My right cheek has caved in. What is causing the atrophy? (Photo)

I treat a lot of patients with this condition, i am sorry this has happened. I suggest you see an expert to evaluate you for Parry-Romberg Syndrome and treat you appropriately.  Best, Dr. Emer.

This may have other causes but from a dermatologist's perspective it looks similar to an uncommon condition called Parry Romberg syndrome.  In this condition, there is progressive atrophy of the face, typically on one side.  Although an autoimmune etiology is suggested, it is not truly understood why this happens.  Please consult with a dermatologist and they can help you figure out what the diagnosis is.  Good luck.Best, Payman Kosari, MD, FAAD    

You may have idiopathic muscle atrophy of the masseter, temporals and other facial muscles on the right side. You should have an MRI, CT Scan and neurological consultation to evaluate the trigeminal nerve, skull base and central nervous system to identify any treatable causes. Nerve damage from tumors or demyelinating disease process should be considered. In the absence of trauma or infection, a complete workup and evaluation is indicated and perhaps an etiology can be identified. Best wishes.