Dentistry

Question 1

Radiographic signs of EOTRH

Answer 1

1) Varying degrees of tooth resorption
2) Loss of periodontal ligament space
3) Alveolar bone loss
4) Hypercementosis
5) Dental fractures

Question 2

Clinical signs of EOTRH

Answer 2

Varying degrees of oral pain

Periodontitis

Gingivitis, gingival hyperplasia or recession

Fistulas (often with a focal subepithelial swelling referred to as parulis or gum boils)

Bulbous enlargement of dental structures

Tooth mobility

Tooth fractures

Missing teeth

Question 3

Radiographic signs of apical infection

Answer 3

1) Widening or loss of the lamina dura denta
2) Apical blunting/change in shape of the root
3) Periapical sclerosis
4) Periapical lucency (halo)
5) Dental fractures/root fragments
6) Cementoma

Overall low sensitivity for detecting apical infection (53% Luiti 2018 EVJ)

Radiography has moderate to high specificity (70% to 90%) but poor sensitivity (52% to 69%) for the assessment of dental disorders

Question 4

Components of the peridontium (4)

Answer 4

Gingiva

Cementum

Periodontal ligament

Alveolar bone

Question 5

CT signs of apical infection

Diagnostic accuracy of CT for dx of peri-apical infection

Answer 5

1. Hypodense widening of the apical periodontal tissues
2. Periapical sclerosis
3. Deformation or disintegration of the apical aspect of the lamina dura denta.
4. Concurrent thickening of the overlying periapical soft tissue, sometimes containing gas inclusions
5. Granuloma formation appears as a soft tissue mass around the apical area of the affected tooth (teeth), which is a feature of chronic dental disease
6. Concurrent maxillary sinusitis
7. Gas within the pulp cavity (ies)
8. Root clubbing/blunting +/or fragmentation

97% agreement with histology for detection of peri-apical infection (Luiti et al 2018 EVJ)

Question 6

Types of dental malocclusion

Answer 6

Class 1: Also called neutroclusion, this describes a normal rostral-caudal relationship of the maxillary and mandibular dental arches but there is malposition of one or more individual teeth.

Class 2: Also called mandibular distoclusion, mandibular brachygnathism or mandibular retrognathism. In layman’s terms this is referred to as an overshot jaw or a parrot mouth.This describes an abnormal rostral-caudal relationship between the dental arches in which the mandibular arch occludes caudal to its normal position relative to the maxillary arch.

Class 3: Also called mandibular mesioclusion, mandibular prognathism. In layman’s terms this is referred to as an undershot jaw. This describes an abnormal rostral-caudal relationship between the dental arches in which the mandibular arch occludes rostral to its position relative to the maxillary arch.

Question 7

Equine deciduous dental formula and deciduous eruption times

Answer 7

I3/3, C0/0, PM3/3, M0/0

Incisors erupt 6d, 6w, 6mo (central to corner)

Permanent incisors erupt on the labial aspect of deciduous ones

PM erupt - present at birth or erupt within the first few weeks. Caps shed as permanent premolars erupt

There are no deciduous molars (ie can’t have caps on 9-11)

Question 8

Equine permanent dental formular and eruption times

Answer 8

I3/3, C0(1)/0(1), PM(4)3/(4)4, M3/3

Incisors erupt 2.5, 3.5, 4.5yrs (central to corner) -> in wear 6mo after eruption

C if present erupt by 5yrs

PM - 2.5, 3, 4yrs. Wolf tooth, if present usually by 1 yr

M 1, 2, 3.5 yrs

Question 9

Maxillary tooth anatomy; no of infundibulae and roots

No of pulp cavities per tooth

Answer 9

2 infundibulae,

3 roots, 2 buccal, 1 palatal

Triadan 7-10 have 5 pulps. The 06 has 6. The 11 has 6 or 7 (labelled 7 or 8)

Numbered bucally first and from rostral to caudal

Question 10

Mandubular tooth anatomy; no of infundibulae and roots

No of pulp cavities in each tooth

Answer 10

No infundibulum

2 roots - 1 rostral, 1 caudal

Tooth 7-10 have 5 pulp cavities, 6 has 6, 11 has 6 (labelled 7)

Labelled from buccal to lingual and rostral to caudal

Question 11

Describe the CT abnormalities

Answer 11

Both 09 teeth have buccal slab fractures (yellow arrows)

