Hello. Thanks for asking from HCM. I can understand your concern. The dent in skull could be due to various reasons : Bone moulding - It is a normal process which shapes skull and occurs during first 7 years age. During this, skull bone is formed from soft membrane cover and sutures between different skull bones fuse. No need to do anything for it. The dent due to it will be painless and present for long time. : Age related change - It is due to age causing bone sclerosis and areas of lysis which lead to irregular bone. It usually occurs after 45-55 years. It is also a normal process No need to do anything for it. The dent is painless. : Post traumatic - Head injury can cause dent at impact site. It may be dent or depressed fracture. For confirmation, CT head is required. If there is any history of significant head injury before noticing dent, it could be the reason. You have to consult doctor for evaluation. Treatment will be decided after CT report. Depressed fracture may require surgery. Otherwise, normal dent is usually managed conservatively. : Bony lesion - it could be due to bony lesion like dermoid cyst/osetoma/fibrous dysplasia. It can be suspected if at dent site, you are feeling some kind of swelling. For confirmation, you have to consult doctor. He might take tissue from it to confirm diagnosis. Treatment usually requires surgical excision. Hope it will help you. Thanks. Take care.