Setting his jaw

Miss Edie is great and works so hard with both boys, but sometimes...last week she noted that it is really hard to get Allan to make any noise when he is really concentrating on a task because he clenches his jaw so tightly. I hate to break it to her, but that ain't nothing but a family trait. Uncle Eddie, Tim and Momma all have a tendency to set their jaws when they are working on something. Or mad. I don't think that speech therapy is going to help that. Maybe valium.