Mechanical Aspect of Orthodontic Tooth Movement

Orthodontic treatment is brought about by application of force which moves the teeth in the desired direction. All the orthodontic appliances are based on the same fundamental principles of engineering and mechanics. Understanding these universal principles helps us to effectively select, design and manipulate the appliance for efficient tooth movement and render quality treatment to our patients. The force systems produced by the orthodontic appliance consists of both force and moments, move the teeth in the manner which is both predictable and controllable by us. The Newton's 3rd law of motion "To every action there is equal and opposite reaction", also applies to our treatment mechanics. In the past couple of decades, there have been paradigm shifts in orthodontic diagnosis, imaging, treatment planning and treatment mechanics. However, the essentials of Orthodontic Biomechanics remain the same.