Meyerpires do not have fangs. This was mentioned by Bella during a conversation with Jacob (Eclipse, page unknown). Also, Bella had a crescent-shaped scar after being bitten by James, thus Meyerpires have normal human-like teeth. In that case, how do they suck blood? Animals who feed on blood don't have teeth similar to us for a reason. That is because sucking blood with teeth such as ours is impossible. This is another proof that Meyer did not do any research and didn't use her common sense. Meyerpires are a disgrace to the vampire lore. Or maybe they're just advanced zombies.