A method (300) for localizing an oral cleaning device within a user's mouth. The method includes the steps of: (i) providing (310) an oral cleaning device (10) with a motion identifier (28)； (ii) estimating (335), based on sensor information received from the motion identifier, a probability of a first location of the oral cleaning device within the user's mouth； (iii) receiving (340) information from the motion identifier regarding a completed transition to a second state within the user's mouth； (iv) comparing (350) the completed transition to a defined set of possible transitions between each of a plurality of possible states within the user's mouth to determine a transition probability； and (v) determining (350), using a probabilistic graphical model comprising the first location probability and the transition probability, a probability of the location of the second state.
