Class I Malocclusion Flashcards
Aetiology of crowding
Imbalances in…
Jaw size
Tooth Size
Arch perimeter
Reduction in size of jaws
Solving crowding
Expansion - anterior, posterior (distal)
Distal movement
Enamel stripping
Extraction
Expansion e.g posterior crossbite
Methods
Widen upper arch
Bring incisors forward
Problems with expansion
Expansion to treat crowding
Relapse if over expanded
Fenestration of labial plate
Aesthetics
Schwarz appliance not good to expand lower arch
Relapse is
Inevitable by 50% in most cases
Expansion of arches is not very stable
Relapse - Non-extraction arch development
10% long term success
Relapse - Premolar extractions
30% long term success
Limits of expansion
Canines
Incisors
Breadth
0mm
2mm
3mm
Fenestration of labial plate
Over expansion may lead to roots moving past plate
Aesthetics
Lip support - thin - non extraction
Full lips and protruded incisors - think about extraction
Distal movement
give e.g
Retract upper 6 and 7 if erupted
Retract premolars and canine
Align canine
Distal movement of upper arch methods
Headgear
Non-compliance appliances
temporary anchorage devices
Distal movement in lower arch
Lip bumper
Non compliance appliances
Pendulum
Distal jet
Distal movement of upper buccal segments
Well aligned lower arch Half unit class II molars
Lower arch
Lip bumper
Doesn’t work
Enamel stripping/interproximal reduction
Remove up to 0.25mm enamel from contact points
Extraction
Most common solution
Spacing - 3 issues
Midline diastema
Generalised spacing
Missing teeth
Midline diastema
Mesial movement
Generalised spacing
Difficult if associated with missing teeth
Missing teeth e.g missing laterals
Options
Take into account
May be restorative issue Open space Close space Restorative replacement Malocclusion Molar relationship Space.
Missing lateral incisors
Class II
Class III
Close space
Open space
Displaced teeth
Most common is?
Upper permanent canine