209 has gas in pulp horn (1 or 2), widened periapical periodontal space, overlying sinus mucosal thickening, and soft tissue swelling over the adjacent maxillary bone, indicating that the pulpar exposure was not sealed off by tertiary dentine in this tooth, with subsequent peri-apical infection

Question 12

Grades of caries (0-4)

Answer 12

0 = normal

1 = involvement of cementum only

2 = involvement of cementum and enamal

3 = involvement of cementum, enamal and surrounding dentine

4 = dental fracture

Question 13

Describe the CT findings and most likely underlying cause

Answer 13

Sagittal fracture of 109

Disruption of the underlying aleolar bone

Rostral max and ventral conchal sinusitis

Most likely infundibular caries associated sagittal fracture

Question 14

Peripheral caries grades (0-4)

Answer 14

0 = normal

1. 1 = cementum only, pitting or erosive lesions, some cementum remains
2. 2 = cementum only, all involved exposing underlying unaffected enamel

2 = cementum and enamel affected

3 = cementum, enamel and dentine affected

4 = secondary dental fracture present

Question 15

What are cups and stars of the incisors

Answer 15

Cups are infundibulae - wear and disappear by 6 in the central, 7 middle and 8 corner incisor, leaving enamel spot behind

Stars are pulp chambers, located rostral to cups, appear in the central incisor at 8, middle 9 and corner 10 years old

Question 16

Age of appearance of the dental star of incisors

Answer 16

I1 - 5

I2 - 6

I3 - 7 years

(some variation in description, some say 8,9,10)

Question 17

Which teeth are most commonly affected by peripheral caries?

Answer 17

09-11s (ie molars)

Specifically the palatal aspect of the maxillary cheek teeth and the buccal aspect of the mandibular cheek teeth (remember the opposite surfaces to the ones you rasp)

Question 18

Reported incidences of peripheral caries in the UK, Scotland and WA

Answer 18

51. 7% in the UK (Borkent et al 2017 EVJ)
52. 2% UK (Nuttall et al TVJ 2019)

91% in Scotland (72.6% 1.1) (Lee et at EVE 2019)

58.8% in WA (Jackson et al 2018 EVJ)

Question 19

Possible risk factors for peripheral caries

Answer 19

Vary according to literature but may incl

Feed type; particularly elevated quantities of high NSCs in hay is assoc w ↑ peripheral caries in WA (Jackson 2018 EVJ). Feeding of fermented forages & concentrates has also been suggested as a cause of peripheral caries. In the UK population there was no difference in the frequency of peripheral caries in horses feed haylage, hay or chaff.There was an association between feeding of concentrate feeds and peripheral caries in the UK, but no relationship with the time spent at pasture grazing (Borkent 2017 EVJ)

Water: those drinking from dam water were most likely to have peripheral caries, followed by rainwater. Those drinking groundwater were least likely to have a peripheral caries

Dental dz: association with diastemata although not necessarily with infundibular caries

Question 20

Grading scale for fissure fractures proposed by Pollaris et at (EVJ 2018)

Answer 20

Type 1: Fissures that involve the secondary dentine overlying pulp canals

1a Fissure orientation is perpendicular to the surrounding enamel fold, variably involving the adjacent enamel or even the peripheral cementum (Fig 1a, b).

1b Fissure orientation is cranio-caudal, sometimes connecting adjacent pulp horns (Fig 1c, d).

Type 2: Fissures that never involve secondary dentine. They can be located in primary dentine and run parallel to the enamel folds or are seen in enamel or peripheral cementum (Fig 1e, f)

Question 21

Overall prevalence of fissure fractures in cadavar teeth reported by Pollaris et al (2018 EVJ)

Which pulp horns of the maxillary and mandibular teeth are most commonly affected?

Answer 21

72%

Pulp horn 4 of the maxillary teeth

AND

Pulp horns 1 and 2 of the mandibular teeth

Question 22

What is the potential clinical consequence of fissure fractures?

Which fracture type is most likely to be a problem?

Answer 22

Largely remains unknown

Type 1b fissures - those running craniocaudally, possibly connecting 2 pulp horns are speculated to be most likely to be of clinical significane; same orientation as slab fractures so may go on to become complete fractures?

Question 23

Reported incidence of bacteraemia during cheek teeth extraction?

At what time does this become apparent?

Answer 23

90% horses demonstrated transient bacteraemia during extraction (Kern et al EVJ 2017)

During gingival elevation typically

Question 24

What surgical treatment options are available for class 2 malocclusions?

