Dentists are being urged to probe their patients' personal lives to help curb rising rates of oral cancer.

A leading charity wants to see dentists take a more active role in fighting the disease, which is claiming increasing numbers of lives in the UK.

This could mean practitioners asking patients about lifestyle risk factors such as smoking, drinking and sexual behaviour.

"We would like them to be more aware of the risk factors so that they ask the right questions," said Hazel Nunn, head of health evidence and information at Cancer Research UK.

"Dentists should be asking their patients if they smoke or drink heavily. That doesn't necessarily mean following up with a lecture, but they should be aware.

"If a dentist is looking at someone's teeth and knows this person smokes 50 cigarettes a day and drinks well above the recommended amount, he might look that extra bit more carefully."

Oral cancer affects the lips, tongue, cheek lining, gums, palate and floor of the mouth.

By 2030 it is predicted that 9,200 cases of the disease will be diagnosed each year in the UK, compared with 6,240 in 2009 and 3,030 in 1984. Death rates are also expected to rise by around 22% over the next two decades.

The reason for the trend is unclear but thought to be linked to lifestyle. Smoking and drinking are two major risk factors for oral cancer, as is the human papilloma virus (HPV) which can infect the mouth as a result of oral sex.

While fewer people are smoking than they used to, excess alcohol consumption and binge drinking is a growing problem, especially among the young.

There is also evidence that people who have more sexual partners, and are more likely to engage in oral sex, are at greater risk of oral cancer.

Most oral cancers produce a type of tumour called squamous cell carcinoma that spreads quickly.

Early symptoms include sores, lumps or ulcers in the mouth which can easily be dismissed as harmless.

Cancer Research UK, the British Society for Oral Medicine, and the British Association for the Study of Community Dentistry are jointly lobbying the dental profession to take mouth cancer more seriously.

They are pressing the British General Dental Council to make the early detection and prevention of oral cancer a compulsory part of dentists' ongoing training.

In May the council made oral cancer detection a recommended, but not compulsory, subject for continuing professional development alongside legal and ethical issues and handling of complaints.

Ms Nunn said: "We're saying this is halfway there. It's a commitment to doing more, but what we're asking for is for oral cancer early diagnosis and prevention to be up there alongside cross infection control and the risk from X-ray radiation.

"All dentists will receive some initial training on oral cancer, but it's not part of their ongoing training."

Professor Damien Walmsley, scientific adviser to the British Dental Association, said: "Dentists examine soft tissue as part of a routine dental check-up. Dentists also monitor patients' medical histories and provide advice to help patients understand the risks associated with their lifestyle choices, such as tobacco use and drinking alcohol to excess, which is essential for the early targeted detection of oral cancer.

"The British Dental Association has published a clinical guide to early detection and management of oral cancer and Improving Oral Cancer Detection has recently been added to the GDC's recommended list of Continuous Professional Development subjects."

A Department of Health spokesman said: "Dentists are required to ask patients about lifestyle factors like drinking and smoking before any treatment begins.

"Seventy dental practices around the country are also testing a new system where patients are asked questions about their lifestyle as part of a general oral health assessment. The pilot programme will help shape the new dental contract and also help dentists improve oral health."