Bite force is the pressure generated when jaw muscles contract, bringing teeth together. This measurement provides insights into the human masticatory system, essential for chewing, and is relevant for dental health and physiology.
The Average Human Bite Force
The average human bite force is approximately 160 pounds per square inch (PSI). This force is not uniform across all teeth; molars, located at the back of the mouth, can exert significantly more pressure due to mechanical leverage, generating around 171 pounds of force. Incisors, the front teeth, produce considerably less.
Normal chewing, which involves rhythmic jaw movements rather than a sustained maximum clench, typically exerts about 70 pounds per square inch. While these figures represent common averages, the maximum recorded human bite force far exceeds them. Richard Hofmann achieved an extraordinary bite strength of 975 pounds (442 kg) in 1986, though this remains a notable outlier in research settings.
Factors Influencing Bite Force
Several biological elements contribute to human bite force variability. Muscle strength is a primary determinant, with the masseter and temporalis muscles being key contributors to jaw movement. Individuals with more developed muscles in these areas exhibit higher bite force.
Jaw anatomy also plays a role, as craniofacial morphology can influence bite strength; for example, individuals with a “short-faced” facial structure may have thicker masseter muscles, correlating with a stronger bite. Additionally, bone density and the overall health of the jaw joints impact the efficiency and power of the bite. Bite force also changes with age, generally increasing through growth and development to peak in young adulthood, typically between 20 and 50 years of age, before gradually declining.
Gender is another influencing factor, with males generally demonstrating a higher bite force than females. This difference is often attributed to males typically having greater muscle mass, a larger bone structure, and sometimes larger dental sizes. For example, the mean maximum bite force for males can range from 262.8 to 999.3 Newtons, while for females, it ranges from 108.9 to 834.6 Newtons. Dental health significantly affects bite force; conditions such as missing teeth, misaligned bites, cavities, or temporomandibular joint (TMJ) disorders can reduce a person’s ability to exert maximum pressure.
Measuring Bite Force
Scientific measurement of bite force relies on specialized instruments. Devices known as gnathodynamometers or bite force transducers are commonly used. The fundamental principle involves placing a sensor, often a small, flat component, between the teeth.
As a person bites down, the sensor records the applied pressure. Modern gnathodynamometers frequently incorporate advanced electronic sensors, such as strain-gauge or piezoelectric transducers, which convert the physical force into measurable electrical signals. These signals are then processed and displayed digitally, providing precise readings of bite force in units like pounds, kilograms, or Newtons.
Human Bite Force in Perspective
Compared to many animals, human bite force is not exceptionally powerful, averaging between 120 and 160 PSI. For context, some of the strongest bites in the animal kingdom belong to apex predators adapted for crushing or tearing. Saltwater crocodiles, for instance, can exert a bite force ranging from 3,700 to 5,000 PSI, while great white sharks are estimated to have a bite force of around 4,000 PSI.
Other animals with formidable bites include hyenas, capable of 1,000 to 1,100 PSI, and jaguars, whose bite can reach 1,500 PSI. Gorillas, despite their herbivorous diet, possess a strong bite of 1,000 to 1,300 PSI, used for processing tough plant material. Even some domestic dogs, like pit bulls, are cited with bite forces around 235 PSI, sometimes comparable to or slightly exceeding average human bite force. While human bite force may not match the raw power of many predators, it is highly effective for its evolutionary purpose of chewing and processing a varied diet.