Question:

Which has a better long-term success rate, safety track record, and better aesthetics when considering tooth number 24 recession on a 12-year-old girl, connective tissue graft or soft tissue allograft?

Answer:

It depends on the severity of the problem. We want soft tissue to protect underlying bone and root surface. If the kid has a muscle pull extending from her lip and pulling her gum line down, we know that it will get worse and it is better to take care of it before it gets worse.
 
Remember if she has little gums there, she probably has a thin bone layer underlying if any. Also, if this kid is going to have orthodontic treatment, you should have the soft tissue graft before any orthodontic work. 

But if she already has attached gums protecting underlying bone (despite some recession), if she has no sensitivity when she brushes, eats etc, and she keeps the area clean, if her gums looks healthy with no redness, and no bleeding when brushing, you can keep her in maintenance and ask the dentist to check the area every time she goes to have cleaning.

For more information:

Go to the Gum Diseases health topic.