Answer 24

1. Growth retardation of the maxilla w cerclage wire from incisors to between the premolars (overjet) plus biteplate (overbite). Relyson sufficient remaining growth potential and is most effective with less severe deformities
2. Bilateral mandibular osteotomy and LCP fixation (2 plates each side) (Spoormakers et al 2019 EVJ)
3. Rare reports of osteodistraction using IMEX ESFx`
4. Type 1 ESF been used with high morbidity rates

Question 25

Describe the sx technique reported by Spoormaker (2019 EVJ) for tx of class 2 malocclusion with short LCPs

Answer 25

• GA dorsal. Incisors shortened and mouth taped closed with the teeth in occlusion
• 8-cm Y-shaped skin incision, starting over the symphysis with the arms of the Y running over the ventral aspects of the mandibular rami. Periosteum incised similarly & reflected
• Mandible cut using an oscillating saw perpendicular to its long axis, through the caudal third of the symphysis (=SYMPHYSEAL OSTEOTOMY), i.e. cranial to the interdental space and mental foramen, leaving the oral soft tissues intact where possible
• Mandibles distracted rostrally and then rotated ventrally to achieve normal incisor position (see pic; incisors not in occlusion initially to achieve full cheek teeth occlusion which is necessary immedately post-op)
• All 5 cases had 2 short 3.5 LCPs applied to the ventrolateral aspect of the mandibles after significant bending, secured w 2-3 3.5mm self-tapping LHS on each side of the osteotomy
• 1 had osteotomy filled with BM
• Closure in 3 layers, vicryll SC in the periosteum and SQ then intra-dermal monocryll

Question 26

Key findings of Spoormaker 2019 (EVJ) for WTR sx tx of class 2 malocclusions

Answer 26

1. Good outcome for class 2 malocclusion was achieved with mandibular osteotomy and LCP fixation young & mature horses 8mo-6yrs, in 5 cases
2. 2/5 had second sx and 3 had plates removed dt ongoing draining tracts
3. Key point of sx is to achieve incisor allignment without functional occlusion and correct occlusion of the cheek teeth. Full cheek tooth occlusion is necessary IMMEDIATELY after sx
4. Symphyseal osteotomy utilised in this technique - divides the mandible into 2 (vs 3 parts with more caudal osteotomies) - negates the need for longer implants described in prev studies where the mandibles are cut in the interdental space being separated into 3 parts)
5. Smaller implants = less invasive and preservation of the mental nerve and roots of the cheek teeth/incisors (care re cranial screws and incisor roots)
6. Technique technically challenging

Question 27

Relative mineral content and critical pH of each of the 3 mineralised dental tissues

Answer 27

Enamel = 96-98% mineral. pH 5.5

Dentine = 70% pH 6.2

Cementum = 65% pH 6.7

Cementum most prone to caries as decalcification occurs more rapidly dt lower mineral content

Higher critical pH of cementum means demineralisation occurs at higher pH (ie less acidic environments)

Question 28

Possible sequalae of gingivitis

Answer 28

Gingivitis can lead to painful infection, (quidding and/or weight loss) and in more severe cases early tooth loss, apical infection or osteomyelitis

Question 29

Causes of gingivits/periodontal dz

Answer 29

Usually initiated by the entrapment of feed between the teeth and often occurs secondary to diastemata

Diastemata can be 1ary (teeth form too far apart dt inadequate angulation/arcade compression) or 2ary (to overgrowths, displaced teeth, reduced angulation with age (‘senile’ diastemata), rotated teeth, supernumerary teeth or loss of interproximal calcified dental tissues (for example loss of peripheral cementum)

Question 30

What were the main findings of Jackson et al (EVJ 2019) WRT peripheral caries in WA?

Answer 30

Horses with peripheral caries, and in particular, horses with mandibular cheek teeth with peripheral caries are significantly more likely to also be affected by disease of the periodontium than horses without peripheral caries.

Histo corroborates the gross and clinical features in that the loss of peripheral cementum, particularly in the mandibular arcades, leads to diastemata formation.

Diastemata formation allows feed accumulation between the teeth and may lead to the development of gingival recession and disease of the periodontium.

