Any info on what causes frontal bossing?

Yes. It may be congenital, or acquired secondary to excess gh or blood vessels in the calvarium bones. Other potential causes of frontal bossing include use of the anti-seizure drug trimethadione during, pregnancy, basal cell nevus syndrome, congenital syphilis, cleidocranial dysostosis, russelsilver, syndrome, rubinstein- taybi syndrome pfeiffer syndrome hurler syndrome.