Sagittal cross-sections of the head of Caucasian female subject, age 63.
Dissection done as a part of studies to scientifically determine typical characteristics for genders/racial descent. For centuries, people have known that people descended from different races “typically” had different characteristics from others. However, it wasn’t until the turn of the 20th century that the first big studies were done to determine exactly how different characteristics manifested themselves, and what differences were significant enough to use in identification. Though it’s still far from an exact science, those studies were the first major steps forward in working off of evidence rather than stereotypes and supposition when identifying the “race” of anthropological remains.
Proceedings of the Aberdeen University Anatomical and Anthropological Society. 1902-1904.

Trepanning, also known as trephination, trephining or making a burr hole, is a surgical intervention in which a hole is drilled or scraped into the human skull, exposing the dura mater in order to treat health problems related to intracranial diseases. It may also refer to any “burr” hole created through other body surfaces, including nail beds. It is often used to relieve pressure beneath a surface. A trephine is an instrument used for cutting out a round piece of skull bone.
Evidence of trepanation has been found in prehistoric human remains from Neolithic times onward. Cave paintings indicate that people believed the practice would cure epileptic seizures, migraines, and mental disorders. The bone that was trepanned was kept by the prehistoric people and may have been worn as a charm to keep evil spirits away. Evidence also suggests that trepanation was primitive emergency surgery after head wounds to remove shattered bits of bone from a fractured skull and clean out the blood that often pools under the skull after a blow to the head. Such injuries were typical for primitive weaponry such as slings and war clubs.
There is some contemporary use of the term. In modern eye surgery a trephine instrument is used in corneal transplant surgery. The procedure of drilling a hole through a fingernail or toenail is also known as trephination. It is performed by a physician or surgeon to relieve the pain associated with a subungual hematoma (blood under the nail); a small amount of blood is expressed through the hole and the pain associated with the pressure is partially alleviated.
