As I child I had the habit of chewing on ice cubes and was told that this damages your teeth. Now my son has this habit and I'd like to know if it is true. Does chewing on ice cubes damage your teeth?
There is certainly a lot of people claiming it to be true, including various dentists.
Visiting the ADA web-site, the closest I found was the claim appearing in some unreferenced teaching materials.
But what scientific evidence is there?
I only did a quick literature search, and what I found was less than convincing.
One article in an industry journal made the claim:
Teeth with occlusal interferences, especially in patients with pathological occlusal habits, are more likely to develop fractures due to nonaxial forces directed on cuspal inclines. Other habits, especially ice chewing, eating pretzels or hard candy, or even gum chewing contribute to tooth fracture formation.
but did NOT provide a cite. Shame.
(Ref: Managing Incomplete Tooth Fractures, J. Edward Ailor Jr., The Journal of the American Dental Association August 1, 2000 vol. 131 no. 8 1168-1174)
In the book Endodontics: Principles and Practice, by Richard E Walton and Mahmoud Torabinejad, chapter 7, it is claimed:
Cracked teeth are often found in patients who chew hard, bittle substances (ice, unpopped popcorn kernels, hard candy, and so on). These patients may have prominent masticatory muscles and show excessive occlusal wear as a result of heavy occlusal forces.
Annoyingly, I can see that they do have a cite for this, but Google Books won't show it to me. :-(
Amongst 15-16 year old girls, a statistically significant association was found between "crushing ice and muscle sensitivity to palpation". (Of course, correlation does not imply causation, and ice chewing was determined by survey.) The researchers were looking for "temporomandibular disorders", so tooth fractures were probably outside their remit. Nonetheless, this may be enough to encourage people to avoid chewing ice.
[Ref: Oral habits and their association with signs and symptoms of temporomandibular disorders in adolescent girls, A Gavish, M Halachmi, E Winocur, E Gazit, Journal of Oral Rehabilitation (2000), Volume: 27, Issue: 1, Pages: 22-32, ISSN: 0305182X, PubMed: 10632840]
A somewhat negative result was found by one report: [Ref: Risk indicators for posterior tooth fracture, James D Bader, Daniel A Shugars and Jean A Martin. The Journal of the American Dental Association July 1, 2004 vol. 135 no. 7 883-892]
Similarly, the behaviors of chewing ice and biting or holding hard objects in the mouth were not significantly different between case and control subjects.
This report looked at one class of tooth fracture, and the results probably cannot be extended to all teeth.
Ingle's Orthodontics 6 by John Ide Ingle (2008) sits on the fence:
With respect to care of teeth, a question sometimes raised is, it it damaging to chew on ice? The dental literature is not very informative on the topic; Brown et al in 1972 used thermal cycling-alternating exposure to very cold and very hot stimuli to extracted teeth - and reported extensive cracking in the teeth. It is not clear if this information can be applied to the question of ice chewing, but until more information becomes available, it seems reasonable to advise against chewing on ice.
(His reference to Brown is to: Brown WS, Jacobs HR, Thompson RE. Thermal fatigue in teeth. J Dent Res 1972;51:461-7. I haven't read this.)
I note Ingles is referring the cracking through thermal cycling, whereas others have reported "microcracks" and "pitting" due to the hardness of the ice. These effects seem unrelated.
There are some reputable people and organisations making the claim.
However, having looked at many of the claims on the web, I can see few providing links to scientific evidence of it occurring in practice.
The limited scientific evidence I was able to find did not suggest that there was a link. Absence of evidence proves little in this case; a more thorough literature search may provide the smoking gun.
In my opinion, for what little that is worth, it is probably true. I'm going to start avoiding chewing on ice in the meantime.
There is definitely some basis for this claim. According to Dr. Michael Payne, damage to teeth due to chewing on ice occurs:
Keep in mind that chewing ice on a regular basis can cause damage to your teeth....
chewing ice can cause fracture lines in your teeth which might lead to cold sensitivity, pain or biting pressure. The habit may actually cause a tooth to fracture.
This question was also asked on theanswerbag.com, and I don't know how much trust could be placed on this, but one of the users states:
It does cause damage. My mom used to be a dental assistant and she said that you could see the tiny holes it puts in your teeth when you looked carefully. But it's not like that stopped me, I love ice!
Interesting to note that there is a thing called pagophagia, which is the compulsive disorder to chew on ice.
From a dental clinic,:
The dangers of chewing ice are real enough that American insurance companies do not include dental procedures for teeth damaged as a result of, well, chewing ice.
For more, see this link, where Dr. Bill Dorfman explains the Dangers of Chewing Ice.