Dentistry
The dentition of a horse is quite different than humans or many other species. A thorough knowledge of anatomy, eruption times, oral diseases, sinusitis, pathology, breed variations, etc. make it important that your equine veterinary dentist be thoroughly trained and have proper equipment to deal with all the problems that may pop up.
Horses are best served by twice yearly dental exams just like us. Most horses will suffice with a once yearly dentistry. Young horses, especially two and three year olds, may need 2 - 3 dentals per year to keep their teeth in the best condition. This is due to the shedding of their molar and incisor caps during this time frame. Between 2 ½ years and 5 years of age horses lose 24 deciduous teeth and erupt 36 - 44 teeth.
Numbering systems are used to identify individual teeth for record keeping. The most popular system is the Modified Triadan System. The teeth are numbered by location and quadrant. The upper right is quadrant 1, the upper left is quadrant 2, lower left is quadrant 3 and the lower right is quadrant 4. The numbers start with the central incisor being number 1, 2nd incisor is number 2, 3rd incisor is number 3. The canine tooth is number 4. Number 5 is the wolf tooth which is often extracted. There are 3 premolars numbered 6, 7, and 8. They are followed by 3 molars numbered 9, 10, and 11.
Horses' ages can be estimated by tooth eruption schedules, amount of wear and changing anatomy of the teeth as they wear. A foal's incisor teeth erupt at approximately 6 days for the first (middle) incisors, 6 weeks for the second incisors, and 6 months for the third incisors. Adult incisors erupt at approximately 2.5 years of age for the first incisors, 3.5 years for the second incisors, and 4.5 years for the third incisors. Galvayne's groove is a landmark on the upper corner of the incisors that can be used to age a horse. It appears at age 10, is approximately half way down the tooth at 15, extends to the bottom at 20, will be half gone at 25, and completely gone near age 30.
The Modified Triadan System is used to identify teeth by their location
The first set of premolar caps are shed at approximately 2 years and 8 months of age, the 2nd premolar caps are shed at approximately 2 years and 10 months, and the 3rd premolar caps are shed at 3 years and 8 months. This is a total of 12 premolar caps being shed in a 12 month period. Dentistry is important during this time, because if any caps are retained they can cause discomfort and pain, some horses may quit eating or be difficult to ride. Retained caps can even delay eruption of the premolars beneath the tooth. The chart below outlines the normal eruption schedule of equine teeth.