My baby is teething and 5 teeth are coming out all at the same time. is this normal? how often should we brush his teeth and what are safe toothpastes that we can use for him? he is 16 months old with allergies to milk protein and eggs. thank you?

Tooth eruption patterns vary widely & this should not be considered worrisome. Some favor fluoride free paste in early childhood but I like a soft bristle brush loaded with a kernel of rice sized amount of regular fluoridated paste for 2x/d use.

PLEASE take your child for 1st dental examination. See Dentist or preferably a children's dental specialist (a Pedodontist) for all the same reasons he sees a children's medical specialist (Pediatrician). All children should be seeing a Dentist bother 1st b'day. That way personalized oral hygiene program, fluoride balance, familiarity w surroundings, diet, sealants, etc., can all be addressed.