Week 1: Teeth, jaws, and their movements Flashcards
Describe the basic structure of the tooth, using the words root, crown, alveolus, gingiva.
The root of the tooth is embedded in the alveolus, while the crown of the tooth protrudes above the gingiva
What are the 3 mineralised tissues forming the tooth?
Cementum, dentine, enamel
Describe the formation of enamel
Enamel is formed by ameloblasts, which deteriorate after enamel is formed. It is the hardest substance in the body.
What contributes to the formation of odontoblasts.
Dentine is formed by odontoblasts.
How does dentine assist in the transmission of pain in the tooth.
Dentine is formed of microtubules, which in response to a stimuli (heat, cold, air, drilling, mechanical) fill the tubules, which transmit pain.
How is cementum anchored into the alveolus?
Via collagen fibres that extend into dentine
What structure lies between cementum and the bone (maxilla/ mandible)?
Periodontal membrane
What ligament holds the tooth in place, and must be broken when removing the tooth?
Periodontal ligament
What structure in the tooth contains the blood vessels/ nerves
Pulp cavity
Compare the growth of brachydont/ hypsodont teeth.
Brachydont: teeth stop growing once mature
Hypsodont: continual growth of tooth throughout life
Compare the crown: root ratio of the brachydont/ hypsodont teeth
Brachydont: deep root in comparison to crown
Hypsodont: high crown in comparison to root
How many teeth do adults cats/ dogs have
Cats: 30
Dogs: 42
What is the dental formula of an adult cat?
2 (I 3/3 C 1/1 P 3/2 M 1/1) = 30
What is the dental formula of an adult dog?
2 (I 3/3 C 1/1 P 4/4 M 2/3) = 42
Which tooth in the dental formula of cats and dogs are the carnassial teeth?
Cat: P3 /M1 (upper P3, lower M1)
Dog: P4/M1 (upper P4, lower M1)
How many deciduous teeth does a cat/ dog have?
Cat: 26
Dog: 28
What tooth group do young animals not have?
Molars
What is the deciduous dental formula of a cat?
2 (i 3/3 c 1/1 p 3/2) = 26
What is the deciduous dental formula of a dog?
2 (i 3/3 c 1/1 p 3/3) = 28
What side (lingual or buccal) does the permanent tooth grow on (in relation to the deciduous tooth)?
Lingual (tongue)
What substance resorbs the root of the deciduous tooth?
Odontoclasts
What can cause the deposition of cementum-like tissue, resulting in the fusion of the surrounding bone and loss of the periodontal ligament. And prevents the deciduous tooth falling out, impairing the tooth replacement process.
The process of resorption involves periods of rest and repair, if the repair prevails over resorption this occurs.
What are the 5 surfaces of the tooth?
Occlusal: surface facing upper/ lower tooth (grinding surface)
Lingual: surface facing the tongue
Vestibular/ buccal: surface facing the cheek
Mesial: surface of tooth as you move towards the middle line of the mouth
Distal: surface of tooth as you move away the middle line of the mouth
What are the 3 roots of the carnassial tooth and which is it in the dog/cat?
Dog: P4/M1
Cat: P3/M1
3 roots: mesiolingual, mesiovestibular, distal
How many planes does the mandible move in, and which planes are more free in herbivores than carnivores, why?
3 planes.
Frontal and transverse planes are more free in herbivores because of their diet (grinding of food in mouth)
What are the 4 pairs of muscle in the jaw involved in closure/ mastication?
Temporalis, masseter, lateral and medial pterygoid
What is the origin and insertion of the temporalis muscle
Origin: temporal fossa
Insertion: coronoid process (mandible)
What is the origin/ insertion of the masseter muscle?
Origin: zygomatic arch
Insertion: masseteric fossa
What is the origin/ insertion of the medial/ lateral pterygoid? And which head is larger?
Origin: pterygopalatine fossa
Insertion: medial mandible
Medial is much larger than lateral
What is the innervation of fascial musculature?
Facial nerve (CN 7) - opening/ fascial musculature
Trigeminal nerve (CN 5) - closing, fascial sensory nerve
