2Horses' teeth are often used to estimate the animal's age, hence the sayings "long in the tooth" and "Don't look a gift horse in the mouth".
3The Importance of Determining the Age of Horses Uses:Validate advertised age when buyingConfirming age when racing or showingFeeding for proper nutrition at various life stages
4Aging by Teeth Not foolproof An art that requires skill and experience Very old method of aging horsesError increases with horse’s ageBecomes an educated guess after horse is older than 14 yearsStabled horses tend to appear younger (less tooth wear)Pastured horses tend to appear older (more tooth wear)Bishoping- altering teeth to hide age
5Equine Tooth Structure CaninesIncisorsWolf Tooth (when present)MandiblePremolarsMolarsMaxillaHorses have 24 temporary teeth and up to 42 permanent teeth
6Deciduous- ID3/3 CD0/0 PD3/3 MD0 Permanent-I 3/3 C 0-1/0-1 P 3-4/3 M3/3
7How many teeth does a horse have? A typical adult male horse has 42 permanent teeth, while a typical mare may have 36 teeth, because mares are less likely to have canine (bridle) teeth.A horse’s permanent teeth are about four inches long.
8Dentition Hypsodonts Two times Young horse has 24 deciduous teeth Incisors 3/3Canines 1/1Premolars 3 or 4/3Molars 3/3Male total of 40 or 42; female total 36 to 40Young horse has 24 deciduous teethMilk teeth12 incisors12 molars
9Do horses have “baby” teeth? Like humans, horses have two sets of teeth in their lifetimes.The baby teeth, called deciduous teeth, are temporary.The first deciduous incisors may erupt before the foal is born.The last deciduous teeth come in when the horse is about eight months of age.These “baby” teeth will begin to be replaced by adult teeth around the age of 2 ½, and by age 5-6, most horses have all of their permanent teeth.
10Estimating age using tooth eruption There are 24 deciduous teeth (“caps”). These come out in pairs, and are pushed out later by the permanent teeth.The “caps” are usually present at birth or by 1 to 2 weeks of age.Rule of 3 eights: I1- 8 days, I2- 8 weeks, and I3- 8 months-charts may show these as Di1, Di2, Di3The number of permanent teeth may vary, depending on if the horse has wolf teeth or canines.
12Cups, stars and spots:The cup is the center of the infundibulum. Wear of the occlusal surface causes the cup to get smaller and eventually disappear from all lower incisors at about 6-8 years of age leaving the enamel spot in its place. The enamel spot is the deepest part of the infundibulum. The dental star corresponds with the pulp cavity and appears at 8 years of age in the first incisor. It appears as a line and then changes to a large, round spot as the occlusal surface is worn further.
13The anatomic relationships between incisor anatomy and the cups and stars seen on the occlusal surface as they wear are depicted in the images and diagrams immediately above. The image on the right is shows an incisor of a young horse cut longitudinally while still in the jaw.
14Equine Tooth Structure Central Incisors(also pincers or nippers)Intermediate IncisorsCorner IncisorsAge is determined using the 12 front teeth (incisors)
15Mouthing a Horse for Age In Real Life: Hold the tongue out and to the side with your hand. This restraint provides an unobstructed view and is not painful to the horse.
21What are wolf teeth?Wolf teeth are the remnants of the first premolars that have now become obsolete with the evolution of the horse.The most common first premolars seen in the horse are the uppers and they are shaped similar to small canine teeth.This is why they are often described as wolf teeth. These sharp teeth, if present, are in the area of the mouth where the bit fits.Wolf teeth may cause the horse some discomfort when pressure is placed on the bit. Therefore, these teeth are usually removed in young riding horses.
22Wolf toothA typically small maxillary wolf tooth (premolar [PM] 1) is present just rostral to PM2.
23First premolar (PM1):Wolf tooth6 monthsDeciduous premolars:Present at birth.Shedding teeth or caps.
24Usually appears around the age of 10 years. Galvayne’s GrooveA mark on the upper corner incisors that appears and disappears in a predictable pattern as horses ageUsually appears around the age of 10 years.
25Groove is usually half way down at age 15 Galvayne’s GrooveA mark on the upper corner incisors that appears and disappears in a predictable pattern as horses ageGroove is usually half way down at age 15
26By age 20 the groove usually extends the full length of the tooth Galvayne’s GrooveA mark on the upper corner incisors that appears and disappears in a predictable pattern as horses ageBy age 20 the groove usually extends the full length of the tooth
27Groove begins to recede around age 21 Galvayne’s GrooveA mark on the upper corner incisors that appears and disappears in a predictable pattern as horses ageGroove begins to recede around age 21
28Galvayne’s GrooveA mark on the upper corner incisors that appears and disappears in a predictable pattern as horses ageGroove is halfway gone by age 25 and disappears completely around age 30.
