Avril and Mario
Hal inherited the dental problems from Himself; Himself had horrible dental problems; half his teeth were bridges.
Context
Teeth as inheritance, stated flat. Hal's chronic dental trouble came straight from Himself, whose own mouth was half bridgework — one more thing handed down the male line alongside the talent, the drink, and the spider-dread. The book makes teeth a running motif of what passes father-to-son (cf. the plan's Teeth catalog), and here it's at its most literal and bodily: the son's mouth carrying the father's ruin.