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extractions in the field of orthodontics
1.
2. Introduction
What is extraction??
Extract or not to Extract?? Controversy
Edward Angle – Non extraction
Calvin Case – extraction
1940’s Charles Tweed reintroduced
extractions in Orthodontics
3. Why extractions
Arch length tooth material discrepancy
Correction of molar relationship
Abnormal size and shape, position
Skeletal jaw malrelations
4. Arch length tooth material discrepancy
Ideally arch length and tooth material should be in
harmony with each other.
Tooth material excess can result in crowding or
proclination of anteriors
Disproportion can not be treated by increasing the
arch length, thus decreasing the tooth material is the
only alternative
5. Correction of Sagittal inter arch relationship
Abnormal sagittal malrelationships such as class II
or III malocclusion may require extractions of teeth
to achieve interarch relation
Angle’s class I:
Normal sagittal interarch relation
Not advisable to discourage development of one arch
over the other
Preferable to extract in both arches
Example – Bidental protrusion
6. Angle’s class II :
In most cases upper dental arch is forwardly placed or the
lower arch placed backward
Extraction of teeth only in upper arch to correct maxillary
protrusion.
Angle’s class III:
Beneficial to avoid extraction in upper arch
Preferably treated with extraction only in lower arch
7. ABNORMAL SIZE AND FORM OF TEETH
Abnormality in tooth size and shape may require extraction to achieve good
occlusion
Such anomalies may include:
Macrodontia
Severly hypoplastic teeth
Dilaceration
Abnormal crown morphology
8. Factors affecting choice of teeth for extraction
Arch length discrepancy
Direction and amount of jaw growth
Profile
State and position of the teeth
Age of the patient
9. General factors for extraction of teeth
Grossly decayed
Malformations
Unfavorably impacted
Blocked out tooth
To maintain arch symmetry
Trauma
Gingival recession
10. Incisor extraction
• Unfavourably impacted upper incisor that cant be brought to normal occlusion.
• Buccaly/ lingually blocked out lateral incisor
• Unilteral Congenitally missing lateral incisor, opposite lateral incisor may be
extracted to maintain arch symmetry
• Grossly carious incisor
• Malformations of incisor crown that cannot be restored by prosthesis
• Trauma or irreplaceable damage to incisors by fracture
• Dilacerated roots in incisor
11. Lower incisors
Avoided as far as possible
INDICATIONS :
Completely blocked out incisor
Trauma, severe caries, gingival recession, bone loss
Fan shape flaring out of lower incisors due to severe arch
length deficiency
Mild class III cases with lower incisor crowding
Previous loss of premolars in each quadrant with late
lower labial segment crowding in adults
12. Canine extraction
Extraction of canines are advocated in :
Ectopic eruption and impaction of canines
Blocked out canine with good inter dental contact
between remaining teeth
Premature shedding of deciduous canines indicates
extraction on opposite side
Extraction of deciduous canines as part of serial
extractions
13. First premolar
Reasons why first premolar is
advocated for extraction -
Location of teeth allows for
correction of both anterior and
posterior segment
Contact between canines and second
premolars is satisfactory
Extraction leaves a posterior segment
that offers adequate anchorage for
retraction of anteriors
14. Second premolar
Indications:
Extracted in cases that require mesial
movements of posteriors and to correct
mild crowding in anterior segments
Unfavorable impaction of second
premolars
Grossly carious or deeply filled second
premolars
Premature loss of deciduous molar leads
to migration of permanent molar and thus
inadequate space for 2nd premolar
15. First molars
Indications:
Minimal space requirement for
correction of mild anterior crowding
or proclination
Grossly decayed or heavily restored
teeth
Open bite cases may benefit as they
tend to deepen the bite
16. Wilkinson extraction
• Extraction of all 4 1st permanent molars between the ages 8 ½ - 9 ½ yrs
• This is bases on the fact that these teeth are highly susceptible to caries
• Provides additional space for 3rd molar eruption
• Crowding of arch and risk of caries is minimized.
Drawbacks:
• Limited space to relieve anterior crowding
• 2nd premolars and molars may tip into extraction space
• Loss of adequate anchorage for orthodontic appliance
17. Second molars
Extraction although not common
Advocated in certain situations:
To prevent 3rd molar impaction
Enable distalization of 1st molars
Open bite cases: extraction of 2nd molars allows for deepening of bite in certain
cases
18. Extraction without appliance therapy
Teeth have a natural tendency to shift into
extraction spaces
The long term effect following extraction of
permanent teeth is the mesial migration of
posterior teeth.
Extractions of lower 1st premolars are often
associated with spontaneous decrowding by
drifting of teeth. This is called as
DRIFTODONTICS
19. Balancing extractions
Removal of tooth from one side of a
dental arch results in a tendency for
rest of the teeth to move towards
extraction space
These shifts may lead to unwanted
midline discrepancies.
Hence same tooth is extracted on the
other side of the arch.
20. Compensating extractions
Compensating refers to extraction of
teeth in opposite jaws. These are
carried out to preserve the buccal
occlusal relationship.
In class I relations it is usually
advisable to extract in both the
arches to preserve the buccal occlusal
relationship