Oral Cavity & Teeth Flashcards
Three types of head shapes in the dog
-dolichocephalic
-mesaticephalic
-brachycephalic
Dolichocephalic (define + 3 examples)
Head, particularly the nose, is long and narrow
-greyhound
-borzoi
-afghan hound
“-cephalic” means
Head
Mesaticephalic (define + 3 examples)
Normal or average shape of skull
-Labrador
-beagle
-pointer
-dalmation
Brachycephalic (define + 3 examples)
Cranium is more rounded with a short nose
-boxer
-bulldog
-pug
6 functions of the oral cavity
-selection
-pretension
-mastication
-ensalivation
-forming a bolus
-swallowing/deglutition
The 5 boundaries of the oral cavity are
-lips
-cheek
-hard and soft palate
-tongue
-floor
How the teeth come together is called
Occlusion
Three spaces within the oral cavity are
-vestibule
-interdental space
-oral cavity
Normal teeth occlusion is (2)
-lower canines rostral to upper canines
-upper teeth lateral to lower teeth
Rostrally the oral cavity communicates with the nasal cavity via
Incisive ducts
Caudal to the central incisors and the opening to the oral cavity are
Incisive papilla
In some species, the incisive ducts may connect to the
Vomeronasal organ
Caudal communication to the oropharynx is via
Isthmus Faucium
Horses lack ___ ducts
Incisive
The vomeronasal organ is located
In soft tissue of the nasal septum, within the nasal cavity
Jacobson’s Organ is also called
Vomeronasal organ
Vomeronasal organ (2)
-paired auxiliary olfactory (smell) sense
-receptors detect pheromones
Labial means
Lips
The assessment of perfusion and hydration status of mucous membranes is called
Capillary refill time
Mucous membranes should be
Pink and pigmented
Buccal means
Cheek
Prolonged capillary refill time takes how much time and is an indication of what
->2 seconds
-decreased peripheral perfusion
Normal capillary refill time is
1-2 seconds
Lingual means
Tongue
Yellow mucous membranes indicates
Jaundice
Purple/bright red mucous membranes indicates
Septic shock
Grey/white/muddy mucous membranes can indicate (2)
-anemia (not enough RBCs)
-hypovolemia (not enough blood)
Lips/Labial (3)
-internally covered with Labial Mucosa
-mucosal layer is continuous with gingiva (gums)
-made of stratified squamous epithelium
Rima Oris (3)
-dorsal and ventral lips
-where food goes in
-where vocalisation comes out
The corners of the lips is called the
Commisure
The most rostral part of the lips is called the
Philtrum
Labial glands of the horse are located in ____ and allow for ___
-margins of mouth
-high mobility of the lips
Camels are able to open/close its ___ in order to ___
Nostrils; keep sand out
Papillae in bovid cheeks are ___ to ___
-aborally directed
-keep food between teeth
Sharp edges on the teeth can
Cause damage to the mucosa (especially in horses)
The cheeks/buccal includes (2)
-external skin
-internal mucosa lined with stratified squamous epithelium
Buccal glands (2)
-dorsal
-ventral
The dorsal buccal gland in carnivores is called the
Zygomatic
Hard palate (4)
-lacks glands
-covered with thick stratified squamous epithelium
-contains a venous plexus underneath epithelium
-can be pigmented
Three bones of the hard palate
-incisive
-maxilla
-palatine
Rugae and median raphe are part of the
Hard palate
What is A and B?
