Equine dentistry 2 Flashcards
Define brachygnathism and prognathism
Brachygnathism = overly long maxilla compared to mandible Prognathism = relative overgrowth of the mandible
What are the consequences of brachygnathism is horses?
- Ulceration of behind upper incisors
- Maxillary rostral 06 overgrowths and mandibular 11 overgrowths which will need lifelong attention
What is campylorrhinus lateralis?
- ‘Wry Nose’
- Deviation (and occasional rotation) of the entire maxilla, involving the incisive region, nasal septum and nasal bones
How does campylorrhinus lateralis vary in severity?
- Minor occlusal problems: routine dentistry every 6 months
- Severe occlusal and breathing problems
- Surgical correction can be attempted but is complex
Describe the features and issues of malocclusion
- Secondary to problems involving the cheek teeth
- Diagonal bite or ‘slant mouth’ is indicative that the horse is eating predominantly on one side of the mouth and may indicate shear mouth formation of the cheek teeth
How are retained deciduous incisors treated?
- Loose: remove with forceps
- Firmly attached: remove with dental elevators
What is a supernumerary incisor?
Additional to usual 6 permanent incisors
What is the treatment for supernumerary incisors?
- Usually cause little problem
- Often best not to remove
What are the issues surrounding incisor diastemata?
- There should not be any spaces between adjacent teeth
- Narrow spaces can be most problematic
- Trap food causing gingivitis, periodontitis and potentially loss of the tooth
- Food should be removed from these spaces
Describe Equine Odontoclastic Tooth Resorption and Hypercementosis (EOTRH)
- Recently described condition, unknown aetiology
- Horses aged 14 and over
- Swelling and/or draining tracts over multiple mandibular and maxillary incisors.
- Pain, difficulty prehending food
How is Equine Odontoclastic Tooth Resorption and Hypercementosis (EOTRH) diagnosed and treated?
- Diagnosis: visual, radiography
- Extraction of the loose incisors is curative
How is oral neoplasia classified?
- According to tissue of origin: Dental, Bone, Soft tissue
- According to clinical behaviour + pathological features e.g. benign/malignant, invasive/localised
Why is histological diagnosis sometimes difficult for oral neoplasia?
- Infection
- Unclassifiable tumours
- Rarity
Name 3 tumours of dental origin
Ameloblastoma
Cementoma
Odontoma
Describe the features and appearance of an amleoblastoma
- Most common in: older horses, mandible
- Cause a bony swelling +/-cystic cavity
- Benign/locally invasive
- Surgical excision
Name some examples of oral neoplasia of soft tissue origin
- Squamous cell carcinoma (SCC)
- Epulis
- Fibroma
- Melanoma
- Oral papilloma
- Sarcoid
Describe some canine abnormalities seen in horses
- Rarely cause problems but still need to be assessed
- Calculus around lower canines most common
- Apical infection/ Fracture
Why may wold teeth be removed despite rarely causing issues?
Often removed due to owner / trainer preference/ tradition (bitting problems, an inability to profile the rostral aspect of the 06 or owner preference)
What are 3 indications for wolf teeth removal?
- Bitting problems / ulceration
- Blindly erupted: may be painful
- May become molarised
Which complications may arise when removing wolf teeth?
- Fracture of tooth
- Fracture of bone
- Trauma to the palatine artery – marked haemorrhage
What is needed for wolf teeth removal?
- Local anaesthesia for infra-orbital/maxillary nerve block
- Dental elevators
- Forceps
- Local anaesthetic and speculum
Where is the most common location of dental problems in first opinion equine practice?
Cheek teeth
What are retained caps?
Remnants of deciduous teeth - normally shed during eruption of the underlying permanent tooth
What are the issues with retained caps?
- Loose / retained caps can cause oral pain
- Usually attached to the gingiva in one place & it is this attachment that causes pain
What is the cause of cheek teeth displacements?
Overcrowding due to eruption
Which cheek teeth are most commonly displaced?
- Often bilateral
- Usually 09s & 10s
- Medial / lateral displacement +/- Rotation
What are the consequences of cheek teeth developing too far apart (diastemata)?
→ spaces develop
→ food accumulates
→ fermentation
→ periodontal disease
Why should the number of cheek teeth always be counted?
In case of supernumerary cheek teeth
Where are enamel overgrowths most likely?
