Monday, June 24, 2024
HomeOral Health & Hygiene6 Reasons Why Biting Your Nails Is Bad For Your Teeth

6 Reasons Why Biting Your Nails Is Bad For Your Teeth

It’s been estimated that about half of all humans bite their nails.  At ten fingernails per human (and maybe some toenails thrown in for good measure), that adds up to billions of fingernails that are chewed on everyday.

Fingernail biting has been linked to genetics and occurs more often in females than males.  I bit my nails frequently from the age of 5 up until about 25, when I kind of grew out of it.

Our teeth can do many amazing things, like helping us speak, making us look more attractive than we really are, and allowing us to chew a variety of healthy foods.  One thing that teeth aren’t good for though is biting our nails!

In fact, biting your nails can actually cause harm to your teeth and other structures inside of your mouth.  Here’s a breakdown of some of the negative effects that biting your nails can have on your oral health.

6 Reasons Why Biting Your Nails is Bad for Your Teeth

Nail Biting Can Harm Your Teeth

1– Biting your nails can cause your teeth to get chipped. This is definitely the biggest reason to not bite your nails.  Chewing on hard fingernails can take its toll on your teeth.  Sometimes when bite through a nail, your teeth hit together pretty hard, which could chip a tooth.

Repeated flexing of your teeth’s enamel occurs when you bite your nails and can cause the enamel to fracture or chip.

To find out more about enamel and the other layers of your teeth, read The Anatomy of a Tooth.

For most people, chipping a tooth is the only negative effect that biting your nails might have on your teeth.  In fact, the book Pediatric Dentistry by Pinkham states:

There is no evidence that nail biting can cause…dental change other than minor enamel fractures.

However, various studies have shown that nail biting can cause other oral problems.  Keep in mind that some of the following negative effects are very rare and won’t always occur with everyone, so you might want to take them with a grain of salt!

2 – Biting your nails can cause a diastama — a gap between your two front teeth. If the nail biting habit begins when the child is very young, it has been reported to cause a gap between teeth.  While I was unable to find a study to confirm this, I did find a dentist has a a picture of it on his website here.  While this can occur, it probably won’t unless someone is constantly shoving their nail up between their teeth.

3 – Nail biting can cause the roots of your teeth to become weaker. Nail biting during orthodontic treatment (braces) has been shown to cause root resorption, which is when parts of the roots of your teeth get dissolved by the bone surrounding them.  This causes the roots of the teeth to become weaker.  Here’s one study and another one that explain this phenomenon.

4 – Biting your nails can cause you to lose your teeth. This study claims that biting your nails can cause you to lose your teeth.  Remember — this is the only study that I’ve found that claims this, and we definitely would need more studies to be done in order to verify this.  See my disclaimer above!

5 – Biting your nails can cause TMJ problemsThis study tells how biting your nails can cause disk displacement in the temporomandibular joint.  If you have pain in your TMJ, perhaps it is being caused by your fingernail biting habit.

6 – Biting your fingernails can cause gingivitis. This case report (PDF file) details the story of a young child that bit his fingernails and then shoved them up between his gums and teeth.  The report even has pictures if you’re curious.  You would think that this would be pretty rare but it might not be as uncommon as you’d think.  Here’s another report here and one more here! It does go to show that kids can think of anything to do with their fingernails after they’ve chewed them off of their fingers.


I have talked about some of the extreme cases of biting your nails.  Obviously, many people do bite their nails without any dental problems.  Sometimes, however, people do develop problems.

One interesting fact I found while researching for this article is that biting your nails actually contaminates your mouth with interesting varieties of bacteria that are found on your hands.  Since I’m a slight germophobe (as mentioned here and here), this tidbit encourages me keep my nail biting habit in remission.

Hopefully the information provided above can give you the encouragement you need to help you to kick your fingernail biting habit.  Or, maybe you’re willing to take the risk and keep on biting your nails.

Have you ever hurt a tooth or had any dental problems due to biting your nails?  Please share your comments below!



