###Human: What could a strange deep line on the right side of my head be? ###Assistant: Hello. I carefully saw your uploaded photo (attachment removed to protect patient identity) and would explain that this indentation could be related to differential possible causes like calcium or vitamin D deficiency and bone reformation, chronic inflammation, or a hormonal disorder or etching.  For this reason, I would recommend performing some tests if this phenomenon persists: All the above tests can be performed by your GP (general physician). Hope you will find this answer helpful. For more information consult a neurologist online -->