Tooth Table of a Horse

A full Mouth of temporary incisors, six above and six below. The central temporary incisors erupted between birth and one month , the lateral temporary incisors erupted between one and three months. The corner temporary incisors erupted at about eight or nine months

One Year old

13. Central Temporary Incisor Tooth

14. Lateral Temporary Incisor Tooth

15. Corner Temporary Incisor Tooth

Two Years old

At 2 yrs. it is still showing a full mouth of temporary incisors but all are now in wear.

At about two and a half years old the central permanent incisors replace the temporaries.

Three Years old

At 3 year old has centrals up and in wear , they are easily recognised by their size and shape.

At three and a half years , the lateral permanent incisors erupt .

 16.  Central Permanent Incisor Tooth

Four Years old

As a 4 yr. old , the horse has four permanent incisors and at four and a half years , the corner permanent incisors erupt

 17.  Lateral Permanent Incisor Tooth

18.  Corner Permanent Incisor Tooth

Five Years old

A 5 yr. old horse has a full mouth of permanent incisor teeth in wear      ( i.e. a ‘permanent mouth’ ) . The corner incisors however , occlude each other at their front ends only . The canine teeth ( tushes ) erupt between 4 and 5 years.

16. Central Permanent Incisor Tooth

17. Lateral Permanent Incisor Tooth

18. Corner Permanent Incisor Tooth

Sixe Years old

At 6 yrs. in a well formed mouth , all the incisor teeth are in wear and the tables have worn level . All show a central infundibular depression or ‘cup’

 

From the age of 6 yrs. onwards , determination of age from the teeth must rely upon other factors such as the infundibulum , ‘dental star’ , tooth shape , angle of inclination etc. Each of these individually may be of little value , but when all are considered together , a reasonably accurate estimation is still possible up to the age of 12 years. From 12 onwards only an approximation can be given.

Seven Years old

At 7 yrs. old the ‘cup’ in the central incisor table has grown out , being not as dark as the others. The ‘mark’ ( outline of enamel with a cement filling ) still remains for several years . A hook develops as an overhang at the back of the corner upper incisor due to its not fully meeting its fellow of the lower jaw. This ‘seven year old hook’ may be a useful character, but must be used with some caution since a further hook develops later in life.

1. Cup

2.  Mark

16.  Central Permanent Incisor Tooth

17. Lateral Permanent Incisor Tooth

18. Corner Permanent   Incisor Tooth

19.  7 yr. old Hook

Eight Years old

At 8 years of age  , the ‘cup’ has worn out from the lateral incisor but the ‘ mark ‘ still remains.  Between the ‘mark’ and the front of the tooth a dark yellow-brown line , the ‘ dental star ‘ ( secondary dentine on the now exposed pulp cavity ) makes its first appearance on the central incisors.

The seven year hook has practically worn away.

 1. Cup

2. Mark

9.  Dental Star

Nine Years old

At 9 yrs. old the ‘cups’ are gone from all of the incisors but ‘marks’ are still evident although possibly absent altogether from the centrals. The ‘dental star’ is now apparent on the laterals as well as the centrals and about this age another hook develops on the upper corner incisor as a direct effect of wear. The central incisors are practically triangular in form ( ’rounded off’ ) . Also making its first appearance around nine or ten years is a dark groove known as ‘Galvayne’s Groove’ , on the outer surface of the upper corner incisor. The dark colouration is due to the presence of cement in the groove , while cement has worn off the rest of the tooth uncovering white enamel. The groove is found midway along the length of the tooth so that for some time after eruption it remains hidden in the socket. As the tooth grows out from the gum , the groove will gradually emerge. It first appears at the gum line and with continued eruption of the tooth it gradually extends down the length of the tooth.

2. Mark

9. Dental Star

20. Nine Year Old Hook

21. Galvayne’s Groove

Ten Years old

At 10 yrs. the ‘marks’ are becoming indistinct but the ‘dental stars’ are more pronounced and are tending to round – off especially on the centrals.

The shape of the tooth – tables of centrals and laterals has now become noticeably more triangular ( ’rounded off’ ) . Galvayne’s groove is longer and both upper and lower incisors have begun to slop forwards.

9. Dental Star

20. Nine Year Old Hook

21. Galvayne’s Groove

Twelve-fourteenYears old

By the age of 12 yrs. the ‘mark’ may have gone from the centrals leaving the ‘dental star’ in a central position. The ‘dental stars’ are now noticeably round , dark and distinct. All the incisors are assuming the ’rounded off’ form and Galvayne’s Groove is up to three eights of an inch long.

2.  Mark

9.  Dental Star

16. Central Permanent Incisor Tooth

17. Lateral Permanent Incisor Tooth

18. Corner Permanent  Incisor Tooth

21. Galvayne’s Groove

Fifteen Years old

At 15 years of age , the slope of the incisors is increasing markedly. All ‘marks’ have disappeared and dark , round ‘dental stars’ occupy the centre of each wearing surface.

Galvayne’s groove reaches half way down the length of the tooth and is increasing in length by one third of an inch each year.

Nineteen-twenty Years old

At 19 or 20 years of age , the forward slope of the incisors is most pronounced and Galvayne’s groove extends the whole length of the tooth

Over twenty years old

At 20 to 25 years old the forward slope is even more acute and with continued eruption the part of the upper corner incisor now becoming exposed , shows no Galvayne’s groove.

The groove therefore decreases in length progressively as the tooth wears away to disappear by 30 years.

Leave a Reply