A: median raphe
B: rugae
The hard palate in ruminants (2)
-is called the dental pad
-thick Cornified (keratinised) stratified squamous epithelium
The dental pad of ruminants is there in lieu of
Upper incisive teeth
A defect of the hard palate is called
Cleft palate
5 functions of the tongue
-feeding
-suckling
-drinking
-thermoregulation
-grooming
The sulcus of the tongue
Runs up the median length of the tongue
The attachment of the ventral portion of the tongue to the floor of the mouth in the midline is called the
Frenulum
Four main parts of the tongue
-apex
-sulcus
-body
-root
The root of the tongue is attached to (2)
-hyoid apparatus
-surrounding connective tissue
Lyssa of tongue (4)
-directly beneath mucosa
-not all species have it
-thin and hard
-extends from the tongue apex to the level of the frenulum
Cattle, sheep, pigs, and horses have two additional structure in their tongue called __ which help to ___
-lingual fossa
-lingual torus
Helps to generate negative pressure in the mouth for suction
The caudal portion of the tongue in cattle, sheep, pigs, and horses is called
Lingual torus (tongue prominence)
Four muscles of the tongue
-styloglossus
-hyoglossus
-genioglossus
-geniohyoid
The lingual fossa and lingual torus help to
Generate negative pressure in the mouth for suction
Intrinsic muscles of the tongue (3)
-are within the tongue
-dorsal
-contain many fibre bundles with connective tissue and fat
Both the intrinsic and extrinsic muscles of the tongue are innervated by which nerve
Hypoglossal Nerve (CNXII)
Extrinsic muscles of the tongue (3)
-responsible for major movement
-originate outside the tongue
-more ventral
The styloglossus comes from which bone
Stylohyoid
The hyoglossus comes from which bone
Basihyoid
The genioglossus comes from which bone
Medial surface of the rostral mandible
The geniohyoid runs from the
Mandibular symphysis to basihyoid
“Genio-“ means
Chin
Which muscle elevates and retracts the tongue
Styloglossus
Which muscle depresses and retracts the tongue
Hyoglossus
Which muscle moves the hyoid and tongue rostral and is important during swallowing
Geniohyoid
Which muscle depresses, moves rostral, and curls the tongue
Genioglossus
Label the following muscles of the tongue
Red: Genioglossus
Blue: Geniohyoid
Black: Styloglossus
Yellow: Hyoglossus
The tongue surface is lined with ___ and covered with ___
-stratified squamous epithelium
-papillae
Specialized receptor cells that respond to chemical stimuli in food/drink are called
Taste buds
Taste bud receptor cells activate ___ and release ___
Sensory (afferent) neurons; neurotransmitters
Raised bumps on the tongue are called
Papillae
Papillae can either be
Mechanical or contain taste buds
Two mechanical papillae are
-conical papilla
-lenticular papilla
Taste bud papillae include (3)
-vallate
-foliate
-fungiform
Conical papilla (4)
-mechanical
-big filiform
-located on the root of the tongue
-point caudally (direct food to back of throat)
Lenticular papilla (4)
-mechanical
-flat and rounded
-mainly found on lingual torus of ruminants
-enhance suction from tongue to hard palate to generate negative pressure
Fungiform papillae (3)
-taste
-located on the rostral 2/3 of tongue
-rounded protrusions
Vallate Papilla (5)
-taste
-dorsal root of tongue (2/3 from tip of tongue)
-large
-V shaped
-surrounded by a deep groove
Marginal Papillae (2)
-found in young pups (lost as diet changes to solid
-help seal lips around the nipple to prevent milk spilling
Foliate Papillae (5)
-taste
-lateral root of tongue
-oval shaped
-separated by deep clefts/crypts
-serous gland discharge
Taste buds consist of (4)
-taste pore
-supporting cells beneath taste pore
-neuroepithelial cells
-nerve ending
Taste buds sit on ___ and extend from ___ to ___
-dermal papillae
-basal laminar of stratified squamous epithelium
-surface
Taste buds are innervated by (3) depending on which taste bud is activated
-facial nerve (CN VII)
-glossopharyngeal nerve (CN IX)
-vagus nerve (CN X)
Lingual tonsils are (3)
-aggregated lymph nodules around the base of the tongue
-large in bovines
-not observable in dogs, cats, and small ruminants
Which muscle opens the jaw when it contracts
Diagastric
The surface of the tooth facing toward the tongue is called
Lingual
Which type of tooth does NOT have a deciduous tooth
Molars
Part of the tooth containing blood vessels/nerves
Pulp cavity
Which structure of the tooth is harder than bone and CANNOT undergo repair?
Enamel
Teeth are used for (4)
-pretension
-offense
-defense
-mastication
The root of the tooth is
Embedded in a socket/alveolus
The crown of teeth (3)
-protrudes above the gingiva/gums
-anatomic crown (containing enamel)
-clinical crown (what is visible)
The hardest substance in the body is
Enamel
In hypsodont teeth, the anatomic crown can
Extend below the gingiva
The neck of teeth
Bulges at the level of gingiva (can become visible if gingival recession occurs)
Enamel (5)
-no nerve supply
-harder than bone
-arrange into rods (prisms) of hydroxyapatite
-wears slower than dentine
-cannot undergo repair
Ameloblasts (3)
-create enamel
-degenerate after the enamel is formed
-CANNOT be reformed
The layer under enamel is
Dentine
Why can’t enamel undergo repair
Ameloblasts create enamel and degenerate once enamel is formed. They CANNOT be reformed.
