<prompt> At birth, mental foramen opens:Below sockets of deciduous caninesIn front of socket of deciduous canineBelow sockets of deciduous molarsBehind sockets of deciduous molars  <response>: Key concept:At birth the mental foramen, opens below the sockets for the two deciduous molar teeth near the lower border.This is so because the bone is made up only of the alveolar part with teeth sockets. The mandibular canal runs near the lower border. The foramen and canal gradually shift upwards. 