2. Content
Q1- What is Biology of Orthodontic Tooth Movement ?
Q2- History of OTM ?
Q3-How tooth eruption different from OTM ?
Q4- What are different theory of OTM ?
Q6- what is optimal orthodontic force ?
Q7- What should be the minimal removabable appliance
wearing time?
Q8-Why mastication force is not causing tooth movement ?
Q9- What is secret behind chew of chewing gum during
ortho treatment ?
Q10 –How orthopedic differ from Orthodontic ?
????????
2
3. 3
BIOLOGY OF ORTHODONTIC TOOTH MOVEMENT
….
“The result of a biologic response to
interference in the physiologic equilibrium of the
dentofacial complex by an externally applied force”.
- Proffit,2013
5. Roman physician
First recommended mechanical force to
evoke tooth movement
Book “Operations requisite in mouth ” book viii chapter
xii
“If a permanent tooth happens to grow in children
before the deciduous one has fallen out , that which should
have dropped must be scrapped round and pulled out ;that
which is growing in place of former must be pushed into its
proper place with the finger every day, till it comes to its
own size,’’
5
2nd edition Biological Mechanism of Tooth Movement ,Vinod Krishnan and Ze’evDavidovitch
Page 5
AULUS CORNELIUS CELSUS 25BC-AD 50
6. Roman dentist
Expressed opposition to the extraction of teeth for
the correction of malocclusion and advocated filing
elongated teeth to bring them in to proper
alignment.
6
(2nd edition Biological Mechanism of Tooth Movement ,Vinod Krishnan and Ze’evDavidovitch
Page 5)
Plinius Secundus (23-79)
7. Established experimental medicine and defined
anatomy as the basis of medicine
State that “a tooth that projects beyond its neighbours
should be filed off to reduce the irregularity’’.
7
( 2nd edition Biological Mechanism of Tooth Movement ,Vinod Krishnan and Ze’evDavidovitch
Page 5)
Galen ( 131-201)
8. Pierre Fauchard1678-1761
The father of dentistry
and orthodontics
Book “le chirurgien
dentiste(the surgeon
dentist)
8
( 2nd edition Biological Mechanism of Tooth Movement ,Vinod Krishnan and Ze’evDavidovitch
Page 5)
10. Schange1841
Describe ,
Tooth eruption
cause of irregularities and prevention
First to favour light orthodontic force
important of retaining teeth after OTM
10
( 2nd edition Biological Mechanism of Tooth Movement ,Vinod Krishnan and Ze’evDavidovitch
Page 6)
11. Norman William Kingsley 1880
Book “Oral deformities”
Describe the biological and mechanical basis of OTM
Theory of bone bending
11
( 2nd edition Biological Mechanism of Tooth Movement ,Vinod Krishnan and Ze’evDavidovitch
Page 6)
12. John Nutting Farrar 1888
Father of American Orthodontics
Books “irregularities of teeth”
Optimal tooth movement should
be 1/240 inch twice daily
12
( 2nd edition Biological Mechanism of Tooth Movement ,Vinod Krishnan and Ze’evDavidovitch
Page 6)
13. Carl Sandstedt. 1860-1904
13
( 2nd edition Biological Mechanism of Tooth Movement ,Vinod Krishnan and Ze’evDavidovitch
Page 8)
Father of Biology of Orthodontic tooth movement.
Pressure tension hypothesis
14. Oppenheim 1911-12
14
( 2nd edition Biological Mechanism of Tooth Movement ,Vinod Krishnan and Ze’evDavidovitch
Page 8)
Law of bone
transformation
16. * Mechanisms of Tooth Eruption and Orthodontic Tooth Movement
G.E. Wise and G.J. King
J Dent Res 87(5):414-434, 2008
Q3-How tooth eruption different from OTM ?
17. Tooth eruption Vs OTM
* Mechanisms of Tooth Eruption and
Orthodontic Tooth Movement
G.E. Wise and G.J. King
J Dent Res 87(5):414-434, 2008
INNATE
SIGNALLING
VS
MECHANICAL
18. Orthopedics Vs Orthodontics
* Mechanisms of Tooth Eruption and Orthodontic Tooth
Movement. G.E. Wise and G.J. King
COMPRESSION -
OSTEOGENIC
COMPRESSION -
RESORPTIVE
19. Orthopedics Vs Orthodontics
* Mechanisms of Tooth Eruption and Orthodontic Tooth
Movement.G.E. Wise and G.J. King
LOADING –
BONE
LOADING –
PERIODONTAL
LIGAMENT
20. OTM is considered as a PDL phenomena
Loading of the Periodontal ligament
*Melsen,2001
24. 24
….
