Understanding Linguoverted (Base narrow) Canine Teeth in Dogs

Most people assume their dog’s teeth are fine unless something obvious is wrong — a broken tooth, bad breath, difficulty eating. But some of the most painful dental problems in dogs are completely invisible from the outside. Base narrow canines are a good example. The dog looks normal. They’re eating. They’re not pawing at their face. And every single time they close their mouth, their own teeth are driving into the roof of it.

This is one of the more common dental problems I come across in litter health checks right before the pups are due to meet their new family. It’s a problem where timing genuinely changes outcomes. The earlier it’s identified, the more options there are. Leave it too long, and the window for simple intervention closes.

Here’s what you need to know.

What Are Linguoverted Canine Teeth?

Linguoverted canine teeth — also called base narrow canines or inverted canines — occur when the lower canine teeth angle inward rather than sitting in their normal, slightly outward position. In a dog with normal occlusion, the lower canines slot neatly into the space between the upper canine and upper third incisor when the mouth closes, without touching the palate at all.

When the canines are linguoverted, they don’t fit into that space. Instead, they contact and often penetrate the soft tissue of the palate.

Close-up of a cavoodle puppy's lower canine teeth during a veterinary dental examination, showing base narrow deciduous canines angled medially toward the hard palate Base narrow deciduous (baby) canines in a cavoodle puppy. The lower canines angle inward toward the hard palate rather than outward — a malocclusion worth monitoring closely as adult teeth develop. — Base narrow deciduous (baby) canines in a cavoodle puppy. The lower canines angle inward toward the hard palate rather than outward — a malocclusion worth monitoring closely as adult teeth develop.

Adult dog's open mouth held by a blue-gloved hand showing base narrow lower canine teeth angled medially toward the hard palate during a veterinary dental examination — Base narrow canines in an adult dog. The lower canines sit too far medially, contacting or risking penetration of the hard palate — a permanent malocclusion that often requires dental intervention to prevent chronic soft tissue trauma.

What Causes It?

There are two main causes, and they’re not always mutually exclusive.

Retained deciduous (baby) teeth are the most common culprit. When baby canines don’t fall out at the right time, they block the adult teeth from erupting in the correct position. The erupting adult tooth has no choice but to come through lingually — meaning inward, toward the tongue — because the baby tooth is still occupying the space it should be heading toward. This is particularly relevant in smaller breeds and is why early puppy dental checks matter.

Skeletal jaw conformation is the other cause. If the lower jaw (mandible) is proportionally narrower or shorter than the upper jaw — a Class 2 skeletal malocclusion — the adult canines simply don’t have the space to erupt correctly regardless of what the baby teeth do. This has a significant hereditary component, which matters for anyone breeding from an affected dog (more on that below).

In some cases, a genuinely narrow mandible is the primary issue. Certain breeds are predisposed — particularly long-nosed breeds like Shetland Sheepdogs, Rough Collies, and Shelties — but it can occur in any breed.

What Happens If It’s Left Untreated?

Every time the dog closes its mouth, the lower canines press into the palate. In mild cases this causes chronic ulceration — essentially a persistent pressure sore on the roof of the mouth. In more severe cases, the repeated trauma creates a deep penetrating wound that eventually breaks through into the nasal cavity. This is called an oronasal fistula, and it’s exactly as unpleasant as it sounds — a hole between the mouth and the nose that causes chronic nasal discharge, sinusitis, and recurrent infection.

Dogs rarely show obvious signs of dental pain. They’re stoic by nature and will continue eating and behaving normally even when they’re experiencing significant ongoing discomfort. The absence of obvious symptoms does not mean the mouth is fine.

What Can Be Done — and When?

This is where timing becomes critical. The treatment options available at eight weeks are very different to the options available at eight months, and very different again to what’s available at two years. Acting early keeps more doors open.

6–12 Weeks: Interceptive Extraction of Baby Canines

If the lower baby canines are visibly pressing into the palate and causing trauma, they should come out. This relieves immediate pain and — in some cases — removes the mechanical block that’s forcing the adult tooth inward. When deciduous canine extraction releases what’s called a dental interlock, the lower jaw can sometimes develop more freely and the adult teeth may erupt in a much better position.

This is not guaranteed to resolve the problem permanently. If the underlying cause is skeletal rather than purely a retained tooth issue, the adult teeth are likely to erupt in a similarly compromised position. But even as a palliative step, removing a tooth that’s causing pain every time the puppy closes its mouth is the right call.

5–7 Months: The Critical Window

This is the most important period. Adult teeth are erupting, but they’re not yet fully embedded in bone — they can still be guided. Several approaches may be appropriate depending on severity:

Remove any persistent deciduous teeth immediately. If baby teeth are still present alongside erupting adult teeth, they need to come out without delay. Even partial retention significantly worsens the final position of the adult tooth. You don’t need to wait for the adult tooth to be fully erupted — if the baby tooth is firm and the adult tooth is just beginning to emerge, the baby tooth needs to go now.

Ball therapy can work well for mild cases during this window. An appropriately sized firm rubber ball used for active play — 15 minutes, three times a day — applies lateral pressure to the erupting canines and can guide them outward into a more normal position. Sizing matters: a ball that’s too small will push the teeth in the wrong direction, and one that’s too large will push them down rather than out.

Diagram showing three KONG ball sizes for ball therapy in dogs with linguoverted canine teeth — too small applies incorrect lateral forces, too large pushes teeth downward, correct size pushes canines outward into normal position

Ball sizing matters. Too small and the forces work in the wrong direction; too large and the teeth are pushed down instead of out. Image courtesy of Advanced Animal Dentistry.

