Dentistry Flashcards

Question

Which is the hardest substance in the teeth?

Answer 1

Two additional concentric cup like infoldings of the enamel - infundibular enamel folds (involved in infundibular caries)

Answer 2

Infolding of occlusal surface to increase surface area available for mastication. Incisors have one infundibulum. Each maxillary tooth (aside from wolf tooth 05) has 2 infundibulae.

Answer 3

Hypocementosis

Answer 4

Pulp is innermost layer of the tooth. Contains nerves, blood supply, lymphatics and odontoblasts. Number of pulp horns varies according to tooth. Care when rasping teeth, over-rasping can cause thermal necrosis of pulp

Answer 5

Dynamic structure Protects and supports tooth Secures tooth in alvelous Copes with chewing Goes all round the root of the tooth not just the very bottom

Answer 6

Gingiva Peripheral cementum Periodontal ligament Alveolar bone

Answer 7

Unique to hypsodont periodontum Produced continuously by cementoblasts Deposited at apex and periphery of reserve crown

Answer 8

Covers the alveolar bone, periodontal ligament and reserve crown Acts as a barrier to prevent bacteria entering the periodontal tissues. Composed of keratinised epithelium

Answer 9

Purpose is to relay vasculature to tooth Supports tooth and keeps it stable during chewing

Answer 10

Pathological space between teeth 'open' or 'valve' Older horses usually Easily missed Food packing and rotting food will cause periodontal disease which is incredibly painful Up to 50% in general population. Good prognosis if treated early - if it gets to about 3mm it is going to be much harder to treat May progress to tooth loss Excessive transverse ridge (ETR) in teeth opposing diastema causes or worsens condition

Answer 11

Quidding Dysphagia Anorexia Or none!

Answer 12

Creates open space to reduce valve effect Periodontitis Care to avoid pulp chambers Try conservative management first

Answer 13

2-3 times annual rasping Replace long fibre food e.g. hay with grass, or short chopped foods e.g. grass or alfalfa Monitor carefully for progression

Answer 14

Painful Very common (>75%) esp > 10 yrs Due to entrapment of feed between teeth>bacterial infection of PD tissue> inflammation and pain Severe cases will lead to disruption of periodontum-periodontal ligaments and can lead to periapical infection and tooth loss

Answer 15

Early recognition key to treatment Check for underlying cause eg displacement, dental overgrowth of opposing tooth Severe cases will lead to disruption of periodontum-periodontal ligaments and can lead to periapical infection and tooth loss Mild cases can be managed with routine dental floating Remove any ETR Balance the mouth Can use antiseptic flushes Recheck case in 3 months to reassess Severe cases may need analgesia and nerve block to evaluate If pocketing very deep-extraction may be warranted If PAI, extraction only option

Answer 16

Infundibular caries vary in significance, but deep pockets may predispose to fractures. More prevalent in older animals.

Answer 17

More common in caudal cheek teeth (?less buffering effect of saliva) ?Link between diatemata and peripheral caries

Answer 18

Cheek teeth have between 5 and 9 pulp chambers depending on tooth. Often no obvious clinical signs of disease. Flush mouth well and use mirror and probe to examine. Early cases may benefit from filling. In advanced cases, radiographs or CT warranted to investigate. Occlusal pulpar exposure-black area around pulp horn Fissure in occlusal 2 dentine Can get probe into pulp horn Tooth likely dead Can wall off damaged pulp with 3 dentine

Answer 19

Caries affect the cementum of the maxillary infundibula. Caries usually marked on chart as IC. Can use IC followed by the grade of caries. A probe can be very useful to assess the depth. Grading system 0 degree to 4th degree

Answer 20

Can affect any tooth Grading system described can be used on chart. Erosion of edges of teeth Rough surface that food adheres to Discoloured teeth Often improve with regular dental care Food stasis in mouth is implicated Can lead to fractures

