Equine dentistry Flashcards
1
Q
what type of teeth do horses have?
A
hypsodont (long crowned)
2
Q
what does hypsodont mean?
A
long crowned
3
Q
how fast do horses teeth erupt?
A
2mm/year
4
Q
what is the deciduous dental formula for equids?
A
I 3/3 C 0/0 PM 3/3 (24)
5
Q
what is the permanent dental formula of equids?
A
I 3/3 C 1/1 (0/0) PM 3/3 (4/4) M 3/3 (24)
6
Q
what number is the upper right quadrant of the triadan system?
A
1
7
Q
what number is the upper left quadrant of the triadan system?
A
2
8
Q
what number is the lower left quadrant of the triadan system?
A
3
9
Q
what number is the lower right quadrant of the triadan system?
A
4
10
Q
how is the deciduous teeth of equids numbered using the triadan system?
A
add 4 to quadrant number (upper right =5, upper left =6…)
11
Q
when do the deciduous incisors of horses erupt?
A
(01) central - 1 week
(02) middle - 6 weeks
(03) corner - 6 months
(6 days, 6 weeks, 6 months)
12
Q
when do the permanent incisors of horses erupt?
A
central - 2.5 years
middle - 3.5 years
corner - 4.5 years
13
Q
when do canine teeth of horses erupt?
A
5 years (not all have them)
14
Q
when do wolf teeth erupt?
A
1 year
15
Q
when do deciduous pre-molars erupt?
A
present at birth
16
Q
when do the permanent cheek teeth of horses erupt?
A
1-4 years (06 - 2.5 years 07 - 3.5 years 08 - 4 years 09 - 1 year 10 - 2 years 11 - 3.5 years)
17
Q
how many infundibulae do maxillary cheek teeth have?
A
2
18
Q
what shape are maxillary cheek teeth?
A
square (wide)
19
Q
how many infundibulae do mandibular cheek teeth have?
A
none
20
Q
what shape are mandibular cheek teeth?
A
rectangular (narrow)
21
Q
what are pulp horns?
A
areas of pigmented secondary dentine on the occlusal surface of teeth (cheek teeth have at least 5)
22
Q
what sinuses are close to the cheek teeth?
A
rostral maxillary
caudal maxillary
23
Q
what is anisognathia in relation to horses??
A
maxillary cheek teeth wider than mandibular
24
Q
what are two normal anatomical variations of the mouth?
A
curvature of maxilla
curve of spee
25
when watching a horse with suspected dental disease eat, what is looked at?
normal grinding sounds
chewing with both sides
takes longer chewing
quidding
26
what is assessed when looking at incisors?
masses/trauma
occlusion from side/front
count teeth
27
where should be palpated on an examination of cheek teeth?
```
occlusal surface
edges of teeth
interdental space
buccal mucosa
tongue adjacent to teeth
```
28
what are category one dentistry procedures?
examination
| using manual rasps
29
what is parrot mouth also known as?
overbite
30
what is parrot mouth?
overly long maxilla compared to mandible (brachygnathism)
31
what can overbite cause?
ulceration behind upper incisors
| overgrowth of teeth
32
what is prognathism?
overgrowth of mandible compared to the maxilla
33
what is campylorrhinus lateralis also known as?
wry nose
34
what is wry nose?
deviation of entire maxilla (incisive region, nasal septum, bones)
35
what does slant mouth indicate?
horse is eating predominantly on one side
36
where are retained deciduous incisors found in relation to permanent teeth?
rostrally
37
when incisors are fractured, what determines if they can be repaired or not?
if the pulp cavity is effected
38
what is equine odontoclastic tooth resorption and hypercementosis?
swelling/draining tracts over multiple mandibular/maxillary incisors
39
what is done to treat equine odontoclastic tooth resorption and hypercementosis?
extract loose incisors (may have to remove all)
40
what is the most common oral neoplasm of dental origin?
ameloblastoma
41
what is done to treat ameloblastomas?
surgical extraction
42
what are common oral neoplasias of soft tissue origin?
