The bite mark was important to the Bundy case because it was the only evidence found as Bundy was known for cleaning up his crime scenes. Investigators would have more to work with today as technology for evidence gathering has improved (stuff like DNA and fingerprints).
It would help out figure out who he was since it had his dna. He was known for cleaning up after himself not leaving a trace of who he was. This helped investors track him and figure out who and where he was.
