Broken Teeth on a Aluminum Sprocket

Just wondering what might have caused the loss of 3 teeth on my rear sprocket.
Is it normal being a aluminum sprocket? It has done about 24K & the chain is in good condition.

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Dude you just gotta go easy on the gear, may I suggest throttle restriction to start with

This used to happen to our dirt bikes all the time mate. The ones that are left there look pretty worn. She's well and truly shagged

It's a bit hard to see in the pic but that sprocket looks like it should have been replaced a while ago
The reason i say that is the bottom of the teeth look to be fairly long and flat but the chain lube may be
making it look that way in the pic as for the missing teeth if the sprocket was past it's used by date then
missing teeth is not that uncommon. I would make sure that you replace the chain and sprocket together
and lube regularity

Thanks for the response guys, I was just checking that it wasn't abnormal.
Do I really need to replace the chain as well?

Joe you should do chain & sprockets at the same time
No thanks to the jerk that owned my current roadie before me & did not look after the chain, it now has a huge tight spot & creates a harmonic imbalance at speed, I cant get rid of it no matter how much lube or adjusting is done.
I have been told that it can also ruin the output shaft seal so at 24,000K I am replacing the lot.... tomorrow

In short, yes

I know it's the right thing to do oldmate, just didn't want to spend any more money on the bikes this month.
Just went out to MAS & got the lot.

Don't chew the sprocket, and you won't break your teeth?

Oh, and always change the chain and sprockets together. A worn chain will wear sprockets very quickly and vice versa.