Dentistry Notes

Dentistry

Dental Morphology and Terminology

  • Tooth Structure and Classification     

    •  Brachyodont Teeth:         

      •  Characterized by limited eruption and development time.         

      •  Found in species such as humans, carnivores, and pigs.     

    •  Hypsodont Teeth:         

      •  Characterized by continual growth and eruption over the animal's lifetime.        

      •  Found in horses, rodents, and lagomorphs (rabbits).         

    •  Radicular Hypsodont: Apices eventually close, and growth discontinues.        

    •  Aradicular Hypsodont: Lack true root structure; teeth grow throughout the life of the animal.

  • Types of Teeth in Dogs and Cats     

    •  Incisors: Rostral location; used primarily for gnawing and grooming.     

    •  Canines: Long teeth; used for prehending (grasping) and holding objects or prey.     

    •  Premolars and Molars: Also known as "cheek teeth"; used for shearing and grinding food.     

    •  Diphyodont Definition: Most mammals are diphyodont, meaning they possess two sets of teeth:         

    •  Deciduous Teeth: Also referred to as primary or "baby" teeth.         

    •  Permanent Teeth: Secondary or adult teeth.         

  • Modified Triadan Numbering System     

    •  Quadrants:         

    •  100 series: Right maxillary quadrant.         

    •  200 series: Left maxillary quadrant.         

    •  300 series: Left mandibular quadrant.         

    •  400 series: Right mandibular quadrant.     

    •  Numbering Pattern: Each tooth is assigned a two-digit number starting at the anterior midline and moving caudally along the dental arch.     

    •  Deciduous Teeth Series: Numeral series 500 through 800 are used for deciduous teeth.

  • Anatomical Directional Terms     

    •  Mesial (M): Surface toward the midline of the dental arch.     

    •  Distal (D): Surface away from the midline of the dental arch.     

    •  Coronal: Direction toward the crown of the tooth.     

    •  Apical: Direction toward the root tip.     

    •  Gingival/Cervical: Area near the gum line.     

    •  Interdental space: Space between adjacent teeth.     

    •  Interradicular: Space between the roots of a single tooth.

Professional Dental Roles and Ethics

  • Common Technician Tasks     

    •  Dental cleanings, including periodontal debridement and polishing.     

    •  Obtaining diagnostic information via dental charting and dental radiography.     

    •  Intraoperative assistance during oral surgeries.     

    •  Client education regarding oral health.

  • Dental Care Services Levels     

    •  Professional Dental Cleanings: Performed at most standard clinics.     

    •  Advanced Dental Care: Includes Orthodontics, Endodontics, Exodontics, and advanced periodontal therapy.

  • Ethical and Legal Considerations     

    •  Subject to specific state regulations.     

    •  AVDC (American Veterinary Dental College) Position Statement: Technicians are permitted to perform cleanings and procedures that do not result in alterations in the shape, structure, or position of teeth within the dental arch.    

    •  Support exists for advanced training to allow additional responsibilities.

Occlusion and Malocclusion  

  •  Occlusion: The spatial relationship of teeth within the mouth.     

  •  Malocclusion: An incorrect alignment of the teeth or jaws.     

  •  Scissors Bite: Normal canine/feline occlusion where incisors closely overlap like scissors.     

  •  Anisognathism: A condition where the upper jaw is wider than the lower jaw.

  • Molar Characteristics     

    •  Used for crushing food.     

    •  Dogs: Possess two maxillary molars and three mandibular molars.     

    •  Cats: Possess few flat occlusal surfaces.     

    •  Caries Lesions ("Cavities"): Possible due to incomplete enamel development, though carnivores are generally less susceptible than humans.

  • Secondary Malocclusion Classes     

    •  Class I: Jaw length is normal, but one or more teeth are in an abnormal position.     

    •  Class II (Mandibular Distoclusion): The mandible is shorter than the maxilla.    