squamous cell carcinomas
sarcoid
epulis
fibroma
43
what is the most common problem seen with canines?
calculus build up (remove)
44
what are indications for wolf tooth removal?
bitting problems
ulceration
blindly erupting (pain)
45
what are retained caps?
remnants of deciduous teeth (normally shed during eruption of permanent teeth)
46
how are retained caps usually attached?
in one place to gingiva (site of pain)
47
what causes cheek teeth displacements?
overcrowding during eruption
48
what happens if the cheek teeth develop too far apart?
diastemata forms
food accumulates
fermentation (gingivitis)
periodontal disease
49
where do supernumerary cheek teeth usually develop?
caudal aspect of cheek teeth
50
what aspect of the cheek teeth does enamel overgrowth effect?
maxillary - buccal
| mandibular - lingual
51
enamel overgrowth is more pronounced in horses fed what?
more concentrates and less forage
52
what is wavemouth?
undulation to occlusal surface
53
what is stepmouth?
focal overgrowth of single tooth (reduce in stages) - usually due to missing opposing tooth
54
what is shearmouth?
increase occlusal angle to entire cheek tooth row
55
what is shearmouth usually secondary to?
diastemata or dental fracture
56
how is shearmouth managed?
treat primary problem
| gradual reduction
57
what is bit seating?
rostral profiling of cheek teeth (contraindicated)
58
what is smooth mouth?
cheek teeth enamel worn away, dentine and cementum become smooth (dietary management)
59
what are dental caries?
food material becomes trapped in pits in peripheral cementum
60
what happens when food gets trapped in pits that lead to dental caries?
fermentation
drop in pH
demineralisation
larger pits in cementum form
61
how should diastemata without periodontal disease be treated?
cleaned out completely and packed with impression material
62
how should diastemata with periodontal disease be treated?
widen with a mechanised burr and pack with impression material (feed short fibre)
63
what are the three types of cheek teeth fractures?
buccal slab
midline sagittal
occlusal fissure
64
what are the clinical signs of apical infection?
facial swelling
unilateral nasal discharge
mandibular swelling
65
what can cause apical infections?
anachoresis (blood-borne infection)
fracture
periodontal spread
pulpar exposure
66
what are the ways of removing a cheek tooth?
oral extraction
modified transbuccal extraction
lateral buccotomy
repulsion
67
what is the first step of oral extraction of cheek teeth?
interdental spreading (increase space infant/behind the tooth)
68
what is the second step in oral extraction of cheek teeth?
application of molar forceps and wiggle
69
when is modified transbuccal extraction used?
when the crown is fractured
70
what are the function of the upper airway?
```
air flow
filtering/protection
olfaction
phonation
swallowing
thermoregulation
```
71
what is the respiratory rate of a horse?
15bpm
72
what is the tidal volume of a horse?
5L
73
what is the minute ventilation of a horse?
75L
74
the breathing pattern of a horse is coupled with their gait, how?
inspiration - back feet on the ground
expiration - front feet on the ground
(canter)
75
what does narrowing of the upper airway lead to?
increased negative pressure on inspiration - collapse of structures (pharynx/larynx)
76
where does unilateral nasal discharge come from?
sinus or nasal passage (rostral to nasal septum)
77
where does bilateral nasal discharge come from?
larynx, pharynx, lower respiratory tract (caudal to nasal septum)
78
what is the rebreathing test used on horses?
place bag over nose to increase respiratory rate/force, then take away and examine
79
what should happen in a healthy horse when the bag is removed during the rebreathing exam?
