Animal tooth pendants
Beyond a few very isolated examples, there is no acceptable evidence for the use of tusks and animal teeth as decoration for either pagan or Christian Vikings. Unless specifically mentioned, the following pendants are only suitable for pagan, female Saxons, ie in the Early period (5th-7th centuries).
Boar Tusks
Pairs of boar-tusks, sometimes with bronze mounts, are found in 1st-4th century Roman military cemeteries and seem to have been characteristic of Germanic auxiliaries.
Single boar-tusk pendants are found in 5th-7th century Saxon cemeteries in England; they are plain and unworked, with a simple suspension hole drilled through the tooth, or at most a simple bronze mount. They are also invariably found in graves of women or children.
There is no evidence for boar tusk pendants from Migration- or viking-age Scandinavia. The oft-quoted example from a 9th century warrior-burial at Repton is definitely not a pendant; the (single) boar tusk was broken, fire-damaged, has no suspension hole and was found between the warrior’s legs.
Beaver teeth
Beaver inscisors are also only associated with pagan female Saxons. As with boar tusks, these can be simply perforated or have a bronze mount. The very richest examples are found with gold mounts (the only animal teeth from the period to be found clad in a precious metal).
Wolf/dog/fox teeth
These are usually very simple (i.e. just perforated, no metal mount) and often found associated with children.
Horse
There is little to no evidence that horse teeth were ever worn, though there a single perforated incisor from Jorvik that may have been a pendant.
Bear
Bear tooth pendants are very rare in the Viking world and there is only a single example from Britain. The British find was found in a house and has no associated burial, but a find from Birka was in the grave of a young girl.
Credits: with thanks to Dave Constantine.