Releases for aging children

[dougsmit]

Please excuse if this is a regular question but I do not know what to search on to find the discussion:

If a photo is taken of a minor one gets a release from the parent. What is the status of that release after the minor turns legal age? Does one need a new release from the (now adult) subject? If no release was obtained from a minor at the time the photo was taken but it later becomes desirable to have one, who can give that release - the guardian at the time the photo was taken or the (now adult) subject (either or both?)? It would seem this might come up from Senior photographers who wish to use the best of their work for advertising but the subject might have attained majority in the meanwhile.