Presentation about reliablity of invisalign in intruding and extruding teeth

1. Intrusion and
extrusion with
Invisalign
M.Sanoudos DDS,PhD

2. Force distribution & Type of tooth
movement
Optimal force
• The amount of force and the area of distribution
• The force distribution varies with the type of tooth
movement

3. Force distribution & Type of tooth movement
Strain
• Strain is defined as percentage of
change in length of the material in
relation to original length.
When a force is applied to any material,
such as bone, it undergoes deformation.
Strain = (change in length/original
length) x100
• The amount of deformation in the
material relative to its original
length, is the strain.
Forces should be kept low- high
concentration of forces

4. Force distribution & Type of tooth movement
• Intrusion-very light forces-concentrated in a small
area
• Extrusion-Only areas of tension

5. Optimum forces for various tooth
movements-Proffit

6. 6
Force Duration
• Sustained force- cyclic nucleotides appear- only after 4
hours
• Longer & constant the force- faster the tooth movement

7. Type force duration-force decay
• Continuous force
– Light- frontal resorption
– Heavy- undermining resorption- constant-further U.Resorption
• Destructive to the PDL & tooth
• Force decay
– Light force-FR- no movement till activation
– Heavy–UR- force drops-repair & regeneration occurs

8. Mechanical Signaling

9. Is true intrusion a reality?
Am J Orthod Dentofacial Orthop 2006;130:709-14

10. Is true intrusion a reality?
Am J Orthod Dentofacial Orthop 2006;130:709-14

11. Is true intrusion a reality?
• CONCLUSIONS
● Limited evidence is available about the quantity of
attainable molar intrusion. True molar intrusion appears
to be achievable in the maxillary arch, but the
amount of evidence is minimal.
● The clinical significance of the magnitude of the true
intrusion reported for high-pull headgear is questionable
as the sole treatment option to correct open bites
in clinical situations.
Am J Orthod Dentofacial Orthop 2006;130:709-14

12. How good is Invisalign in moving teeth?
Am J Orthod Dentofacial Orthop 2009;135:27-35

13. How good is Invisalign in moving teeth? Part2
Am J Orthod Dentofacial Orthop 2009;135:27-35

14. How good is Invisalign in moving teeth?

15. How good is Invisalign in moving teeth?
Am J Orthod Dentofacial Orthop 2009;135:27-35

16. How good is Invisalign in moving teeth?
CONCLUSIONS
1. The mean accuracy of tooth movement with Invisalign was
41%. The most accurate tooth movement was lingual
constriction (47.1%). The least accurate tooth movement
was extrusion (29.6%).
2. Maxillary and mandibular canines achieved approximately
one third of the predicted rotation. At rotational movements
greater than 15°, the accuracy for the maxillary canines was
significantly reduced.
3. With the exception of canine rotation, no tooth was
significantly less accurate in movement.
Am J Orthod Dentofacial Orthop 2009;135:27-35

17. How good is Invisalign in moving teeth?
4. Lingual crown tip was significantly more accurate
than labial crown tip, particularly for the maxilary
incisors.
5. The severity of pretreatment overjet might influence
the accuracy of anterior tooth movement with Invisalign.
6. There was no statistical difference in accuracy between
maxillary and mandibular teeth of the same
type for any tooth movement studied.
Am J Orthod Dentofacial Orthop 2009;135:27-35

18. How good is Invisalign in moving teeth? Part2
Angle Orthodontist, Vol 85, No 5, 2015

19. How good is Invisalign in moving teeth? Part2
Angle Orthodontist, Vol 85, No 5, 2015

20. How good is Invisalign in moving teeth? Part2
Angle Orthodontist, Vol 85, No 5, 2015

21. How good is Invisalign in moving teeth? Part2
Most of the studies presented with methodological problems: small sample size,
bias and confounding variables, lack of method error analysis, blinding in
measurements, and deficient or missing statistical methods. The quality level of
the studies was notsufficient to draw any evidence-based conclusions
• CAT is an effective procedure that is able to align
and level the arches in non-growing subjects.
• The anterior intrusion movement achievable with
CAT is comparable to that reported for the straight
wire technique.
• CAT is not effective in controlling anterior extrusion
movement. Contrasting results have been reported
in relation to the posterior vertical control, and a
definite conclusion cannot be drawn.

