Sir, I have the following queries: (1) What is earliest possible age of teething in infants? (2) Does teething cause fever or any other symptoms in infants? (3) My son is 4 months old. He is putting his hands in his mouth a lot. Is that a matter of concern? Do we need to do anything about it? (4) As a Pediatrician, do you recommend the use of 'teethers' available in market for infants? Thanks in advance!