Hi, Thank you for question. Main possibility is of TMJ disorder that can arise due to excessive teeth grinding habits, dental problems, misalignment of the teeth and trauma to the jaws and patient may experience headache, facial pain, ear pain, dizziness and nausea. However, in TMJ disorder, MRI is a useful investigation tool to diagnose the condition and your normal MRI report suggests it is a less likely cause in your case. I would recommend you to see a neurologist who can evaluate the details of your case and could better determine the insight of your situation. Additionally, possibilities of trigeminal neuralgia could also be evaluated. Hope this helps. Take Care & Regards.
I hope you have an excellant spinal surgeon. If he/she is doing a graft from your thigh that is outdated and can also cause more complications. You need to really discuss this with your surgeon. How often has he seen long term swallowing issues after surgery and is it a greater possiblility due to your jaw problems?