Answer 21

Can be idiopathic Rarely iatrogenic Traumatic fractures rare-usually limited to incisors following kick or injury (often haynet). Cheek teeth fractures usually secondary to pulpar disease or caries. May be incidental finding on examination. Fractures usually lead to pulpar exposure, but not all fractures will lead to periapical infection…some cases will wall off infection before abscessation occurs. Pulp exposed in fractures, does not always lead to infection-can wall off Fragment can be removed if pulp walled off Will grow out given time CT ideal to evaluate

Answer 22

Pulpar disease or caries

Answer 23

Quidding Halitosis Sinusitis Facial swelling Can be asymptomatic

Answer 24

Buccal sagittal fractures

Answer 25

Midline sagittal fracture through infundibulae-often associated with PI

Answer 26

Infections of cheek teeth Can involve mandibular, max bones or paranasal sinus Draining tract or swelling in mandible Extension of periodontal dz (diastema etc) Pulpar exposure Anachoresis→blood/ lymph bourne to devitalised pulp Can occur with # tooth Caries- rare

Answer 27

Nasal discharge (malodorous) Dysphagia Anorexia

Answer 28

Radiography □ Limitations - Low sensitivity so it is possible to miss early infections - Warn owner may need repeat x-ray - ?refer for CT…cheaper than 2 sets of radiographs? □ What do you see? - Periapical sclerosis - Periapical halo formation - Clubbing of root apices - Widening of periodontal space and loss of lamina dura indicative, but less reliable - Low false negatives CT, almost 100% sensitive Scintigraphy (56% sensitivity) rarely used for this anymore

Answer 29

Radiography/CT to assess Long term (4-6 wks) abs –not often curative Tooth removal most often indicated Endodontics? Curettage of root?

Answer 30

Common Teeth need opposing surface to grind against Grow approx. 4mm/yr, more in unopposed Tooth will grow into space Causes reduced range of motion of jaw Dental drift occurs post tooth loss Usually minimal and uncomplicated In severe cases can lead to diastema or further tooth loss Regular rasping needed. If corresponding overgrowths large, need staged reduction. In cases with severe dental drift, further extraction may be needed.

Answer 31

Equine Odontoclastic Tooth Resorption and Hypercementosis

Answer 32

Treatment is extraction of affected teeth - can be extraction of all incisors so can be a difficult sell to owners but they often do much better after this

Answer 33

Painful, will not eat carrot with incisors Diagnose based on clinical signs and radiography

Answer 34

Oral extraction has lower complication rate than surgical techniques Usually performed under standing sedation Nerve blocks Domosedan drip Analgesia (NSAIDs Paracetamol) ?Antibiotics, don’t need to usually unless it is immunocompromised or particularly nasty infection Tetanus antitoxin

Answer 35

Ipsilateral infraorbital nerve block for maxillary 06/07 and incisors Maxillary nerve block for maxillary arcade Mandibular nerve block for mandibular cheek teeth Mental nerve block for lower incisors

Answer 36

For maxillary 06/07 and incisors Analgesia of the nostrils and lip Infraorbital foramen If anaesthetised up into infraorbital canal, can get desenstisation of 101-107 and 201-207 Locate infraorbital foramen Push levator nasolabialis m. dorsally 21G needle 4-5ml local

Answer 37

For maxillary arcade Entire upper arcade de-sensitized, including incisors. 22G spinal needle 10-15ml mepivicaine Skin bleb may be useful Insert needle just below zygomatic bone at level of posterior third of eye Insert needle at 90 degree angle to skin Advance needle into periorbital fat pad Withdraw needle slightly before infiltrating local If needle hits ramus of mandible, re-direct Can cause exophthalmos (temporary) if blood vessel traumatised

