Sir, I was about to undertake a routine examination of a new patient and as the patient sat in the chair they removed this device from their mouth (Fig. 1). The device appeared to be made of cobalt-chromium, fitting onto the maxillary dentition, covering the occlusal and also palatal surfaces of the maxillary teeth (Fig. 2). I had not seen anything like it before and on further questioning, the patient reported that she had this device fitted in her teens, on the advice of her treating dentist at the time 'to help correct her bite' and she had worn the device ever since! The patient presented with a moderate/severe Class II skeletal relationship and once the device was fitted, it appeared to cause a very mild anterior open bite which helped to decrease the otherwise traumatic anterior overbite. I have not encountered such an appliance before and discussions with my colleagues left us all wondering about the origins of this dental appliance. Could any members of the dental community help shed further light on the use and indications for such a device?

Figure 1
figure 1

The device as it appeared on the bracket table

Figure 2
figure 2

The device in situ