typically
They will give an estimate based upon what they can see by looking around and crawling underneath the vehicle. Do not be surprised if this isn't a car guy or a mechanic and he doesn't delve in deep and look for every single piece of damage below the surface that isn't blatantly obvious. Alot of times they will just write down obvious damage and starts with an estimate for that. Just ask what the process is if any further problem is found at the body shop.
The few times I've had serious damage, the body shop put in for what is typically referred to as a supplemental estimate. They will get the original estimate and start pulling the car apart and then contact the adjuster for more cash to repair newly discovered damage. Last estimate I went to Geico for when I got rear ended at speed, some girl crawled underneath and walked around and listed everything she could see and tell was obviously broken. It was easy stuff: Replace and repaint bumper, straighten frame. Then she just told me the bodyshop would sort it out and get the extra money for anything else she hadn't found. That's exactly how it ended up working, they showed her how the exhaust got damaged, pushed into the shocks, etc..., how the bumper would need a flex additive in the paint not listed in the original estimate, and Geico simply cut another check. So if they don't get everything you think is wrong they may not be short-changing you, just make sure there is a means to adjust the estimate once the bodyshop takes the car apart and finds everything.