    •  Class III (Mandibular Mesioclusion): The maxilla is shorter than the mandible.    

    •  Wry Bite: Asymmetry between the maxilla and mandible.

  • Skull Shapes and Orthodontics     

    •  Brachycephalic: Short-headed (e.g., Boxers, Bulldogs, Persian cats).     

    •  Mesaticephalic (Mesocephalic): Medium-headed (e.g., Beagles, Labrador Retrievers).     

    •  Dolichocephalic: Long-headed (e.g., Sighthounds, Siamese cats).

Oral Examination Procedures

  • Medical History and Symptoms      Pawing at the mouth.      Dropping food or walking away after the first bite.      Rubbing the face on furniture.      Aggression when the face is touched.      History includes assessment of at-home care, diet, treats, and toys.

  • Extraoral Examination      Assessment of face, head, eyes, ears, and neck.      Checking for symmetry, atrophy, enlargement, pain, or swelling.      Observation of discharge, odor, or pain from ears/eyes.      Bilateral Retropulsion of Eyes: Assessing for resistance or pain.      Palpation of salivary glands and lymph nodes.

  • Intraoral Examination (Performed under general anesthesia)      Evaluation of soft tissues, dental structures, and the periodontium.     

    •  Chronic Ulcerative Paradental Stomatitis (CUPS): Mucosal ulcerations adjacent to teeth with diseased plaque; caused by bacteria.     

    •  Evaluation of: Lip skin/mucosa, caudal cheek lining near carnassials/molars, duct openings, hard and soft palates, pharynx (for inflammation/neoplasia), tongue (dorsal, ventral, lateral, floor, base), and tonsils.

  • Clinical Tools     

    •  Periodontal Probes:         

      •  Williams' markings: Incremental measurements of attachment levels, sulcus, and pocket depths.         

      •  Used to assess furcation, lesion size, and tooth mobility.         

      •  Technique: Insert into sulcus parallel to the root's long axis; "walk" the probe around the tooth.     

    •  Dental Explorer: Used for topographical exploration via tactile vibrations.        

      •  Detects surface irregularities, completeness of debridement, fillings, caries, feline resorption, and pulp exposure.     

    •  Modified Pen Grasp: Using a tripod position with three fingertips for precise tactile control during probing/exploring.

Dental Radiography

  • Importance: Critical for identifying pathology not visible to the naked eye, such as root resorption, caries, periapical radiolucency, bone loss, retained roots, unerupted teeth, osteomyelitis, neoplasia, fractures, and TMJ disease.

  • Equipment:        

    •  Digital Radiography:         

    •  Direct Radiography (DR): Electronic sensor transmits image directly to the computer (most common).         

    •  Computed Radiography (CR): Uses a phosphor plate and scanner; useful for large-breed dogs.

  • Positioning Techniques:     

    •  Paralleling Technique: Film/sensor placed parallel to the long axis of the tooth.    

    •  Bisecting Angle Technique: Used to minimize distortion when the film cannot be placed parallel.

  • Errors: Cone cutting, elongation, foreshortening, and incorrect exposure (too dark/light) increase anesthetic time and radiation exposure.

  • Radiographic Density:     

    •  Radio-dense (White): Areas that block/absorb radiation (e.g., cementum, dentin, bone).     

    •  Radiolucent (Black): Areas where x-rays pass through (e.g., soft tissue, periodontal ligament space).

Periodontal Disease and Treatment

  • Structures of the Periodontium:     

    •  Periodontal ligament (PDL).     

    •  Gingival connective tissue.     

    •  Alveolar bone (forming the socket).     

    •  Cementum.

  • Disease Progression:     

    •  Gingivitis: Inflammation of the gingiva.     

    •  Periodontitis: Accumulation of plaque and the body's resulting immune response.     

    •  Involves Shift from Gram-positive aerobic bacteria to Gram-negative bacteria.    

    •  Results in destruction of junctional epithelium, periodontal ligament, and increased tooth mobility.

