What Causes Dent On Forehead?

my 1 year old son hit his forehead had on sharp edge of the bed.cried but when breastfed stopped crying n back to normal self.i applied ice on the bump.now it appears swollen with a dent on the forehead.am worried.its been 2 days now n the dent is visible and whenever i try to massage the dent theres a squizy sound..am worried whether it may be a fracture or something? help.otherwise baby is acting norml.