Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concerns..
As per your complain at the age of 5 years all the baby teeth are present and is not an abnormality and the first permanent tooth starts to erupt at around 6 years of age which is a permanent molar while the top front permanent tooth erupt approximately at the age of 7 years but in your sons's case it seems to have early eruption..
It is true that in case if the milk teeth does not fall and
permanent teeth starts erupting above them then it is true that there is misalignment, malposition and rotation of teeth.
You should consult a Paediatric
dentist [Pedodontist] and get evaluated and get a full mouth
x ray known as
ORTHOPANTOMOGRAM [OPG] done so that the Pedodontist can rule that whether the baby teeth will fall of naturally as the roots of baby teeth have started getting resorbed or not and will guide you better that whether you should get the baby teeth extracted or let the fall and eruption goes on naturally..
Hope this information helps..
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Thanks and regards..
Dr.Honey Nandwani Arora..