Children have widely spaced teeth only up to a certain age. Before children are 3 they usually have about 20 milk teeth and they are not widely spaced. Closely set teeth are more subject to caries as the saliva with its bactericidal action cannot wash teeth. Eventually dental deposit appears. It must be removed with the help of a toothbrush. As soon as the first tooth of your child appears let your child try to follow the rules of the mouth cavity hygiene. First of all use the so-called zero brushes (a fingerstall with bristles imitate a real toothbrush or a children's toothbrush with a big handle for parents). After your child is 2 he should learn to use a toothbrush independently as he can stand well and can repeat the movements of his parents.
Requirements to the toothbrush:
small size of the head
Artificial bristles
a toothbrush must be soft (you can boil the toothbrush to make the bristles milder)