export_chapter 20 exodontia Flashcards
(71 cards)
1
Q
When is an intraoral approach for equine cheek tooth extraction not possible?
A
- when crown of tooth can’t be grasped such as: Reserve crown fractured, clinical crown brittle dt caries, when reserve crown so large from cemental hyperplasia or dental tumor cant traverse the alveolua
2
Q
What are two extraoral approaches to equine tooth extraction?
A
- repulsing into oral cavity with mallet and punch
- buccotomy after removing lateral plate of alveolar bone
3
Q
Are retained deciduous incisors in a horse a problem?
Where are they usually located?
A
- cosmetic only
- rostral to adult
4
Q
Are supernumerary incisor teeth usually a problem in horses?
What happens to gap in teeth when incisor tooth extracted?
A
- cosmetic only
- teeth realign and gap dissapears
5
Q
Are supernumerary incisors difficult or easy to extract in horse?
Why?
A
- difficult
- long reserve crown and close proximity to other teeth.
6
Q
What should be done for an avulsed equine incisor?
Avulsed equine incisor with some gingival attachments?
A
- extraction
- debridement and reduction of fracture w/ immobilization
7
Q
What are 4 indications for extracting equine canine teeth?
A
- severe periostitis from bit injuries
- fractured tooth or fracture alveolus
- resorptive lesions
- hypercementosis syndrome
8
Q
Why is extracting equine canine teeth not recommended unless absolutely necessary?
A
- tongue will spill out which can affect performance if show horse
9
Q
Why are equine canine teeth extractions difficult?
What nerve can be damaged?
A
- long curved alveolus
- mandibular alveolar nerve
10
Q
What tooth is the equine wolf tooth?
Are they more common in mandible or maxilla?
A
- first premolar
- maxilla (rare in mandible)
11
Q
What percentage of horses have maxillary wolf teeth?
Are they always bilateral?
When do they erupt?
A
- 40-80%
- often only one
- 6 and 18 months
12
Q
Where are wolf teeth usually located?
A
- variable: rostral to second PM, buccal, palatal or close to canine
- subgingival
13
Q
What is problem with subgingival wolf tooth?
A
- occasionally associated with gingival ulceration, discomfort when contacted by bit
14
Q
Why have wolf teeth traditionally been extracted?
Is this necessary?
A
- large, molarized, aberrantly placed
- entrapment of buccal mucosal fold of commisure of lips–> bitting problems
- difficulty in floating second PM
- not sure about 2 and 3
15
Q
What has traditionally been used to extract wolf teeth?
What works better?
A
- burgess elevator
- small curved periodontal elevator (more precise and effective)
16
Q
Should mandibular wolf teeth be extracted?
A
- probably-cause bit discomfort
17
Q
When should deciduous teeth be removed?
When should they not be removed? Why not?
A
- periodontitis from entrapped food
- painful remnant in interproximal space
- if gingival attachments intact b/c underlying permanent tooth may not be doen forming
18
Q
What are complications associated with repulsion of equine cheek teeth?
What are complications of extraction through buccotomy?
What is preferred technique? Why?
A
- dental or osseous sequesta
- oro-antral fistula
- Damage to branches of the dorsal buccal nerve or the parotid salivary duct.
- per os. cheaper, probably easier
19
Q
Why is extraction per os often cheaper than repulsion or buccotomy?
A
- usually can be done with standing sedation
20
Q
Which teeth are the most difficult to extract in the horse?
A
- caudal (10s and 11s)
- young horses with long reserve crowns and little period dz
21
Q
Do all fractured teeth need to be extracted?
A
- no if no evidence of apical infection
22
Q
Which tooth is the most commonly fractured tooth in the horse?
What is typical configuration of fractured tooth in the horse?
A
- maxillary 09
- parasagital lateral slab that is easily removed
- larger non displaced parent fragment that doesn’t need to be extracted if exposed pulps not sealed off and no apical infection present
23
Q
What is possible problem with a diseased maxillary tooth?
How is this treated?
A
- inspisated exudate in sinus
- osteoplastic flap to remove exudate
24
Q
Who first described per os extraction in horse?
A
O’Connor 1942, Guard 1951
25
Between which teeth should spreaders be used gently?
- 06 and 07 when extracting 07
| - 10 and 11 when extracting 10
26
How long do you keep a molar separator in place?
- 5 minutes each side
27
Which equine cheek teeth are are narrowest?
- mandibular
28
How are equine molar extractors used?
