Sir, when I last checked (approximately two years ago), cassettes used for oblique lateral radiography were available by special order from Minerva Dental; films were available from Henry Schein.

The intensifying screens with these cassettes are calcium tungstate and the corresponding films are the 'blue' films. This combination is much slower than speeds achieved with rare earth screens and corresponding film.

I have used DPT cassette and film with the lateral oblique technique with no adverse results. I don't see any reason why cephalometric cassettes and film could not be used.

The typical size of the lateral oblique cassette is 15 × 18 cm, the cephalometric 18 × 24 cm and the DPT 15 × 30 cm. Using either the cephalometric or DPT combinations should result in a lower dose, as both are available with rare earth screens.

Should Mr Greenwood not wish to try these alternatives and can source the film, I would be happy to send him a 15 × 18 cm cassette with screens, which I do not use anymore.