Head Banging mad man

Hey guys just wondering if anyone can help me with my head banger??? He's 18 months old and lately he's gone so bad for throwing his head LITERALLY if he's not head butting me or biting, he's bouncing it off anything he can. It's starting to look like he's growing horns over the bumps on his forehead!!!! He's teething the last few of his molars too, not sure would that be the reason for it? Or is it that he's got a bee in his bonnit for some other reason????? If we're in a shop and he wants something and I say no. he goes to a tantrum and the bam, you're counting ur teeth!!! Is this normal for every child