Wisdom tooth extraction.
Wisdom teeth, commonly called “third molars,” grow at the back of your gums and are the last teeth to come through. They’re called wisdom teeth because they come through at a mature age during the late teens or early twenties.
Sometimes the eruption of wisdom teeth can become a problem if they cause crowding in your mouth, erupt in the wrong position, or become impacted. Wisdom teeth that aren’t in the right position can trap food, which can lead to tooth decay, gum disease, pericoronitis, abscess and even cysts.
In this case, the horizontally impacted lower left wisdom caused decay on itself and the tooth in front of it. The decay on the wisdom tooth caused a lot of pain because it's deep enough to involve the nerve.
Surgical wisdom tooth extraction was performed. The tooth had to be de-crowned and sectioned because it was impacted and had wide and curved roots, which created much more resistance to removal.
The tooth in front of it needed to be fixed as soon as possible because of the root caries. It's very close to the nerve. The prognosis of the teeth was questionable because the decay had extended down to the back root.