I talked to the vet today and he does think its Masticatory Myositis. The cortisone she already got should has another couple of days and we just need to keep a close eye on her. He'll give me a supply of pills, as needed, for her and I should massage her face area regularly. She's back to eating hard food again so I'll know right away if she suddenly doesn't eat one night. You were right about a prior problem. She has dysplasia in her front legs. However, that hasn't bothered her since she was a puppy and was growing too fast. The vet did mention that he was worried a bit about the atrophy elsewhere but that at this point we just need to really watch her. Sigh...the poor thing. She's such a sweetheart. I feel so bad for her.