Several years ago there was a remarkable case of a man whose routine wisdom tooth extraction turned out to be anything but routine. A typical panoramic X-ray showed that the roots of the tooth were close to the critical, main nerve that courses through the lower jaw and innervates the teeth, so extra care would be needed.
After proper loosening, the tooth should have simply popped out with a gentle tug. Astonishingly, it sprung right back into place, as though it were attached to a rubber band. A close, physical examination showed that the root had grown completely around the nerve, like a string through a Life Savers candy. Luckily, the nerve had not been severed, and a quick protocol change allowed the tooth to be removed without damaging the nerve.