Malocclusion — a misaligned bite — is one of the most common dental conditions in dogs, affecting a significant proportion of the canine population. Unlike in humans, where bite correction is largely a cosmetic matter, dental malocclusion in dogs is often a health issue: abnormal tooth contact can cause chronic pain, soft tissue injury, difficulty eating, and accelerated wear. Understanding the types of malocclusion, which breeds are most affected, and what treatment options exist helps owners recognize when their dog’s bite needs veterinary dental attention.
What Is Dog Malocclusion?
Malocclusion refers to any abnormal positioning of the teeth or jaws that causes the teeth to meet incorrectly when the mouth closes. Normal canine bite is called a “scissors bite” or Class I occlusion: the upper incisors slightly overlap the lower incisors, the lower canines position in the gaps between the upper canines and third incisors, and the upper premolars interdigitate with the lower premolars in a “pinking shear” pattern.
Any deviation from this that causes abnormal tooth contact — or prevents the mouth from closing normally — constitutes malocclusion.
Types of Dog Malocclusion
Class I Malocclusion (Normal Jaw Length, Tooth Position Problems)
The jaws are normal length but individual teeth are in abnormal positions. Subtypes include:
- Lingually displaced canines (base narrow canines): The lower canine teeth angle inward toward the tongue, with the tips potentially contacting the palate. Very common in narrow-headed breeds (Shetland Sheepdogs, Collies, Shelties) and as a consequence of retained deciduous canines. One of the most painful and surgically significant malocclusions
- Rostral crossbite: One or more lower incisors are positioned in front of the corresponding upper incisors — a “flip” of the normal incisor relationship
- Rotated teeth: Individual teeth rotated in their sockets due to crowding
Class II Malocclusion (Mandibular Distocclusion — “Overbite”)
The lower jaw (mandible) is shorter than the upper jaw (maxilla), causing the lower teeth to sit behind their normal position relative to the upper teeth. The lower canines often contact the palate directly behind the upper canines. Common in small breeds and some brachycephalic breeds. Also called mandibular brachygnathism. Signs include:
- Visible gap between upper and lower front teeth when mouth is closed
- Lower canines visibly positioned further back than normal
- Possible palatal trauma from lower canine tips
- Difficulty picking up small objects
Class III Malocclusion (Maxillary Distocclusion — “Underbite”)
The lower jaw is longer than the upper jaw, causing the lower teeth to protrude in front of the upper teeth. Visually, the lower incisors and canines are visible when the mouth is closed. Class III malocclusion is breed-normal for brachycephalic breeds (Bulldogs, Boxers, Pugs, Shih Tzus, Boston Terriers) and is considered a breed characteristic — not a defect — in these dogs. In other breeds, it’s a genetic deviation requiring evaluation. Also called mandibular prognathism or “underbite.”
Class IV Malocclusion (Wry Bite)
An asymmetric jaw development where the upper and lower jaws grow at different rates or in different directions, resulting in a twisted or asymmetric bite. One side of the jaw may be a different length than the other. Wry bites range from mild to severe; significant wry bites can cause serious unilateral soft tissue trauma and difficulty eating. This is the most severe form of malocclusion.
Which Breeds Are Prone to Malocclusion?
Any breed can develop malocclusion, but certain breeds have significantly higher rates due to skull shape and selective breeding history:
Class I (tooth position problems): Shetland Sheepdogs, Rough and Smooth Collies, Greyhounds, and other narrow-headed (dolichocephalic) breeds — lingually displaced canines. Any breed with retained deciduous teeth history.
Class II (overbite): Dachshunds, Poodles, Pomeranians, Chihuahuas, Yorkshire Terriers, and other small breeds.
Class III (underbite): Bulldogs (English and French), Boxers, Pugs, Shih Tzus, Boston Terriers, Cavalier King Charles Spaniels, Lhasa Apsos, Pekingese — these breeds have it as a breed standard feature. In non-brachycephalic breeds, it represents a deviation.
Class IV (wry bite): Any breed; not strongly breed-associated but has genetic components.
When Is Malocclusion a Problem That Needs Treatment?
Not every malocclusion requires treatment. The primary question veterinary dentists ask is: Is the malocclusion causing or likely to cause pain, soft tissue trauma, or functional problems?
Treatment is indicated when:
- Teeth contact the opposing palate, gums, or cheek mucosa
- Abnormal tooth-to-tooth contact causes accelerated wear
- The dog has difficulty closing its mouth or eating
- Lower canines contact the upper palate (common in Class I and II) — this causes chronic palatal ulceration and pain
- The bite deviation is progressive
Treatment is generally not required for cosmetic-only malocclusions where teeth fit without contact problems — including the breed-standard underbites of Bulldogs and other brachycephalic breeds.
How Is Malocclusion Diagnosed?
Your vet evaluates occlusion at every physical exam. A definitive evaluation requires examination with the dog awake (to observe the natural bite) and under sedation or anesthesia (to thoroughly assess tooth-to-gum contact, palatal contact, and take dental X-rays). Dental X-rays are important for assessing root position and ensuring there’s no underlying bone pathology contributing to the bite problem.
Treatment Options for Dog Malocclusion
Interceptive Orthodontics (Puppies)
For puppies with deciduous teeth causing bite problems, or where deciduous teeth are predicted to interfere with normal permanent tooth eruption, extraction of specific deciduous teeth can redirect permanent tooth eruption. This is called interceptive orthodontics and is most effective when done early (4–6 months). Early extraction of retained canines, for example, often allows the permanent canine to naturally migrate to a more normal position.
Crown Reduction with Vital Pulp Therapy
When a tooth is causing trauma (e.g., a lower canine tip penetrating the palate), shortening the tooth by removing the offending cusp, then protecting the exposed pulp with a pulp cap (vital pulp therapy), removes the source of injury without extracting the tooth. This preserves the tooth structure and full root support. It’s the preferred treatment for lingually displaced canines when the goal is keeping the tooth functional.
Orthodontic Movement
Veterinary orthodontics can use inclined planes, ball therapy (specific exercise), or brackets-and-wire appliances to move teeth toward better position. These approaches are used by board-certified veterinary dentists. They require compliance — the dog must wear the appliance without damaging it — and multiple follow-up visits.
Extraction
If a tooth is causing significant trauma and crown reduction isn’t appropriate (e.g., necrotic pulp, insufficient crown height for pulp therapy), extraction eliminates the problem completely. Extraction of the offending tooth trades loss of the tooth for resolution of soft tissue trauma.
Can Malocclusion Be Prevented?
Inherited malocclusions (which describe the majority) cannot be prevented, but their consequences can be minimized through early identification and timely intervention:
- Evaluate every puppy’s bite at 4–6 months when permanent teeth are erupting — before positions become fixed
- Extract retained deciduous teeth promptly (the most modifiable risk factor for Class I malocclusion)
- If you’re breeding, have dogs with known bite abnormalities evaluated by a veterinary dentist before including them in a breeding program — many malocclusions are heritable
If your dog has a confirmed malocclusion, the most important step is referral to a board-certified veterinary dentist (AVDC diplomate) for evaluation and treatment planning. The options available depend on the specific malocclusion type, severity, and age of the dog — and the right specialist can walk through all of them with you.
Related reading: Whippet malocclusion and narrow jaw teeth
Related reading: Lhasa Apso underbite and malocclusion guide
Related reading: Xoloitzcuintli dental care and malocclusion
Related reading: miniature bull terrier dental health