1. why was the discovery of helle craft's tooth so important in convicting her husband of
murder?

It allows her remains to be identified through her dental records, thus allowing a murder investigation to be conducted.

Explanation:

Helle Craft was a Danish woman murdered by her husband in the 1980s. She was investigating her husband for his affairs and found several shreds of evidence when she was reported missing several months afterward.

Her body, however, wasn't found, and it was discovered to be so due to her husband, Richard Craft's cunningness since he used a wood-chipper to destroy her body. Only pieces of her were found: hair, bloodstains, fingernails, teeth crown, and human tissues.

At the time, for a murder investigation to be conducted, a body must be found. Since in this case, the remains were completely indistinguishable, it was fortunate that one of her tooth crowns were found, since it allowed the investigators to identify the body to Helle Craft, according to her existing dental records. By doing so, it is proven that the remains were Helle Craft's, and thus a homicide investigation can be opened.

i honestly speaking this is too long