Histo strongly supports that peripheral caries is likely an environmental degradation of the dental tissues so is potentially reversible with manipulation of the oral environment

Question 31

Main findings of Lee et al (EVE 2019) WRT prevalence of peripheral caries (PC) in Scottish horses

Answer 31

1. V high prevalence reported of 91% although mostly grade 1 class 1 (72.6%)
2. PC more commonly affected the three caudal (74.7% PC) than the rostral three CT (32.1% PC), a finding echoed in other studies also
3. PC were > twice as likely to occur on the palatal (51.3% prevalence) vs. the buccal (20.9%) aspect of maxillary CT, and in contrast on the buccal (49.1% PC) vs. the lingual (28.9% PC) aspect of mandibular CT
4. All females were affected whereas 12% males were not
5. Increasing prevalence with increasing age to be expected

Question 32

Describe the intra-oral mental block technique reported by Eckert et al (EVE 2019)

Answer 32

• Mental foramen palpated transcutaneously
• Once IDd - insert 90mm 22g Tuohy needle through oral mucosa on the lateral aspect of the mandible approx 1cm rostral to the foramen
• Advance caudally until approx 1cm within the foramen
• Inject - likely significant resistance to injection within the mandibular canal
• 10ml volume assoc with greater retrograde flow vs 3 and 6ml
• 79% of injections reached PM4 when 10ml volume used

Question 33

Main findings of Ekhert 2019 (EVE) WRT intra-oral mental NB

Answer 33

1. The intraoral approach is useful as an alternative method for performing a mental nerve block for procedures involving the incisive region - uses 90 mm 9 22 gauge Tuohy needle and position of the foramen confirmed by palpation as with transcutaneous blocks; needle inserted on the lateral aspect of the mandible through oral mucosa approx 1cm rostral to the foramen and advanced caudally to 1cm within the foramen
2. Caudal flow of contrast into the mandibular canal after injection suggests that this method might be useful to desensitise structures caudal to the mental foramen with local anaesthetic; 79% of the mandibular canals injected with 10 mL of contrast medium had retrograde flow to the position of the root furcation of PM4 in live horses and cadavers, suggesting this method may be a useful alternative technique for nerve block involving invasive procedures of the more rostrally located cheek teeth (e.g. PM2, PM3 or PM4)
3. Unsure how well tollerated it would be as both live cases were GA
4. Need more cases to fully evaluate safety and efficacy in clinical setting
5. The location of the mental foramen was fairly consistent in the distal (ie away from incisors) 1/3 of the interdental space - found usually 60-80% of the distance between the distal aspect of the lateral corner incisor and the mesial aspect of the second premolar

Question 34

Name the foramina

Answer 34

a) Infraorbital
b) Maxillary
c) Mandibular
d) Mental

Question 35

Uses of infraorbital and mental nerve blocks

Answer 35

Can be desensitised outside the respective foramina for procedures involving the mandibular and maxillary soft tissues, or inside the foramina for painful procedures involving the incisor teeth (such as extraction in EOTRH), mandibular or maxillary fractures of the incisive (premaxillary) bone or extraction of the first cheek teeth (because of branching nerves to these structures)

Question 36

Location of the infraorbital foramen

Answer 36

Palpable but if not can be located roughly half way along a line drawn from the rostral edge of the facial crest to the nasoincisive notch

Question 37

Location of the mandibular foramen

Answer 37

Roughly at the intersection of perpendicular lines drawn vertically from the lateral canthus and horizontally from the occlusal surfaces of the cheek teeth

Question 38

Describe 2 extra-oral and 1 intra-oral mandibular (inferior alveolar) blocking techniqe.

Answer 38

1. VERTICAL approach - spinal needle is inserted percutaneously on the ventromedial aspect of the mandible at the level of the rostral insertion of the masseter muscle (basically at the level of the lateral canthus). The needle is then advanced dorsally aiming towards the medial canthus of the ipsilateral eye, maintaining close proximity to the axial mandibular periosteum, to a depth of approximately 75–100mm reaching the level of the mandibular foramen
2. ANGLED approach - needle is inserted percutaneously at the angle formed by the intersection of the horizontal and vertical rami of the mandible. The needle is then advanced along the axial aspect of the mandible in a rostral-dorsal direction to the same point described above
3. INTRA-ORAL approach - 3.75 cm, 20 gauge needle and extension set attached to a long metal rod, is carefully passed orally to the level of the last molar. The needle tip is inserted through the caudal buccal fold and advanced to the level of the mandibular foramen for the injection of approximately 5 mL of local

Question 39

Describe the different blind approaches for maxillary nerve blockade

Which structures should be desensitised?

