A mother took her young son to the dentist because he had a loose tooth that needed to be pulled.

The boy was nervous from the moment they walked in. He sat in the waiting room gripping his mother’s hand, staring at the door every time someone came out.

Finally, the dentist called him in.

The procedure itself was quick, but the boy screamed so loudly that people in the waiting room jumped in their seats. A few patients looked at each other, grabbed their coats, and hurried out before their own appointments.

A few minutes later, the boy came out perfectly fine, holding a tissue and looking proud of himself.

The mother went to the front desk to pay.

The dentist looked at her and said, “I’m sorry, madam, but that will be one hundred dollars.”

The mother frowned. “One hundred dollars? You told me pulling the tooth would only cost twenty!”

The dentist nodded calmly.

“Yes,” he said. “But your son yelled so loudly that he scared four other patients out of the office.”