Chiildren as young as three are being forced to have their teeth removed due to poor dental care and bad diet.
And hundreds of children aged between four and six are showing such extreme signs of tooth decay that they are left without any milk teeth at all.
In extreme cases, dentists have reported that toddlers need to have their baby teeth removed just six months after they have come through.
A report this week revealed Wales is the third worst area in the UK for children's dental health, behind Scotland and North West England.
NHS figures for Wales for 2002/3 show that more than 30,000 teeth were removed from under 18s, with 548 coming from multiple extractions of five to nine teeth.
The total cost for the NHS for those extractions came to pounds 291,929.
According to the British Dental Association, 1,600 children under 10 have teeth removed in South Wales every year. Many of those require general anaesthetic.
In North Wales, the Community Dental Service administered general anaesthetic to 291 children under four for fillings or extractions during 2002/3.
The figure for children aged between five to 15 in the same period was 1,970.
In Wales, the average five-year-old child has 2.26 decayed, missing or filled teeth, according to the British Association for the Study of Community Dentists.
Victoria Park Clinic, Cardiff, is one of three specialist clinics in South Wales where children's teeth are removed by general anaesthetic.
Director Mark Robothan said
: 'We probably get one child per month here who needs all 20 milk teeth out. Quite often they have all of their front teeth, or all their back teeth out.
'It's not unusual to have children who need more than six teeth out. The youngest was a three-year-old.
'The last baby teeth come through at about two-and-a-half years old, and within six months, they could have them taken out.'
Stuart Geddes, British Dental Association Director for Wales, blames high-sugar drinks.
He said: 'It's due to bottle-feeding and continuous exposure of the teeth to horrible decaying things, like tea with sugar or fruit juice.'