My teenager has juvenile rheumatoid arthritis. She has 2 variants. Both linked. One called Enthesitis Related Arthritis and the other Psoriatic. She has damage to all her joints. But in particular both jaw joints. Known as TMJs.
When she was 12 we were told that she required a jaw replacement, widening and lengthening. Roll on 16 and he tells her... 30... She has a 22mm opening, can only eat soft food. Looks different. Facially. As it stopped growing when she was 10. And now he tells me. There is no point replacing it. It won't stop her jaw hurting. And he might sever a nerve in her face and there is no take backs in this op.
Basically. You are nearly 18 and you just need to live ole this. There is nothing we can do now to help. No more steroid injections and the arthrocentesis (joint washout and lubricant replacement) no longer works for you.
I am utterly devastated. And I can't stop crying. It took me all my strength not to break his fucking nose and tell him to live with that. 
Am I being unreasonable. To him I am a pushy mum. To me... He's a dick