Transcript Extractions in orthodontics

Extractions in orthodontics
Extraction:
 removal of the teeth from the socket
 most common method to gain space in the
arch
Reason for
Etraction
1) To provide space
- Alignment of teeth/ relief
crowding
- Moving anterior teeth
back
- Moving posterior teeth
back
- Reduce overjet
- Reduce arch form
- Improve patient profile
- Anchorage control
3) Abnormal
size/ shape tooth
-dens
invaginatus/evagi
natus
-peg-shaped
2) Forced extraction
-poor prognosis teeth
-badly carious,
unrestorable, heavily
filled, very mobile,
cracked tooth, perio
condition
-teeth in poor position
Factors to be consider before extraction in
orthodontics
1) Malocclusion
–
–
–
Class II div 1: upper 1st premolars and lower 2nd premolars
Class II div 2: upper 1st premolars only
Class III: upper 2nd premolars and lower 1st premolars
2) Crowding
–
–
–
Mild crowding: non extraction
Moderate: 2nd premolars
Severe: 1st premolars
3) Type of appliances
–
Less anchorage if using removable appliances
4) Caries
–
Heavily restored tooth (>2 surface restoration)
5) Tooth abnormality
Tooth for extraction:
• Central incisors
– Rare
– Avulsed/forced xn
– Lateral incisors as replacement
• Lateral incisors
– Abnormal size & shape
– Poor prognosis (trauma, caries or gingival recession)
• Canines
– Rarely extract
– Extract if totally excluded from arch
– Acceptable 1st premolar replacement in upper arch
• Premolars
– Most common
– Each premolar gives 7mm space with maximum
anchorage
– 2nd premolar provide less anchorage than 1st
premolars
• First molars
– Rarely choice of extraction
– Not relieve anterior crowding
– Problem with anchorage control if 2nd molar not
erupted
– Problem of space closure (could add extra 6 months of
tx time)
– Poor contact between 2nd molar and 2nd premolar
• Second molar
– In mild crowding of posterior teeth
– Severe impaction
– Relief crowding of 3rd molars
– Relief crowding vertically impacted 2nd premolar
• Third molar
– Impacted
– Caries
– Distalization or uprighting molars
Points to consider before extraction
1)
2)
3)
4)
5)
6)
Profile
Face height
Lip competence
Dental arch width
Space analysis
Radiographic analysis
• Problem with extration site if extraction done
too early before orthodontic treatment
– Loss of space and anchorage
– Narrowing of dento alveolus
– Loss of cortical and cancelous bone
– Problem with space closure
– Fenestration of the bone
– Tipping of adjacent teeth
– Problem with miniscrew insertion
Care during extraction
• Please extract the CORRECT tooth
• If in doubt, please contact the referring
orthodontist before extraction
• Control infection
• Gentle pressure
• Preserve buccal and lingual alveolar plate
• Care not to damage adjacent teeth