I had square jaw botox and dieting at the same time because my lower ear is convex, but it didn't work..
I got salivary gland botox and it shrank to a level that I could notice.
I highly, highly recommend salivary gland botox! I could definitely feel the thick muscle layer that was tangible when I touched it under my ear was disappearing!
Of course, if you want a definite effect, you should also get a procedure to remove the fat layer! I did it at the same time!