  1. I’m 13. I weigh 103 pounds. I’m 5’2. I have red long curly hair. I have blue eyes. Real straight teeth. And my name is CeCe. I can’t afford bad nails and teeth!

    • Hi Cece – As long as you’re not biting your nails with your teeth, I’m sure you’ll have great nails and keep your teeth looking great.

      Thanks for the comment!

  2. Im 23 y/o and Ive been bittin my nails since I was 4 or 5, and up to this day I place the bitten nails between tooth and gum, I started placing them just between the two frontal when I was 5 or 6 and then tried some other and other, when I was 19 I started placing them even back where my molars are, so Ive been bitting my nails and placing them between tooth (or molar) and gums, and I love how it feels, ive had issues at times like incarnated nails (nails stucked in my gums) and Ive used a needle, or the back or an earing or anything sharp to get it off.
    Indeed my front teeth are chipped, (exactly like in the picture) they are not sharp anymore, lost the sharpness around 3 years ago or so (I used front teeth for everything though, like cutting paper, tape, opening chips bags etc) I have a gap between my front teeth but isnt a regular sexy gap is just a tinny gap that I use to squirt or whatever, even once I wore a diamond earing (a 22 or 20 gg earing is all it takes) and lookes great. Ive never gotten sick over fingernails or anything, I dont have tmj problems, and do not suffer from gingivitis, however I found that sometimes if I hit certain spots I get some reactions, like headache, face ache, headache relief, pain relief etc etc, I guess there are some cool and not so cool nerves connected to the gums.

    • Thanks for letting us know, ow! I did include that one as #6 on the list above. You can view those links if you want to see what happened with the kids. Thanks for your comment!

  3. Tom, I don’t know where you get your facts or statistics. The fact is that nail-biting is much more prevalent in males than females, particularly after age 10. Based on the information I have read, about 1 in 10 males over 30 world-wide bite their nails. Having made that point, I want to emphasize that nail-biting is very bad for one’s teeth and gums. I can attest to that as a life-long habitual nail-biter with serious oral issues.

    • Hi Peter – I looked into it some more and this is the source I used. Referring to fingernail biting it states, “It appears to be familial in nature and occurs most often in females.”

      Digging a little deeper, that paper cites this study as evidence backing up their statement that fingernail biting occurs more often in females.

      I’m not sure if it gives everyone access to that abstract, because I accessed it on my university account, so I’ll summarize:

      The researchers analyzed 338 pairs of twins and found that nail biting was 1.5 times more common in females vs. males.

      So, it looks like a blanket generalization was made assuming that nail biting is always more common in females simply because it was more common in those 338 pairs of twins.

      After researching all of that, I am curious about the studies that you are mentioning that state that it is more common in males. I will change the article if you can point me to some other evidence.

      Thanks for your comment, Peter!

      • Tom, as an incorrigible adult nail biter, I have studied the habit the past year. The undocumented information I provided was gleaned from various internet sources, though I do not know the scientific bases used to support the conclusions. I can refer you to an article in “Daily Health Facts” at www. biting. It states:

        Who Bites Their Nails?

        ■About 50% of children between the ages of 10 and 18 bite their nails at one time or another. Nail-biting occurs most often as teens are going through puberty changes.
        ■About 23% of young adults, ages 18 to 22 years, bite their nails.
        ■Only a small number of other adults bite their nails. Most people stop biting their nails on their own by age 30. About 10% of men over the age of 30 bite their nails.
        ■Boys bite their nails more often than girls after age 10.

        Other references regarding the habit being more frequent in men appear in the World Press site “Health News” at habit and an article “How to Stop Nail Biring for Men in There are many more references throughout the internet that can be googled.

        As I say, I cannot verify any conclusion. But the notion that more males bite their nails seems consistent with my personal observations. As a teen-ager and young adult, I recall that more boys I knew were nail biters than girls. Now, as a middle-aged adult, more guys I know and have seen bite their nails than women.

        Thanks for your interest.


        • Hi Peter – I think we figured it out then! It sounds like girls bite their nails more often in childhood, then it evens out around age 10, and then after age 10 it is guys that end up biting their nails more.

