There is a good reason why our skull is solid. It’s not supposed to have ventilation.
[E]vidence shows that healers in Peru practiced trepanation — a surgical procedure that involves removing a section of the cranial vault using a hand drill or a scraping tool — more than 1,000 years ago to treat a variety of ailments, from head injuries to heartsickness. And they did so without the benefit of the aforementioned medical advances.
Excavating burial caves in the south-central Andean province of Andahuaylas in Peru, UC Santa Barbara bioarchaeologist Danielle Kurin and her research team unearthed the remains of 32 individuals that date back to the Late Intermediate Period (ca. AD 1000-1250). Among them, 45 separate trepanation procedures were in evidence. Kurin’s findings appear in the current issue of the American Journal of Physical Anthropology.
The researchers say it appears the practitioners of trepaning were trying different techniques as a treatment for injuries or illness. There are signs of healing on some of the skulls. It was not used as torture but as a treatment. Weird, yes.
Trepanning was used all over the world, often for mystical reasons or to “allow the brain to grow” (metaphorically or literally). Lately, it’s still considered a very RARELY tried cure for depression. But obviously, it’s not recommended and is unsafe. Only in certain condition is removal of skull pieces really deemed medically necessary. But in the past, people had strange ideas and tried them out. Even with such a tricky treatment, they sometimes succeeded.
There is archaeological evidence for trepanation as a surgical procedure dated to 6500 BC when it may have been used to treat skull injuries. And even today, there are those who will do it for you (and possibly film it, GROSS), who do not have medical licenses. Current uses of trepanning are considered pseudoscience.