The Brussels Griffon's undershot jaw is written into the breed standard, which means it is normal for the breed and still consequential for the teeth. When the lower jaw extends further forward than the upper, the tooth surfaces that were designed to meet each other stop meeting. Some teeth take contact they were never built for and wear unevenly. Others take no contact at all and lose whatever self cleaning benefit they would have had. Meanwhile the shortened upper jaw crowds the teeth it does hold. None of this is a defect you can fix at home, but all of it tells you where to concentrate.
What undershot actually means
In an undershot bite, sometimes described as a class three malocclusion or a prognathic mandible, the lower incisors sit in front of the upper ones rather than just behind them. In many Brussels Griffons the effect extends further back, changing how the premolars and molars line up.
Occlusion is not cosmetic. A normal bite means the upper and lower teeth shear past each other during chewing, which wipes plaque off certain surfaces as a side effect. Change that relationship and the wiping stops happening in some places while pressure concentrates in others.
The three consequences that matter
Uneven wear. Where teeth contact at the wrong angle, enamel wears faster in one spot. Worn enamel is a rougher surface, and rough surfaces hold plaque.
Surfaces that never get cleaned. Teeth that no longer meet an opposing surface get no mechanical action at all during eating. Those are the teeth that accumulate deposit fastest and the ones owners are least likely to inspect, because they are not the obvious ones at the front.
Soft tissue contact. In some dogs a lower canine or incisor sits against gum or lip tissue instead of slotting into its normal space. Persistent contact irritates that tissue. This is a finding for a veterinarian to assess, because whether it needs intervention depends entirely on where the contact is and how much damage it has caused.
Where to look, structure by structure
Go through that list once a week and you are covering the geography that actually fails in this breed rather than the parts that are simply easy to see.
Adjusting the brushing technique
A short muzzle and an offset bite change the mechanics of brushing. Support the head from beneath the jaw rather than gripping over the top of the muzzle, which presses on an airway that already has less room than most.
Approach from the side with the lip lifted rather than trying to open the mouth. You want the bristles at a shallow angle against the gum line on the outer surfaces. The upper front teeth deserve extra attention here precisely because the bite gives them so little natural cleaning, which is the opposite of the usual advice to prioritise the back.
Keep sessions brief. Flat faced dogs tire under restraint faster than others, and a Griffon breathing hard should be released at once and tried again later. Use dog toothpaste only.
What belongs to your veterinarian
Malocclusion assessment is not a home task. A veterinarian examining your dog can tell you whether the bite is causing tissue trauma, whether any teeth are being worn to a degree that threatens the pulp, and whether any of it warrants intervention. Puppies deserve particular attention, because an adult tooth erupting into the wrong position is easier to address early than late. Raise the bite specifically at your next appointment rather than assuming it has already been noted.
That same appointment is where the interval for professional cleaning gets set. Everything covered above is home care, and home care works only on the visible crown and the gum edge. Assessment and treatment below the gum line require probing, full mouth radiographs and general anesthesia, and no amount of diligence with a brush changes that. The two run in parallel. The Merck Veterinary Manual's chapter on mouth disorders in dogs covers malocclusion among the conditions worth understanding, and the AVMA's pet dental care page explains why the anesthetic step is not optional.
The chew that suits a small, awkward bite
An offset jaw makes some chews genuinely hard to work through, and a dog who cannot get purchase on a chew simply abandons it. Ark Naturals' Soft Brushless is the softer format in the line, intended for dogs who do better with something that yields rather than something rigid, and it is worth considering for a Griffon that struggles with firmer chews. You can find it and the rest of the range in the Ark Naturals dog collection, with the full catalogue at Ark Naturals.
Match the size to your dog, supervise every chew, and count it in the daily calorie total. A Brussels Griffon has very little margin for extra food.
Signs that need attention today
A swelling on the face or under the jaw. A tooth that has fractured with pink or dark tissue visible at the break. Gums bleeding without contact. A sore or ulcerated patch where a lower canine touches. Dropping food, pawing at the mouth, or refusing to chew. And any increase in breathing effort, which in a brachycephalic dog always takes priority over the dental question.
Frequently asked questions
Is an undershot jaw a health problem or just a breed trait?
Both, in a sense. It is standard for the breed and not something to correct cosmetically, but it does change how teeth wear and where plaque collects, which is why it deserves specific attention rather than being ignored.
Do the misaligned teeth need to be removed?
Sometimes, and sometimes not at all. That judgement requires an examination and radiographs, and it depends on whether a particular tooth is causing tissue damage or has been worn far enough to threaten the pulp.
My puppy's bite looks very undershot. Should I wait and see?
Have it looked at rather than waiting. Bites change as adult teeth erupt, and problems caught during that window are usually simpler to manage than the same problems addressed in an adult mouth.
Which teeth should I prioritise when brushing?
The upper front teeth and the upper cheek teeth. The bite leaves the upper arcade with the least natural cleaning, so it needs the most help from you.
Does a softer chew clean less effectively than a hard one?
Not necessarily. What matters is contact time with the tooth surface, and a chew a dog can actually work through delivers more of that than a rigid one the dog gives up on or breaks a tooth against.