Final answer:
Depressed skull fractures are caused by strong blows that push bone fragments inward, potentially leading to serious complications like hematomas, brain injury, and increased intracranial pressure.
Step-by-step explanation:
Characteristics of depressed skull fractures include a scenario where the bone is broken and pushed inward towards the brain. This type of injury often occurs due to a strong blow to the head and can lead to severe complications such as bleeding inside the skull, injury to the brain, and sometimes formation of a hematoma if an artery is damaged, particularly with fractures around the pterion. These hematomas can exert increasing pressure on the brain if left untreated. Closed or open reduction may repair such fractures, with healing involving hematoma formation and subsequent callus formation.