A human bite, while often underestimated, possesses a measurable force. This exploration delves into the typical strength of a human bite, how it is measured, the biological elements influencing its power, and how it ranks among the diverse bite forces found in the animal kingdom.
Understanding Human Bite Force
The force generated by a human bite can be quantified, typically expressed in pounds per square inch (PSI) or Newtons (N). The average human bite exerts approximately 162 PSI. When measured in Newtons, the average voluntary bite force ranges from 100 to 150 N, with maximum forces reaching between 285 and 700 N.
Bite force is commonly measured using specialized instruments known as gnathodynamometers or bite force meters. These devices are placed between the teeth, and an individual bites down with maximum effort, allowing the instrument to record the exerted force. Individual bite force can vary considerably.
Factors Contributing to Bite Strength
Several biological and physiological elements influence an individual’s bite strength. The primary muscles responsible for jaw closure, known as the muscles of mastication, include the masseter, temporalis, medial pterygoid, and lateral pterygoid muscles. The size and strength of these muscles directly correlate with the force they can generate.
The structure and health of the teeth also play a role in bite force. Molars, situated at the back of the mouth, are designed for grinding and crushing and can withstand greater force than the incisors at the front. Healthy teeth and gums are important for optimal bite force, as missing or damaged teeth can reduce it. Bone density in the jaw, particularly the mandible, also affects bite strength, as a denser jawbone can withstand greater force exertion.
Other factors influencing bite strength include age and gender, with bite force peaking in adulthood and being slightly higher in men due to differences in muscle mass and bone structure. Craniofacial morphology, which describes the shape of the skull and jaw, also impacts the leverage and efficiency of muscle contraction. Individual genetic variations contribute to the overall variability observed in human bite force.
Comparing Human Bites to Other Species
The human bite force, averaging around 162 PSI, is relatively modest when compared to many animals, especially large predators. For instance, some of the weakest bites among animals with jaws belong to creatures like anteaters, which have virtually no bite force and can barely move their jaws, relying instead on their long tongues for feeding. In contrast, a domestic dog, such as a German Shepherd, typically has a stronger bite force than a human, around 238 PSI.
Apex predators exhibit significantly greater bite forces. The Nile crocodile holds one of the strongest bites among living animals, capable of exerting an astounding 5,000 PSI. Saltwater crocodiles also demonstrate immense power, with bite forces ranging from 3,700 to 4,000 PSI. This allows them to crush bones and overpower large prey. Other powerful biters include the American alligator (2,125 PSI), the hippopotamus (1,800 to 2,000 PSI), and the jaguar (1,500 PSI).
Even among primates, human bite force is not the strongest. While human jaws are considered efficient for their size, larger apes like chimpanzees can exert around 1,300 PSI. Gorillas also possess considerably stronger bites than humans, capable of generating forces 30 to 50 percent greater. The spotted hyena, known for its bone-crushing capabilities, can bite with 1,000 to 1,100 PSI, making its bite almost seven times stronger than an average human’s.