Flat-faced dogs carry the same 42 adult teeth as any other dog, packed into a jaw that selective breeding shortened by 20 to 30 percent. The teeth themselves never shrank to match. They rotate, overlap, and sometimes fail to erupt at all, and every point of overlap becomes a sheltered pocket where plaque sits undisturbed by tongue, lip, or chewing.
What does brachycephaly actually change?
The skull shortens along its length while the width stays roughly the same. Picture a shelf built for twelve books that gets cut down to nine inches without anyone removing books. Something has to turn sideways.
In a Pug or a French Bulldog, the premolars are usually what turn. The second and third upper premolars rotate 30 to 90 degrees out of alignment, so instead of sitting in a neat row with clear gaps between them, they wedge against each other at odd angles. Radiographic surveys of brachycephalic breeds routinely find rotated premolars in the majority of dogs examined, along with unerupted or missing teeth that never had room to come in.
Which teeth end up out of position?
The pattern is consistent enough to predict:
- Upper second and third premolars — the classic rotation, often sitting nearly perpendicular to the arcade.
- Lower first premolars — frequently absent or impacted below the gum.
- Incisors — crowded into a curved row, sometimes with a tooth pushed forward or backward out of line.
- Upper first molars — occasionally tilted inward toward the palate.
- Lower canines — displaced by a jaw that grew at a different rate than the upper.
An impacted tooth that never erupts is not harmless. It can form a dentigerous cyst, a fluid-filled sac that slowly expands and erodes the surrounding bone, and it does so silently.
Why does crowding matter more than crookedness?
Because of what collects in the gaps. Two teeth touching along a flat face create a sliver of space that nothing mechanical can reach — not a brush bristle, not a chew, not the tongue. Bacteria colonize that sliver, the gum next to it inflames, and inflammation goes to work on the bone anchoring both roots.
Small brachycephalic breeds also have thinner alveolar bone to begin with. There is less material between the root and the outside world, so bone loss that a Labrador could absorb for years becomes structurally significant much faster in a Shih Tzu. That combination — trapped plaque plus a thin bone budget — is why flat-faced dogs feature so heavily in discussions of periodontal disease. The 2019 AAHA dental care guidelines recommend earlier and more frequent assessment for exactly these breeds.
Do all flat-faced breeds crowd the same way?
No. The degree of shortening and the shape of the lower jaw both vary.
A Boston Terrier and a Pug both have short faces, but the Pug's undershot lower jaw pushes its incisors forward into a fan, while the Boston's narrower jaw drives rotation further back. Care that ignores this ends up generic and unhelpful.
What does a workable daily routine look like?
Start with access. Many flat-faced dogs resent having their mouths opened because their airway already feels compromised, so lip-lifting beats jaw-opening every time. Work along the outer surfaces with a soft brush or a finger sleeve, spend the most time on the rotated premolars, and keep sessions to 30 seconds per side at first.
For dogs who won't accept a brush, a chew that flexes rather than fractures gives you some mechanical action. Soft Brushless was formulated for smaller, less powerful jaws — the texture yields under moderate bite pressure, which matters when a dog's occlusion doesn't let them apply force evenly. Flat-faced dogs also carry meaningful anesthetic considerations, so discuss airway management with your veterinarian well before scheduling any cleaning, rather than on the morning of the appointment.
If you're building a routine from scratch, our guide to brushing frequency covers realistic starting points.
When should you ask about extractions?
When a tooth is causing more trouble than it is worth. That sounds harsh, and owners resist it, but a rotated premolar sitting in a pocket of inflamed tissue is not doing meaningful chewing work and is actively costing the dog bone.
Veterinary dentists often recommend selective extraction of crowded premolars in brachycephalic dogs precisely because it converts an unmaintainable geometry into a maintainable one. After the crowded tooth is gone, the gap can be cleaned. Dogs eat normally afterward, including dry food, and the ones who were quietly uncomfortable frequently become noticeably brighter.
Retained deciduous teeth deserve the same urgency. If a baby canine is still present alongside the adult canine past about seven months, two roots are occupying one socket and the crowding is permanent unless someone removes one of them.
Frequently asked questions
At what age should a flat-faced puppy get a dental assessment?
Around six to seven months, when the adult teeth have erupted but the jaw is still developing. This is the window where retained baby teeth can be removed cleanly and where a veterinarian can radiograph for unerupted premolars. Waiting until the first adult cleaning at two or three years means missing the chance to act on both.
Is anesthesia riskier for a Pug or French Bulldog?
There is added complexity rather than automatic danger. Narrow airways, elongated soft palates, and a tendency toward regurgitation mean these dogs need careful pre-oxygenation, prompt intubation, and closer monitoring during recovery. Practices that handle brachycephalic patients regularly build these steps into their protocol as a matter of routine.
Can crowded teeth be straightened?
Orthodontic movement is possible in dogs and is occasionally used to relieve a tooth striking soft tissue, but it is rarely used for cosmetic straightening. In a crowded brachycephalic mouth there is nowhere to move a tooth to, so extraction or diligent maintenance are the realistic options.
Why does my Frenchie's breath change so quickly after a cleaning?
Odor comes from volatile sulfur compounds produced by anaerobic bacteria living in oxygen-poor spaces. Crowded mouths have more of those spaces than open ones, so the bacterial population that produces odor rebuilds faster. Consistent daily disruption slows the rebound more effectively than any single deep clean.
Do dental chews work if my dog's bite doesn't line up?
Partially. A misaligned bite means the chew contacts some teeth well and others barely at all, so coverage is uneven. Softer chews conform better to irregular surfaces than hard ones, and pairing a chew with even brief brushing on the rotated teeth closes most of the gap.