2. CONTENTS
ď Introduction
ď History of extraction philosophy
ď Decision making aids
ď Effects of extraction and non extraction treatments
ď Non extraction treatments
ď Class III borderline
ď Conclusion
3. INTRODUCTION
ď Extraction of permanent
teeth is required to reach a
stable and functional
occlusion
ď When patient has good
facial esthetics that could be
disturbed by extractions
5. DECISION-MAKING AIDS
ď 1948, Downs
ď Acceptable ranges of ten
diagnostic variables
ď Earliest cephalometric
analyses
ď âSingle readings are not so
importantâ
6. ď Vorhies and Adams
ď âdifficulty of developing a
suitable mental picture.â
ď Organized data describing
acceptable ranges
ď Wigglegram
ď Efficient method to analyze
cephalometric measures
7. ⢠Rody and Araujo
⢠Relationships of
dental, skeletal, and
facial cephalometric
measurements
⢠Extraction Decision-
Making Wigglegram
(EDMW)
9. DENTAL VARIABLES
ď Dental discrepancy
ď Curve of spee
ď Boltons discrepancy
ď Peck and peck analysis
ď Irregularity index
10. DENTAL DISCREPANCY
ď Carey 2.5mm to 5mm TASLD as borderline case
ď McNamara arbitrary borderlines of 3 to 6 mm
ď Luppanapornlarp and Johnston
ďź1mm of crowding in either arch definitive non extraction
ďź Definitive extraction therapy in maxillary and mandibular
arches was 5.8 and 7.3 mm, respectively
11. Proffit and Fields
ď Less than 4 mm ALD:
ďź Extractions rare (only in incisor protrusion or posterior vertical
discrepancy)
ď ALD 5mm to 9 mm:
ďź Extraction/non-extraction decision depends on characteristics
of patient
ď ALD 10mm or more:
ďź Extractions always required
12. CURVE OF SPEE
ď 1 mm of arch circumference for each millimeter of
curve of Spee
ď Recent studies suggest ratio1:3
⢠Woods- variable depending on type of mechanics used.
⢠Roth - 3 to 6 mm of curve of Spee mild
⢠Baldridge > 6 mm is severe
13. ďBOLTONS DISCREPANCY
ď 4 mm limit to anterior reduction.
ď Extraction necessary discrepancy greater than this
ď Neff
ďźMaxillary to mandibular cuspid-to-cuspid ratio -1.22
ď Anterior Bolton ratio of .772
14. ď PECK AND PECK ANALYSIS
ď An index between 88 -95 indicates good anatomical shape.
ď Index > 95 M-D width greater than buccolingual width.
ď Borderline patients with narrow lower incisors need extraction
15. ď IRREGULARITY INDEX-LITTLE
ď Mandibular incisor alignment
ď Adding linear distances
between five adjacent
anatomical contact points
ď Perfectly aligned incisors-zero.
ď Score > 6.5 millimeters
likelihood for extraction.
16. CEPHALOMETRIC VARIABLES
ď HORIZONTAL PLANES
ď FMA
ď SN-MP
ď PFH/AFH
ď FMIA
ď IMPA
ď 1-A-POG LINE
ď UPPER AND LOWER CENTRAL INCISOR TO N-A AND
N-B LINE
18. INCISOR POSITION
ď Orthodontists may disagree which incisor is of greater
diagnostic value
ď Margolis IMPA 90+/-3 degrees in normal, balanced faces
ď Charles Tweed - âuprightâ and âverticalâ lower incisors
ď 85 and 95 degrees, according to ethnicity
ď Due to functional and esthetic impairment, an IMPA greater
than 96° is an indication for extraction
19. ď Frankfort mandibular
incisor angle (FMIA).
ď Norm 60-70°.
ď A value < 60°
indicates proclination
ď Value > 70° incisors
retroclined
20. ď McNamara
ď 1 to 3 mms anterior to
(A-Pog)
ď Regardless of age
21. ď STEINER
ď Extraction more likely as
incisor positions and angles
exceed values Horizontal
planes
NB
NA
22. FACIAL VARIABLES
Profile of the patient
Lower lip to E âline
Lower lip to B-Line
Naso labial angle
Upper lip morphology
Midline Deviation
23. ď Lower lip to E âline
ď Age and sex
ď Standard deviation - 3mm
25. ď EFFECT OF EXTRACTION ON LIPS
ď Ramos et al, for each 1 mm retraction upper lip retracts 0.75
mm
ď Talass et al 1/0.64
ď Massahud and Totti 1/0.5
ď Regarding lower lip, for 1 mm retraction, retracts 0.6 mm
26. ď Nasolabial angle
ď Burstone 73.8 degrees +/- 8
ď Recent studies range of 90
to 115 degrees.
ď Drobocky and Smith
Extraction of four bicuspids
increase nasolabial angle
5.2 degrees
27. ď Upper lip morphology
ď Thickness measured in two
different areas
ď Borderline patients with strained
lips
ď Incisors retracted without altering
soft tissue profile
ď Lip needs to reach normal form
before retraction
ď Lips would immediately follow
tooth movement in normal lips.
28. Effect of extraction on Soft tissue profile
L.A.Bravo, extractions of upper 1st premolars
ď 3.4 mm backward movement of upper lip related toâEâ line
ď 3.7° increase in NLA
ď 0.9 mm decrease in superior sulcus depth (Holdaway)
29. Extractions contraindicated
ď Nasolabial angle > 110°
ď Ls to Sn âPogâ line < 3mm
ď Li to Sn-Pogâ line < 2mm
ď Ss to H line < 3mm
ď Li to H line < 0mm
30. Six Keys to Nonextraction Treatment
DAN COUNIHAN 2005 JCO
ď First Key: Leeway Space
ďź7mm in lower arch and 5mm in upper arch
ďź Lip bumper, lingual arch, or palatal bar before second
deciduous molars exfoliate
ď Second Key: Mesial Molar Rotations
ďź Rotated upper molar occupy 12mm width, compared to
10mm for a properly oriented first molar
31. ď Third Key: Passive Uprighting
ďź Constrictive forces of lips and cheeks removed
ďź Studies shown 4mm increase in arch width
ďź Achieved with lip bumpers or Fränkel appliances
ď Fourth Key: Active Uprighting
ď Fifth Key: Distal Movement
ď Sixth Key: Skeletal Modification
32. Borderline Class III Malocclusion
ď KERR ET.AL. ( BJO 1992)
ď Establish cephalometric yardsticks
ď Surgery performed
ď ANB angle < -4°
ď M/M ratio of 0.84
ď Inclination lower incisors 83°
ď Holdaway angle of 3.5°
33. STELLZIG-EISENHAUER
ď Formula developed
ď On basis on the four variables:
ďźWits appraisal
ďź Length of anterior cranial base
ďźM/M ratio
ďź Lower gonial angle
35. CONCLUSION
ď Experience plays significant role
ď Any decision regarding need for extraction not only dependent
on presence or absence of space
ď Other issues
ďź Proper malocclusion correction
ďź Improvement of facial aesthetics
ďź Result stability