1. ANCHORAGE Dr.Enas Talb

2. DEFINITION
* Anchorage in orthodontics as the nature and degree of resistance to displacement offered by an anatomic unit for the purpose of tooth movement.

3. according to Newton's Third Law of Motion
“To every action there is an equal & opposite reaction”
ANCHORAGE = resistance to unwanted tooth movement.
ANCHORAGE UNITS : The areas or units which provide this undesirable movement.

4. Each orthodontic appliance consists of two elements
Anchor Unit
Moving Unit

5. [ { Types of Anchorage Intra-oral { Extra-oral { Space Availability {
Single
Compound
Reinforced [
Simple Anchorage
Stationary Anchorage
Reciprocal Anchorage
Intra-maxillary
Inter-maxillary
Cervical
Occipital
Cranial
Facial
Minimum Anchorage
Moderate Anchorage
Maximum Anchorage
Absolute Anchorage
Space Availability {

6. Classification of Anchorage
Manner of Force Application
Simple Anchorage
Stationary Anchorage
Reciprocal Anchorage

7. ((Resistance to tipping))
Simple Anchorage
When the manner & application of force is such that it tends to change the axial inclination of the tooth or teeth that form the anchorage unit in the plane of the space in which the force is applied.
((Resistance to tipping))
Simple anchorage is obtained by engaging a greater number of teeth than are to be moved

9. (( Resistance to bodily movement))
Stationary Anchorage
When the application of force tends to displace the anchorage unit bodily in the plane of space in which the force is being applied.
(( Resistance to bodily movement))
The anchorage potential of teeth being moved bodily is considerably greater as compare to teeth being moved using a tipping force.

11. Reciprocal Anchorage
When two teeth or two sets of teeth move to an equal extend in an opposite direction .
Here the root surface area of the anchorage unit is equal to that of the teeth to be moved.
The effect of the forces exerted is equal.

13. Classification of Anchorage
According to Jaw Involved
Intra-maxillary
Inter-maxillary

14. Intra-maxillary
teeth are to be moved and the anchorage units are in the same arch ( either maxilla or mandible )
Eg.Elastic chains are used to retract the anterior segment using the posterior teeth as anchorage
unit Eg.TPA
SUB DIVISION :
Simple
Stationary
Reciprocal

15. Transpalatal Arch

16. Lingual Arch

17. Inter-maxillary Also called “Baker’s anchorage” SUB DIVISION :
Teeth are to be moved in one arch and resistance units are in opposite arch
Eg:-class ii ,class iii elastics
SUB DIVISION :
Simple
Stationary
Reciprocal

19. Classification of Anchorage
According to Site Involved
Intra-oral
Extra-oral
Cervical
Cranial
Facial
Muscular

20. Intra-oral
The anchorage units lie within the oral cavity. They include: • The alveolar bone • The teeth • The basal bone • The cortical bone • The musculature

21. Extra-oral
(anchorage obtained from outside mouth) Cervical Occipital Facial Muscular

22. 1)cranium(occipital anchorage):-anchorage obtained from occipital bone
eg:-head gear to restrict maxillary growth
2)cervical:-anchorage from cervical or neck region
eg:-cervical head gear
3)facial bones:-face mask used to protract maxilla take anchorage from forhead and chin
4-musculature:hypertonic labial musculature used for anchorage in lip bumper

23. High Pull Headgear

24. Cervical headgear

25. Face Mask

26. Lip Bumper

27. Classification of Anchorage
According to Number of Units
Single or Primary Anchorage
Compound Anchorage
Reinforced Anchorage

28. Single or Primary Anchorage
The resistance provided by single tooth with greater alveolar support is used to move another tooth with lesser alveolar support.
Eg. Molar being used
to retract a premolar

29. Compound Anchorage
The resistance is provided by more than one tooth with greater support is used to move teeth with less support.
Eg. Retracting incisors
using loop mechanics

30. Anterior inclined plane Exerts a backward pull
Reinforced Anchorage
The anchorage units are reinforced by the use of more than one type of resistance units.
Anterior inclined plane
Exerts a backward pull
On the maxillary appliance
through the mandible.

31. To engage labial surface of
SVED BITE PLANE :
Prevent from being inclined
labially.
A rigid labial bow :
To engage labial surface of
the incisor at the junction
of cervical & medial third
of each crown.

32. Banding of 2nd molar for the retraction of permanent canine.

33. Classification of Anchorage
According to Space Available
Minimum Anchorage
Moderate Anchorage
Maximum Anchorage
Absolute Anchorage

34. 2/3rd space utilized by the movement of anchor unit
Minimum Anchorage
2/3rd space utilized by the movement of anchor unit

35. Moderate Anchorage
1/2 space utilized by the movement of anchor unit & remaining 1/2 by the movement of moving unit

36. Maximum Anchorage Anchorage demand is very high
Not more than ¼ th of the extraction space should be lost by forward movement of the anchor teeth

37. Absolutely no movement of anchor unit e.g. Implants
Absolute Anchorage
Absolutely no movement of anchor unit e.g. Implants

38. Classification of Anchorage
Mini implants :Miniscrews are designed to mechanically retains into bone and not to undergo osseointigration for their easy removal. They should be preferably self drilling to make placement procedure simple. The design provide provision for attachment of orthodontic spring or auxiliary or bracket head to receive an archwire.

39. Implants have become one of the best sources of reliable anchorage.

40. Factors affecting anchorage
1-Teeth:When one teeth moves the others can act as anchorage units, it depends on
-Root form
-Root size
-No. of roots
-Root length
-Root inclination

41. Root form: different root form like,
Round – resistance is same in any direction
Flat – resist tooth movement in M-D direction eg. mand. Incisors & molars , buccal roots of max. molars ( tripod arrangement of roots )
Triangular – offers greater resistance to movement. Eg. Maxillary canine & lateral incisor

42. Size and number of roots:
Multirooted teeth and large surface area >Anchorage
Root length;-directly proportional to anchorage
Axial inclination;-anchorage is more when force exerted is opposite to that of axial of inclination of teeth

43. 2-Alveolar bone: Alveolar bone resist tooth movement up to its limit, beyond that it allow tooth movement by remodeling.
Healthy alveolar bone-more anchorage

44. 3-basal bone: Certain areas act as resistance areas-provide good anchorage like hard palate, lingual surface of mandible

45. Anchorage planning Depends on : - The number of teeth to be moved
The type of teeth to be moved
Type of tooth movement
Periodontal condition
Duration of tooth movement

46. Anchorage value can be improved
Incorporate as many teeth as possible in anchorage unit
Reduce number of teeth in moving unit
Use of anchorage bends
Reduce the force applied to the optimal for producing the required tooth movement
Reinforce intra-oral anchorage with extra-oral anchorage
Use of palatal or lingual arch
Use of intra/inter maxillary elastics
Use of lip bumper------anchorage from musculature
Cortical anchorage

47. Anchorage to be Considered
In Antero-posterior plane
(Anchorage loss appears in the form of movement of anchor unit in antero-posterior plane e.g. bodily mov. or tipping)
In Vertical plane
(Anchorage loss appears in the form of extrusion of molars or Tip back of molars so care must be taken when planning to treat High angle cases)
In transverse plane
(anchorage loss in the form of buccal flaring)