Sir, as a retired orthodontist I would take issue with some points in Mr Horobin's letter of 14 January (BDJ 2006; 200: 3).

I would ask, what is his scientific evidence that 'It has long been obvious that malocclusion, like asthma and diabetes, is a disease of modern civilisation'? Secondly, 'Soft food and a congested upper airway are, without doubt, the prime aetiological factors in modern day crooked teeth'. Thirdly, 'It is the narrow maxilla that these factors produce, crowds the teeth and holds back the developing mandible'.

These myths were firmly debunked 72 years ago by Professor James Brash in his Dental Board Lectures of the 1920s, and supported by the work of researchers such as Professor C. F. Ballard and R. Rix and others in the 1950s. Their conclusions that malocclusion is basically of genetic origin, and that environmental factors play a very small almost negligible part, were truly scientific investigations and ones that form the basis of modern orthodontics.

It is sad to see Mr Horobin making statements that 'The above seems so self evident' without a shred of scientific evidence to support them.