Bone
Transformation
Conducted OTM on Baboon
Performed all sorts of tooth movement
Did histological analysis of jaw tissue
PRESSURE TO TOOTH
STIMULUS TO BONE
BONE TRANSFORMATION
TOOTH MOVEMENT
26. 26
PRESSURE TENSION Vs BONE TRANSFORMATION
Contemporary Orthodontics 5th edition W.R.Profit
27. ….
SILENT FEATURE OF
Pressure- tension hypothesis
4 degree of Biologic effect response to magnitude of force
with capillary blood pressure
1ST Degree of
biologic
effect
2nd Degree
of biologic
effect
3rd Degree
of biologic
effect
4th Degree
of biologic
effect
Short /light
noreaction
Gentle
<20-
26gm
No
resorpti
on
Fairly
strong
Resorpti
on
Strong
Bone /root
resorption
Blood capillaries pressure 15-20mm of Hg
28. • Light Forces : Primary
osteoclasts
• Heavy Forces :
Secondary osteoclasts
from adjacent unaffected
sites
• Followed by : Tertiary
Osteoclast
from far off sites
* Biological mechanisms of tooth movement : 2nd edition
Vinod Krishnan & Davidovitch
- Oppenheim ,
1944
SILENT FEATURE OF
Pressure- tension hypothesis
240-360GM FORCE
31. 31
* Mechanisms of Tooth Eruption and Orthodontic Tooth Movement
G.E. Wise and G.J. KingJ Dent Res 87(5):414-434, 2008
32. PDL : A “Viscoelastic
system”
that
Damps the mechanical
forces with interacting
fluid systems
Namely,
i. Vascular system
ii. Interstitial fluids
iii. Cellular fluids
i
ii
iii
Fluid dynamic
Bien 1966
33. Silent feature
Fluid Dynamics
Bernoulli’s principle
Pressure drop - gas bubble formation –
favourable area resorption
(Vacuole in histologic sections)
GAS FORMATION
BONE RESORPTION
34. Draw back of Pressure – Tension &
Fluid dynamic Hypothesis
Pascal’s
law
PDL – Continuous hydrostatic system
35. 35
“alveolar bone does indeed deflect
under mechanical loading and these can be
produced by forces lower than those required
to produce consequential changes in the PDL
width”
ALVEOLAR BONE
BENDING
Baumrind
36. 36
Orthodontic appliance placed
Force applied to tooth ,bone ,PDL
Elastic properties = Deformation
Bone >Pdl
Remodelling and reorganisation occurs
Tooth movement
Silent feature
37. Bone deflection
studies :
Zengo et al 1973
Concavity : Resorption
Convexity : Deposition
* The tissue, cellular, and molecular regulation of
orthodontic tooth movement: 100 years after Carl
Sandstedt
Murray C. Meikle
European Journal of Orthodontics 28 (2006) 221–240
doi:10.1093/ejo/cjl001
38. 38
BIO ELECTRIC SIGNAL IN
ORTHODONTIC TOOTH MOVEMENT
Fukada, Yasuda : 1957
BONE
SURFACE
CHANGE
-----
-----
-----
-----
++++
++++
++++
C
O
M
P
R
E
S
S
I
O
N
T
E
N
S
I
O
N
* Biological mechanisms of tooth movement : 2nd edition
Vinod Krishnan & Davidovitch
39. Drawbacks…
Hydroxyapatite : has INVERSION
CENTRE – centrosymmetric
( Piezoelectricity is found in crystals
without an inversion centre
Dry collagen : strongly
piezoelectric
Hydrated collagen : not so
* Biological mechanisms of tooth movement : 2nd edition
Vinod Krishnan & Davidovitch
41. OPTIMAL ORTHODONTIC FORCE
Force capable of generating maximal cellular
response for the tooth supporting tissue ,including
apposition and resorption of alveolar bone, while
maintaining the vitality of these tissue.
Burstone 1962.
Optimal orthodontic force should be 20-26g/cm2
as capillary bed blood pressure is 15-20mmHg
(Schwarz 1932 ).
41
* Biological mechanisms of tooth movement : 2nd edition
Vinod Krishnan & Davidovitch
42. 42
Mechanical input that leads to maximum rate of
tooth movement with minimal irreversible damage to
the root periodontal ligament and alveolar bone .
