Five-year-old Kaisley Blake had big plans for her first-ever loose tooth -- and they involved a pillow, not a swallow, according to her dad.

Things didn't go as planned for the Oklahoma kindergartner on her first day of school at Henryetta Elementary.

After having wiggled the tooth all morning on August 10, Kaisley accidentally gulped it down, along with a bite of her burger at lunch, Worren Blake told CNN on Thursday.

"While she was chewing on it, she thought that the hamburger had seeds," said Blake, a father of four girls.

She reached for her wiggly tooth and realized it was gone.

"She was pretty upset about it," Blake said.

Principal Roger Williams helped save the day. Williams learned what happened as an aide walked Kaisley to him while he monitored the cafeteria that afternoon.

"Kaisley opened her mouth and showed me her little bottom tooth was missing," Williams told CNN on Friday. "I said, 'You know, I think we could probably do something about that.'"

He went to his office and typed the Tooth Fairy a note that Kaisley could place under her pillow that night in lieu of the lost tooth.

"My goal was to make sure the little girl still had the magic of the Tooth Fairy coming to see her," Williams said.

His note mentioned that he's a "hobby dentist" -- but Williams clarified that his actual dental experience only stems from his years as an educator and being a father to two children.

Kaisley's dad says she was still crying when she got home.

"She said she didn't know if the Tooth Fairy was going to come and visit her," Blake said.

He opened her backpack to find the principal's note, which read in part, "please accept this letter as official verification of a lost tooth and provide the standard monetary exchange rate you normally use for a real tooth."

"I was like, wow, that just saved me a whole lot of trying to come up with something," Blake said. "He was able to really keep that magic alive."

The relieved dad, who said the thoughtful letter touched him, later shared it via Facebook with a "shout out" to Williams.

"Not all people will take time out and actually care about the little things that are these kids' whole world. I have a lot of respect for you. Thank you sir," Blake wrote.

The principal's letter earned Kaisley $5 from the Tooth Fairy, according to Blake.