Exam 3 (Lecture 3) - Mastication and Bite Evaluation Flashcards
List the two types of teeth that erupt from the gumline.
1) Brachydont
2) Hypsodont
List 5 structures derived from the epidermal-dermal interaction.
1) Birth feather
2) Mammalian hair
3) Vertebrate tooth
4) Mammary gland
5) Cosmoid scale
Describe the five steps of brachydont deciduous and permanent tooth formation.
Step 1:
- Enamel organ (from the epidermis) appears
- Dermal papilla (from the dermis) appears
Step 2:
- The enamel organ produces ameloblasts
- Ameloblasts secrete enamel
- Dermal papilla produces odontoblasts and future pulp within
cavity
- Odontoblasts secrete dentin
- Bone appears and begins to delineate the socket in which
tooth will reside
Step 3:
- The primordium (an organ, structure, or tissue in the earliest
stage of development) of the permanent tooth appears
Step 4:
- Tooth development continues
- First = crown of tooth
- Second = Root of tooth (shortly before eruption)
- Third = Cementum and periodontal ligament
Step 5:
- Deciduous tooth erupts and is anchored in the socket by the
periodontal ligament
- The enamel organ and dermal papilla of the permanent tooth
primordium will not begin to form the tooth until shortly before
the deciduous tooth is lost
What can happen if the enamel is compromised in a brachydont tooth?
Tooth may become painful, infected and/or need extraction.
Arrange the following in the order of hardness: cementum, dentin, enamel.
1) Enamel
2) Dentin
3) Cementum
Rodent and rabbits have _______ teeth. Rodents have _________. Rabbits have _________, _________, _________. Rodents and rabbits must have ________ to keep teeth worn down.
1) Hypsodont
2) Top and bottom incisors
3) Incisors, premolars, molars
4) Proper diet/chew toys
Compare and contrast the structure of brachydont and hypsodont teeth.
Brachydont Teeth:
- Once teeth emerge, they begin to wear and are not replaced
- Molars are covered entirely on the occlusal surface by enamel
- Smooth edges and not sharp
- Protects the softer dentin and pulp cavity throughout the
life of the animal
- Once the enamel is compromised the tooth may become
painful, infected, and/or need extraction
Hypsodont Teeth:
- Erupt from the gumline at a continuous rate as the animal ages
- Stem cell niche at the apical rim of the enamel organ
- Mediated by specific signaling molecules
- Enamel > Dentin > Cementum
- Occlusal surface has irregular and very sharp edges
- Premolars and molars are very effective at grinding and
shearing plant cell walls
Mastication starts the ___________ digestion process.
Mechanical
What is the function of the following teeth: incisors, canines, premolars/molars? What else is added during mastication? Function?
Incisors:
- Cutting
Canines:
- Piercing
Premolars and Molars
- Grinding (increases surface area available for saliva)
- Important for high refractory materials
- Molars help to break down plant cell walls
Saliva is secreted by the salivary glands
- Moistens, lubricates, starts chemical digestion process
Define occlusion. What is a bite (occlusal) evaluation?
Normal way that teeth fit together when mouth is closed
- Required for normal mastication
Bite Occlusal Evaluation:
- Ensures there is a good fit and even wear
- Checks to make sure all teeth are aligned properly
Does the dog’s normal bite (teeth occlusion) provide a good fit and even wear or not a good fit and uneven wear? What are some common problems that can arise from malocclusion in the dog?
Good fit and even wear.
Common problems:
- Further hinder mastication
- Soft tissue injuries
- Periodontal disease
- Extra wear on the teeth
- Fractures
Describe normal teeth/dental pad occlusion in the horse. What tissue needs to be filed due to the sharp edges?
Not a good fit between upper and lower arcade; uneven wear.
- Maxilla is 70% wider than the mandible
The enamel is filed down due to sharp edges.
- The wider maxilla and narrower mandible creates lateral points
on upper teeth and medial points on lower teeth.
What are some common problems that can arise from malocclusion in the sheep?
Malocclusion will cause decreases in:
- Grazing efficiency
- Body condition
- Meat production
What are some common problems that can arise from malocclusion in the rabbit?
1) Anorexia
2) Pain
3) Decreased cecotrophy
- provides proteins and vitamins synthesized in the cecum
4) Weight loss
5) Excessive amounts of salivary secretions around the mouth, chest,
and front limbs
6) Matted fur (inability to groom)
What virus causes decalcification (loss of enamel)?
Distemper virus
