We have one pony that developed it and had all the 12 front teeth removed. He still eats hay well (bermuda - which is softer here than our timothy which can be rather stalky) and a simple bucket feed as he has molars for chewing, treats no problem (he is not metabolic). He can even graze a bit on grass but we only allow him a little pick as he can tear his gums repeatedly trying to pull grass - if we let him have longer he would keep going. I was told some horses learn to use their lips to pull the grass up. The dental specialist vet who did it for us (our usual vet brought him in as a consultant) was confident (from Thailand but trained in Australia) and had it done under standing sedation in less than 1 hr 30 min. He explained to me that it was painful (our vet showed us that the pony flinched when the gums/teeth were touched) and that the pony would be much more comfortable after the affected teeth were removed (he checked by xrays to decide which ones needed removal) and that not removing, it would continue to advance. The risk factor he told us was more in older horses (our pony was about 19 when diagnosed) and he also thought that it seems more "common" these days because it is better diagnosed. The main thing for aftercare was to flush it a few times daily with some antiseptic/antibacterial wash and also water to get food out from being stuck and our usual vet followed up to recheck.
In contrast the dental specialist vet at the hospital attached to the racetrack told us it would take (I think - it was a few years back) at least 2 hours under general anaesthetic and he could only remove 2 teeth first and we would have to repeat again later. The risk of GA was concerning as our pony was not young so I'm glad we had the other option that went very well. He also said he had never dealt with EOTRH before (I suppose they don't get that old at the racetrack).
Cindy and Glow - Sep 2017, Singapore
ECIR Primary Response
Case History: https://ecir.groups.io/g/CaseHistory/files/Cindy%20and%20Glow