Herbivore Dental Flashcards
Describe the anatomy of herbivore teeth
- Hypsodont
- Large reserve crowns
- Enamel extends below the gum line
Describe the anatomy of horse teeth
- Hypsodont (high crowned teeth, with enamel extending below the gum line)
- Radicular (have closed roots, meaning growth decreases with age)
Describe the anatomy of rabbit teeth
- Hypsodont (high crowned teeth with enamel extending below the gum line)
- Elodont (teeth grow continuously throughout life)
- Aradicular (the teeth do not develop anatomical roots)
An unsuitable die tor anatomical malformations can result in what for herbivore teeth?
Formation of excessive sharp points or spurs on the teeth where the hard enamel has grown unchecked
What is the permanent dental formula of a horse?
I 3/3 C 1/1 or 0/0 PM 4/4 or 3/3 M 3/3 = 36-44 teeth
Canine teeth can develop in some horses, at what age would they erupt?
4.5 - 5 years old
In the triadan numbering system what number would a canine be?
104 or 204
Wolf teeth are present in some horses, what age do they erupt and shed?
Erupt at 5-6 months
Shed at 2.5 years old
In the triadan numbering system what number would a wolf tooth be?
1,2,3 or 4 - 05
What is the permanent dental formula of a rabbit?
I 2/1 C 0/0 PM 3/2 M 3/3 = 28 teeth
Describe the formation of the incisors in a rabbit
The second maxillary incisor sits behind the first, forming a peg tooth
The lower incisors, sit between the first and second maxillary incisors, creating a scissor action for cropping grass/forage material.
Give the age of the horse when each of the incisors has permanently erupted
1 (central) = 2.5 years old
2 (middle) = 3.5 years old
4 (corner) = 4.5 years old
Following permanent eruption, how long does it take before an incisor is ‘in wear’
6 months
Incisor 1 in wear starts at 3 yo
Incisor 2 in wear starts at 4 yo
Incisor 3 in wear starts at 5 yo
Give a definition of eruption
the time at which the tooth becomes visible at the gum margin
Give a definition of in wear
The time at which the incisor teeth meet (lower with upper). This occurs approx. six months after eruption.
Describe the appearance of deciduous incisors
Small and white, with small ridges on the labial surface
The cementum filled depression on the occlusive surface of the tooth is called the…?
Infundibulum
Initially the infundibulum is empty and collects food particles – at this stage it is referred to as a … ?
Cup
Once the cementum is in wear and the cup appears filled in, it is referred to as a …?
Mark
At what age does the cup disappear in each of the incisors?
1 = 6-7 yo 2 = 7-11 yo 3 = 9-15 yo
At what age does the mark disappear in each of the incisors?
1 = >12 years 2 = >14 years 3 = >15 years
What is the dental star?
Production of secondary dentine by the pulp cavity as the incisor wears
How does the dental star shape change as a tooth is worn?
It is fairly linear initially and becomes rounder and more central as wear progresses
At what age does the dental start appear in the each incisor of a horse?
1 = 5yo 2 = 6yo 3 = 7yo
What appears in the dental star after 2-3 years in wear?
White spots
A horse has a dental star visible in all of its teeth, with white marks visible in the central incisor, how old is the horse?
8 years old
How does the shape of the occlusal surface change with age?
From oval through trapezoid to triangular
Describe how the shape of the corner incisor changes and how that can be used to determine a horses age
At 5-9 years old: the corner incisor is wider than it is tall
At 9-10 years old: the corner incisor is square
>10 years old: the corner incisor is taller than it is wide
Galvayne’s groove can appear on which incisor?
Maxillary corner
How can Galvayne’s groove be used to estimate a horses age?
- It appears at the gum margin at around 11years old - Groove is halfway down the tooth at 15yo - whole way down by 20 - halfway out by 25 - gone by 30
Which deciduous equine cheek teeth are present at birth?
PM 2, 3 and 4
In 2-4 year old horses, during eruption of the cheek teeth, what can be observed?
4 year old bumps = firm swellings form on the ventral aspect of lower jaw indicating the rapidly developing dentition within the mandible
How is the anatomy of the maxillary and mandibular cheek teeth different?
- The maxillary cheek teeth are square in shape, with two infundibulae and usually three roots
- The mandibular cheek teeth are more rectangular and have no infundibulae but lots of folding of peripheral enamel and usually two roots
How do rabbits cheek teeth differ to a horse?
They are open rooted
If you remove either a problem incisor or a problem cheek tooth in the rabbit you must ensure that you destroy the germinal bud
otherwise the tooth will simply regrow
Equine teeth erupt at roughly how many mm per year?
3-4mm
In horses and rabbits a routine dental examination should consist of what 4 parts?
History
Extra oral exam
Intra oral exam
Dental charting
What should always be checked for when looking at or taking an animals dental history?
- Previous issues
- Date of last examination
- Diet/management
- Riding concerns
What should be assessed in an equine extra-oral examination?
- Facial symmetry
- Sinuses
- Palpate for swellings or discomfort
- Lymph nodes
- Lateral mandible movement
- Incisor occlusion
- Lips for scars/masses
What do horses require to restrain them for an intra-oral exam?
Sedation
Before applying a gag in horses where might be useful to rasp?
Buccal angle of the maxillary cheek teeth
Give examples of abnormalities that should be noted on a dental chart
- missing teeth
- calculus
- gingivitis
- periodontal pockets
- diastema
- fractures
- loose or mobile teeth
What is the aim of rasping teeth?
Remove sharp enamel points/dental overgrowths which are causing, or are likely to cause, progressive malocclusion of the arcades, or damage to the soft tissues of the
mouth.
- not aiming for all of the teeth to be smooth
Where are sharp points commonly located on the maxillary and mandibular teeth?
Maxillary = buccal surface Mandibular = lingual surface
At what angle should the rasp blade be held at?
45◦ angle to the buccal aspect of the tooth
When rasping how can you check that your technique is correct?
You should see an even distribution of tooth particles along the blade
Which side do horses like being approached from?
The left
On which teeth and aspect would you use a straight rasp?
Lingual aspect of the mandibular teeth
Buccal aspect of the caudal premolars and rostral molars in the maxillary arcade
On which teeth and aspect would you use a forward facing rasp?
Caudal molars in the maxillary arcade
On which teeth and aspect would you use a backwards facing rasp?
Rostral premolars in the maxillary arcade
Caudal molars in the mandibular arcade
