Mandibular advancement device (MAD) for Joshua

This is my son Joshua.  He was born with Chromosome 22q11.2 micro-deletion syndrome or Di'George syndrome.  Because of this, he was born with a heart defect that was repaired by open heart surgery.  During the repair his aortic valve was replaced by a prosthetic valve.  He was 3 yrs old then.
Further, he was born with a solitary left kidney and suffers from severe sleep apnea.  His kidney is now below 40% functionality while his valve is leaking and regurgitating. 
He was admitted to Toronto General Hospital last 25 September 2019.  All his organs are being tested to determine viability for surgery to replace the valve.  To help the heart and the kidney, the sleep clinic orthodontist recommended a Mandibular advancement device (MAD).
We have looked everywhere for funding of this device but were unsuccessful.  We are raising funds to cover for this device which he needs as soon as possible.
Thank you so much for your generosity.