Answer 39

1. Perpendicular approach: The site is located about 2.5 cm ventral to the lateral canthus of the eye and ventral to the zygomatic arch. The needle is directed medially and somewhat rostrodorsally and advanced deeply about 6.5–7.5 cm.
2. Angled approach: The needle is inserted caudal to the bony orbit, at the ventral border of the zygomatic process of the temporal bone at the narrowest point of the zygomatic arch and directed rostromedially and ventrally until bone is contacted, or the horse exhibits a head jerk indicating the nerve has been contacted. These 2 were compared by Bardell 2010
3. Staszyk 2008 looked at palatine bone inertion technique - perpendicular needle insertion ventral to the zygomatic arch between the middle and the caudal thirds of the eye through the masseter mucle and subsequently through the extraperiorbital fat body (total insertion depth: 65–70 mm) until the tip of the needletouched the perpendicular plate of the palatine bone

and 4. the same but with insertion depth 45-50mm to avoid contact with the bone, instead injecting into the extraperiorbital fat body

5. Retrograge approach: blocking via the infraorbital canal with a Tuohy needle has been described

Structures desensitised incl maxillary teeth and sinuses (although may be some contribution from opthalmic br of CN V)

Question 40

Possible complications of the mandibular nerve block

Answer 40

Main problem is self trauma to the tongue following blocking of the lingual nerve. This is a branch of the mandibular nerve before it enters the mandibular foramen to become the inferior alveolar nerve, and the 2 are in close proximity.

Injection site infection etc are described

Question 41

Expected success rates with MTE extractions

Answer 41

For standing cheek teeth extraction (Langeneckert et al. 2015). Good overall success (81%) and minimal post-operative complications were reported, the technique was less successful in teeth that were carious and friable

Question 42

What technique was reported by Pearce et al (2019 EVE) for oral extraction of cheeck teeth with sagittal fractures? What were the success rates?

Answer 42

Use of PMMA stableisation of the fracture gap to fix the 2 fragments together

Use of PMMA facillitated extraction in 16/22 teeth (73%) - no control for comparison but clinical experience and prev reports suggest significantly poorer success with oral extraction of sagittal fractures. 21 were maxillary and 1 mandibular

Minimal complications - no known with PMMA itself - didn’t seem to bone to mesial/distal surfaces of adjacent teeth; spreading was not obstructed

Question 43

Expected occurrence rate of orosinus fistula formation following maxillary cheek tooth repulsion

Answer 43

7-33%

Question 44

Management options for oronasal or orosinus fistulas (see CC Stoll 2019 EVE)

Answer 44

Routine tx

• Alveolar flushing and debridement (remove necrotic tissue/food material after tooth extraction). Debridement should not be too aggressive to prevent unnecessary enlargement of the defect
• Gauze packing - can combine w crystallised honey into the apical part of the alveolus or other substances that may have +ve effect on healing. This also prevents gauze being inserted too deeply which would inhibit granulation. Packing needs to be changed/renewed with a MAXIMAL interval of 10 days
• Sinus trephination (FST and removal of MSB most appropriate; frontal and maxillay flapsare described but the flap may become necrotic dt extreme contamintion so trephine preferable)
• Concurrent ABs - should encompass anaerobic cover (penicillin, metro) and pref guided by C/S
• With progressive granulation, can be difficult to get a shallow covering that remains in place
• Where possible to keep the fistula covered, mechanical debridement of the fistula to induce bleeding blood clot formation, or perhaps use diode laser to debride the fistula; destroy the epithelium which seems to induce a healing process if the setting is low enough to prevent underlying tissue from becoming necrotic due to the heat production
• Ongoing debridement is v important as when the fistula fails to close spontaneously, it remains patent and gets epithelialised; which usually has no tendency to heal spontaneously. The blood clot formed after mechanical debridement should be protected against dislodgement

Surgical tx -

• Some surgical techniques are reported for covering the defect in the alveolus but these are only possible in the mesial and not the distal arcade dt the length/shape of the mouth
• Reported techniques incl. mucoperiosteal flap (Barakzai and Dixon 2005) and an alveolar bone flap (Easley and Freeman 2016) or the transposition of a facial muscle such as the levator nasolabialis (Orsini et al. 1992) or the levator labii superioris (Brink 2006) - more realistic approach in the molar region
• Additionally (used commonly in humans and cats) - CR of the tx of orosinuidal fistulas in a donkey with auricular cartilage graft (Stoll 2017). Auricular cartilage is biocompatible, highly resistant to infections, easy to harvest and nonresorbable. This graft does not require vascularisation for the integration to the recipient site. The challenge is to fix and protect the area of the fistula and to cover the cartilage (ideally w buccal mucosal flap)
• There is a commercial alternative to auricular cartilage grafts - collagen membrane made of equine macerated tendons, coated with fibrinogen and thrombin

