Tooth space maintainers for 7 year old?

Sometimes: They are used mainly to maintain the space of a tooth that is missing or has not erupted yet, it is done because teeth tend to move into the empty space making it problematic when the permanent tooth erupts.

If needed yes: Space maintainers are for purpose of keeping the distance between two teeth that have a missing baby teeth in between them because it will stop teeth from migrating and taking up the space where the adult tooth is supposed to erupt. That is the basic concept need to see an x ray to give proper diagnosis. Hope this helps you.

Definitely: If baby tooth lost prematurely, space maintainer is absolutely required. Also, have your 1st orthodontic check-up (usually complimentary) now, especially if there is a disturbance in normal exchange of baby/permanent teeth. Better to hear, "you're a little early" than, "oops, you should have been here months ago." ask your dentist to recommend an orthodontist.