EQUINE DENTISTRY Mike Black, DVM Nebraska Equine Veterinary Clinic Omaha NE History Of Equine Dentistry Some evidence of equine dentistry dates back to 2,000 B.C. Bit-Seats: Information on bit-seats dates back to the British Veterinary Journal 1865 Equine dentistry was much better in late 1800 s then in the 1900 s 1900-Present Day: Many advances are made in equine medicine including most recently equine dentistry Who Should Do Equine Dentistry? Only veterinarians It is illegal to float teeth as a lay person unless it is on your own horse Considered the act of practicing veterinary medicine No protection for consumer if not licensed Sedation Some Facts To Know About Teeth Human teeth Brachydont = short crowned teeth. Crown is covered with enamel Once through the enamel the softer dentin, nerves and pulp chamber are exposed. Humans chew their food in a pounding motion. Some Facts To Know About Teeth Horses Hypsodont = long crowned teeth Enamel ridges throughout The crown has exposed enamel, cementum, and dentin and pulp chambers run throughout Horses grind their food in a circular motion! Enamel Dentin Pulp Our Teeth
Occlusal View Of A Molar Horses Anatomy! Enamel Folds: Hardest substance (Red Lines)! Cementum: Supports the enamel (Blue Arrows)! Dentin: Prevents access to pulp cavity (Green Arrows) Incisors Canines Wolf Teeth Premolars Molars Anatomy: Incisors Purpose: To bite off grass or hay Should be even and parallel to the ground at eye level. Upper and lower incisors should touch when at rest. Contact (occlusal) surface is level Lower incisor are directly below uppers Anatomy: Incisors Incisors Anatomy: Cheek Teeth Have to be level to maintain normal molar occlusion (contact when chewing) Mandible moves to the side for molar contact NO molar contact at rest 3 premolars per arcade Have baby teeth 3 molars per arcade No baby teeth Black line show position of the last cheek tooth to the corner of the eye
Anatomy: Cheek Teeth Anisognathic Unequal jaws Upper row of teeth wider than lower row of teeth Anatomy Cheek Teeth Chewing surface tilted 12-15 degrees Outer edges of upper and inner edges of lower arcades get sharp points Tongue presses outward on lower teeth Cheek presses on the upper teeth Anatomy Cheek Teeth Chewing Motion Resting position Incisors in contact Molars not in contact Chewing Motion Chewing Motion Lateral movement of lower jaw Power Stroke Molars in contact with cutting and grinding feed
Back to resting phase Incisors come back into contact Chewing Motion Anatomy Teeth grow until erupt into wear Teeth erupt until the root is reached Teeth last 20 to 30 years Roots Are Deeply Imbedded ROOT FORMATION Teeth Erupt All Throughout A Horses Life How Age Affects Teeth 3 year old 24 year old AGE 3 33 Age 26
Dental Examination History Examination of head and oral cavity Oral disease and malocclusions Correction Dental Tools Full mouth speculum Essential for examining and treating dental and oral problems Common Dental Problems 1-5 Years Baby teeth Malocclusion from cap retention Eruption bumps Wolf Teeth Routine floating necessary Bit seats Canine Teeth Males Erupt 4 to 5 years of age Deciduous Teeth Deciduous Teeth are also known as caps or baby teeth. The incisors and premolars are deciduous. In the process the deciduous tooth is absorbed and the permanent tooth moves into position. It takes approximately 4-6 months for a tooth to reach full wear. When Do They Shed? Deciduous Tooth Is Ready Approximate Times for Incisors Central Incisors 2 Years 6 months Lateral Incisors 3 Years 6 months Corner Incisors 4 Years 6 Months Approximate Times for Premolars 2 Years 8 months For 1st Set 3 Years For 2nd Set 3 Years 8 months for 3rd Set
