The skull belongs to a female between 61-71 years of age and dates to the 16th century. Nat Geo describes the reason for the brick in the mouth as follows:
Belief in vampires was rampant in the Middle Ages, mostly because the process of decomposition was not well understood, Borrini says.
For instance, as the human stomach decays, it releases a dark “purge fluid.” This bloodlike liquid can flow freely from a corpse’s nose and mouth.
Since tombs and mass burials were often reopened during plagues to add new bodies, Italian gravediggers saw these decomposing remains and may have confused purge fluid with traces of vampire victims’ blood.
In addition, the fluid sometimes moistened the burial shroud near the corpse’s mouth so that the cloth sagged into the jaw. This could create tears in the cloth that made it seem as if the corpse had been chewing on its shroud.
Vampires were thought by some to be the causes of plagues, and the superstition took root that shroud-chewing was the “magical way” that vampires infected people, Borrini said.
Inserting objects—such as bricks and stones—into the mouths of alleged vampires was thought to halt the spread of disease.
The bones were subjected to forensic analysis, a stable isotope analysis, and the taphonomy of the find was studied. Eventually, a paper on the find was published in the <em<Journal of Forensic Sciences. Inevitably, a second paper critiquing the first appeared in the same journal along with a response by the authors of the first papers. The gist of these latter papers can be found here.
Another vampire story comes from Bulgaria. Two skeletons with iron rods piercing their chests have been excavated. From the link:
“These skeletons stabbed with rods illustrate a practice which was common in some Bulgarian villages up until the first decade of the 20th Century,” explained Bozhidar Dimitrov who heads the National History Museum in the Bulgarian capital Sofia.
People believed the rod would pin the dead into their graves to prevent them from leaving at midnight and terrorising the living, the historian added.
Note: If anyone has access to the Journal of Forensic Sciences could you send me copies of the three articles I linked to? My email address is on the “about” tab.