hello and welcome to HCM forum,
i am glad you wrote in, according to the dental history provided here, i would like to inform you that during teething
a child tends to get slight fever
and in some cases diarrhea
, but teething cannot be linked to a long term illness.
Prolonged antibiotic course has side effects like stomach upset
is one of them, do not overdose your child with antibiotics until prescribed by your doctor.
as your child is 1 year and 9 months old, his deciduous or milk teeth(canines /molars) might be erupting, premolars are not present in children.
but do not worry just make your son eat healthy food, drink lots of water and he will be fine.
i hope i answered your query,
i wish you and your son good health,