finger Spring
- Z Spring
- T Spring
- Flapper Spring
- Buccal Canine Retractor
Components of a Finger Spring and what they do (4)
Tag (attaches to acrylic)
Coil (Where force comes from)
Guard (Allows active arm to slide along it)
Arm
What is a Z Spring used for? (3)
Used to push teeth forward
Can be used for small amounts of rotation
Uncoiled to activate it
What is the function of a buccal canine retractor
Moves teeth back into the line of arch
What can be done for Class III patients (interceptive orthodontics)
If the patient can achieve edge to edge bite on incisors, camouflage/URA is possible
If not, refer patients before they reach the age of 10
Why are posterior cross bites overcorrected
As 50% of them relapse
What age should orthodontic assessment be carried out? (2)
Brief - Age 9
Comprehensive - 11/12
Contraindications to orthodontic treatment (4)
- Allergy to nickel or latex
- Epilepsy/drugs
- Drugs
- Imaging
Skeletal Base Class I
Maxilla 2-3mm in front of mandible
Skeletal Base Class II
Maxilla more than 3mm in front of mandible
Skeletal Base Class III
Mandible in front of maxilla
FMPA
Frankfort Mandibular Planes Angle
Incompetent lips
Lips that do not meet at rest