History and Development of Anchorage in Orthodontics
- Henry Albert Baker developed the intermaxillary anchorage or Bakers Anchorage.
- Bakers Anchorage uses elastics to move upper or lower teeth back.
- Intramaxillary anchorage involves using E-chain to move teeth back in the same jaw.
- Anchorage has been used in orthodontics for a long time.
- Different types of anchorage have been developed over the years.
Classification of Anchorage based on Site
- Intraoral anchorage is established within the mouth.
- It involves primary and compound anchorage.
- Extraoral anchorage is established outside the mouth.
- It can be achieved using headgear or face masks.
- Extraoral anchorage has some disadvantages but can be effective.
Classification of Anchorage based on Number of Teeth
- Anchorage can be classified as simple/primary, compound, or reinforced.
- Simple/primary anchorage uses one tooth as an anchor.
- Compound anchorage uses two or more teeth as anchors.
- Reinforced anchorage uses additional teeth or appliances to reinforce the primary anchorage.
- Reciprocal and stationary anchorage are types of reinforced anchorage.
Classification of Anchorage based on Space Closure
- Space closure in orthodontic treatment can be achieved by moving back teeth forward or front teeth backward.
- Group A anchorage involves bringing front teeth back by 75% and posterior teeth by 25% into the extraction space.
- Group B anchorage involves equal movement of anterior and posterior teeth into the extraction space.
- Group C anchorage involves moving posterior teeth forward 75% and front teeth backward 25% into the extraction space.
- Absolute anchorage involves no movement of posterior teeth forward and 100% movement of anterior teeth backward.
Classification of Anchorage based on Implant
- Orthodontic mini-implants can be used for anchorage in orthodontic treatment.
- They can provide direct or indirect anchorage.
- Direct anchorage applies force directly from the implant to the teeth.
- Indirect anchorage stabilizes teeth into a unit using an implant and applies force against this unit.
- Implant location is important for direct anchorage but less important for indirect anchorage.
Note: The information about Terry Dischinger, William B. Downs, John Nutting Farrar, Rolf Frankel, and Sheldon Friel does not fit into any of the comprehensive groups about anchorage in orthodontics.
Anchorage in orthodontics is defined as a way of resisting movement of a tooth or number of teeth by using different techniques. Anchorage is an important consideration in the field of orthodontics as this is a concept that is used frequently when correcting malocclusions. Unplanned or unwanted tooth movement can have dire consequences in a treatment plan, and therefore using anchorage stop a certain tooth movement becomes important. Anchorage can be used from many different sources such as teeth, bone, implants or extra-orally.
Certain factors related to the anatomy of teeth can affect the anchorage that may be used. Multi-rooted, longer-rooted, triangular shaped root teeth usually provide more anchorage than the single-rooted, short-rooted and ovoid rooted teeth.
