Small animal dentistry Flashcards
Canine dental formula
3142
3143
(Ones with no baby tooth: 1st premolar, all molars)
Cat dental formula
3131
3121
Ones with no baby tooth: upper 1st premolar, lower 1st and 2nd premolar, + all molars)
Where does inferior alveolar canal run (including trigeminal)
Mandible
Where does intra-orbital NVB run
Maxillal close to upper carnassial
In notation which tooth is always 04
Canine
In notation which tooth is always 9
1st molar
Tooth eruption times in dogs
Primary dentition around 3-5 weeks
Then from 3.5-6 months get replcament with adult teeth; incisors/premolars first then canines (~5mo) then molars
When do canine erupt in dogs
5 months age
Cat tooth eruption times
Primar dentition: around 2-3 weeks
Adult dentition from 3-6 months; starts with incisrs then get molars/premolars/canines at same time (premolars take longest)
What substance makes enamel and dentine
Hydroxyapatite (crystalline vs mineralised)
- In dentine it is mineralised and interlinked with organic compponents
What is the periodontal ligament
Soft tissue b/w alveolus bony socet and teeth root
Has innervation for sensation of pressure on tooth + pain from damage/infection
Normal gingival sulcus depth in dogs vs cats
Dogs: 1-2mm (up to 3 in large teeth in large dogs)
Cats: 0.5mm
3 characteristics of healthy gingiva
No redness
No oedema
No bleeding (on probing)
Which areas can sense pain in tooth
pulp
periodontal ligament
Gemination meaning (shape abnormalityy)
Teeth try and duplicate
- Can get 2 independent teeth = twinning
Or two still connected teed = Siamese
WHat is enamel hypoplasia
Normal quality enamel but reduced in thickeness in some areas
What is hypo-calcification of teeth
Normal thickness enamel but improper calcification so weak and porous; can stain and may break
What are calcification impurities
Chemicals that chelate calcium can become incorporated into tooth if systemic during calcification
Dolichocephalic meaning
long skull compared to width e/g whippet
What does anisognathic mean
Mandible is narrower than maxilla to fits within upper jaw arch
What is the canine teeth interlock
Lower canine should fit into diasterma b/w upper canine tooth and lateral incisor
What is a scissor bite incisor relationship
INcisal edges of lower incisors touch back surface of upper incisors
So upper incisors are rostral to all lower ones
What is a dento-alveolar defect
Localised abnormality of position of a tooth; out of alignment but within normal size/shape jaw
Brachygnathic meaning
Mandible short relative to maxilla i.e overbite
Prognathic meaning
Mandible long relative to maxilla i.e underbite
What is an incisor cross bite
When middle two incisors of maxilla are behind the middle two on mandible
- Can happen in 6 month old puppies which slip out of scissor bite because mandible is one of the last bones so stop growing
Risk with crown reduction and pulp capping as a way to fix malocclusion
Chornic pulipitis
What is a snaggle tooth
When the upper canine erupts pointing to far forward (45 degrees) so less space for lower canine to rest in
– Lower canine tips OUTWARD towards lip keeping mouth open
e.g Shetland sheep dogs
Seen in Persions but doesnt cause soft tissue trauma etc
What breed commonly gets persistent deciduous canines
Yorkshire terriers
How does bisecting angle x ray technique work
Direct X ray beam 90degrees to the BISECTING ANGLE halfway between the angle of tooth and the film
Upper incisors: sternal recumbency
Upper canines/cheek teeth: lateral recumbency
Lower incisors and canines: dorsal recumbency
[NB: lower molars done via parallel placement technique]
What is needed to form plaque
salivary glycoproteins, commensal flora
Together form polysaccharide matrix
How long does it take for mature plaque to form
2 days
What in gingivitis
Inflammation of gingival margin due to irritation from plaque anaerobic bacterial products in contact
= reversible and non-painful
What happens in periodontal disease
Following long standing gingival inflammation, body response to plaque changes
Start getting destruction of structures including collagen fibres holding gum in place and bone forming socket with tooth
= irreversible changes
Why do we get pocket formation in periodontal disease
Because there is breakdown of fibres holding gum on
So gum margin stays where it is but the attachment moves down
What is the biggest pre-determining factor than changes body response to plaque
Genetics
i.e breed
– Pure breeds more predisposed, esp oriental and siamese cats
Risk factors for periodontal disease
Pure breed
Immune compromise
Overall helth
Body size; SMALL animals at higher risk
Plaque retention factors
= anything that faciltates plaque being held onto tooth
- Calculus, enamel defects, exposed dentine from subgingival fracures, root surface exposure during gum recession as covered in cementum
Plaque stagnation factors
= anything that holds plaque in hard to reach place
- Periodontal pocket = main one
Also tooth crowding, reduced self cleansing by teeth e.g in malocclusion, abnormal gingival margin position (recession exposes roots/furcation space while hyperplasia creates false pockets)
What is the main factor in periodontal disease that determines prognosis
Clinical pocket depth
(NB: remove gingival overgrowth before measuring this)
Indicators for tooth extraction
Mobility grade 3 or more (i.e movement >1mm in any direction)
Pocket depth - >5mm (or 7 for canines)
Furcation exposure from gum recession F3
Can do selective extractions with tooth crowding
What is specific to greyhound mouths
Receding gums are common but doesnt necessarily indicate extraction
What is traditionally used to ‘stage’ periodontal disease
% of attachment loss
- But can only get this from X rays and probing
AND doesn’t actually correlate with outcome/best care
How does a polyphosphate coating on food work
Chelates calcium and keeps it soluble so it doesn’t form tartar
How do we label the quadrants of the mouth
Start top right = 1; then go round in a circle
(if imagine dog facing you = clockwise)
Deciduous teeth noted as 5-8
WHat do different notations on a dental chart mean
o = tooth missing
X = tooth extracted
M = tooth mobility grade
H = hyperplastic margin/R = receeded
Gingivitis index goes in box
Periodontal pocket depth goes on plan view
What numbers go in the box on a dental chart
gingival index number (from 0-3 based on redness, oedema and bleeding)
What is calculus
Mineralised plaque; because of calcium in saliva
What diseases are associated with periodontal disease
Cardiovascular disease
Pre-term birth and low birthweight
Diabetes (two way link)
Endothelial/renal disaese
Chronic obstructive pulmonary disaese
At what clinical pocket depth should we remove a tooth
> 5mm (or 7 for large canines)
- 2mm for cats; on 3mm on canine
Rule of thumb with scaling below gumline
Only up to 2mm below gumline and only for 2 secs; for ultrasonic
Larger pockets need handheld scaler
What speed do we want polishing done at
3000rpm; low hum
How can we turn a dog during a dental
Legs under body to avoid debris falling down throat; want head to tip forward
What is root planing
removing cementum from the root in a periodontal pocket; this will be necrotic and infected + is plaque retentive
