Treatment of Class I Malocclusion Flashcards
Define class I
Lower incisor occludes at or below the upper incisor cingulum plateau
What causes crowding?
Imbalance in jaw size, tooth size, arch perimeter
How to treat crowding?
Expansion
Distal movement
Enamel stripping
Extraction
Problems of expansion?
Relapse (average expansion = 3.7mm, average relapse = 2mm)
Fenestration of labial plate
Aesthetics
What appliance is used to expand the upper arch?
Quad helix
What are the limits of expansion in mm?
Central incisors = 2mm outwards/buccally
Posteriors outwards/buccally = 3mm
Canines outwards = 0mm
How to cause distal movement of the upper arch?
Headgear (plus URA, TB or FA)
Non-compliance appliances
Temporary anchorage devices
How to cause distal movement of the lower arch?
Lip bumper
Name the non-compliance appliances
Pendulum appliance
Distal jet
Give an example of a TAD (Temporary anchorage device)
Mid-palatal implants
When to do distal movement of upper buccal segments?
Well aligned lower arch
Half unit class II molars
Co-operative patient
Does a lip bumper work?
No - very difficult to move lower arch distally - relapse will happen
What is enamel stripping?
Remove up to 0.25mm enamel from contact points by abrasive metal strips and air-rotor stripping
Usually done after the teeth are aligned (sometimes proclined) rather than crooked
How is space created in class I incisors?
Upper midline diastema
Generalised spacing
Missing teeth
Options for missing lateral incisors
Open space = restorative replacement
Close the space
What to consider when opening or closing the space?
Malocclusion
Molar relationship
Space present
What to do for missing upper lateral incisors for class II incisors and class III incisors?
Class II incisors = close space
Class III incisors = open space
Name the most common displaced tooth
Upper permanent canine
- palatal impaction 85% or buccal impaction 15%
What to do when a displaced canine is palatally impacted?
Leave in situ, monitor
Extract
Expose and align
Transplant
What to do when a displaced canine is buccally impacted?
Open exposure (apically repositioned flap) Closed exposure (attach gold chain)
