Worn chain = Missing tooth on sprocket?

dogsballs the chain was cleaned very regularly, though i probably should've changed it a week or 2 earlier. don't think coming down muswell hill the other day did it any favours :O

went up muswell hill for the first time last week. that hill deserves a bit of respect - really drags on.

never had problem with losing teeth off the sprocket. just the chainrings.