What can be a consequence of untreated severe decay in teeth?

When severe decay in teeth goes untreated, one of the primary consequences is tooth extraction. Severe decay often progresses to the point where it compromises the structure and health of the tooth, leading to irreparable damage. This decay can invade the inner pulp of the tooth, causing infection and pain, which can result in the need for extraction if the tooth cannot be saved through restorative procedures such as fillings, crowns, or root canals.

The other options suggest positive outcomes or enhancements that would not occur as a result of untreated severe decay. Enhanced chewing ability and improved dental integrity imply the teeth are functioning well and structurally sound, which is contrary to the scenario of severe decay. Similarly, increased smile brightness suggests aesthetic improvement, which would not happen; rather, untreated decay typically leads to discoloration and additional dental issues. Thus, the correct consequence of untreated severe decay is that it may lead to tooth extraction due to the extent of damage that occurs.