Complex sentence: While at the school he also underwent the Zanaki tooth filing ritual to have his upper-front teeth sharpened into triangular points, and it may have been at this point that he took up smoking, a habit he retained for several decades.
Split into simpler sentences: While at the school he also underwent the Zanaki tooth filing ritual to have his upper-front teeth sharpened into triangular points. It may have been at this point that he took up smoking, a habit he retained for several decades.