- placed on tooth being careful not to overlap teeth
- Handles fixed with rubber bandage or locking mechanism
- moved in slow, low amplitude, horizontal, to and fro oscillation along longitudinal axis of tooth (check after first few to make sure hasn't slipped)
- gradually increase amplitude as tooth loosens
- when squelch heard, apply fulcrum, advance caudally - apply firm steady pressure
29
What can cause teeth to fracture during extraction?
- torsional movement along axis of extractor handles
| - excessive force, or too wide of an arc
30
How long does it take to extract a cheek tooth?
- an hour or more
31
What is done after a cheek tooth is extracted?
- curette any fragments with an angled currette
| - pack with polysiloxane putty, dental wax, metronidazole paste (packing extruded as tooth heals)
32
What happens if the tooth breaks during extraction and leaves an apical fragment?
- try to elevate per os using long, right-angled elevators and extracted with long right angled elevators
- if can't be extracted per os, repulse using a special root fragment punch or a steinman pin
- extract via buccotomy
33
How do you extract a root fragment via osteotomy?
- create 4 mm osteotomy over retained fragment with Steinman pin or drill bit
- repulse fragment with Steinman pin or root fragment punch
- clean alveolus with spoon currette, then irrigate
- leave skin incision to heal by second intention
34
How do you extract a root fragment via buccotomy?
| What are risks with this method?
- make stab incision at level of alveolus, insert elevator, elevate, extract per os
- can damage facial nerve or parotid salivary duct or could innoculate subQ tissues with bacteria
35
What should be done if parasinuses are infected?
| What if alveolus communicates with parasinuses?
- debride through osteoplastic maxillary or frontonasal flap or trephine hole or lavage through catheter and small trephine hole
- seal off with polysiloxane putty or PMM bone cement
36
If plug is inserted into alveolus after extraction where should it be?
What is purpose of plug?
- coronal 1/3, flush with gingival margin
| - to prevent food impaction
37
What are potential complications of per os extraction?
- fracture of tooth w/ retained fragment
- damage to healthy adjacent teeth
- fractured jaw
- feed impaction
- oroantral fistula
- alveolar bone sequestra dt microfracture
38
How are oro-antral or oronasal fistulas treated?
- debride dental or osseus fragments
- remove food and exudate
- seal the oral aspect with an acrylic plug, mucoperiosteal flap, transposted muscle belly
39
What are the two surgical extraction techniques in the horse?
- repulsion
| - buccal flap and partial alveolar osteotomy
40
Why is repulsion not good way to extract teeth?
- high incidence of complications
41
What should be done before extracting a tooth by repulsions?
- Use forceps per os to disrupt ligament as much as possible
42
How is tooth extracted through repulsion in the horse?
- expose apex through trephination, drill bit, bone saw or chisel/osteotome OR frontonasal or maxillary osteoplastic flap if completely within maxillary sinuses 09-11s
43
How do you find the root apex for repulsion of 2nd or 3rd premolars?
How do you find the root apex for repulsion of 08-11?
What is best way to find root apex?
- center of clinical crown
- caudal contact of tooth if 9
- radiographs
44
Is anesthesia or sedation used for repulsion of horse teeth?
- anesthesia
45
When performing osteotomy for repulsion, what teeth may result in damage to infraorbital n or facial artery?
What structures may need to be reflected for 309, 409?
- 06-08
| - facial a and v and parotid salivary duct
46
Which teeth require an osteoplastic flap through the paranasal sinuses?
- 09-11
47
What imaginary line is used to find level of osteotomy?
Ventral or dorsal to this line?
If horse is less than 8 years old?
If horse is old where should dorsal aspect of a maxillary osteotomy be?
If horse is young where should ventral aspect of osteotomy be?
- course of the nasolacrimal duct--medial canthus of eye to infraorbital foramen
- ventral
- close to the line
- close to the facial crest
- at border of mandible
48
After making incision or flap in skin, what are next steps in repulsing and equine tooth?
- remove periosteum
- create osteotomy 1.5 x 2 cm trephine or 0.95-2.7 cm drill
- expose apex with bone curette or rongeur
- transect apical end of tooth
- seat punch
49
Where should trephine hole be created for Maxillary M1?
| - M2?
- paranasal sinus midway between rostral end of facial crest and point on crest at level of medial canthus, 1 cm ventral to line btween io foramen and medial canthus
- paranasal sinus rostroventral to ventral orbital rim (varies with age)
50
What is the triple trephine technique?
