Losing teeth

When should pups start losing their teeth? I've just noticed Rubio has lost one this morning (probably due to crunching his way through a bone).

Is there anything I can do to help the discomfort and should I be avoiding bones at this time?

sorry for hijack
my pup on the first day i got her picked up one of my older dogs nuts and her front canine tooth broke, well that's when i noticed she had a broken tooth and suspect it was the nut.

I then read online that pups lose the milk teeth around 6months and get their 'real' teeth. Anyways i have always had dogs/pups and realised i have never noticed them losing teeth before,maybe i was too young to realise. but where do the milk teeth go? do they swallow them or just randomly lose them in the grass etc

Darcy's started to come out about 4/5 months I managed to fine 2 or 3 that I've kept but no idea about all the others, possibly lost outside during play or eaten lol!

Bane teethed around 3-4 months and they all vanished! I think they swallow most of them as they eat and think Bane choked a bit on one of his bigger back teeth.
Frozen things are good, we were advised to freeze a wet tea towel so it's not too hard for them to chew and nice and cold to soothe any discomfort Frozen Kongs are good too.

Same as Hayley above. I froze yoghurt in his Kong, froze a Kong water ring & gave him ice cubes.

You can find them or they swallow them or they just get lost. I wouldn't use a bone - as mentioned frozen tea towel - frozen carrots are perfect when they are loosing there teeth - you don't want to damage the new ones coming through