Inattentional blindness

Sir, following on from successful trials, the EU adopted a new Tobacco Product Directive in 2016 requiring large pictorial health warnings on the front and back of cigarette packets. Three sets of 14 pictorial warnings with a statement are rotated annually. The pictorial warnings of relevance to oral health in particular, are 'Smoking causes mouth and throat cancer' and 'Smoking damages your teeth and gums'. Three images for each statement are used (examples can be seen online).

Looking at these images and health warnings, it is important to be aware that our attention can become overloaded. In fact, the term 'inattentional blindness' describes the phenomenon whereby we fail to recognise something unexpected when our attention reaches its limit.

In the context of recognising abnormalities in the mouth, inattentional blindness can have significant consequences. For example, can you spot all the images which show oral cancer? Despite the given statements there are in fact three images showing changes typical of oral cancer.

In one image, while the statement warns 'Smoking damages your teeth and gums', there is a large raised erythematous mass on the left soft palate. Until proven otherwise, this should be treated as an oral cancer. We can only assume an error has occurred in placing the warning statement with the image in this instance.

Following the COVID-19 pandemic there is now pressure on both GDPs and specialists in secondary care to 'catch up' on those patients who missed appointments during the pandemic. Our hours of work may also be shifting to include 'long days' which may lead to poorly perceived levels of inattention towards the end of the day. The pitfall of inattentional blindness can be mitigated by carrying out oral soft tissue examinations at every visit, in a systematic manner and with intent.

Simple strategies to aid attentive soft tissue examination include illuminating the oral mucosa well during the soft tissue exam. We should also be cognisant of the typically symmetrical appearance of the oral soft tissues. Subtler changes can therefore be compared to the contralateral side to help confirm abnormality. Palpating, in particular the ventrolateral tongue, for both firmness of lesions but also for subtler nodular textural changes can also prove very effective in picking up more concerning lesions.

In my experience, the dental community is generally quite attentive to areas of leukoplakia or other white lesions with specific causes. The risk of inattentional blindness and potential for later presentation is greater where oral cavity cancer presents as a subtler diffuse area of erythema. In their thorough review of oral potentially malignant disorders and risk of progression to malignancy, Speight and colleagues¹ reference the work of Mashberg,² who felt the disparity in attention given to white lesions over red lesions, which have far greater risk of progression, is a factor in limiting early diagnosis of oral cavity cancer.