Describe the dental adaptations that equines have
Limited rostrocaudal movement of temporomandibular joint
Increased lateral movement of TMJ
TMJ allows occlusal contact of all cheek teeth simultaneously
Well developed masticatory musculature
Adapted for contant grinding - hypsodont and irregular enamel ridges
What do the two numbers indicate in the triadan system of dental nomenclature?
First number is arcade
Second number indicates tooth
What are the ages of eruption of permanent equine teeth?
1st incisor - 2.5 years
2nd incisor - 3.5 years
3rd incisor - 4.5 years
Canine - 4.5 years
2nd premolar - 2.5 years
3rd premolar - 3 years
4th premolar - 4 years
1st molar - 1 year
2nd molar - 2 years
3rd molar - 3.5 years
What is anisognathism?
Maxillary arcade is wider than the mandibular arcade
What is the angle of the occlusal surface?
What is the Curve of Spee?
Upward slope of occlusal surface at caudal aspect of the equine mouth
Describe the 5 layers of normal cheek tooth anatomy
Cementum - attaches to periodontal ligament
Dentine - bulk of tooth, tubular structure
Enamel - hardest tissue, laminated sheets
Pulp - blood and nerve supply to tooth
Infundibulum - infolding of enamel from occlusal surface
What is the difference between maxillary and mandibular cheek teeth in the horse?
Maxillary teeth are more layered ridges of infundibulum - straight lines
Mandibular teeth have more random infundibulum - flower like
What are the reasons for an equine dental exam?
Annual checkover for prohpylaxis
Owner notices problem:
- Weight loss
- Biting problems
- Unilateral nasal discharge
What should be done during an equine dental examination?
External examination - condition score
- Nasal discharge
- Pain on palpation
- Incisors for malocclusion
- Interdental space for wolf teeth
- Biting injuries
- Tongue injuries
- Cheek teeth
What needs to be done during oral examination?
Restraint and sedation
Head support if sedated
Gags - Hausmann/wedge
What else can be used as diagnostic aids during an equine dental exam?
Give some examples of things to examine cheek teeth for
Buccal and lingual points/ulceration
Molar table angle
Excessive transverse ridges
Caries (infundibular in maxillary arcades and peripheral)
What are the effects of enamel overgrowths?
Prevent jaws moving freely
Oral pain leading to quidding and weight loss
Severe cases develop shear mouth
Occlusal angle greater than 15º
Occurs over a long period of time
Muscles, ligaments and joints remodel to compensate
How would you treat shearmouth?
Reduce buccal and lingual points
Reduce angle starting at high side
Regular treatments every 3-6 months
Address any underlying pathology
Describe the differences between carbide chip blades and tungsten carbide blades
- OK for routine work
- Hard work with hooks
- Excellent for routine work
- Remove hooks well
- Often cut only one way
What are the four basic types of rasp required for routine rasping?
Which teeth are they used for?
Straight head, long length - for all lower cheek teeth, 3rd-6th upper cheek teeth
Obtuse angled head, long length - caudal upper cheek teeth and curve of Spee
Angled offset head, medium length - upper 1st-4th cheek teeth
S float - smooth off first cheek teeth and 6th maxillary cheek teeth, bit seat and angle of curve of Spee
What should you take care of when using power tools for equine surgery?
Why are power tools good for equine dentistry?
Remove hooks quickly
When should deciduous premolars be shed?
2.5, 3 and 4 years
What can retained deciduous premolars lead to?
How should 'caps' be removed?
Remove with forceps or screwdriver while not damaging permanent tooth beneath
Which teeth in the horses mouth are the ones that usually overgrow?
106, 206, 311 and 411
What are rostral and caudal overgrwoths usually associated with?
Rostral displacement of maxillary arcade (parrot mouth)
What are the causes of focal overgrowths?
Diastema - gap between two teeth
What can multiple dental overgrowths result in?
What two things should be taken care of when removing tooth overgrowths in the horse?
What covers the pulp at the occlusal surface?
What stimulates deposition of secondary dentine?
Why is there a greater risk of pulp exposure with overgrowths?
Decreased occlusal contact
Decreased secondary dentine
Greater risk of pulp exposure
How can exposed pulp be identified?
Probing secondary dentine overlying pulp horns
What can pulp exposure be caused by?
Apical tooth infections
What can infundibular caries lead to?
What percent of horses older than 15 years are affected by infundibular caries?
What can cause sagittal fractures of the equine tooth?
How should excessive transverse ridges be treated?
Reduce larger ridges
Maintain normal ridging
What three things does periodontal disease affect?
What causes primary periodontal disease of horses?
What is the most painful equine dental disease?
Which equine teeth are most frequently affected by periodontal disease?
Mandibular cheek teeth
What percent of horses older than 15 years are affected by periodontal disease?
Describe how periodontal disease occurs
Localised gingivitis with pocket formation
Trapped debris stagnates
Feed compressed deepening pocket
Destruction of alveolar bone
Bacteria enters pulp cavity
Where does periodontal disease usually begin?
- Buccal interproximal spaces of maxillary arches
- Lingual interproximal spaces of mandibular arches
How can diastemata be a problem with horses?
Food trapped between teeth
Packs into periodontal spaces
Pressure leads to pain and subsequent quidding
Can lead to bone infection
How should diastemata be treated?
Remove impacted food
What should be used to remove impacted food in equine teeth?
Long handled dental pick
High pressure water/air picks
How should diastemata be managed?
Replace long fibre food or short chopped foods
Remove overgrowths that develop opposite diastemata
Describe developmental cheek teeth displacements
Arcades overcrowd during eruption
Often bilateral usually in 4th and 5th cheek teeth
Medial or lateral displacement
Tooth may also be rotated
Are congenital or acquired displacements in horses more common?
What can displacements of cheek teeth lead to?
What can cheek teeth fractures in horses occur secondary to?
What can cheek teeth fractures in horses lead to or be the cause of?
Can cause acquired overgrowths
Which horses are apical tooth infections most common in?
Younger horses - mean age 5 years
What are the clinical signs with apical tooth infections?
Asymmetrical jaw swelling
Ventral discharging tract
Submandibular lymph node enlargement
What is the aetiology of maxillary apical tooth infections?
Premature pulp exposure during wear
Pulp exposure after transverse fracture
Iatrogenic from excessive rasping
What occurs with maxillary apical tooth infections in 08 to 11?
Sinusitis - unilateral nasal discharge
What are some radiographic signs of dental disease?
Loss of the lamina dura denta
Localised maxillary bone proliferation - osteitis
What are the radiographic signs for apical tooth root infections?
Clubbing of tooth roots
What are computer topographic signs of apical tooth infections?
Gas within bulging root area
Fragmentation of the root
Increased pulp volume
Abnormal pulp morphology
What are the main treatments of apical tooth infections?
Conservative - antibiotics
Tooth removal by repulsion
Tooth removal by extraction
Tooth removal by lateral buccotomy
What are the incidence rates of complications with repulsion of apical tooth infections?
32% of mandibular cheek teeth
33% of maxillary teeth
68% of maxillary teeth with sinusitis
How much less is the complication rate with extraction compared to repulsion?
Which teeth is oral extraction difficult in?
Caudal cheek teeth of young horses
What are the 6 steps during the oral extraction procedure?