- one hole dorsomedial to the medial canthus of eye to place punch on apex of tooth
- second hole ventrorostral to medial cnathus to guide punch onto apex and allow post op explore of alveolus
- third hole at agnle formed by orbit and faical crest to place catheter into sinus for post op lavage.
51
How can maxillary sinus of old horses be accessed?
| What is disadvantage?
- maxillary or frontonasal flap
| - have to reopen to monitor healing or to currette alveolus (vs. unsutured trephine hole)
52
How is apex of M3 exposed?
What kind of punch must be used?
Why?
- trephine hole in frontal bone or frontonasal osteoplastic flap
- offset
- root is below orbit and caudally curved
53
How is mandibular 10 or 11 removed?
- incise ventral aponeurosis of masseter, reflect masseter
54
How should punch be aligned and what is problem if unable to do this?
- along axis of tooth
| - if oriented obliquely need more force and more likely to result in sequestra
55
Should a tooth be transversely sectioned as it is repulsed?
- No-should not be necessary
56
How should alveolus be treated after repulsion of a equine tooth?
- coronal 1/3 plugged
- if left unsutured rolled gauze impregnated with dilute povidine-iodine packed into the apical aspect prior to plugging the coronal apect then gauze gradually remove
57
How do you keep a maxillary PM2 plug or plug of two adjacent teeth in place?
- mesh with wire
58
How do you lavage paranasal sinuses after repulsion of maxillary 10 or 11?
How does fluid exit?
How often should this be done?
- trephine hole into conchofrontal or caudal maxillary sinus. Trephine hole into conchofrontal sinus 2-3 cm medial to madial canthus, trephine hole into caudal maxillary sinus through straight incsion 1.5 cm ventral to ventral lid of eye
- insert foley catheter, flush with isotonic saline or povidone-iodine
- through nasal cavity via nasomaxillary aperture
- 1-7 days
59
What are complications associated with extracting a cheek tooth by repulsion?
What is most common?
What increases risk?
- damage to other teeth, io or mandibular nerve, palatine bone, medial or lateral lamina of mandible or maxilla
- early loss of plug->contaminated alveolus or paranasal sinus
- oro antral fistula
- damage to nasolacrimal duct, parotid salivary duct, IO n, palatine a
- chronic draining tract from sequestra
- most common is sequestra
- more caudal, more complications
60
What tooth cannot be removed by buccotomy?
- 11s
61
Does buccotomy require anesthesia?
| What are advantages of buccotomy?
- yes
| - more controlled disruption of PDL
62
Which teeth are accessed by vertical buccotomy incision?
| Horizontal?
- 09, 10
| - 06-08
63
Where is incision for horizontal buccotomy made?
| Where is vertical buccotomy incision made?
- curvilinear skin incision centered over the tooth at level of tooth's gingival reflection in the buccal cleft
- parallel to the linguofacial artery and vein
64
Why are mandibular first and second molar teeth accessed with vertical incision?
- to avoid the linguofacial artery and vein and the parotid salivary duct
65
What nerves can be damaged when removing maxillary teeth via buccotomy?
mandibular?
- dorsal buccal branch of facial nerve
| - ventral buccal branch of facial nerve
66
Where is maxillary buccotomy incision made with respect to parotid papilla?
Where is mandibular buccotomy incision made with respect to parotid papilla?
- what is landmark for the parotid papilla?
- dorsal
- ventral
- rostral aspect of 108/208
67
What structures are encountered during deep dissection of tissue for buccotomy?
- ventral buccal glands, buccal venous plexus
68
What vessels make up the buccal venous plexus?
- labialis communis, labialis maxillaris, labialis madinulars vv,
69
What are the steps for a buccotomy once the oral mucousa is incised?
- gingival flap
- incise periosoteum and reflect
- incise buccal alveolar bone parallel to long axis of tooth with oscillating saw, surgical fissure burr or sharp chisel, remove plate
- elevate (split tooth longitudinally or transect transversely first)
- pack alveolus with gauze and put through adjacent stab incision
- suture flap or leave open
- close buccotomy in 3 layers
70
How much lateral wall is removed in buccotomy procedure to expose apical end of tooth?
- 2/3
71
What are complications of horizontal or vertical buccotomy extractions?
How common are complications?
- damage to ventral or dorsal buccal nerve or parotid salivary duct
- temporary facial nerve paralysis from trauma to dorsal buccal branch of facial nerve
- partial dehiscense
- one study only 1 out of 44 needed second surgery
