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.