Overview of Canine Dental Health and Disease

Susan E. Anderson, DVM, DABVP
University of Florida, College of Veterinary Medicine

Why is veterinary dentistry important?

every pet has a mouth
85 percent of pets over two years has some evidence of periodontal disease
dental health contributes to overall health
goal should be prevention rather than treatment
Dental Disciplines
Pedodontics: puppy dentition
Orthodontics: guidance and correction of malocclusion
Periodontics: treatment of supporting tissues of teeth
Endodontics: treatment of disease affecting tooth pulp
Exodontics: extraction of teeth
Oral surgery: surgery of the oral cavity
Restorative Dentistry: restoration of form and function
Prosthodontics: construction of appliances to replace missing teeth and/or adjacent structures

Anatomy
Head
Mesocephalic: German Shepherd Dog, Labrador
Brachycephalic: Boxer, Bulldog
Dolichocephalic: Collie, Greyhound

Dentition
• Incisors: nibbling grooming
• Canines: holding, tearing, largest and strongest teeth
• Premolars: cutting, holding, shearing
• Molars: grinding

Tooth Structure
• Teeth designed to self-cleaning
• Natural diets of fiber, sinews, tendons
• Conical in shape
• Few contact points to trap debris
• Alkaline pH of saliva deters bacteria

Periodontium
• Supporting structures of the teeth
• Gingiva, periodontal ligament, alveolar bone

Tooth Anatomy
• Crown
• Root
• Enamel: covers the crown, hardest substance in body
• Dentin: bulk of the tooth structure
• Pulp: blood and nerve supply
• Gingival sulcus: space between gingival and tooth, 1-3 mm
• Cementum: covers root


Eruption Times

Deciduous teeth
• Incisors: 3-4 weeks
• Canines: 3 weeks
• Premolars: 4-12 weeks

Permanent teeth
• Incisors: 3-5 months
• Canines: 4-6 months
• Premolars: 4-6 months
• Molars: 5-7 months

Normal Occlusion
• Upper incisors in front of lower incisors (scissors bite)
• Lower canine fits evenly between upper canine and 3rd incisor
• Premolars fit in a “pinking shear” fashion, interdigitate
• Upper 4th premolar fits outside (lateral) to lower 1st molar

Malocclusion
Class 0 occlusion: normal or normal for breed
Class 1 occlusion: jaw relationship normal but one or more teeth out of position
• Base narrow canines
• Anterior crossbite
• Lance canine (spear, tusk)
• Posterior crossbite
Class 2 occlusion: mandible short in relation to maxilla – brachygnathic
• Overbite
• Unilateral wry (1/2 maxilla short)
Class 3 occlusion: maxilla short in relation to mandible – prognathic
• Underbite
• Unilateral wry (1/2 mandible short)

Pedodontics

Missing teeth
• Never developed, never erupted, trauma
• Radiograph (x-ray)

Retained deciduous teeth
• No 2 teeth of the same type should occupy the same space!
• Causes malocclusion, crowding
• Increased incidence of periodontal disease and tooth loss
• Extraction as soon as possible
• Caution not to disturb developing permanent tooth

Interceptive orthodontics
• Early extraction of deciduous teeth to prevent “interlock”
• Removes interference to allow for maximal jaw growth
• Will not cure a pre-existing genetic problem
• DO NOT trim or cut deciduous teeth – pain, infection, potential damage to permanent
tooth

Fractured deciduous teeth
• Frequent: running into objects, catching hard toys, overzealous play or tug-o-war
• Requires extraction
• If untreated: pain, infection, damage to permanent tooth especially enamel

Supernumerary teeth
• Extra teeth
• Usually incisors or premolars but can be canines
• Can cause crowding; if so, extract

Cranial mandibular osteodystrophy

• Inherited condition, most common in West Highland White Terriers
• Non-neoplastic (not cancerous) bone formation of the temporomandibular joint and occ
spreads to mandible
• Pain, fever, reluctance to eat, difficulty opening jaw
• Treat symptoms of pain, lessens with age.