297 year notch Length with age Disappears at 8 years,returns at 11“long in the tooth”
30Shape of teeth Round 9-11 years Triangular 14-17 years Baby erupt8 days8 weeks8 monthsPermanents erupt2 1/23 1/24 ½Cups gone6 years7 years8 yearsDental Star8years9 years10 yearsGalvayne’s groove10-30 yearsSeven year notch7years, and 11 yearsShape of teethRound yearsTriangular yearsBiangular years
31Determine the most likely age for the following horse Aging Using TeethDetermine the most likely age for the following horse7 years14 years21 years28 yearsWear – No Cups
32Determine the most likely age for the following horse Aging Using TeethDetermine the most likely age for the following horseOval Shaped TeethNo Canines1 year8 years17 years26 years
34Common ages for tooth eruption (page 248 LACP) Type of toothNumberDeciduousPermanentIncisorFirst (central)birth to 8 days2.5 yrsSecond (intermediate)4.5-6 weeks3.5-4 yrsThird (corner)6-9 months4.5-5 yrsCanineAbsent3.5-5 yrs, some around6 yrs (if ever)PremolarFirst (wolf)6 months to 3 years (if ever)Secondbirth to 2 weeks2-3 yrsThird2.5-3 yrsFourth3-4 yrsMolarFirst9-12 months2 yrs
35How do diet, pasture management and stabling impact dental wear? Mother Nature designed horses to be pasture grazing animals.Horses in the wild normally spend 16 hours a day with their heads down, grazing grass.For a horse to properly process pounds of wet-grass forage a day, it uses a wide, crushing chewing pattern.This allows the incisor teeth and cheek teeth to wear at a normal and even rate.Under artificial conditions, horses are fed an abnormal diet (grain and hay) for shorter intervals during the day, with an abnormal head posture (feed tub or hay rack).All of these conditions alter the chewing pattern and adversely affect the way teeth are worn over time.
36What is cribbing and how does it affect dental care? Cribbing is a stereotypic behavior, or vice, that some horses develop.The horse exhibits cribbing by grabbing onto an inanimate object (fence posts, buckets, stall walls, etc.) with its incisor teeth, pulling the object and often making a sucking sound.Because these horses spend the majority of their time during the day preoccupied with this behavior rather than grazing or eating, they quite often have dental wear problems.The upper incisor teeth (front teeth) are often worn excessively from hours of abnormal attrition. These horses are referred to as "stump suckers.”
37What does it mean to “float” a horse’s teeth? Routine maintenance of a horse’s mouth has been historically referred to as “floating.”Floating removes the sharp enamel points.Occlusal equilibration is the term now used to describe smoothing enamel points, correcting malocclusion (faulty meeting of the upper and lower teeth), balancing the dental arcades and correcting other dental problems.
38Equine Dentistry: General Principles HypsodontReserve crownElliptical mastication patternWear pattern:Results in sharpenamel points.Buccal aspect (upper)Lingual aspect (lower)
39Triadan Numbering System 100’s = Right maxilla200’s = Left maxilla300’s = Left mandible400’s = Right mandibleIncisors = 1,2,3Canines = 4Wolf teeth = 5Premolars = 6, 7, 8Molars = 9, 10, 11
40Upper R Cheek Upper incisors Upper L Cheek Lower R Cheek Lower Incisors Lower L Cheek
41Dental Examination Visually inspect: Prior to rinsing mouth After rinsing mouthDigitally palpate:Individual teethGingivaPalateTongueRecord findings on a standard form
42Historical Clues to Dental Problems Performance habitsHead tiltHead tossingRefusing the bitEating habitsQuiddingSlow, deliberate masticationExaggerated tongue movement
43Change in fecal character Increase in fiber lengthWhole grain in fecesWeight lossPoor body conditionFacial asymmetryUnilateral nasal dischargeHalitosis
44Dental Examination: Juvenile Age: 6 months to 7 yearsIncisorsCheck occlusionInspect eruption patternCanines erupting at this age.Premolars:Look for wolf tooth.Inspect for caps.Periodontal diseaseMolarsInspect eruption pattern.Exam frequency: semiannual
45Age: yearsIncisorsInspect forInjury or damageSupernumerary teethMissing incisorsMisalignmentWear pattern
46Age: 7 – 15 yearsCanine teethCheck for sharp pointsCheck for tartar
47Age: 7 – 15 yearsPremolar and molar teeth:Enamel points (odontophytes)Occlusion abnormalitiesHooks and rampsUnopposed teethWave/Shear mouthExam frequency - Annually
48Dental Examination: Geriatric Age: 15 years and olderPremolar and molar teeth:Periodontal diseaseo Most common condition affecting horse > 15 years of ageo Gingival recessiono Diastema formationMolar cuppingWearing of infundibular enamelDental cariesTooth root abscessTooth lossExam Frequency - Semiannual