Question 45

What is the prevalence of periodontal disease, diastemata and peripheral caries in the UK reported by Nuttall (2019 TVJ)

Answer 45

Periodontal disease - 13.9% prevalence. More commonly affects mandibular arcades vs maxillary & more often seen in the premolars (06–08) vs molars (09–11). Incr prevalence w incr age; , for every year of age gained, the probability of a horse having periodontal disease increased by 10.6%

Peripheral caries - prevalence 8.2% with no sig diff between mandibular and maxillary arcades. Significantly more likely to affect the molars (09–11) than the premolars (06–08)

Diastemata - prevalence 8.7%. higher occurrence in premolars (06-08) than molars (09-11), as for periodontal disease; since the 2 conditions are likely related - horses with diastemata were significantly more likely to also be affected by periodontal disease. Incr prevalence w increasing age

Question 46

Key findings of Nuttall 2019 TVJ WRT prevalence of periodontal disease, peripheral caries and diastemata

Answer 46

1. Peripheral caries - 8.2% prevalence (lower vs Boorkent 2017 - 52% and Lee 2019 - 91% and Jackson - 58.8%
2. PCs more commonly affected molars vs premolars in lone with other studies
3. Periodontal disease 13.9% prevalence - more commonly found in the mandibular arcades than maxillary & more often seen in the premolars (06–08) than in molars (09–11)
4. Significant assoc between presence of periodontal disease and diastemata
5. Diastemata prevalence 8.7% - lower than other reports (38.6% - Lee et al 2019 EVE)
6. Both diastemata and periodontal dz observed more commonly in the premolars than the molars, as well as in the mandibular arcades compared to the maxillary

Question 47

4 main cheek tooth extraction techniques

Answer 47

1. Intraoral extraction,
2. Repulsion
3. Lateral buccotomy
4. Minimally invasive buccotomy +/- transbuccal screw extraction (MITE) - overall 81% success rate and low complications

Question 48

Success rates with partial coronectomy to facillitate intra-oral extraction of cheek teeth reported by Rice et al (2018 EVJ)

Answer 48

99.4%

1. Cuts were always made toward the cheek ie lingual or palatal to buccal
2. 99.4% successful oral extraction although 15% needed MTE or tooth sectioning in addition to partial crown removal technique. Only 1 horse required repulsion
3. Only complication was root tip fracture (6.7%), all maxillary tips (9) were successfully removed, mandibular tip removals not successful (2)
4. 6 had PO complications - alveolar sequestration most commonly

Question 49

Main findings of Dubois 2019 (JAVMA) WRT CT findings of cheek teeth and successful intra-oral extractions

Answer 49

1. 67% success rate of intra-oral extraction lower than other reports
2. High rate of failure (5/9) for mandibular exodontia owing to difficult extractions; MTE also quite unsuccessful (1/4 attempts) and repulsion used in 5 cases
3. No association between age and extraction success was identified (although all predominantly middle aged)
4. Only CT factor significantly assoc w successful oral extraction was presence of (simple) dental fracture vs no fracture - fractured teeth significantly less likely to be extracted orally successfully in a single procedure
5. Low numbers of other abnormalities probably contributed to lack of stat sig findings - eg small or partially absent clinical crowns will create difficult extractions, but not enough of these for significance

Question 50

Reported complication rates of exodontia via repulsion

Answer 50

20-47%

Incl dental or alveolar sequestration, inadvertent disruption of adjacent structures, palatine artery laceration, and alveolar plug failure & fistula formation

Question 51

Medical management of oronasal or orosinus fistulas

Answer 51

Most can be treated by removing the infected tissue and feed material from the alveolus, placing a temporary alveolar plug on the coronal aspect of the alveolus until granulation tissue fills the remainder of the socket, and treating the sinusitis.

The alveolar plug can be maintained in place for most oromaxillary fistulas because 2 teeth are present, 1 rostral and 1 caudal to the fistula, providing a gap in which to wedge the plug and solid surfaces for it to adhere to. For horses in which the plug approach fails to resolve the oromaxillary fistula, various muscle transposition techniques can be used to treat fistulas that occur caudal to the maxillary fourth premolar teeth

Question 52

Oronasal fistular repair technique described by Lores et al 2020 (JAVMA)

Answer 52

Initial repair w bone and palatal mucoperisoteal flap failed

Then repaired with autologous tensa fascia lata graft and oversewn with oral mucosal pedicle flap