Toothbrush Tracking System: novel tool for recording motion and position

Objectives:

To demonstrate that the Toothbrush Tracking System accurately records toothbrush position and motion during toothbrushing.

Method:

The Toothbrush Tracking System uses 3 sensors, one attached to the head, one to the chin and one to the toothbrush. Each sensor records its spatial position and sends this information to a computer which relates each sensors' location to the other to provide a 3-dimensional map and to calculate the position of the toothbrush relative to all the teeth. The angulation of the brush relative to the tooth can be calculated. Virtual models are created to visualise the individual's toothbrushing action. To trial the technique, 13 healthy adult subjects were recruited. For each subject, virtual jaws were created. Subjects were asked to brush their teeth normally (without a mirror). The data were recorded and the total time spent toothbrushing and time spent in contact with teeth in each quadrant calculated. Plaque was assessed before and after toothbrushing using the Modified Quigley Hein Index. The overall brushing time was also recorded using a stopwatch.

Results:

For this group of subjects a wide range of brushing styles were observed, overall significantly more time was spent brushing the front teeth than the back (p=0.002).

The brushing times measured by different methods correlated well(r=0.93).

The time in contact with the teeth is significantly less than the overall brushing time(p<0.001)

There was a weak correlation between brushing times and plaque index after brushing. (r=0.48)

Conclusion:

The toothbrush tracking system can be used to quantify brushing behaviour and hence assess the effectiveness of, for example a new toothbrush design in changing the usage pattern or a hygienist instruction on toothbrushing patterns.