Periodontal Disease
• Inflammation of the structures supporting the teeth
• Normal gingival: smooth, coral pink, well attached, sulcus 1-3 mm
• Plaque: accumulation of bacteria, glycoproteins, polysaccharides that adhere to tooth

•  Tartar (calculus): plaque mineralizes within 48 hours, forms more readily in alkaline saliva
Predisposing Factors for Periodontal Disease
• Overcrowded, rotated teeth
• Retained deciduous teeth
• Soft, sticky diet with no brushing
• Slab fracture of tooth exposing rough surface for plaque accumulation
• Malocclusions
• Trauma
• Chemical irritants
• Systemic disease: uremia, diabetes
• Open mouth breathing: dries saliva

Clinical Signs of Periodontal Disease
• Halitosis
• Inflamed gums and/or bleeding
• Asymmetrical facial swelling
• Mobile teeth
• Gingival recession
• Nasal discharge
• Exposed roots
• Gingival pockets (> 3mm)
• Vertical and horizontal bone loss

Smaller Breeds More Predisposed to Periodontal Disease
• Closer teeth decreases tooth’s self-cleaning ability
• Smaller the dog the thinner the supporting bone
• Bacterial and inflammatory by-products can damage thin bone quickly
• Bone thinnest at incisors, frequent location of disease loss
• Smaller dogs live longer
• Open mouth breath more frequently

States of Periodontal Disease
Stage 1: gingivitis
• Only reversible state
• Gingival becomes swollen, rolled and red

Stage 2: early periodontitis
• Increased gingival pocket depth
• Up to 25 percent attachment loss
• Bacteria begins to change from aerobic to anaerobic
• Teeth stable

Stage 3: moderate periodontitis

  • • Deeper pockets anaerobic bacteria colonizes
  • Up to 50 percent attachment loss (bone and gingival)

• Slight mobility of teeth

Stage 4: severe periodontitis
• More than 50 percent attachment loss
• Increased severity of infection
• Salvageability of teeth is questionable
• Tooth mobility can be great

Treatment of Periodontal Disease
• Thorough prophylaxis – complete oral exam, supra gingival scaling, root
planning/subgingival curettage, polish, flush, repeat exam
• Radiographs
• Root planing – closed (<5 mm) vs. open (>5 mm)
• Extractions, periodontal surgery, endodontics (root canal)
• COMMITMENT to home care
• Reassess in 1-3 months

Indications for Antibiotic Use
• Oral ulceration
• Severe periodontitis
• Evidence of systemic disease (renal, cardiac, diabetes, Cushing’s)
• Additional surgery being performed
• Bone implants (hip replacement)
• Pulp capping

Antibiotics
• Ampicillin
• Amoxicillin
• Amoxicillin-clavulanate (clavamox)
• Clindamycin (antirobe)
• Metronidazole (Flagyl)
• Doxycycline

Other Dental Abnormalities
Caries (cavities)
• Bacterial degradation of enamel, not common in dogs
• Maxillary 1st molar most common

Abrasions (external source)
• Excessive grooming
• Toys especially tennis balls
• Rocks, fences, cages

Attrition (wear from other teeth)
• Malocclusion especially level bite
• Increased risk of fracture if mid tooth (canine)

Enamel hypoplasia (reduced formation of enamel, enamel dysplasia)

• Hereditary
• Systemic infection causing high fever during tooth formation
• Viral infection during tooth formation (distemper)
• Enamel organ damaged during early extraction of deciduous tooth
• Other trauma during formation

Discolored teeth
• Pink – purple – tan
• Pulpal hemorrhage and/or tooth death usually due to trauma
Inapparent oral nasal fistula
• Pocket that communicates with nasal cavity
• Lingual side of upper canine
• Rest of tooth may have little disease present
• More common in small dogs

Foreign bodies
• Wedged between upper 4th premolars
• Sticks, bones

Home Care
Brushing
• Gradual training with reward/positive reinforcement
• Ideal is daily
• Cleaning under edge of gums most important (gingival sulcus)
• Nothing truly replaces the mechanical disturbance of plaque
• Finger brush, gauze over finger (doesn’t clean sulcus well)
• Pet designed brush or small, soft child’s brush
• DO NOT use hand scalers or curettes regardless of training
o Trauma to gingival
o Excessive wear to enamel (not that thick)
o Without polishing, roughened surface of the enamel allows plaque to return
that much faster

Toothpastes
• Many choices
• Avoid human toothpaste
o Too much fluoride – dogs don’t spit
o Foaming agents can cause vomiting

Rinses
• Chlorhexiding gluconate 0.12 percent oral rinse
o CHX, Nolvadent, Hexarinse
o Inhibits plaque formation
o Bacteriostatic and bactericidal
• Zinc gluconate/Vitamin C
o Maxiguard
o Promotes healing of ulcerated oral tissues

Chew Toys

• Monitor to avoid swallowing, fractured teeth, choking
• Kong toys – dental
• Nylabone products
• Rawhides, some have tartar control coating (CET)

Diets and Treats
• T/D (Hill’s Pet Nutrition) fibers designed to squeegee teeth
• Tartar Check (Heinz) coated with hexametaphosphate
• Dentabone (Waltham)
• Dental Chew (Waltham)

Dog Owners and Breeders Symposium
July 28, 2001
University of Florida
College of Veterinary Medicine