In a preadolescent child, the maximum midline diastema that will be closed spontaneously after canine eruption:: (A) 1 mm, (B) 2 mm, (C) 4 mm, (D) 5 mm
Answer is B. The maximum midline diastema that will be closed spontaneously after canine eruption is not more than 2 mm. 
This is an example of transient malocclusion.