Watching my small dogs go to town on a beef rib I started wondering, we humans break teeth all the time on things harder than a marshmallow. So how is it that a dog can utterly demolish a hard bone in minutes without breaking half the teeth in their mouth? I figure it is one or both of two things but does anyone know for sure:
Geometry: Dogs teeth are conical and ours our flat. This means the tooth can put more pressure on the bone and crack it before the teeth crack. I also suspect that through the geometry the force vectors look very different between pointy and flat teeth.
Mineralization: Dogs are carnivores and we are omnivores. Does that mean that because of the different ways ours and dogs’ bodies process food via evolution that their teeth are chemically different? Do they have thicker enamel than ours? Are they just made to resist cracking and breaking more than ours?
Actually, dental fractures are very common in dogs. In particular, the fourth maxillary premolar is predisposed to fracture. Several of our dogs have had dental fractures, none went on to abscess, though.
Along the same lines as the OP … I’ve noticed that my dog thoroughly enjoys gnawing on plastic chew toys that are so abrasive (prom previous chewing) they hurt my skin at the slightest contact. They clearly don’t bother the tissues of his mouth. Dogs’ mouths are built different, obviously, but I’m curious about the details.
Human and dog teeth and shaped differently but have the same rudimentary structure, with an outer enamel protective armor. Enamel can decay, but that is a long process, and of course dogs don’t live very long. A 15-year-old dog is quite an old dog. A 15-year old human is nowhere near done with their teeth. A human’s teeth has to last a lot longer than a dog’s, so if your tooth breaks apart at 41 (like one of mine did) hey, it went through a LOT more than a dog’s.
Humans also host a nastier bacteria for your teeth, streptococctus mutans, which really enjoy chomping down on your chompers. Dogs, who have different microbiomes in their mouths and of course don’t eat as much sugar as humans, have their teeth eaten by less enthusiastic species of bacteria.
Cats suffer a lot of tooth decay, so maybe their bacteria are more like ours.
Yeah that bit is huge, but the article cited was focused on one even more mundane:
Big jaws with big teeth and big chewing muscles were not needed with softer foods. Softer foods saved energy, more than the researchers were expecting, and allowed for more energy and nutrition to be extracted from many foods. Our guts adjusted too.
That left more energy for the needs of a larger brain that our smaller jaws made more room for …
Yes a pretty decent trade off. Of course dogs did well in that deal too. They got us to give them food and shelter … and I’d be unsurprised to read that modern pet dogs have relatively smaller teeth and jaws than their wild ancestors did, based on years of eating softer food that we provide.
ETA - not Lamarkian, just that we have selected for other features in head shape rather than the need to chew hard things.
I’m over 70 and have never broken a tooth. I don’t try to shred bones, but I do gnaw on them sometimes, to get the last of the meat off.
Maybe I’m an odd case and it’s very common for humans to have broken teeth? I think of it as something that might happen in a fall, or due to a blow in the mouth; not as something that routinely happens while eating. And human populations prior to modern culture often chewed on tough skins while turning them into leather goods, and ate grains that were by our standards poorly cleaned. They got a lot of wear on their teeth; but did they often just break them?
I stopped giving my Russell Terrier bones when our vet pointed out they weren’t good for his stomach. Most of his stomach issues went away once we stopped. Instead, he gets rawhide treats that last much longer than bones. He could gnaw through a beef bone fairly quickly, so it became a food source rather than a chew thing. Fortunately no broken teeth yet, but he’s only 10 years old.
I spent close to $1000 having the vet repair my dogs broken molar. I don’t think it would have been much cheaper to just pull it. The dog was under a year old, so I didn’t think letting a broken tooth fester in his mouth would be a good thing. The vet told me that if you can’t bend it or break it easily, don’t give it to the dog to chew on. I use to always give my dogs raw bones from the butcher to chew on when they were outside. It kept them quiet for hours. No more. Even rawhide chews are too hard. The problem is that there isn’t anything long-lasting for big dogs that are safe. So now I take the big rawhide rolls and soak them in water until they’re flabby. I think the dogs like them even more when they’re like that.
My dogs chew on Benebones which are made of nylon and they get bloody pretty quick. It definitely irritates their tissues. They don’t chew on them for long, just a few minutes usually to quell anxiety.
Actually what usually happens is my boy will start chewing on it, then the girl slips in and takes it from him and chews for a bit while he skulks around, then when Her Highness is done he’ll go for another round.
My guy just gnaws on these hard rubber things for hours. They’re so spiky I couldn’t close one in my fist without pain, but I never see any blood on them.
He’s also a fool for an elk antler. Never seen a broken tooth.
My dog Duke is an omnivore, where ‘omni’ means everything and anything. His teeth are sharp as well as strong. He has bitten through several ‘indestructable’ chew toys. OTOH my friend used to have a very docile hound that refused to bite into anything hard. That dog didn’t chew soft food either, at meal time he scoop up everything in his bowl with a longer than you’d expect tongue, load it into his mouth and swallow it all in one gulp. His teeth were virtually unused.
According to my dentist, human teeth become more brittle, and therefore more likely to break, as we age. Bite force (some of us bite down much harder than others) & grinding your teeth while you sleep also make breakage more likely. It’s usually just a piece of the tooth that breaks off – I’ve broken off several cusps, but, thanks to modern dentistry, they could be repaired.
My mother’s teeth started to break apart – but not until she was in her late 80’s. Then they (along with a lot of the rest of her) just seemed to start falling apart; no real force needed.
Maybe this happens a lot sooner with some people than with others.