Is a scalloped tongue serious? indentations go away when i move my tongue around, etc, but am worried about this...

No, but.....: The scalloping comes from the tongue being forced into the teeth. The tongue is a bag of muscle and muscle is mostly water. It is squished against the teeth when you clench. I am always concerned when i see scalloping as it is a calling card for clenching. Clenching you teeth can lead to fractures and mobility of the teeth and possible tooth loss.

Sleep bruxism: Scalloped tongue is a good indication that you clench or grind your teth during the night. It is also very common in patients with sleep apnea. Many times bruxism is part of a sleep disorder.

Sleep Apnea: A common cause of tongue with scalloped edges is sleep apnea which consists of breathing cessations.