          Thanks for sharing your experience and letting me know!

  4. Thanks for the information, Tom! I’ve been biting my nails since I had teeth, and was always more insulted than anything else whenever someone suggested I quit. I have very soft nails and am particular about cleanliness, and never really heard any reason against nail-biting that seemed to have any bearing on my own habit; having a tendency to pick at anything as a kid–eg. scabs–especially when nervous, it always seemed like a convenient solution that was always on hand (no pun intended) and caused no harm. It seemed like most parents I had heard of who tried to stop their own children from chewing their nails or thought that I should do the same were doing so simply because it wasn’t considered proper!

    Now that I have read your list, it occurs to me that I do occasionally have jaw problems, and although I don’t think they were caused by nail chewing it probably doesn’t help; I’d never heard of any correlation before but I’m glad to know this may be worsening the problem. I’m not quite 22–perhaps I’ll quit yet, and save my jaw the trouble.

    • Hi Gwen – I used to be a big nail biter, but I suddenly stopped sometime right around when I turned 18. I’m glad the article helped. Let me know if you have any questions, Gwen. Thanks for your comment!

  5. Im 13 y/o and i’ve been biting my nails my whole life. i used to bite my toe nails to but stopped about 6 yrs ago. anyways i still bite my nails and they look pretty awful. i’ve noticed tht my teeth have this strange curve upwards lik a triangle on my top and bottom teeth right in the center like ur pic. shows. when i clench my jaw down my teeth fit perfectly together but they still look not very attractive. Im trying to stop biting my nails but i dont know how to. Can you help me??? and if i go to the dentist could they file or fill my teeth in so they look straight again??? plz answer my q’s. thxs!(:

    • Hi Lala – Biting your nails can wear away your tooth structure. One thing that helped me stop biting my nails was to start using fingernail clippers to cut my nails nice and smooth. Once they looked good, I didn’t want to bite them. Your dentist will be able to smooth out your teeth for you and possibly replace the missing tooth structure that got worn away.

      I hope that helps. Let me know if you have any other questions. Thanks for your comment, Lala!

      • Nail files are even better than nail clippers, since you can always get perfectly smooth nails with no irregularities. Nail clippers are good, but not good enough for me. Even the tiniest imperfection from nail clippers drives me crazy. I effectively stopped biting my nails by carrying around a nail file everywhere i go, so if i ever notice an irregularity, i can file immediately instead of biting.

  6. Yep, been biting my nails pretty much my whole life (34 now). Tried to stop for a while (a year maybe?) because I was scared that it would damage my teeth. Somehow, I forgot this and started back up again. I consider my nails relatively soft, and my teeth still look straight/flat. Anyhow, I just chipped the corner of my bottom front tooth when I bit through my nail today. It left a sharp edge that is irritating the tip of my tongue and driving me crazy. Good thing I already had a dentist appointment coming up next week… In summary, stop it. Stop it right now! 🙂

    • Ben, I’m a contemporary who also has dental problems from doing it but am so hard-wired to bite my nails that I could never stop no matter what I did. Even though I try not to eat my nails in front of other people I do it anyway. It’s a horrible habit. Good luck, man! Hope you overcome it.

  7. Whenever I decide to quit biting my fingernails and look up ways to quit online, people say “Find something else to do with your fingers.” However, my problem is I need something to do with my teeth! Gum doesn’t work, I can’t chew it at school. Please advise!

  8. I learned the hard way about this today. A little piece of my top front tooth chipped off today when I was biting my thumb nail. I’m prett upset about it.