(Daskalogiannakis 2000)
Recent concept …
•Optimal force may differ for each tooth and each
individuals patient
* Biological mechanisms of tooth movement : 2nd edition
Vinod Krishnan & Davidovitch
46. 46
Optimum Force Magnitude for Orthodontic Tooth Movement:
A Systematic Literature Review
Yijin Ren, DDS, MSca; Jaap C. Maltha, PhDb; Anne Marie Kuijpers-Jagtman, DDS, PhDc
47. 47
* The Importance of Force Levels in Relation to Tooth Movement
Birte Melsen, Paolo Maria Cattaneo, Michel Dalstra, and David Christian Kraft
ASemin Orthod 2007;13:220-233
48. PHASES OF TOOTH MOVEMENT
* TEXTBOOK OF
ORTHODONTICS
S GOWRI
SHANKAR
49. CYTOKINES
MOLECULE RANKL M-CSF OPG TNF-ALPHA
PRODUCED
BY
Osteoblast & apoptotic
Osteocytes
Osteoblast Activated monocytes &
macrophages; also by
osteoblasts
BINDS TO RANK c-fms RANK p55 receptor
EFFECT Osteoclastic
Differentia
tion
Osteoclastic
Differenti
on
Antagonist
to RANKL
Apoptotic factor for
osteocytes
* Inflammation and Tooth Movement: The Role of Cytokines, Chemokines, and Growth Factors
Ildeu Andrade Jr, Silvana R. A. Taddei, and Paulo E. A. Souza Semin Orthod 2012;18:257-269
RANK : Receptor activator of nuclear factor kappa
c-fms : Colony stimulating factor 1 receptor B
50. CL CCL CXCL CX3C FUNCTION
2,3,5 9 Chemotaxis of
osteoclasts
2,3,5,7 12 RANKL induced
differentiation
of osteoclasts
2,3 Prolonged
osteoclast
survival
1,3,4,5 Osteoblast
CHEMOKINIS
51. GROWTH FACTORS
resorption
VEGF
FGF – 2
EGF
resorption
TGF-beta
BMPs
IGF
* Inflammation and Tooth Movement: The Role of Cytokines, Chemokines, and Growth Factors
Ildeu Andrade Jr, Silvana R. A. Taddei, and Paulo E. A. Souza Semin Orthod 2012;18:257-269
53. * Inflammation and Tooth Movement: The Role of Cytokines, Chemokines, and Growth Factors
Ildeu Andrade Jr, Silvana R. A. Taddei, and Paulo E. A. Souza Semin Orthod 2012;18:257-269
COMPRESSIO
N
55. * Inflammation and Tooth Movement: The Role of Cytokines, Chemokines, and Growth Factors
Ildeu Andrade Jr, Silvana R. A. Taddei, and Paulo E. A. Souza Semin Orthod 2012;18:257-269
TENSION
56. In the case of minor external impact,
damage to the periodontium is
prevented by the cushioning effect of
pdl, elongation of collagen fibers of
up to 5% of their initial length and
the elastic deformation of tooth
sockets.
CLINICAL IMPLICATION
Why not INTERMITTENT MASTICATORY LOAD
cause tooth movement..??!!!
57. PRESSURE--Occlusion of blood vessel= Cell Death
Release of
Neuroactive peptides
Eg : CGRP , Substance P
PERCEPTION
OF ‘PAIN’ ,WHY??
( HYALINISATION )
Injury to the
associated
nerves
64. References………
BIOLOGICAL MECHANISMS OF TOOTH MOVEMENT – 2nd edition Vinod
Krishnan, Ze’ev Davidovitch
Contemporary Orthodontics : William R. Proffit, Henry W. Fields, David M.
Sarver
TEXTBOOK OF ORTHODONTICS - GURKEERAT SINGH
TEXTBOOK OF ORTHODONTICS - S GOWRI SHANKAR
Cellular, molecular, and tissue-level reactions to orthodontic force : Vinod
Krishnan and Ze’ev Davidovitch
The tissue, cellular, and molecular regulation of orthodontic tooth movement:
100 years after Carl Sandstedt Murray C. Meikle European Journal of
Orthodontics 28 (2006) 221–240
The Importance of Force Levels in Relation to Tooth Movement Birte Melsen,
Paolo Maria Cattaneo, Michel Dalstra, and David Christian Kraft
The “Mechanostat Theory” of Frost and the OPG/RANKL/RANK System :
Joanna B. Tyrovola* and XX Odont
Mechanical Loading Stimulates Dentin Matrix Protein 1 (DMP1) Expression in
Osteocytes In Vivo
65. 65
“I will prevent disease whenever I can, for prevention is
preferable to cure.”
( Hippocratic oath line 7)
Upcoming seminar…….
Biomechanics of OTM
