A Dutch man described by media as the "Dentist of Horror" has gone on trial in France accused of mutilating the mouths of more than 100 patients, reports BBC News.
Jacobus van Nierop allegedly took out healthy teeth and caused horrific injuries to dozens of patients in a remote French town.
He faces assault and fraud charges and up to 10 years in jail if convicted.
Mr van Nierop fled to Canada when suspicions arose and strongly fought against extradition to France in 2014.
Correspondents say that while he is not obliged to offer a plea under French law, Mr van Nierop has previously argued that he suffers from "psychological problems" including gender identity issues and suicidal thoughts.
The BBC's Hugh Schofield in Paris says that Mr van Nierop was many people's worst nightmare.
Like many parts of rural France, the small town of Château-Chinon is badly served for medical provision, our correspondent adds.
Initially locals seemed delighted by the hard-working and smiley dentist, a larger-than-life character who witnesses said was rarely seen without his "big 4x4, a big dog and a big cigar".
But then the horror stories began. People said they had teeth ripped out for no reason - they were given heavy anaesthetic, then left with abscesses and infected gums.
Fillings were pulled out simply to be replaced by more expensive composite and some said their mouths bled for days.
Lawyer Charles-Joseph Oudin represents some of Mr Van Nierop's alleged victims - he said they wanted answers.
"We first hope to have some explanations, to... understand how Mr Van Nierop has been able to behave in such a way for so long, how things became so serious," he said.
The story of alleged victim Sylviane Boulesteix, 65, is typical of the allegations made against the dentist.
She visited him in March 2012 to have braces fitted. "He gave me seven or eight injections, and pulled out eight teeth in one go. I was gushing blood for three days," she told the AFP news agency.