- Buccal aspect of upper CT
- Lingual aspect of lower CT
What are the clinical signs of enamel overgrowths?
Quidding, pain when eating, +/- colic
What is wavemouth?
Marked undulation to the occlusal surface
What is shearmouth?
- Increased occlusal angle of the entire cheek tooth row
- Usually secondary to diastemata formation/dental fracture
How is shearmouth managed?
- Treat primary problem
* Gradual reduction of the angle should be performed (will occur rapidly when the horse begins to chew more normally)
How must overgrowths be managed?
- Hand or power rasps - Do NOT cut/shear teeth
- Must reduce in stages - Maximum 3-4mm q 6mths
What can happen if rasping is done in excess?
- Pulp exposure
- Thermal damage
- Risk apical infection
What is smooth mouth?
Senile change:
• Cheek teeth enamel largely worn away
• Some worn down to individual roots
• Softer dentine & cementum become smooth
What causes dental caries to occur?
Occurs when food material becomes stagnated in pits in the peripheral cementum
- Fermentation
- Drop in pH of the environment
- Demineralisation
- Pits bigger and blackening of the peripheral cementum
Describe how infundibular caries occur
- Cemental hypoplasia
- Food accumulates in infundibulum
- Fermentation -> decay
Why are infundibular caries so problematic?
- Progressive, irreversible
- Predisposes to fracture
- Varying degrees of severity
What is the cause of peripheral caries?
Increased sugars in the diet
- Haylage
- Molasses
How can peripheral caries be managed?
- Palliative rasping of the roughened cementum
- Removal of excess sugars from the diet
How is diastemata without periodontal disease managed?
- Must be cleaned out COMPLETELY use a dental Pick / High pressure lavage
- +/- Pack with impression material
How is diastemata with periodontal disease managed?
- Widen with mechanised burr: Painful!! Lidocaine splash block
- +/- Pack with impression material
- Dietary management essential: avoid long stem hay / haylage
Name the 3 main types of cheek teeth fractures
- Buccal (lateral) slab fracture
- Midline sagittal fracture
- Occlusal fissure fractures
Which cheek teeth fracture types is not associated with apical infection? What is the importance of this?
Buccal (lateral) slab fracture
- Pulp horns seal off
- Extraction may not be required
Midline sagittal fractures most commonly occur on which teeth?
109 and 209 - oldest teeth in the mouth
What is the result of a midline sagittal fracture?
- Result in apical infection +/- Sinusitis
- Extraction required
An apical infection with facial swelling +/- draining tracts is associated with which teeth involvement?
Maxillary 06 and 07
An apical infection caused by maxillary cheek teeth 09, 10 and 11 shows which clinical sign?
Unilateral nasal discharge
An apical infection caused by all mandibular cheek teeth shows which clinical sign?
Bony mandibular swelling +/- draining tract
What are the causes of apical infections?
Pulpitis
→ pulpar oedema → vascular occlusion → necrosis
What are the causes of pulpitis which lead to apical infections?
- Anachoresis (bacteria present in the blood would be attracted to the dental pulp following trauma)
- Fracture
- Periodontal spread (Diastema)
How are apical infections diagnosed?
- Clinical signs
- Oral examination
- Imaging
What are the main considerations surrounding cheek tooth extraction?
- Advanced procedure
- Can be performed standing
- Regional anaesthesia
- Heavy sedation
- Vet surgeon only
What must be aimed to preserve when cheek teeth are extracted?
Alveolus
Describe the steps in the first part of cheek teeth extraction
Interdental Spreading
• Placed in the interdental space in front and behind the tooth
• Closed gradually to stretch the periodontal ligament - Approx 30min
• Can cause further fracture - must be applied carefully!
Describe the steps in the second part of cheek teeth extraction
Application of Molar Forceps
- ‘Oscillation’/’Wiggling’
- Horizontal rocking / lateral strain of the ligament
- Molar forceps tightly applied to tooth
- Many different types: depending on tooth shape, must grip specific tooth well
Which type of extraction is used if the crown is fractured?
Modified transbuccal extraction
Describe a lateral buccotomy
- Incision through cheek, removal of lateral alveolar bone
- Often requires general anaesthesia
What risks come with performing a lateral buccotomy?
Potential damage to: • facial nerve • parotid duct High morbidity rate: • Iatrogenic trauma • Wound breakdown
