The medical term leontiasis ossea was first used by ancient Greek physician Rufus of Ephesus to describe bone changes caused by disease that made the sufferer appear to have a lion-like face. Although Rufus thought that ‘lion face’ syndrome was caused by leprosy or elephantiasis, today doctors know that it can be the result of a number of different diseases.
Lion face syndrome is quite rare and involves extra growth of the bones of the face, particularly the maxilla or upper jaw. Growth in this area narrows the nasal opening, modifies the mouth, and can even press on the eye orbits and optic nerve, compromising vision.
The term leontiasis is not used much anymore, since historically it was attributed to a number of different diseases. Although it can be the result of conditions such as syphilis, tumors, and gigantism, the most common disease that causes a non-cancerous overgrowth of the maxilla is craniofacial fibrous dysplasia, a gene mutation that occurs in the early stages of fetal development.
Also uncommonly found, fibrous dysplasia mostly affects children and young adults whose skeletons are still developing. In these cases, there is simply too much fibrous bone — the type of bone formed to heal a fracture — that gets in the way of normal bone development. This condition can occur in any bone in the human body; when it occurs in the maxilla or other facial bones, it’s called craniofacial fibrous dysplasia.
As a result of its rarity, discoveries of leontiasis ossea are beyond rare in the bioarchaeological literature. A paper by Mexican and Chilean researchers, published in 2009 in Forensic Science Medicine and Pathology, attempted a facial reconstruction of a pre-20th century adult female skull with cranial bone overgrowth. The skull was excavated at the turn of the 20th century by Nicolás León, the founder of Mexican physical anthropology. Noting the excess bone growth, researchers diagnosed leontiasis ossea and produced a facial reconstruction that clearly shows the effects of the growth on the woman’s physical appearance.
One intriguing hypothesis is that leontiasis ossea is much more famously portrayed in the visage of the Great Sphinx of Giza. With the body of a lion and the head of a human, the sphinx represents a mythological hybrid creature. Or could it instead reflect a living model who suffered from overgrowth of the facial bones? In 2005, medical doctor Hutan Ashrafian argued just that in the Journal of Endocrinological Investigation.
Ashrafian sees in the Sphinx a moderate amount of prognathism — or a jutting-out — of the jaw. Rather than the jaw being on the upper end of human variation, Ashrafian instead suggests that it could be the result of a pathological condition. Since the Sphinx is part-lion and since leontiasis has been known for millennia, it is possible that the model for the Sphinx was someone suffering from a condition that led to leontiasis. This is all very circumstantial, but if the Sphinx is meant to represent someone specific – such as 4th Dynasty Pharaoh Khafra – it may be worth looking more closely at any mummies that are discovered to see if there is evidence for overgrowth of facial bones.
The rarity and confusion around the origin of leontiasis means that few cases are published in the medical and anthropological literature. But since craniofacial fibrous dysplasia very obviously affects the physical appearance of its sufferer, it is likely that historical cases of it have been written up in a variety of languages around the world. An historical synthesis of leontiasis ossea would be an excellent topic for a future undergraduate paper or master’s thesis.
