Abstract: A teeth whitening system includes a head unit adapted to be worn on a user's head, a light housing supported by the head unit proximate to the user's mouth, the light housing including a light source, and a mouth piece including a tray portion adapted to surround the user's teeth. At least one of the light housing or the mouth piece includes a receptacle, and the other of the light housing or the mouth piece includes a plug portion adapted to engage in the receptacle. The present application also provides an apparatus for whitening teeth, a mouth piece for use in whitening teeth, and a method of whitening teeth.