Types of Intrusion - True Intrusion: Incisors move towards the bone without movement of posterior teeth - Relative Intrusion: Extrusion of posterior teeth to correct deep bite - Can be performed in adolescents with deep bite tendency

Methods of Intrusion - Burstone's Intrusion Arch: Segmental arch method with low magnitude forces - Ricketts Utility intrusion arch: Continuous wire with statistically indeterminate system - Three-Piece intrusion arch: Developed for retraction and intrusion simultaneously

Types of Cases for Intrusion - Deep bite with vertical facial growth pattern: Manage vertical growth and prevent eruption of posterior molars - Deep bite with horizontal facial growth pattern: Increase vertical height through relative intrusion

Major Principles of Intrusion - Controlling force magnitude and consistency - Single point contacts on anterior teeth - Point of force application and center of resistance - Selective intrusion based on anterior tooth geometry - Control over reactive units and avoidance of extrusive mechanics

Force Magnitude in Intrusion - Force magnitude must be constant throughout application - Higher force can lead to side effects such as root resorption and extrusion of posterior teeth - Equal and opposite forces are produced at incisors and molars - Use wire with low load-deflection rate for constant force of intrusion