So out of those 24 photos, only the Helmet Oswald grinning has all his teeth visible.
And only 3 out of 24, have Oswald grinning, one of which (fat nose in 2nd row down )has his teeth darkened out completely, and the other, (teenager Oswald )missing a tooth.
Could that USMC photo be Oswald with his false tooth in place, so as to look his best for that brief time where he might have considered it an important photo?