Dentition

Question 1

Describe the structure of a generalised tooth

Answer 1

1. outer enamel
2. Dentine
3. Pulp chamber
4. Gingival cervice
5. Gingiva
6. Peridontal ligament
7. Root canal
8. Cementum
9. Apical foramen
10. Genioglossus msucle

Question 2

Enamel

Answer 2

 Hard outer part projecting above gums
 Ectodermal origin
 Formed by ameloblasts
 It is acellular and cannot regenerate so if chipped, remains

Question 3

Dentine

Answer 3

1. Mesodermal in origin.
2. Formed by ODONTOBLASTS
3. Forms the bulk of the tooth
4. 2nd hardest tooth material, enamel is harder
5. Structure is similar to bone
6. Secondary dentine is darker in appearance than primary dentine.
7. Tertiary dentine may occur at sites of injury.

Question 4

What is the difference in dentine to bone

Answer 4

1. in bone the OSTEOBLASTS stay within the bone matrix, in teeth the ODONTOBLASTS (the dentine producing cells), recede from the newly formed dentine and remain as a continuous layer on the surface of the pulp cavity. This produces SECONDARY DENTINE throughout life, which gradually reduces the size of the dental pulp cavity. – more an more dentine produced throughout life = reduces bulk cavity

Question 5

Cementum

Answer 5

 Mesodermal in origin
 Formed from calcified connective tissue
 Forms the outer lining of the tooth in the socket in brachydont teeth
 It is the least hard of the calcified tissues of the tooth
 It is continuously, but slowly, produced throughout life, so is thicker in older animals.

Question 6

Pulp cavity

Answer 6

 It reflects the external shape of the tooth i.e. is present in each tooth root.
 It is open at the apical foramen. (lower teeth = bottom, upper = top)
 Central part of tooth containing nerve fibres, lymphatic and blood vessels
 Smaller in older animals as secondary dentine fills in pulp cavity.

Question 7

Periodontium
What it consists of
Role

Answer 7

This term described the functioning unit of several anatomical components

1. It consists of the Gingiva, periodontal ligament, cementum and alveolar bone.
2. Functional unit
3. Role = anchor tooth into skull and provide a suspensory apparatus to absorb stresses induced at biting

Question 8

Gingiva

Answer 8

1. oral mucosa that covers the alveolar processes of the jaws and covers the neck of the teeth. It is composed of keratinized stratified squamous epithelium
2. At coronal bit = proud = free ginigiva

Question 9

7Periodontal Ligament

Answer 9

1. Is made of collagen fibres
2. Attaches to the cement of the tooth and the Alveolus
3. These fibres are arranged in a sling formation – allowing small movements of the teeth during mastication, and acting as shock absorbers.

Question 10

What is the innervation of the teeth?

Answer 10

1. All teeth are innervated by branches of the TRIGEMINAL NERVE - cranial nerve V

Question 11

What are the upper and lower teeth innervated by?

Answer 11

1. Upper = supplied by the MAXILLARY (or superior) ALVEOLAR NERVE (from the maxillary division of the Trigeminal Nerve).
2. Lower = supplied by the MANDIBULAR (or inferior) ALVEOLAR NERVE (from the mandibular division of the Trigeminal nerve).

Question 12

What type of teeth do we describe out domestic species as having and what to these terms mean?

Answer 12

1. Diphyodont Heterodont
2. D = deciduous and permanent teeth = adult and baby
3. H = diff type of specialised teeth

Question 13

list 6 dental terms

Answer 13

1. Hypsodont
2. Brachydont teeth
3. Aradicular/ Elodont
4. Radocular/ Anelodont
5. Clinical crown
6. Anatomical crown

Question 14

Hypsodont

Answer 14

those of horses, high or long crowned with unerupted crown lying beneath the gum in all but very aged animals. The root of the tooth is generally shorter than the crown.

Question 15

Brachydont teeth

Answer 15

those of the dog and cat (and human), are low crowned - where all of the crown has erupted by adulthood. The root of the tooth is generally longer than the crown.

Question 16

Aradicular/ Elodont

Answer 16

teeth grow throughout life and never develop true roots. Always hyposodont.

Question 17

Radocular/ Anelodont

Answer 17

teeth with a true anatomical root structures and do not continuously grow throughout life. Can be hypsodont or brachydont

Question 18

Clinical crown

Answer 18

this is the exposed part of the tooth, regardless of structure.

Question 19

Anatomical crown

Answer 19

this is the enamel covered part of the tooth regardless of location.

Question 20

Name and describe orientations

Answer 20

1. Surface next to the lips – LABIAL
2. Surface next to the cheek -BUCCAL
3. Surface next to the tongue - LINGUAL
4. Surface touching the tooth in front – MESIAL
5. Surface touching the tooth behind - DISTAL
6. Masticatory surface (‘table’) - OCCLUSAL

Question 21

The healthy mouth

What maintains pH?

Answer 21

1. Normal occlusion
2. Normal oral pH in dogs and cats is 7.5
3. Saliva maintains this and also contains enzymes, lysozymes and immunoglobulins that moderate bacterial colonisation. Also mechanically washes teeth. Also has some anti-fungal and antiviral actions.

Question 22

What are commonly occurring dental problems in small carnivores?

Answer 22

1. CONGENITAL MALOCCLIUSIONS
2. Malocclusion – different head shapes – esp brachycephalic, but also sometimes seen in dolicocephalic breads.
3. Prognathism = lower jaw to long (brachycephalic)
4. Brachygnathism = lower jaw too short (dolicocephalic

Question 23

What is the most common oral disease seen in small animals?

Answer 23

1. Periodontal disease
2. a. First stage is gingivitis - inflammation of the gingiva
   b. Second stage - early periodontitis – inflammation of gingiva and periodontal ligament
   c. Third stage - further breakdown of support tissues, tooth mobility, tooth loss. Advanced periodontal disease in the upper dental arcade, especially of the canine teeth, can lead to oronasal fistulas

Question 24

Pig dentition

Answer 24

1. Omnivores like us to more generalised dentition
2. Lower incisors point forward
3. Canines (tusks) remain open rooted in the male and continue to grow
4. Upper and lower canines rub = sharp
5. Females roots remain open for 2 yrs = grow, after = stop
6. Little differentiation between premolars and molars but become larger the more cuadal
7. very tumercular (lumpy) occlusal surface for crushing food

Question 25

What are piglet teeth like?

Answer 25

1. born with 8 upper and lower incisors and canines 2. v sharp and point forward so often nipped by stock men 3. full adult dentition after 18 months