Gingivoplasty is a minor surgical procedure that reshapes the gum tissue between the upper third incisor and upper canine to create a guiding ramp. As the lower canine erupts, it contacts this ramp and is directed outward into the correct position. Where it works, it’s often the only treatment needed.

Alt text: Dog's open mouth held by a blue-gloved hand showing a fresh palatal wound after gingioplasty, with palatal trauma visible from base narrow lower canine teeth in a white fluffy dog Title: Palatal Trauma and Post-Gingioplasty Wound in a Dog with Base Narrow Canines | Personalised Mobile Vet Caption: Description: — Post-gingioplasty palatal wound in a dog with base narrow canines. The small bleeding wound on the hard palate shows where the lower canine tooth had been making contact — a direct consequence of the malocclusion left unmanaged.

Crown extensions (inclined plane) are acrylic extensions placed on the lower canines — or an acrylic device attached to the upper jaw — that the teeth contact and tip outward against. The dog cannot fully close its mouth initially, but teeth typically shift into a noticeably better position within around four weeks. This approach is generally preferred over extraction where it’s a suitable option, as it preserves the teeth without requiring lifetime monitoring.

Close-up of a black dog's lower canine tooth fitted with a purple acrylic crown extension or inclined plane orthodontic appliance, held open with a blue-gloved hand during a veterinary dental procedure — A purple acrylic crown extension fitted to a lower canine tooth as an orthodontic inclined plane. The dog contacts the extension when closing, which tips the lower canine outward over approximately four weeks — preserving the tooth without extraction.

7–8 Months and Beyond: Definitive Treatment

If the earlier window has passed or earlier interventions haven’t produced adequate results, definitive treatment options are:

Crown height reduction with vital pulpotomy — The crown of the affected lower canine is surgically reduced in height to a level where it no longer contacts the palate. The pulp chamber is exposed in the process and must be sealed with restorative material. This procedure preserves the tooth root and the structural integrity of the jaw, but it requires lifelong dental radiographic monitoring to confirm the tooth remains healthy.

Anaesthetised dog on a pink towel showing lower canine teeth after crown height reduction procedure, with flat-topped canines visible and pigmented tongue lolling, dental suction tubing in frame — Lower canine teeth following crown height reduction under general anaesthesia. The flat cross-sections of the reduced crowns are clearly visible — a procedure used to eliminate palatal trauma from base narrow canines while preserving the tooth root and vitality through vital pulp therapy.

Post crown height reduction — Image courtesy of Advanced Animal Dentistry.

Extraction of the lower canines is the other option. It solves the problem permanently and requires no ongoing monitoring. The trade-offs are cosmetic rather than functional — occasional tongue protrusion (rare), some narrowing of the lower jaw profile over time, and a small but real risk of jaw fracture during the extraction procedure itself. None of these are reasons to avoid extraction when it’s the right choice; they’re simply things to be aware of going in.

Whatever the situation, there is always a path to making an affected dog comfortable. How that’s achieved varies with the individual — but improving quality of life is always the goal, regardless of which route gets you there.

A Note for Breeders

If your dog has been diagnosed with base narrow canines, the question of whether to breed from them deserves a direct answer: the advice is not to.

Jaw conformation abnormalities have a well-established hereditary basis. Breeding from affected dogs carries a real risk of passing the same trait — and the same problems — to their offspring. This recommendation holds regardless of whether the affected dog has been successfully treated; correcting the tooth position in one animal doesn’t change what they pass on genetically.

This applies even when the cause appears to be primarily a retained baby tooth. Where there is genuine uncertainty about whether the underlying conformation is hereditary or purely developmental, a conversation with your vet before breeding decisions are made is strongly recommended.

The American Veterinary Dental College (AVDC) and the European Veterinary Dental College (EVDC) both advise against breeding from dogs with hereditary malocclusions. Most national kennel clubs hold the same position.

When Should You Raise It With Your Vet?

If you have a puppy — especially from a breed known to be predisposed — ask your vet to check the canine teeth at every puppy visit. The earlier an issue is identified, the more options are on the table.

For breeders, a dental check at the 6–8 week litter vaccination is the right time to flag any concerns. Baby teeth that are visibly pressing into the palate at that age should not be left until the next visit.

If your adult dog has never had their teeth properly assessed, it’s worth doing. Palatal scarring from years of chronic trauma can be present in dogs that show no outward signs of discomfort at all.

References

1. Wiggs, R.B. & Lobprise, H.B. (1997). Veterinary Dentistry: Principles and Practice. Lippincott-Raven, Philadelphia.
1. Niemiec, B.A. (ed.) (2010). Small Animal Dental, Oral and Maxillofacial Disease: A Colour Handbook. Manson Publishing, London.
1. Gracis, M. (2014). ‘Orthodontics’, in Tutt, C., Deeprose, J. & Crossley, D. (eds.) BSAVA Manual of Canine and Feline Dentistry, 4th edn. BSAVA, Gloucester, pp. 233–265.
1. Hale, F.A. (2009). ‘Juvenile veterinary dentistry’, Veterinary Clinics of North America: Small Animal Practice, 35(4), pp. 789–817.
1. American Veterinary Dental College (AVDC) (2019). Nomenclature: Abnormalities of Occlusion. Available at: avdc.org (Accessed: July 2026).
Advanced Animal Dentistry (2024). Linguoverted Canine Teeth in Pets. Available at: https://animaldental.com.au/linguoverted-canine-teeth-pets/ (Accessed: July 2026).

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