A Montgomery County man is accused of forcibly extracting teeth from a 4-year-old autistic boy, prosecutors said.Nicholas Kernechel, 27, faces aggravated assault and related charges in what prosecutors have called a horrific case of child abuse.Kernechel was babysitting the boy, who is the son of his girlfriend, when the abuse occurred. He sent him to bed, crying and bleeding, prosecutors said.RELATED: Teen pinned under forklift dies in joyriding accident.The victim's's mother discovered the boy — identified only as JN by prosecutors — sleeping on the floor in a pool of dried blood when she went into his room in the morning..She brought the boy to the Upper Perkiomen Police Department, along with a bag containing three of the teeth."The teeth were bloody but intact, from the tooth through the top of the root," authorities said in a statement.