Dentine is formed from
Odontoblasts at the base of dentine layer
Dentine (7)
-similar to bone
-layer under enamel
-formed from odontoblasts
-line the outer pulp cavity
-remain viable for the life of the tooth
-hollow microtubules within a 70% hypocyapatite matrix
-sensitive to pain if enamel layer is breached
Primary dentine
Is laid down before tooth eruption
Secondary dentine
Is produced as the tooth develops
Tertiary dentine (3)
-formed in response to trauma (bacterial, thermal, chemical, and/or mechanical)
-few tubules, more dense
-darker in color
Dentine lines the
Outer pulp cavity
How do teeth become sensitive
If enamel layer is breached, fluid flows through dentine tubules
What structure covers the root of the tooth
Cementum
What structure holds the tooth in place
Periodontal ligament
Cementum (6)
-thin and calcified
-covers root of tooth
-capable of formation, destruction, and repair
-remodels continually throughout life
-attaches to periodontal ligament
-relatively immune to abrasion
In order to remove a tooth, what structure needs to be broken down?
Periodontal ligament
Periodontal ligament (3)
-network of collagenous fibres and fibroblasts
-holds tooth in place
-embedded in cementum and into alveolar bone
What part of the tooth contains blood supply/nerves
Pulp cavity
Bacteria that reaches the pulp cavity, from a lack of dental care, can quickly form a
Tooth Root Abscess
Pulp Cavity (3)
-contains blood supply and nerves
-exact location may vary tooth to tooth
-connected to alveolus via root canal
Brachydont teeth (4)
-stop growing at maturity
-firmly anchored in jaw
-deep root in relation to crown
-enamel is NOT replaced
What type of teeth continuously grow?
Hypsodont
Which teeth have one root? Which teeth have multiple roots?
One root = incisor and canine
Multiple roots = premolars and molars
Which teeth stop growing once the animal reaches maturity
Brachydont
Hypsodont teeth (4)
-high crown in relation to roots
-take a long time to fully erupt
-enables more wear and tear (grinding)
-crown covered in enamel and cementum
What type of teeth are hypsodont
-cheek teeth (premolars and molars) of herbivores
-incisors of horses
As hypsodont teeth surface wear (3)
-pulp cavity may become exposed
-sealed with secondary/tertiary dentine
-helps with ageing
The canine teeth of horses are
Brachydont
What type of tooth has a deep root in relation to the crown
Brachydont
Four types of teeth
-incisors
-canines
-cheek teeth (premolars and molars
Incisors (4)
-cutting pieces of food
-typically 3 upper, 3 lower in each half of jaw
-Brachydont in most species (exception: horse)
-important for grooming
Which type of tooth has a high crown in relation to its roots
Hypsodont
Canines (4)
-grasping and/or offense/defense
-very deep roots
-Brachydont
-lower canine sits rostral to upper canine
Cheek teeth include
Premolars and molars
Cheek teeth (4)
-slicing, grinding, and crushing food
-Brachydont in carnivores and omnivores
-hypsodont in herbivores
-premolars have a precursor (deciduous teeth), molars do NOT
How many teeth do dogs have
42
In dental formulas, the number that comes first indicates
The upper jaw (ex. M 2/3 = 2 molars on upper, 3 molars on lower)
Dog dental formula
2 (I 3/3 C 1/1 P 4/4 M 2/3)
How many incisors in the dog
6 upper and 6 lower
How many canines in the dog
2 upper, 2 lower
How many teeth do cats have
30
How many premolars in the dog
8 upper, 8 lower
Carnassial teeth (5)
-used for cutting and shearing
-dog: P4 / M1
-cat: P3 / M1
-last premolar in upper jaw
-first molar in lower jaw
How many molars in the dog
4 upper, 6 lower
What is the dental formula for cats
2 ( I 3/3 C 1/1 P 3/2 M 1/1)
The carnassial teeth in the dog are located at
P4 / M1
The carnassial teeth in the cat are located at
P3 / M1
How many incisors in the cat
6 upper, 6 lower
How many canines in the cat
2 upper, 2 lower
How many premolars in the cat
6 upper, 4 lower
How many molars in the cat
2 upper, 2 lower
Deciduous teeth (6)
-ie. baby teeth
-smaller and fewer in number
-NO molars
-allows jaw to grow and increase capacity of teeth
-replaced in fixed sequence
-can sometimes be retained
How many deciduous teeth in the dog
28
How many deciduous teeth in the cat
26
Dental formula for deciduous teeth in dog
2 (i 3/3 c 1/1 p 3/3)
How many deciduous incisors, canines, premolars, and molars in the dog?
