Yong Kim was watching "Titanic" in 3-D on April 11 with his girlfriend and had asked the people sitting behind him to quiet down. But they responded only by laughing at him, he said.
"I got so mad that it just happened," Kim told police.
According to the police report, Kim said something to the effect of "You know what, I paid a lot of money to see this movie." He also told police that the boys' behavior was worse than talking. He said they were hitting him and his girlfriend with popcorn, running back and forth in the aisle and bumping him with their arms.
Prosecutors say Kim hit the boy in the mouth so hard that he knocked one of the boy's teeth out.
"I went to the movie theater (to) enjoy a movie, not hitting somebody," he said.
Kim told police he thought the boy was an adult. He now faces a second-degree assault charge. If convicted, he could be sentenced to three to nine months in jail.
The Associated Press contributed to this report.