Yes, i would recommend you to visit a dentist and get OPG Xray done. Before starting any treatment its better to get the exact diagnosis. To stop bleeding you can put tea bags into the mouth and ask your son to chew on it. Tannic acid present will cause vein and arteries to constrict thereby causing ceasation in bleeding. Also place  a gauze pack and bite on it. Apply an  Ice pack over the swelled area....but do visit a dentist for Xray ...for more info you can visit the link...http://www.identalhub.com/articlecategory-dental-pain-42.aspx