Tooth brushing monitoring system is disclosed that includes an oral hygiene device with a separate an optical sensor to track positional changes of the oral hygiene device. The optical sensor may alone or in combination with motion sensor data determine position and orientation of an oral hygiene device with respect to a user's mouth. The system may then determine the quality, quantity and location of brushing and provide feedback on the quality of brushing. This feedback provides motivation for users to increase their brushing habits, leading to a decrease in plaque, tooth decay and gingivitis.
