Retromolar space

The retromolar space or retromolar gap is a space at the rear of a mandible, between the back of the last molar and the anterior edge of the ascending ramus where it crosses the alveolar margin.

Retromolar gap is found in some Neanderthals because they had midfacial prognathism. This caused the lower tooth row to move forward, which led to the retromolar gap.