teeth and mastication 1 + 2 Flashcards
what are the roles of teeth (separate into categories of teeth type)
incisors: nibbling, grooming and cutting
canines: grasping, fighting/defence, stabbing, toxin injection
premolars and molars: depends on diet, variously crushing, shearing, dripping and grinding
attached to which bones of the skull will you find teeth
- incisive bone
- maxilla
- vomer (frogs!)
- palatine
- pterygoid (snakes!)
- mandible
mammals will have teeth on the incisive, maxilla and mandible
what word describes the cheek side of the tooth
buccal
what word describes the tongue side of the mandibular teeth
lingual
what word describes the medial side of the maxillary teeth
palatal
what word describes the rostral aspect of the teeth
mesial
what word describes the caudal aspect of the teeth
distal
what word describes the meeting surface of the teeth
occlusal
what word describes the raised parts of the occlusal surface of the teeth
cusps
what word describes the indented parts of the occlusal surface of the teeth
grooves
what word describes the area of the tooth where the roots come together
furcation
what word describes the part of the tooth towards the tip of the crown
coronal
what word describes the area of the tooth towards the root
apical
label
hypsodont describes teeth that belong to: and are:
equids and bovids –> high crowns
- most of the tooth hidden in jaw bone
brachydont describe teeth that belong to: and are:
Carnivorous animals (dogs and cats) –> low crowns
- approx 1/2 of the tooth in jaw and 1/2 visible
homodont describes
one type of toothe throughout the mouth
heterodont describes:
different types of teeth in the mouth
diphyodont means:
2 sets of teeth (deciduous and permanent sets)
discuss the difference in jaw bones of herbivores vs carnivores and why they make a difference to chewing action for their respective diets
in herbivores: longer vertical ramus radius gives more even occlusion in herbivores
in carnivores: shorter vertical ramus radius produces scissor action in carnivores
what is a diastema
gap between incisors and cheek teeth
label
what is the gingiva
gums - tissue surrounding base of teeth and covering jaws
mucoperiosteum -> the oral mucosa is firmly attached to the underlying periosteum
what is the crown
- visible/supragingival part of tooth
- includes enamel: hard smooth outer layer
- dentine: hard tubules under enamel
- pupl cavity
- coronal to cemento-enamel junction
what is the root
- part under gingiva
- cementum: bit that holds the tooth into the root
- dentine
- root canal
- apex-apical delta
- single and multi rooted
- divergent mechanical attachment
- apical to cemento-enamel junction
label the parts of the tooth
what is enamel and discuss
- hardest biological substance
- 97% hydroxyapatite
- acellular
- no collagen (have specialized support proteins)
- no repair possible but enamel calcium is in equilibrium with salivary caclium
- dissolves in acid
- only on crown
- not always present
what is dentine
- living tissue
- contains odontoblasts which produce the dentine tubules
- primary, secondary and tertiary dentine
what are odontoblasts
produce dentine tubules
discuss the differences between primary secondary and tertiary dentine
primary:
- most of dentine
- formed as the tooth grows
- mineralized collagen
secondary:
- grows slowly on daily basis
- formed after eruption
- makes pulp cavity smalle as it is made
- brown ish colour distinguishes older animal
tertiary:
- formed in reaction to damage
- irregular structure
- helps to fill in damage
what is pulp
- in the pulp cavity
- contains blood vessels, lymph and nerves
- secondary dentine deposition leads to it narrowing with age
what is cementum
- similar to bone
- peripheral to dentine or enamel
- attachment for periodontal fibres
- completely covers herbivore teeth (because continuously errupt)
what is a closed root
- root apex closed off = do not grow once formed
- teeth either then erupt slowly and continuously once reached max adult length OR erupt to a fixed height and do not erupt further
what is an open root
- root apex is open and tooth grows continuously
- teeth continually grow and erupt
- rodents for example
what is the periodontinum and what does it consist of
supporting structure for teeth
- alveolar bone/lamina dura
- periodontal ligament
- cementum
- gingiva
what features of the gingiva
- squamous epithelium
- dense fibrous layer
- closely bound to the periodteum
- reflects at the cemento-enamel junction to form a pocket (gingival sulcus)
what is the periodontal ligament
- series of angled collagen fibres (at right angle to tooth)
- supports the tooth
- sock absorber
- spreads load into whole socket
discuss tooth development
- line of epithelial cells condenses along the jaw margins
- invaginate to form a dental bud
- the epithelial cells become ameloblasts and form enamel
- bud in-folds to form a dental cap under which neural crest-derived mesenchyme form a dental papilla
- the mesenchymal cells become odontobalsts and form dentine
- cap remains connected to epithelium via a cord of cells which give off-shoots to further buds
- mesenchyme around the bud forms a vascular dental sac
- inner layer forms cementoblasts which make cementum
- outer layer forms osteoblasts which form the alveolar bone
- enamel organ comprises stellate reticulum plus ameloblasts (inner enamel epithelium) and outer enamel epithelium
discuss tooth eruption in horses
- teeth erupt as they grow
- roots close later in life
- teeth grow and wear most rapidly in first 5 years after eruption
- means up to 9 years old there is higher risk of points being formed
discuss arterial supply to the teeth
each arcade has own arterial supply
major ones burried inside bone
clinical significant of major palatine artery
runs along hard palate - can be damaged during extraction of upper teeth
the maxilla is supplied by which nerve
infraorbital nerve (branch of maxillary branch of trigeminal)
- enters maxilary foramen
- sensory branches to tooth roots
- exits at infraorbital formen
what nerve supplies the mandible
mandibular nerve (branch of trigeminal)
- enters mandibular foramen
- travels in mandibular canal
- sensory branches to tooth roots
- also motor to jaw muscles
list major dental nerve block sites of the maxilla
list dental nerve bloc sites on the mandible
discuss the temporo-mandibular joint
- synovial joint
- hinge joint but also has lateral movement, rostrocaudal movement and allows for grindinf and opposing of teeth
- well developed meniscus
what is the triadan system
way to label teeth
how many teeth do cats have
30
how many teeth do dogs have
42`
what is the dental formula for dogs
upper: 3.1.4.2
lower: 3.1.4.3
meaning upper has 3 incisors, 1 canine 4 premolars and 2 molars
i.c.p.m
what is the dental formula for cats
3.1.3.1
3.1.2.1
i.c.p.m
is the carnissial tooth a molar or premolar on the upper arcade? lower?
- premolar on upper
- molar on lower
discuss aging in horse teeth
what are tushes
- equine canine teeth
- brachydont
- permanent
- in stallions and geldings (rarely females)
- no clinical problems
- sometimes calculus build up with age needs to be removed
what are wolf teeth
- first premolar of upper jaw in horses
- rarely first premolar of lower jaw
- redundant regressed teeth
- in both sexes
- appear at 3-5 years if at all
- small ones wobble and interfere with the bit so need to be removed under sedation
- large ones can be left in if stable