Incisors: 6 upper, 6 lower
Canines: 2 upper, 2 lower
Premolars: 6 upper, 6 lower
Molars: NONE
Dental formula of deciduous teeth in cats
2 (i 3/3 c 1/1 p 3/2)
How many deciduous incisors, canines, premolars, and molars in the cat?
Incisors: 6 upper, 6 lower
Canines: 2 upper, 2 lower
Premolars: 6 upper, 4 lower
Molars: NONE
Odontoclasts
Resorb the roots of deciduous teeth, breaking down hard tissue and releasing the minerals
Permanent teeth grow on the ___ of the deciduous teeth
Lingual (medial) side —> ie. side of tongue
Premature loss of deciduous tooth can lead to
Disorganized permanent teeth
Resorption of deciduous teeth involves
Periods of rest and repair
In resorption of deciduous teeth, if the repair process prevails over resorption…
Deposition of cementum-like tissue can cause the tooth to ankylose (fuse) to surrounding bone with the loss of the periodontal ligament (ie. tooth can’t fall out and growth of permanent tooth is impeded)
In dogs, the incisor and canines have a
Single long root
In dogs, the incisor crown is (2)
-tricuspid (3 points) in upper jaw
-bicuspid (2 points) in lower jaw
Canine tooth shape (2)
-curved into alveolus
-laterally compressed
Premolars increase in
Size and complexity
Cusps of premolars form a
Discontinuous serrated cutting edge
The cusps of molars is mostly used for
Crushing food
Most of the cheek teeth in dogs have
More than one root
The smallest of the cheek teeth in dogs are ___ and contain ___ root(s)
-1st premolars
-lower 3rd molars
-one root
The large carnassial teeth of dogs (2)
-P4, M1, and M2
-has 3 roots (mesiolingual, mesiovestibular, and distal)
In the dog, the rest of the cheek teeth including the lower carnassial tooth M1 have
2 roots (medial and distal)
Extraction of cheek teeth involves
Sectioning the tooth: cutting through the crown to enable independent root extraction
In cats, the first premolars have ___ root(s), upper carnassial (P3) has __ root(s), and the rest have __ root(s)
First premolars: one root
P3: three roots
Rest of teeth: two roots
Brachycephalic breeds often have ___ due to ___
Malocclusion, compaction, and/or missing teeth due to overcrowding
Occlusial tooth surface
Where the teeth come together
Lingual or palatal tooth surface
Faces the tongue
Jaws are divided into
4 quadrants
Vestibular/buccal/labial tooth surface
Faces the cheek
The front side of the tooth surface is called
Mesial
The back side of the tooth surface is called
Distal
The right lower jaw is quadrant
4
The left upper jaw is quadrant
2
The right upper jaw is quadrant
1
The left lower (mandible) jaw is quadrant
3
First molar is always
09
The last premolar is always
08
The central incisor is always
01
The canines are always
04
What is tooth 304 in the cat
Lower left canine
What is tooth 201 in the dog
Upper left central incisor
What is tooth 103
Upper right incisor
What is tooth 411 in the dog
Lower right molar
Cats lack which tooth numbers (6)
105, 205, 305, 405, 306, 406
Upper incisors are located in which bone
Incisive
All teeth, except the upper incisors and lower teeth, are located in which bone
Maxilla
The lower teeth are located in which bone
Mandible
Brachygnathic or parrot mouthed means
The mandible is too short (ie. overbite)
A mandible that is too long, resulting in an underbite is called
Prognathic
The angle of the mandible should lie directly
Ventral to the temporomandibular joint
The mandible can move in
3 planes
Jaw down movement is caused by which muscle
Diagstric
Jaw up or closing the jaw is due to which muscle
Temporalis
Jaw closing muscles include
Medial and lateral pterygoid
In the pterygoid muscle, which is larger: medial or lateral?
Medial
Which jaw muscle is very important in carnivores
Temporalis
Four muscles of the jaw
-Temporalis
-masseter
-lateral and medial pterygoid
-Diagastric
Innervation of the jaw is done by
-facial nerve (CN VII)
-trigeminal nerve (CN V)
The facial nerve (CN VII) (2)
-opens the mouth (ie. Diagastric m.)
-facial expression
The trigeminal nerve (CN V) (2)
-closes the mouth
-facial senses