  • Periodontal Debridement:     

    •  Nonsurgical removal of hard/soft deposits from supragingival and subgingival surfaces.     

    •  Includes scaling, root planing, and polishing.

  • Power Scaling:     

    •  Sonic Scalers: Driven by air compressors; frequency range of 2000 – 9000{ cycles per second (cps); audible sound.     

    •  Ultrasonic Scalers: Driven by electrical energy; frequency range of 18000 – 50000 { cps}. Processes include acoustic turbulence (microstreaming) and cavitation.     

      •  Types: Magnetostrictive (metal stack/ferrite rod) and Piezoelectric.     

  • Hand Instruments:     

    •  Sickle Scalers: Supragingival use; triangle shape; coronal scaling.     

    •  Curettes: Subgingival use; semicircle shape; used for scaling and root planing (e.g., Gracey, Langer).     

    •  Three parts: Handle, Shank, and Working end.

  • Polishing: Removes extrinsic stains and smooths the surface. Usually performed with an electric motor or air compressor prophy angle.

Advanced Procedures and Pathologies

  • Regional Nerve Blocks:     

    •  Benefits: Preemptive analgesia, prevents "wind-up pain," provides postoperative pain relief, and allows for lower inhalant anesthetic concentrations.    

    •  Types:         

      •  Infraorbital: Ipsilateral maxilla.         

      •  Middle Mental: Ipsilateral rostral lower lip near labial frenulum.         

      •  Inferior Alveolar: Blocks soft tissue and bone; Lidocaine often preferred.         

      •  Maxillary: Blocks entire quadrant (buccal and palatal sides).

  • Management of Bone Loss:     

    •  Vertical Bone Loss: Along the long axis; easier to treat.     

    •  Horizontal Bone Loss: Involves multiple furcations; more difficult to treat.

  • Specific Dental Conditions:     

    •  Tooth Resorption: Common in cats; increasing in dogs. Involves cervical portions or roots. Treatment includes extraction or crown amputation. 5 stages based on involvement amount; 3 stages based on root structure.     

    •  Endodontics: Treatment of the pulp and periapical tissues (root canal). Includes disinfecting and obturation (filling).     

    •  Restorative Dentistry: Crowns (metal or zirconium) to maintain function, especially for canine and maxillary fourth premolar teeth in dogs.     

    •  Oral Neoplasia: Rare but aggressive. Cats often have Squamous cell carcinoma (SCC). Dogs may have benign gingival tumors (fibromas) or malignant options like melanoma, SCC, or osteosarcoma.     

    •  Stomatitis: Diffuse oral cavity inflammation, common and painful in cats; may require full-mouth extraction.     

    •  Masticatory Myositis: Immune-mediated disease targeting myosin in jaw muscles. Acute phase involves swelling; chronic leads to atrophy.     

    •  Jaw Fractures: Symphyseal separation often requires rigid fixation or a tape muzzle.

Equine Dentistry

  • Anatomy and Physiology:     

  •  Deciduous Teeth: 24 teeth.     

  •  Permanent Teeth: 36 to 44 teeth.     

  •  Cementum covers occlusal surfaces with thin enamel underneath; both wear down over time.     

  •  Age Determination: Assessing occlusal features, eruption times, and the presence of the "dental star."     

  •  Canine Teeth: Usually absent or rudimentary in females; four permanent teeth in males.     

  •  Premolars: "Wolf teeth" are small premolars.

  • Common Equine Problems:     

    •  Tooth Root Abscess: Caused by pulp exposure, fractures, or decay.     

    •  Jaw Discrepancies: Mandibular brachygnathism ("parrot mouth," lower jaw short) and Maxillary brachygnathism ("monkey mouth," upper jaw short).     

    •  Wry Nose: Deviation of the nose from the midline.     

    •  Cemental Hypoplasia and Caries: Other common conditions affecting horses.