For instance, haplorhines have a middle ear with two chambers and a plate of bone that shields the eyes from the chewing muscles
As a person grows, he argues, genetically constrained chewing muscles
lead to relatively small jaws, thus permitting the deposition of additional cranial bone to encase a large brain.
Researchers thought that with the development of thick enamel, robust skulls and large chewing muscles
, these species had evolved to eat hard, brittle foods.
As in gorillas today, the heavy brow ridge of Sahelanthropus worked with other skull elements to anchor powerful chewing muscles
Spasm of chewing muscles
, often as a result of clenching or grinding teeth due to emotional tension, will affect the TMJ too, as will head or neck injuries, even osteoarthritis.
aethiopicus had enlarged molars and premolars and beefed- up chewing muscles
, mouth specializations that are often viewed as adaptations for eating tough grasses rather than the softer fruits of the woodlands.