dillema in orthodontics whether to extract or not

1. BORDERLINE CASES

2. CONTENTS
 Introduction
 History of extraction philosophy
 Decision making aids
 Effects of extraction and non extraction treatments
 Non extraction treatments
 Class III borderline
 Conclusion

3. INTRODUCTION
 Extraction of permanent
teeth is required to reach a
stable and functional
occlusion
 When patient has good
facial esthetics that could be
disturbed by extractions

4. HISTORY OF EXTRACTIONS

5. DECISION-MAKING AIDS
 1948, Downs
 Acceptable ranges of ten
diagnostic variables
 Earliest cephalometric
analyses
 “Single readings are not so
important”

6.  Vorhies and Adams
 “difficulty of developing a
suitable mental picture.”
 Organized data describing
acceptable ranges
 Wigglegram
 Efficient method to analyze
cephalometric measures

7. • Rody and Araujo
• Relationships of
dental, skeletal, and
facial cephalometric
measurements
• Extraction Decision-
Making Wigglegram
(EDMW)

8. Extraction decision-making wigglegram. J Clin Orthod 2002;36:510-519

9. DENTAL VARIABLES
 Dental discrepancy
 Curve of spee
 Boltons discrepancy
 Peck and peck analysis
 Irregularity index

10. DENTAL DISCREPANCY
 Carey 2.5mm to 5mm TASLD as borderline case
 McNamara arbitrary borderlines of 3 to 6 mm
 Luppanapornlarp and Johnston
1mm of crowding in either arch definitive non extraction
 Definitive extraction therapy in maxillary and mandibular
arches was 5.8 and 7.3 mm, respectively

11. Proffit and Fields
 Less than 4 mm ALD:
 Extractions rare (only in incisor protrusion or posterior vertical
discrepancy)
 ALD 5mm to 9 mm:
 Extraction/non-extraction decision depends on characteristics
of patient
 ALD 10mm or more:
 Extractions always required

12. CURVE OF SPEE
 1 mm of arch circumference for each millimeter of
curve of Spee
 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. BOLTONS DISCREPANCY
 4 mm limit to anterior reduction.
 Extraction necessary discrepancy greater than this
 Neff
Maxillary to mandibular cuspid-to-cuspid ratio -1.22
 Anterior Bolton ratio of .772

14.  PECK AND PECK ANALYSIS
 An index between 88 -95 indicates good anatomical shape.
 Index > 95 M-D width greater than buccolingual width.
 Borderline patients with narrow lower incisors need extraction

15.  IRREGULARITY INDEX-LITTLE
 Mandibular incisor alignment
 Adding linear distances
between five adjacent
anatomical contact points
 Perfectly aligned incisors-zero.
 Score > 6.5 millimeters
likelihood for extraction.

16. CEPHALOMETRIC VARIABLES
 HORIZONTAL PLANES
 FMA
 SN-MP
 PFH/AFH
 FMIA
 IMPA
 1-A-POG LINE
 UPPER AND LOWER CENTRAL INCISOR TO N-A AND
N-B LINE

17. HORIZONTAL PLANES
 Highly divergent planes
favors extraction.
 Parallel horizontal planes not
favor extraction.

18. INCISOR POSITION
 Orthodontists may disagree which incisor is of greater
diagnostic value
 Margolis IMPA 90+/-3 degrees in normal, balanced faces
 Charles Tweed - “upright” and “vertical” lower incisors
 85 and 95 degrees, according to ethnicity
 Due to functional and esthetic impairment, an IMPA greater
than 96° is an indication for extraction

19.  Frankfort mandibular
incisor angle (FMIA).
 Norm 60-70°.
 A value < 60°
indicates proclination
 Value > 70° incisors
retroclined

20.  McNamara
 1 to 3 mms anterior to
(A-Pog)
 Regardless of age

21.  STEINER
 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 –line
Lower lip to B-Line
Naso labial angle
Upper lip morphology
Midline Deviation

23.  Lower lip to E –line
 Age and sex
 Standard deviation - 3mm

24.  Lower lip to B-Line
 2.5 ± 1.5mm anterior

25.  EFFECT OF EXTRACTION ON LIPS
 Ramos et al, for each 1 mm retraction upper lip retracts 0.75
mm
 Talass et al 1/0.64
 Massahud and Totti 1/0.5
 Regarding lower lip, for 1 mm retraction, retracts 0.6 mm

26.  Nasolabial angle
 Burstone 73.8 degrees +/- 8
 Recent studies range of 90
to 115 degrees.
 Drobocky and Smith
Extraction of four bicuspids
increase nasolabial angle
5.2 degrees

27.  Upper lip morphology
 Thickness measured in two
different areas
 Borderline patients with strained
lips
 Incisors retracted without altering
soft tissue profile
 Lip needs to reach normal form
before retraction
 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
 3.4 mm backward movement of upper lip related to‘E’ line
 3.7° increase in NLA
 0.9 mm decrease in superior sulcus depth (Holdaway)

29. Extractions contraindicated
 Nasolabial angle > 110°
 Ls to Sn –Pog’ line < 3mm
 Li to Sn-Pog’ line < 2mm
 Ss to H line < 3mm
 Li to H line < 0mm

30. Six Keys to Nonextraction Treatment
DAN COUNIHAN 2005 JCO
 First Key: Leeway Space
7mm in lower arch and 5mm in upper arch
 Lip bumper, lingual arch, or palatal bar before second
deciduous molars exfoliate
 Second Key: Mesial Molar Rotations
 Rotated upper molar occupy 12mm width, compared to
10mm for a properly oriented first molar

31.  Third Key: Passive Uprighting
 Constrictive forces of lips and cheeks removed
 Studies shown 4mm increase in arch width
 Achieved with lip bumpers or Fränkel appliances
 Fourth Key: Active Uprighting
 Fifth Key: Distal Movement
 Sixth Key: Skeletal Modification

32. Borderline Class III Malocclusion
 KERR ET.AL. ( BJO 1992)
 Establish cephalometric yardsticks
 Surgery performed
 ANB angle < -4°
 M/M ratio of 0.84
 Inclination lower incisors 83°
 Holdaway angle of 3.5°

33. STELLZIG-EISENHAUER
 Formula developed
 On basis on the four variables:
Wits appraisal
 Length of anterior cranial base
M/M ratio
 Lower gonial angle

34.  Ind Score= -1.805+0.209Wits+0.044SN+5.689M/M ratio
0.056Go
 Cr Score = - .023
 < Orthodontic- orthognathic therapy
 > Orthodontic therapy

35. CONCLUSION
 Experience plays significant role
 Any decision regarding need for extraction not only dependent
on presence or absence of space
 Other issues
 Proper malocclusion correction
 Improvement of facial aesthetics
 Result stability