Jaw pain/jaw bone decay/sunken cheek

Over the past 2 months I have noticed my left cheek has taken on a sunken in look.  I have a bad cavity on the left side but the dentist said the tooth wasnt yet dead.  I've been to an oral surgeon, dentist, and doctor for x rays. Each of them have said that they see no signs of an infection.  My cheek continues to sink in on that side and I have no explanation as to what is happening. I looked inside my mouth today and noticed on my very back, left, upper tooth there is a red spot right above it.  This seems to be the site of where I am noticing my cheek sinking in.  Is this bone decay? is this an infection that has spread to the jaw bone? I've only had 2d panoramic x rays done. Perhaps a 3d would find this? Thank you so much for your help. I am at a loss on what to do for help and curious as to how I can get a dentist or doctor to acknowledge this and not attribute it to something completely mental. I can feel this in my cheek. I've felt spasms in my jaw. Thanks.

[hollyallexx]

A related discussion, Left cheek sinking in - Told I need 4 wisdom teeth out was started.