Retromolar_space
Retromolar space
Anatomical space at the back of the skull
The retromolar space or retromolar gap is a space at the rear of the mandible, between the back of the last molar and the anterior edge of the ascending ramus where it crosses the alveolar margin.
This gap is generally small or absent in modern humans, but it was more often present in Neanderthals,[1] and it was common among some prehistoric Amerindians, such as Arikara and Mandan.[2][3]