At the time of filming "The Case of The US Space Camp Mission", nine-year-old Mary-Kate and Ashley had both lost their front teeth. In order for the gaps not to show in the video, both girls had custom-made fake teeth, known as "flippers", done. They were used to having to wear flippers from their time on "Full House"; when the girls each lost different teeth, flippers were used to make the girls look more identical since they shared the part of "Michelle". However, when leaving for Alabama to shoot "The US Space Camp Mission", both Mary-Kate and Ashley ended up forgetting their flippers back at home, so they were forced to run around Huntsville, Alabama, in search of a dentist who could make them new, emergency flippers before they could begin filming.