My tooth situation was incredibly complicated too. I'm 22 and still seeing my orthodontist every 6 months or so to make sure everything is settling properly. I started in a palate expander (I understand that sort of thing is commonly called "Tier 1" now or somesuch.) at 7.
15 years and counting. Orthodontist work can be a major undertaking if your kid's mouth is really messed up, so by all means you should give as much careful consideration to picking the best orthodontist you can find as you would to finding a general practitioner or any other long-term doctor.
Shop around. Talk about their policies, get estimates on cost and what phases they expect to go through (For me, oral surgery to remove fused baby teeth, palate expander, braces, chains on the braces at a later point to move ingrown teeth into proper position, retainers, etc.)
See what their policies are. My ortho for braces proper gave a 2.5 year estimate and that's what my parents paid for on his plan. Turns out it took 3 years, but after my parents had paid for that 2.5 years, he didn't charge them anything because it was his estimate that he personally made that was off, and I was doing everything perfectly on my end so why should they pay. A year later my teeth moved and I had to get another set on the top. No charge because he didn't get it right the first time. A few years later we still couldn't get a front tooth to stay straight so I have a permanent gold wire in the back now. No charge.
I'm sure my ortho's policies are the exception rather than the rule, but my cousin had an ortho who did the braces, and then despite religious retainer wearing the same way I did, the teeth moved back. His mom had to pay for a whole new set. So you need to know that since this is a process that can take years, what the policies are if/when something doesn't go according to plan.
Anyway sorry for rambling but that is the advice I have to give. Too many people think it's a quick 2 or 3 year thing and it's done when that's far from the truth. So my short answer: YES! Get a second, third, whatever opinion. I would ask your normal family dentist who put braces on his kids, if that's applicable. That's how we found my guy and he's easily the best one in the county, if not the state IMHO.