1 or 2 deep breaths with no coughing
80
what are normal sounds heard on exercise?
snorting
high blowing
sheath noise
thick wind
81
what are the main methods of diagnostic imaging used for the head?
endoscopy (resting/exercise)
radiography
sinoscopy
CT
82
what are the standard radiographic views to assess the horses head?
latero-lateral
lateral oblique
dorso-ventral
83
what is latero-lateral radiographic views of the head good for assessing?
paranasal sinuses, guttural pouch, pharynx
84
what is the lateral oblique radiographic view used for?
assess periodontal regions of cheek teeth
85
what is the dorso-ventral radiographic view of the head used for?
paranasal sinus
nasal septum
teeth
(compare left/right)
86
what are the indications for CT scanning of horses head?
dental disease
masses of paranasal sinus
trauma
87
what can cause facial nerve paresis/paralysis?
recumbency with pressure on nerve
| iatrogenic
88
what are the clinical signs of facial nerve paresis/paralysis?
facial swelling/asymmetry
| reduced airflow and stertor
89
why is minimal debridement need for lacerations of the nares?
good blood supply (preserves tissues)
90
how many suture layers should be used to close a laceration of the nares?
2-3
91
what is nasal atheroma?
cyst within the nasal diverticulum
92
what is the major clinical sign of nasal atheroma?
non-painful swelling at nasoincisive notch
93
what is done to treat nasal atheroma?
surgical removal
94
what are the clinical signs of alar fold collapse?
flaccid alar folds
respiratory noise
exercise intolerance
95
what are the three meati formed from the turbinates?
dorsal
middle
ventral
96
why is the sinus drainage angle an important anatomical feature?
(narrow passage from paranasal sinus to nasal passage)
| cannot access using endoscopy
97
what is the significance of ethmoturbinate 2?
when passing a gastric tube must push down to avoid damaging
98
how can iatrogenic trauma to the nasal passage be prevented when passing a tube?
pass ventral to middle meatus
smooth tube
lubricate
(do not force!!)
99
what is a progressive ethmoid haematoma (PEH)?
encapsulated non-neoplastic mass
100
where can progressive ethmoid haematomas grow into?
nasal passage and paranasal sinus
101
what are the two main clinical signs of progressive ethmoid haematoma?
```
epistaxis
facial swelling (sinuses)
```
102
how do progressive ethmoid haematomas appear on endoscopy?
yellow/green mass
103
what can be done to treat progressive ethmoid haematoma?
```
intralesional formalin (care with cribriform plate)
laser excision (sinus flap surgery)
```
104
what can fungal rhinitis commonly occur secondary to?
bacterial sinusitis
105
what are the main clinical signs of fungal rhinitis?
purulent/haemorrhagic discharge
malodorous smell
nasal stertor
106
what can be done to treat fungal rhinitis?
```
remove plaques/necrotic bone
topical antifungals (enilconazole)
```
107
how many pairs of paranasal sinuses are there?
7
108
what are the two functional groups of paranasal sinuses?
rostral
| caudal
109
what paranasal sinuses are included in the rostral group?
rostral maxillary
| ventral conchal
110
what paranasal sinuses are included in the caudal group?
```
caudal maxillary
frontal
dorsal conchal
sphenopalatine
ethmoid
```
111
what structures are the paranasal sinuses near?
brain
| teeth
112
what separates the rostral and caudal paranasal sinus groups?
oblique bony septum
113
why is paranasal sinus drainage often inhibited in horses?
drain when head is down eating grass (modified diet causes issues)
114
what are the most common diseases effecting paranasal sinuses?
primary sinusitis
| secondary sinusitis
115
what are the two most common presenting signs of paranasal sinus disease?
nasal discharge
| facial swelling
116
what can cause secondary sinusitis?
dental disease
sinus cyst
progressive ethmoid haematoma
neoplasm
117
what is done to treat primary sinusitis?
culture sensitivity testing then one course of antibiotics
NSAIDs
feed from ground (drainage)
turn out and reduce dust
118
what is the most common cause of secondary sinusitis?
dental disease
119
what age animal are paranasal sinus cysts most common in?
young horses
120
what is done to treat paranasal sinus cysts?
surgical remove by sinus flap
121
what are common neoplasm of the paranasal sinuses?
