Fastenable device for oral cavity position detection

An oral-area position-detection device comprising:

• (a) housing;
• (b) at least a first fastener configured to fasten the housing to an oral-care implement;
• (c) at least one electrode pair disposed on the housing and having an impedance formed between the electrodes when electrified, wherein the housing houses an impedance-measurement unit electrically coupled to the electrode pair for measuring impedance values between the electrodes, and wherein the housing comprises a base portion, a head portion opposite to the body portion, and a body portion between the base portion and the head portion,
• wherein the base portion comprises the at least one fastener as a first fastener defining an opening, wherein the opening is configured to be slideable along a neck portion of the oral-care implement,
• wherein the at least one electrode pair is disposed on the head portion and wherein the at least one electrode pair comprises at least a first electrode, a second electrode, a third electrode, and a fourth electrode, wherein said electrodes are configured to form electrode pairs with one another,
• wherein the head portion further comprises at least one fastener as a second fastener defining a snappable channel configured to be releasably fastenable to the neck portion of the oral-care implement;
• and
• wherein the device further comprises a frequency generator electrically connected to the electrode pair for applying a voltage having at least two different frequencies between the electrode pair, wherein the impedance-measurement unit measures the impedance values between the electrodes at the at least two different frequencies.