How does extinction fit in the 12 links? I'm thinking that the presence itself, in sense objects, of ignorance, the first link, is never erased; that with final nirvana something has being, the absence of the 12 links. Can the absence of causation itself be present like sense objects are, in absolutely any Buddhist philosophy? 

Or is that silly, like saying that the there exists the non existence of a crow's teeth?
In Buddhism, there are many kinds of causation. See this link about the five 'niyama' or 'laws of causation' (physical, biological, mental, moral &amp; dhamma/spiritual). 

The twelve links are the conditions leading to suffering; the cessation of which leads to Nirvana. They are 'dhamma niyama' or 'spiritual causation'. The twelve links are not mental causation (citta niyama).

Therefore, sense objects can be experienced without ignorance because mere sense objects (which are mental causation) are not suffering in themselves. 

The only absence of causation is Nirvana, when the twelve links stop creating suffering. 

As for the other four kinds of causation, they keep rolling on (unless human life becomes extinct, which would make extinct moral causation &amp; leave three laws of causation).