SCC
adenocarcinoma
myxoma
fibro-osseous tumour
122
what are potential complications of sinus surgery?
haemorrhage
infection
poor cosmetics
reoccurring sinusitis
123
what is suturitis?
inflammation in the suture line (where bones join)
124
what separates the nasopharynx and oropharynx?
soft palate
125
where is the larynx found?
in the soft palate
126
why is pharyngeal collapse during exercise common?
pharynx lacks rigid support (bones/cartilage)
127
what are the functions of the pharynx?
passage of air and ingesta
128
what happens in the pharynx to protect the airway during swallowing?
arytenoid closure
vocal cord closure
epiglottis retroversion
129
what are the functions of the larynx?
breathing
protect lower airway
vocalisation
130
what cartilage rings make up the larynx?
cricoid
thyroid
epiglottic
arytenoid (paired)
131
what are the three process of the arytenoid cartilage?
muscular
corniculate
vocal
132
what is the the muscular process of the arytenoid cartilage for?
cricoarytenoideus dorsalis (CAD) muscle attachment
133
what is the the vocal process of the arytenoid cartilage for?
vocal cords attach
134
what process of the arytenoid cartilage can be seen on endoscopy?
corniculate
135
what are the two ways the larynx can move?
abduction (breathing)
| adduction (swallowing)
136
what muscle abducts the larynx?
cricoarytenoideus dorsalis (CAD)
137
what muscle adducts the larynx?
cricoarytenoideus lateralis
138
what nerve innervates the muscles that abduct and adduct the larynx?
recurrent laryngeal nerve
139
what are the key clinical signs of a horse with laryngeal/pharyngeal disease?
respiratory noise
exercise intolerance
poor performance
140
what are the two main modes of imaging used to asses the larynx/pharynx?
endoscopy
| ultrasound
141
what is DDSP?
dorsal displacement of the soft palate
142
when is intermittent DDSP seen?
during intense exercise (expiratory obstruction)
143
how is intermittent DDSP correct by the horse?
swallowing returns it to normal
144
what can persistent DDSP be secondary to?
epiglottic entrapment
sub epiglottic ulcer
sub epiglottic cyst
145
what can cause intermittent DDSP?
neuromuscular dysfunction
lower airway disease
structural abnormalities
146
how can lower airway disease cause intermittent DDSP?
increases negative pressure
147
how can the majority of intermittent DDSP cases be treated?
conservative - maturity, get horse fit, change tack, tongue tie, treat inflammation
148
what surgeries can be used to treat DDSP?
tie forward
| palatoplasty
149
how is a tie forward surgery for DDSP treatment carried out?
suture from basihyoid bone to thyroid cartilage (larynx postponed more rostrally/dorsally)
150
how does palatoplasty work to treat DDSP?
thermal/laser cautery causing a stiffened soft palate
151
what is pharyngeal lymphoid hyperplasia?
enlargement of lymphoid follicles of the walls/roof of nasopharynx (incidental)
152
what can nasopharyngeal collapse cause in neonates?
dysphagia and respiratory distress
153
how is nasopharyngeal collapse treated in neonates?
self-resolves
154
which side does recurrent laryngeal neuropathy usually effect?
left unilateral (paresis/paralysis)
155
what is the pathophysiology that causes recurrent laryngeal paralysis?
loss of myelinated fibres of recurrent laryngeal nerve leading to atrophy laryngeal muscles
156
what are the surgical options for treatment of recurrent laryngeal neuropathy?
prosthetic laryngoplasty (tie back)
ventriclo-cordectomy (hobday)
laryngeal re-innervation
arytenoidectomy
157
how is prosthetic laryngoplasty (tie-back) carried out?
suture placed from cricoid cartilage to muscular process of arytenoid (mimics CAD)
158
what is the disadvantage of prosthetic laryngoplasty (tie-back)?
permanent abduction of left arytenoid (may struggle to protect airway when swallowing)
159
what are potential complications of prosthetic laryngoplasty (tie-back)?
coughing
seroma formation
infection
dysphagia
160
how does a vocalcordectomy work to treat recurrent laryngeal neuropathy?
remove vocal cord to remove collapsing tissue into the airway
161
how is laryngeal re-innervation carried out?
