Well it depends on what’s causing your pain: it could be bone structure related (an X-ray will show any issues/deformity with your temporomandibular joint), or it may be muscle related.
If you do have a physical issue with your TMJ, surgery could be an option but my consultant said that surgery is an absolute last resort in recent years as it’s efficacy is debatable now.
My pain was caused by the muscle, my muscles weren’t super enlarged though. I grind/clench my teeth, wake up with jaw pain, jaw locking/clicking, struggled eating chewy/hard food and even had ear pain too. Flares up during stressful times. I’ve had this for the past 4 years so Botox was a last resort. The mouthguard didn’t stop the pain or stop me from clenching/grinding during my sleep - it did stop further wear to my teeth though and probably stopped my teeth from grinding as viciously as it acts as a barrier. Your maxillary consultant will have wanted you to try a mouthguard before they try anything else so it’s not a waste of time.
I had 3 injections of Botox (dysport) in my masseter muscles, per side. Essentially Botox just paralyses the muscle (temporarily) so it’s not over-working anymore and becoming inflamed and fatigued. Will also help with teeth grinding and clenching as you should hopefully stop doing this subconsciously during sleep as the muscle won’t move as much. I’m probably explaining this awfully, sorry. Essentially the more you use a muscle, the larger it gets and with the masseter this excessive use can cause pain, jaw locking, teeth grinding etc so Botox acts as a muscle relaxant. It only lasts 4-6 months and you might not need more injections after the first set. My hope is that a combination of Botox and my mouthguard will permanently stop my teeth from grinding, so in the future TMJ will never be a problem for me. No pain since!
Negatives of Botox include facial numbness, changes and asymmetry. Having said that, Botox in the jaw is a cosmetic procedure for facial slimming so you may actually like the changes.
Also sorry for essay but would recommend speaking to your dentist too, they’ll be able to make a mouthguard for you or refer you faster.