ANCHORAGE
DEFINITION
Resistance to Displacement
It obeys Newton's Third Law of Motion
“To every action there is an equal & opposite reaction”
Each orthodontic appliance consists
of two elements
1) Anchor Unit
2) Moving Unit
Types of Anchorage
{
[
Intra-maxillary
Intra-oral
Simple Anchorage
Stationary Anchorage
Reciprocal Anchorage
Inter-maxillary
Extra-oral
{
Cervical
Occipital
Cranial
Facial
Space Availability
{
Minimum Anchorage
Moderate Anchorage
Maximum Anchorage
Absolute Anchorage
{
Single
Compound
Reinforced
Classification of Anchorage

Manner of Force Application

Simple Anchorage
Resistance to tipping

Stationary Anchorage
Resistance to bodily movement

Reciprocal Anchorage
Two or more teeth moving in opposite direction
(Resistance to each other is equal and opposite)

According to Jaw Involved
Intra-maxillary (Anchorage established in same jaw
e.g. Intra-maxillary elastics, TPA)
Inter-maxillary (Anchorage distributed to both jaws
e.g. Inter-maxillary elastics)

According to Site Involved
Intra-oral (Anchorage established within mouth e.g. TPA)
Extra-oral (anchorage obtained from outside mouth)
Cervical
Occipital
Cranial
Facial
Muscular
Low pull Head gear
Medial pull Head gear
High pull Head gear
Chin cup, Face mask
Vestibular Shields
Transpalatal Arch
Lingual Arch
Lip Bumper
Lip Bumper
High Pull Headgear
Straight Pull Headgear
Cervical headgear
Face Mask
Intermaxillary elastics
Implants
 According to Number of Units
Single or Primary Anchorage
(Anchorage involving one teeth)
Compound Anchorage
(Anchorage involving two or more teeth)
Reinforced Anchorage
(Addition of non-dental anchorage)
 According to Space Available
Minimum Anchorage
(2/3rd space utilized by the movement of anchor unit)
Moderate Anchorage
(1/2 space utilized by the movement of anchor unit &
remaining 1/2 by the movement of moving unit)
Maximum Anchorage
(1/3rd space utilized by the movement of anchor unit)
Absolute Anchorage
(Absolutely no movement of anchor unit e.g. Implants)
 Anchorage Loss
Unintentional movement of anchor unit
 Anchorage Burn
Intentional movement of anchor unit
Principals of Anchorage
1st Principal of Orthodontic Anchorage
A tooth with a large root surface area has a greater
anchorage value than with a small root surface area
2nd Principal of Orthodontic Anchorage
Tooth which is free to tip has less anchorage value
than a tooth which is restricted in tipping by the
application of a force couple
Anchorage Value
Basics Determinants of Anchorage Value
Force Magnitude
Pressure Distribution in PDL
Root Morphology
Space Available
Neighbouring Structures
Anchorage value can be improved
1)
Incorporate as many teeth as possible in anchorage unit
2)
Reduce number of teeth in moving unit
3)
Use of anchorage bends
4)
Reduce the force applied to the optimal for producing the required tooth
movement
5)
Reinforce intra-oral anchorage with extra-oral anchorage
6)
Use of palatal or lingual arch
7)
Use of intra/inter maxillary elastics
8)
Use of lip bumper------anchorage from musculature
9)
Cortical anchorage
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)
Conclusion
 Anchorage Management
 Anchorage Planning