22. How good is Invisalign in moving teeth? Part2
• CAT is not effective in controlling rotations, especially of rounded
teeth.
• CAT is effective in controlling upper molar bodily
movement when a distalization of 1.5 mm has been
prescribed.
• CAT is not based on aligners alone. It requires the
use of auxiliaries (attachments, interarch elastics,
IPR, altered aligner geometries) to improve the
predictability of orthodontic movement.
Angle Orthodontist, Vol 85, No 5, 2015

23. Case 1 (From Invisalign Global Gallery)
• Treatment Information
• Age: 20
• Gender: M
• Invisalign Treatment Option: Full
• Diagnostic Summary:
• Class I relationship
• Anterior open bite
• Crowding
• Use of:
• Intrusion
• Extrusion
• IPR
• TADs inserted buccally between 1.6 (UR6) and 1.7 (UR7), and between 2.6 (UL6)
and 2.7 (UL7), and lingually between 1.5 (UR5) and 1.6 (UR6), and between 2.5
(UL5) and 2.6 (UL6) for 20 months
• Elastics
• Optimized Extrusion
• Optimized Rotation

24. Case 1 (From Invisalign Global
Gallery)

25. Case 1 (From Invisalign Global Gallery)

26. Case 1 Ceph data
(From Invisalign Global Gallery)
1. ANB 2.3
2. SNA 81.4
3. SNB 79.1 deg
4. Wits -1 mm
5. Μx/Md
differential 47 mm
6. LAFH 91.3 mm
7. MP-SN 35.5 deg
8. IMPA 86.4 deg
9. UI-SN 105.5 deg

27. Case 1
(From Invisalign Global Gallery)

28. Case 1
(From Invisalign Global Gallery)

29. Case 1
(From Invisalign Global
Gallery)
Treatment Summary
Results Achieved:
 Maintained initial Class I occlusion
 Normal overjet and overbite achieved
 All treatment goals were achieved
Total treatment time:
 24 months
Number of Aligners:
 Maxillary: 42+27=69
 Mandibular: 42+27=69
Comments:
 Orthognathic surgery avoided
Retention:
 Maxillary: Vivera retainer
 Mandibular: Vivera retainer

30. Case 2
Treatment Information
 Age: 60
 Gender: F
 Invisalign Treatment Option: Full
Chief Concern:
 Open bite and affected speech
Diagnostic Summary:
 All permanent dentition present
 History of severe bruxism
 History of TMJ with severe pain (~2 years
prior to orthodontic evaluation)
Treatment Plan and ClinCheck Analysis:
• TADs to intrude maxillary posterior 1st,
2nd, and 3rd molars
 Extrude upper 2-2 by 1mm
 Distalize upper left quadrant with
precision cut
 Button for class II elastics on the left side
to correct class II occlusion
 Patient strongly advised but declined all
3rd molars extraction –
 Maxillary 3rd molars finally extracted after
completion of Invisalign treatment
Use of:
 Distalization
 Extrusion
 Intrusion

31. Case 2

32. Case 2

33. Case 2

34. Case 2

35. Case 2

36. Case 2 Treatment Summary
Results Achieved:
 Anterior and posterior crossbites closed
 Dental midlines corrected
 Class II malocclusion on left side corrected
 Unable to extrude upper anterior teeth since
patient declined to allow attachment
placement on upper 2-2; results were
obtained by intruding posterior dentition only
 Mandible auto-rotated
 Overjet and overbite corrected
 Patient extracted U8's after completion of
treatment; open-bite closed despite presence
throughout treatment
 11 TADs placed due to patient's uncooperation
with foods and likely unfavorable bone quality

37. Case 2 Total Treatment time:
 17 months
Number of Aligners:
 Maxillary: 51
 Mandibular: 51
Comments:
 4 TADs used to help intrude maxillary 1st,
2nd, and 3rd molars
 Class II elastics used to correct class II on
the left side
Retention:
 Maxillary: Other clear
• Mandibular: Other clear

38. Discussion