implant C1/C2 nerves onto effected CAD
162
what can cause bilateral laryngeal paralysis?
hepatic disease
toxins
post anaesthetic complications
163
what is laryngeal dysplasia?
congenital abnormality in the development of the laryngeal cartilage (4BAD)
164
what dysfunction does laryngeal dysplasia lead to?
limited abduction of right arytenoid cartilage
165
when is a noise heard with vocal cord collapse?
inspiration (whistle)
166
what is the only way of detecting vocal cord collapse?
overground scope (only happens at exercise)
167
when is noise heard with medial deviation of the aryepiglottic folds?
inspiration
168
what is done to treat medial deviation of the aryepiglottic folds?
laser removal of aryepiglottic folds
169
what is used to treat sub epiglottic cysts?
laser extraction
| snare excision
170
what is arytenoid chondritis?
infection/inflammation of arytenoid cartilage
171
what are guttural pouches?
air filled out-pouchings of the auditory tubes connecting the middle ear to the nasopharynx
172
what sits close to the guttural pouches dorsally?
skull/1st cervical vertebrae
tympanic bulla
auditory meatus
173
what sits close to the guttural pouches ventrally?
nasopharynx
| retropharyngeal lymph nodes
174
what sits close to the guttural pouches laterally?
parotid and mandibular salivary glands
175
what significance does the stylohyoid bone have to the guttural pouches?
separates them into medial and lateral (medial larger)
176
what arteries pass through the guttural pouch?
internal and external carotid arteries
177
what vessels supply the brain makes surgery of the guttural pouch more complex?
circle of willis (base of the brain)
178
what are the most important clinical signs of guttural pouch disease?
epistaxis
dysphagia
nasal discharge
179
why do horses with guttural pouch disease get dysphagia?
swallowing nerves pass through guttural pouch
180
what is the best way to image the guttural pouch?
endoscopy
181
what is guttural pouch mycosis?
fungal infection of the guttural pouch (artery erosion)
182
what are the clinical signs of guttural pouch mycosis?
```
nasal discharge
epistaxis
nerve dysfunction (horners, dysphagia, laryngeal paralysis)
```
183
what are the differential diagnoses for epistaxis?
guttural pouch - mycosis
paranasal sinus - trauma, progressive ethmoid haematoma
nasal passage - trauma
lower respiratory tract - exercise induced pulmonary haemorrhage
184
where should endoscopy of suspected guttural pouch mycosis be done?
surgical facility (high risk of haemorrhage)
185
how must arteries be occluded for guttural pouch mycosis surgery?
on cardiac and cerebral side (internal/external carotid depending on what's effected)
186
when can guttural pouch mycosis be managed medically?
if there is no plaques overlying the arteries (fungal flush)
187
what causes rupture of rectus capitis and longus capitis muscles?
head trauma (rearing and falling)
188
what is the clinical sign of rupture of rectus capitis and longus capitis muscles?
blood emanating form the guttural pouch (they haemorrhage into the guttural pouch)
189
what is guttural pouch empyema?
purulent material in the guttural pouches (chondroids is when it hardens)
190
what are the clinical signs of guttural pouch empyema?
purulent nasal discharge
lymph node enlargement
dysphagia
191
what are chondroids?
inspissated purulent material (chronic infection)
192
what age animals does guttural pouch tympani occur in?
less than 1 year old
193
what is guttural pouch tympani?
air gets trapped
194
what are the clinical signs of guttural pouch tympani?
retropharyngeal swelling
respiratory stridor
dysphagia
195
what is usually done to treat guttural pouch tympani?
catheters placed until animal matures and valves start operating normally
196
what is temporohyoid osteoarthropathy?
progressive arthritic disease of stylohyoid
197
what are the main clinical signs of otitis media?
headshaking
| vestibular
198
what is otitis media?
infection of the middle ear
199
what is the most common neoplasm of the guttural pouch?
melanoma in grey horses
200
what is the location for a tracheostomy?
midline on the upper third of the neck
201
what incisions are made for a tracheostomy?
vertical through the skin
| horizontal between the rings
