No glitchs as of now.
A method many people use is play point of contact with a relic
If you beat you get 2 teeth, or 3 if you complete all challenges along beating it.

Add me on xbox and help me with it il be on tomorrow gt is :
(Flux iDylann x)

PerfectExample wrote Add me on xbox and help me with it il be on tomorrow gt is :
(Flux iDylann x)

I'm on Xbox one, I see your on 360. Sorry man can't help you out

If you get a decent team just run 1 relic on point of contact with 3 players and look for newcomers that haven't escaped and help them escape, here is the list of ways to get teeth:

Completing a map (+1)

Completing a map with a Relic (+1, whether you have one or all five active)

Completing with a player that has never completed a map before (+1)

Completing a map in Hardcore Mode (+1)

Take out 600 Cryptids (+1)

Obtaining Ranks 2, 6, 11, and 21 (+1 for each, only counted the first time that Rank is achieved)

Reaching a new Extinction prestige level (+1, plus another for each prestige level you have obtained prior to this update)

There is also a Bonus Pool that offers up to 3 Teeth every week. Each time you destroy a Barrier Hive in any episode by the chopper near the lodge in Point of Contact, the Breeder in Nightfall, the tentacle in Mayday you will be awarded one of these bonus Teeth. This a great way to easily build up your supply over time. A counter next to the Bonus Pool displays how many days are left before it resets for the following week.