98 Elantra broken timing belt

The belt broke on this 1.8L engine at 140,000 km. (The second owner had
thought the first had already changed it -but not so.)
What kind of damage should you look for when the head is off?
Obviously bent valves, but what about things like damaged piston heads etc.
Any pointer?
Thanks,
BCinBC

Do your best to determine there's damage prior to pulling the head.
Although it's very likely, you don't want to pull the head if not
necessary. At the very least, you can install the timing belt and slap
the crank pulley on to hold it in place and then see if the engine starts
and runs normally.

If the valves are bent, have a look at the pistons and upper cylinder
walls to be sure there's no significant damage. Bent valves rarely
significantly damage the pistons. On the other hand, if one of the valves
broke, you'll see a pretty good sized mess when you pull the head.