[kronckew]

Mine below:

I gather they were kind of a chef's utility knife for cutting food stuff in general, and are fairly small (mine is 9 in. overall). Not really a weapon. They did occasionally eat 'long pig', usually an enemy defeated in battle to absorb his 'mana', so it is possible for those with real sharks teeth to be used in preparing meat (or fish), they generally used the 6 or 7 gilled shark's teeth. (photo of a single tooth below - the teeth are about an inch long)

Nowadays most are made toothless for 'those who travel'... your pics above have stylised 'teeth' carved in, or what appear to be carved plastic strips cut to look like a series of non-pointy teeth.

Anyway, Shark teeth weapons were more a Hawaiian thing...

The teeth are held in the 'edge' by tree resin and sometimes also with linen string wrapping. Note the lanyard holes in the older ones were carved , chiselled in rather than drilled neatly - a practice that started after trade with the UK and introduction of twist hand drills.

the hand weapons, Mere, Patu, Wahaika, Kotiate, etc. with twist drilled holes were being produced for tourists in the 18c, usually the fancy carved ones as they soon replaced their wood, whale bone and stone weapons with steel blades and firearms, tho they retained them for religious and ceremonial use (like in the Haka) and along with the staff weapons like the Taiaha are still popular for martial arts (and gang use).