My bearded dragon was at the vet a few months ago and she said he had a bit of an underbite she she gave me calcium gluconate to supplement alongside the calcium powder I dust his food with. I also alternate with a reptivit powder. I have always used a t-18 bulb for uvb and it hangs inside his tank, I just recently replaced with a new one too. I give 3.5ml of calcium gluconate once a day for about 2 1/2 months so far-but I noticed a hump on his back I’ve never seen before. Am I crazy or is this normal?
From what I can see, it doesn’t quite look like MBD, but I would take him to the vet just to be sure. Maybe, if you are comfortable, post a few more pictures of him from different angles. That would make it easier to tell.
I see a bit of an underbite, but it doesn't look too bad. A calcium rich diet including things like collards and turnip greens etc along with calcium rich feeder bugs like black solider fly larvae should provide adequate calcium. Especially since you're providing calcium supplement as well. The MBD may have been stopped early on. It doesn't get reversed, but progress can be halted and they can live a good life.
As far as lighting goes, how far above the main basking area is your T8? Those are best at relatively short range. If you have a large enclosure, a T5 might be a better fit in the long run. Providing high levels of UVB will help him utilize the calcium you are providing in his diet.