Many of the kings and queens of the Spanish Habsburg dynasty, which ruled across Europe from the 16th to the start of the 18th century, had a distinctive facial deformity: an elongated jaw that later became known as the “Habsburg jaw.” Now, a new study suggests this facial feature was likely the result of centuries of inbreeding.
[Researcher Roman] Vilas and his team found 10 maxillofacial surgeons and asked them to analyze 66 portraits of 15 members of the Habsburg dynasty.
The surgeons searched for 11 features that defined “mandibular prognathism,” or protrusion of the jawbone. They also looked for seven features that define “maxillary deficiency,” a related condition in which the maxillary bones — or the bones that form the upper jaw — don’t fully develop.
The authors then calculated the amount of inbreeding that occurred throughout the centuries, using information from a large family tree that included 6,000 people spanning 20 generations. They then correlated the inbreeding with the degree of facial deformity seen in the paintings and found that there was a strong link between the degree of inbreeding and the degree of mandibular prognathism.
In other words, the people who were the most inbred, had the most pronounced case of this facial deformity.
Read full, original post: Inbreeding Caused the Distinctive ‘Habsburg Jaw’ of 17th Century Royals That Ruled Europe