A French court has found a Dutch dentist guilty of assault and fraud and sentenced him to eight years in prison.
Jacobus Van Nierop, 51, showed no signs of emotion when the court in the central town of Nevers returned its verdict.
The court also barred him from practising dentistry for life.
Around 100 people had issued complaints against Van Nierop, ranging from having multiple healthy teeth removed, pieces of drills left in their gums and teeth, or abscesses and misshapen mouths after he carried out work on patients.
Van Nierop, dubbed the "horror dentist" by the French media, was accused of causing "mutilations" or "permanent disabilities" to scores of patients from 2009 to 2012, of overcharging patients and billing them for imaginary procedures and of illegally practising dentistry in France.
In their 130-page ruling, the judges convicted the Dutchman of 85 counts of assault, including 45 counts of mutilation, and of 61 counts of fraud against patients, their health insurance companies and the local social security agency.
They fined him €10,500 and said they will decide the amount of damages due to 62 plaintiffs in June.
The court acquitted the defendant of six counts of assault and some counts of fraud.
Van Nierop has 10 days to file an appeal. He has been detained in a French prison since January 2015.
Marie-Jo Lemoine, a victim of Van Nierop, celebrated the verdict.
She said: "It's silly to say that but I say it: It feels good. He will have time to think about us. But, as for the rest, nothing has changed regarding what we'll be given in terms of compensation. It won't be enough to repair the harm he caused. "
In her closing speech last month, prosecutor Lucile Jaillon-Bru said that in Van Nierop "there was only greed, indifference to another, even some enjoyment in making others suffer" and that for the victims "the price of pain is enormous".
The dentist's goal "was to always make more money", she said.
Delphine Morin-Meneghel, the lawyer for Van Nierop, acknowledged her client was responsible for some bad procedures but she insisted he committed no intentional or premeditated violence towards any of his patients.
One patient, Sylviane Boulesteix, 65, told the court she was unexpectedly summoned to the Dutchman's dental office in May 2012.
Without warning, the dentist pulled eight of her teeth out and immediately fixed dentures on her raw gums. For hours, the woman said she sat "gushing blood".
In the following days, she said Van Nierop refused to relieve her pain.
A judicial expert described the dentist as a "cruel and perverse" man whose incompetence made Ms Boulesteix lose several healthy teeth, go through a trauma and suffer irreversible damage to her mouth.
When the dentist opened his office in late 2008, he was first welcomed by residents in Chateau-Chinon, a small town located in a rural and remote part of France's Burgundy region known as a "medical desert" because of a lack of medical professionals.
Van Nierop provided false documents to practise dentistry in France and concealed that he was the subject of disciplinary proceedings in his own country.
While living in an imposing home with a swimming pool, driving expensive cars and visiting luxurious hotels, the Dutchman had debts of nearly €1m, according to court documents.
He may be insolvent, which worries the plaintiffs who had claimed more than €3m overall in damages.
In late 2013, the Dutchman fled to Canada before being extradited to the Netherlands and then deported to France.
Psychiatric experts said Van Nierop shows a narcissistic pervert personality with an absence of all moral sense and that he does not feel any compassion.
During the trial, the lawyer for one patient told the dentist his client was just waiting for apologies.
Van Nierop replied: "I have no feelings anymore. So, if I was offering my apologies today, I would be lying."