If a child gets his/her tooth during 2 or 3 or 4 or 5th month then father needs to perform shanthi for self. If the child gets tooth in the 6th month then shanthi has to be done for the child for this dosha.; . If a child is born with a tooth, it is not considered auspicious for the family. Shanthi parihara has to be done for the whole family Purva Parasharyam mentions the Shanthi Pariharam as Abhishekam to Lord Shiva,  anna daanam to Brahmins,  gift of gold tooth to Brahmins.