This would be a total coincidence in my opinion. It does not make sense either medically or biologically.
During my years in practice I have had a few patients present with osteomas. They are harmless lesions and in fact many pathologists do not regard them as true neoplasms but as a reactionary process (the body is reacting to something and laying down bone). They nearly always occur on the skull like yours. You might shake your family tree to see whether any intestinal polyps, epidermoid cysts (sometimes erroneously called sebaceous cysts) or fibromas pop out. If so you might have Gardners Syndrome of which osteomas are a key part.
I referred them to a plastic surgeon and the problem was corrected with surgery. Sometimes the plastic surgeon justs buffs the osteoma down. ( You might ask the plastic surgeons on this worthy site how exactly they treat this problem. An Erbium Yag laser approach can also be taken.