If I were you, I’d move forward with investigation and any surgery very cautiously. I can see that @Isaiah_40_31 is excitedly suggesting to get the growths removed, but there are a few observations from my side:
a) in general, the 3D model shows a few additional things than elongated styloids/calcified SH ligaments. I highlighted them. Also the neck is quite unevenly looking, some spots might be just due to the position while lying in the scanner, but others could be something due to arthropathies/AS or other possible causes.
2, 6 - right side arcuate foramen
1, 5 - while many facet joints look uneven on the left side vs the right side, the left side facet joint I marked with 1 (and 5 in the other view) seems to look really odd to my eyes. Could be just position while lying in the scanned, could be some muscular tension pulling it sideways, or something else.
3 - I highlighted the part of SH apparatus which in my opinion shows just where the styloid process ends and the calcified ligament begins. While in reality they can be hard to tell apart as they eventually may become “one”, I believe this is quite a visually nice case where it might be possible to say, the styloid process looks quite normal length but the ligament starts becoming calcified/ossified.
4 - something that I have no good idea what this might be. Some calcification/growth is seen only on one side, opposite from the arcuate foramen, and it’s hard to tell what it is from just the 3D view. But it’s not supposed to be there in “typical” anatomy. I would guess it could be some congenital “bump”, a calcified lymph node, a growth (benign calcified tumour?), something like calcified tendon of one suboccipital muscles (ever had a trauma on the side of the head, or whiplash from one side?) or calcified segment of a blood vessel.
b) AS is a sneaky condition. I don’t know if it’s safe to have surgery in that area with active AS which is not for AS-related reasons, but that’s better to discuss with the experienced surgeon who had seen similar cases. I would be cautious about how the increased inflammation after any surgery may impact the spine in that area.
c) Given AS, there is a chance, that the body put the calcifications in place as the neck in that area was “too weak” to deal with all the affected joints, and surgery might destroy that additional reinforcement. Some people with mild instabilities in C0/C1/C2 area reported that the styloidectomy surgery worsened their instability. So that’s something to considered as well, and discuss with the surgeon before committing.
d) There is always a good chance the jaw pain and other issues aren’t caused by the styloids or calcified ligaments and they might have been just an accidental finding, but by ongoing inflammatory condition as you mentioned. Nerves can be very sensitive to inflammation in general without being directly irritated by bony structures.
P.S. Just found something not exactly related (the article talks about intervertebral ligaments) , but worth skimming through re AS and calcifications
https://pubs.rsna.org/doi/10.1148/38.2.160
