Top 10 Longest Teeth

I know it's old, but Spinosaurus' teeth, wich are greatly underestimated in this list, are longer than T.rex's, wich are overestimated in this list. Spinosaurus' teeth are the longest among Theropods. We know an incomplete Spinosaurus tooth wich is already 23 cm long, a complete one would likely exceed 30 cm, exceeding 'Sue''s longest tooth (30.5 cm).

One thing that isn't specified on the list and is being mixed up is the size difference between rooted and unrooted teeth.  In dinosaur teeth the root can be up to 2/3 of the length of the tooth.  Some of the measurements being used are quoting maximum size ranges for unrooted teeth while others are using size measurements for rooted teeth, so the comparisons aren't valid.  Typically when people talk about sizes of dinosaur teeth they use the unrooted length, since very few teeth are found with their full roots (they are much more delicate than the crowns of the tooth)

For example with Allosaurus on the list the unrooted tooth size is being used.  The maximum size of an unrooted Allosaurus tooth is just over 3 inches long (2+ inches is pretty large for an Allosaurus).  If you include the root, you're talking about a 6-7 inch tooth.

Where with T-Rex and many of the other dinosaurs on the list the size of of the rooted teeth is being used.  The largest T-Rex tooth (not including the root) is just over 6 inches.  With the root it's  around 13-14 inches.

Torvosaurus definetely would be on the list.  This is a fully rooted tooth of the newly announced "Elvis" specimen.  The tooth is about 12 inches long and to my knowledge is the largest tooth ever found from a Jurassic aged dinosaur.