Skull of a Black Bear

Saggital crest: This protrusion is for attachment of chewing muscles. Animals with a large saggital crest have a powerful bite. The saggital crest is much bigger on male black bears than it is on females, giving males a more powerful bite when fighting over females. Males and females have similar diets.

Old male bear skull

Teeth: Black bears have 42 teeth adapted to an omnivorous diet of vegetation, nuts, berries, insects, and some meat.

The incisors can be used for cutting meat but are usually used to clip grass, clover, and newly emerging plants on the forest floor.
The canines can be used to grasp prey and to wound opponents but are usually used to tear open logs for ants and grubs.
The premolars are the four teeth behind each canine tooth. Usually the 2nd and 3rd premolars on the bottom jaw are missing, leaving a space (diastema) like herbivores have. Moose use their diastema to strip leaves off branches as they draw the branches sideways through it. Black bears use it the same way when eating young leaves in spring.
The molars are the 2 back teeth on the top and the 3 back teeth on the bottom. They are broad and flat like they are in raccoons and people and are used for crushing nuts and acorns and for grinding up vegetation. Black bears eat little meat, so they don’t need their molars to be sharp and scissor-like as they are in animals like wolves and cats that eat mostly meat.