Retainer Premolar Cap Caps Continued Caps Continued Caps Continued Retained Incisor Cap 2 year old Arabian gelding Eruption Bumps White arrows are permanent teeth erupting Orange arrow is retained deciduous tooth
2 year old lateral mand rad Wolf Teeth 2 year old eruption bumps. Wolf Teeth Vestigial teeth Serve no useful function Usually removed Wolf Tooth Extraction Un-erupted wolf tooth Un-erupted Wolf Tooth
Wolf Teeth Floating Is Necessary Properly Floated With Bit-Seat Canine Teeth Erupt 4-5 years Found in stallions and geldings Small in mares Used for fighting Not for chewing Common Dental Problems Adults Soft tissue damage from points Pain and inflammation Tall molars Excessive crown Excessive transverse ridges Hooks Ramps Wave mouth 3 year old Arabian gelding Soft Tissue Ulcers
Tartar Canine teeth Floating Excessive Crowns (Example) Removal of sharp enamel point Excessive Crown Results Of Excessive Crowns Are Painful
Excessive Crowns Excessive Transverse Ridges Preventing Free Caudal-Rostral Movement Excessive Transverse Ridges Ramps Normal Ridges Ramped Lower Premolars Rear Ramps
Ramps And Waves Removed Hooks Hooks Upper Front Hooks Waves Wave Mouth
Tooth Extractions Proper equipment Difficulty is directly related to age of horse and tooth being removed Eating Signs of Dental Disease Dribbles grain Fills mouth with hay before eating grain Dunks hay in water Excessive salivation Foul odor from mouth Head tilt while eating Weight loss Eating Signs of Dental Disease Long (greater than _ inch) fiber length in manure Grain in water bucket Playing with tongue Whole grain in manure Refuses to eat Manure Performance Problems Locating Upper Arcade Resists turns (may be very subtle) Head tossing or shaking (slightly flips nose) Unexplained subtle lameness Mouthing or chewing the bit Excess salivation with bit Head tilt while riding or lunging Resists bridling Refuses to maintain frame or vertical head carriage Cheeks sensitive to touch
Bit Seats Incisors Abnormal wear will interfere with chewing Straight Overgrown Smile Frown Slant or tilt Missing or broken teeth Abnormal Incisor Shapes Slant or Tilt Frowning Smiling Slant or tilt Irregular Diagonal Bite Overgrown Incisors
Overgrown Incisor Correction Overgrown Incisor Correction Overlong Incisors Incisor Lip Incisor length inhibits molar contact Incisors side view These pictures taken 10 seconds apart. What was done? Before Correction Smile After Correction
Ventral Curvature (Smiling Incisors) Frowning Incisors Same Basic Problems As Smiling Before Correction After Correction Diagonal Bite Example Missing or Broken Teeth Before Correction After Correction Equipment Power equipment versus hand instruments QUESTIONS?
Guide for Determining Horse s Age Mike Black, DVM Nebraska Equine Veterinary Clinic Omaha Nebraska Guideline 5 to 9 wider than long 9 to 10 square 10 plus longer than wide Guideline 5 to 9 central incisor OVAL 10 to 15 central incisor triangular or round 16 to 20 central incisor biangular Guidlines Infundibular cup Central smooth at six Intermediate smooth at seven Corner smooth at eight Uppers Nine, ten, and eleven Guidelines Incisor angle changes with age
Guidelines Guidelines Birth to two weeks Galvayne s Groove Guidelines One year of age All baby teeth All in wear Guidlines Two years Baby teeth All in wear Guideines Three years Central permanent in wear Guidelines Four Years Central and intermediate are permanent
Guidelines Five years All incisors are permanent Guidelines Six years Central incisor smooth Corner wider than long Guidelines Eight years All incisor tables smooth Corner almost square Guidelines Ten years Corner square and Galvayne s groove Guidelines Fifteen years Corner taller than wide Galvayne s groove Guidlelines Twenty years Corner tall and long Galvayne s groove
QUESTIONS?