  9. Oh, dear! My mother and I have both been terrible nail-biters our whole lives, and we are both *well* into adulthood. I remember stopping, at times, even for years, but it always came back again! I’d like to add, in case this helps anyone out there (especially the young ladies above) the only trick that really ever worked for me was to get acrylic nails. They glue these strong plastic nails on top of your real nails and they are so hard to bite that you will be forced to give up!! It’s like wearing a steel shield over your nails 🙂 It’s costly, but after reading this article, I suppose I will have to go back to it. In addition, I’d like to say that Tom, your comment about cutting your nails made my skin crawl. My nails are soooo bitten that they are bloody and I bite and eat the flesh of my fingers too, often causing them to bleed. So cutting is not an option. However, I have found that filing with an emery file does help curb the desire to bite because the edges are not so ragged! however, most of the time there is nothing left to file or cut to smooth down. It’s horrible; I can bite my nails down so low that it’s painful and scabs form 🙁 When I go in to get my nails done at the salon the ladies are shocked and horrified at what they see, but they can still glue acrylic nails to what little natural nail stumps I have left. So, I recommend it.

  10. help!!! i was chewing my nails then it got stuck behind my top left front tooth! I’ve tried everything , floss, toothpick, and brushing my teeth very hardly. I need help I’ve tried everything.

  11. I am a 12 year old female 5’0
    I have been hitting my nails since I was 3 or 4 and my teeth are healthy no cavities or puffy or swollen gums. But my teeth are wobbly or loose.
    My dentist checks them and says there healthy just don’t play with them.
    My gums don’t bleed, there not puffy or reseeding but my teeth are still loose.
    Are they loose because I bit my nails?
    Please suggest any conclusions as to why my teeth may be loose?

  12. I’m a 18 yr Old male who has been biting his nails for over 10 years consistently and today I mark the day that I get my first chipped tooth. Woohoo! It feels weird and ridged & totally not smooth compared to the rest of my tooth. Run it across the back of my hand and it leaves a scratch. Although I’d love to say my nail bitin days are over, that would be a blatant lie. I think this is a thing that’ll stick with me until I die. But anyway don’t start if u haven’t already!!

  13. Hi my name is Rachel I am 13 years old, I woke up this morning with a loose front tooth. It isn’t extremely loose but I am scared. I bite my nails but I also only brush my teeth once a day and there is dark plack build up behind my teeth my mom and I are trying to schedule a dentist appointment but in the mean time can you help me?

  14. I’ve been biting my nails since I was probably 7 and I’m now 29. I bite my nails and stick them in between teeth often. It is a horrible habit and now have a few small gaps near the gums in between my two front teeth and in other spots. How do I get rid of them? Will they go away if I stop this horrible habit over time or is this permanent…??

  15. I’m an adult nail biter who’s been biting for as long as I can remember. My parents tried to get me to stop when I was little and nothing really worked. I’m currently going on week two of trying not to bite and readng articles about all the negatives really helps (not having “manicure perfect” hands was never a big motivator for me). The enamel on my two front teeth and two bottom teeth (the ones I use to bite) has worn away at the tips and is translucent and that’s worrying for me. I suppose I should ask my dentist about this, hopefully there’s something that can be done (other than quitting, I’m working on that!!).

  16. Hi Tom,
    I’ve been biting my nails for as long as I can remember. I’m 45years old. I have jaw joint pain every day from clenching/bruxism. I have had 5 root canals …3 in the last 6 months. My front tooth and baby tooth directly next to it have been hurting me so badly and I went to the dentist about it. The dentist said there is no infection but the teeth are hurting me so much that it is disrupting my life. These teeth and many others are very sensitive…I think mainly because I chew dead skin and nails on them. I have been biting for so long though…it just seems there’s no going back. However i don’t want to keep suffering with tooth pain all the time.

  17. I have TMJ issues so bad that my left ear rings and I get stabbing pains in my ear. I am convinced it is from biting my nails and skin on exclusively on my left front teeth. I used to do it for so long my jaw would get sore on that side. Now it is sore all the time even after stopping for months. I have have spent $4000 on a neuromuscular splint. I am also taking amitrpylline, soma, and indomethacin. Relief is very very slow coming. At this rate it will take me years to fully recover if that is even possible. I fear that nail biting is potentially much more destructive then one would be led to believe.

  18. I’m a 41 year old female & have been chewing my nails as long as I can remember. My teeth are slowly separating. I’m not positive but I’m almost positive it from my terrible habit of nail biting. I never had any gap at 25 years old. Now I definitely notice it.


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