Integrated Six-Degree-Of-Freedom Sensing for Orthodontic Smart Brackets

We report for the first time on an orthodontic smart bracket capable of detecting all six externally applied force and moment components. This information is capable of providing important feedback to the orthodontist during therapy. By measuring the stresses in the plane of a sensor chip inside the bracket, it is possible to extract the forces and moments externally applied to the bracket. The stress sensing device consists of an integrated CMOS circuit packaged within a bracket demonstrator for application in orthodontics. By measuring 64 stress signals within the chip plane the sensor is capable of extracting all six components of the force and moment at the interface between the orthodontic bracket and the base onto which it is mounted.