My 10 year old son's front (adult) teeth have come in but behind one is another tooth, what could this be?

2 possibilities: Either your child's dental arches are crowded and the lateral incisor has erupted behind the central incisor, or your child has a supernumerary (extra) tooth. At 10 he is 3 years past due for his Initial Orthodontic Examination. Please see a qualified Orthodontic Specialist for an examination (usually free) and a discussion of your son's malocclusion and treatment options.