Nail biting is a habit that can ruin more than just a pretty manicure. Fingernails are among the hardest surfaces of the body, so it should not come as a surprise that chomping down on one can apply enough force against your teeth to cause damage.
Most people bite their nails out of habit without even realizing they're doing it — usually out of boredom, nervousness, frustration or stress. Unfortunately, this bad habit can unknowingly result in cracks, chips, or erosion of the front teeth.
Even more alarmingly, delicate tooth enamel can actually fracture from the force of nail biting. Frequent nail biters may notice a change in the shape of the teeth, as the front teeth may even appear squared off or worn down.
If you bite your nails regularly, you may also notice increased tooth sensitivity or even pain as the tooth enamel wears away.
In most severe cases, consistent nail biting can actually cause temporomandibular joint dysfunction or TMJ, a painful condition that causes jaw pain, headaches and popping or clicking of the jaw. Severe TMJ can cause problems with opening and closing the jaw properly.
People with braces experience the worst complications from nail biting, since the teeth are already in a compromised position from the pressure of the braces. Prolonged nail biting can compromise the result of orthodontic treatment, cause root resorption, or compromise the tooth alignment.
Aside from the oral health problems, one of the more unappealing aspects of biting your nails is the possibility of transferring bacteria from under your fingernails into your mouth. As many as 150 species of bacteria exist on the fingers and in the spaces under the nails.
Allowing these bacteria to enter the mouth can cause a world of troubles starting with the risk of illness, but also the increased risk of gum infections, bad breath and generally compromised dental health.
If you think about all of the surfaces that you touch with your fingertips throughout the day, then you can imagine the various types of bacteria that you might have unknowingly picked up and put into your mouth.