Sir, the majority of your readers will be aware of the ability of a certain proportion of the population to roll or fold their tongue. This is often a source of amusement and a useful party trick!

Your readers may also wish to be made aware of a third sub-group with the ability to 'swallow' their tongue. Figure 1 shows a patient who was referred for a routine appointment to the Department of Oral Medicine at Liverpool University Dental Hospital. As part of the intra-oral examination, the patient was instructed to roll her tongue and touch the roof of her mouth in order for the ventral surface and floor of mouth to be examined effectively. To our astonishment and amazement, we were presented with a 'tongue-less' oral cavity that was momentarily disorientating. This is an oral physiological phenomenon that is rarely seen.

Figure 1
figure 1

The 'tongue-less' oral physiological phenomenon

We are not aware of either the proportion within the population with this ability nor of any clinical or genetic implication of this. Nevertheless, we felt this case was hard to swallow!