Answer 38

For mandibular cheek teeth Desensitises all mandibular arcade Used for extraction or severe PD disease Mandibular nerve enters mandibular canal on the dorso-medial aspect of the horizontal ramus of the mandible Mandibular foramen-at intersection of vertical line at the caudal limit of the orbit with a line parallel to the occlusal surface of the rostral 4 CT 15cm 18G spinal needle Walk up medial aspect of the mandible 20-30ml mepivicaine deposited at and 1-3cm dorsocaudally Don't do both at the same time as they could chew their tongue off

Answer 39

For lower incisors Blocks lower lip and mandible up to 306 and 406 Sometimes called mandibulo-alveolar nerve Site: mental foramen 22 G 1 ½ inch for lower lip 5-10ml local If caudal anaesthesia required, use 3 inch needle inserted into canal

Answer 40

Used to expose crown on side of tooth. Local infiltration of lidocaine useful Expose as much crown as possible- tooth like an iceberg, can be quite brutal with the gum Oral endoscopy may facilitate To minimise the risk of the tooth breaking, get the forceps as far down as possible

Answer 41

Narrow blade CT separator inserted into interdental space rostral and caudal to tooth Kept in place for circa 5 mins to excessively stretch and damage the periodontal ligaments Can use series of wider separators Do not use between 06/07 when extracting 07 as will loosen 06

Answer 42

Appropriate CT extractor then applied Extractor forceps kept tightly shut using bungee cord Verify correct position visually Extractors then moved gently sideways in a horizontal plane Care must be taken to avoid fracturing the crown Ensure the extractor forceps are in place tightly at all times as if loose will only excoriate the crown increasing risk of fracture Success is close once a “squelching” sound is heard and foamy blood is visible Greater movement can then be applied Fulcrum used to aid extraction once tooth digitally loose or can be removed by hand

Answer 43

If fragments of tooth remain, horse may still show clinical signs May be clinically silent but will not heal ? Significance Should always be removed if possible

Answer 44

Check for root fragments or alveolar bone Alveolus plugged with honey soaked swabs - 24 hrs →avoids food impacting alveolus before granulation tissue has formed Pack with dental acrylic If <5cm deep (old horses) then no need to pack Should have smooth outline- rough areas usually due to sequestra- removed digitally or curretted

Answer 45

When first pack removed, check alveolus Rough areas curetted and lavaged Smaller sequestra may be removed by granulation tissue Larger sequestra removed with forceps If granulation tissue not forming in first few days suspect problem

Answer 46

In cases with sinusitus, the ipsilateral sinus often be trephined and irrigated daily for 5-7 days Sinoscopy helpful, particularly in refractory cases Frontal sinus trephined and flushed in all extractions involving a sinus In cases where RMS involved, this must be flushed separately BID 5-7 days

Answer 47

Vestigial premolar Brachyodont teeth- no deciduous precursor Erupt at 6-18 months old Mandibular wolf teeth-rare (standardbreds) Blind wolf teeth occasionally- 1-2cm rostral to 06, under the mucosa, →poor performance. Radiography used to evaluate blind or displaced teeth- need extraction Erupted and non-displaced classed as Cat 2. Can be removed by EDT under direct and continuous VS supervision Blind/unerupted/displaced classed as Cat 3 - incision into vital tissue. VS only. Local anaesthetic into palatine ridge NSAIDs and TAT/toxoid Elevation of gingiva and breakdown of the periodontal ligaments Avoid Palatine Artery! If palatine artery lacerated, insert towel or cotton wool roll in horse's mouth, shut mouth, keep head (not nose) elevated (head up so pressure reduced but nose pointing down so that the blood runs out and doesn’t drown them.

Answer 48

Oral extraction Invasive transbuccal screw technique Repulsion under GA Endodontic techniques

Answer 49

Oral extraction has lowest complication rate Method of choice where possible Always have back up plan Be aware of complications

Answer 50

Clinical crown cannot be grasped Reserve crown fracture If the apex is bigger than alveolus eg dental tumour/reactive hyperplasia of cementum

Answer 51

Conchofrontal sinus

Answer 52

Ventral conchal sinus