Dentistry - Tooth Anatomy

Enamel (3)

• 0.5mm thick

• covers entire crown

• contains no blood vessels or nerves

What is the formation of enamel?

Amelification by aneloblast cells

What is acellular?

has no cells and unable to repair itself if damage

What happens if enamel is damaged?

Retains plaque more easily

What is dentine?

• hard dense bony tissue

• makes up a large amount of tooth

Features of dentine (3)

• sensitive to pain

• able to repair itself

• formed throughout an animals life

Where is dentine located?

lies beneath the enamel

Pulp cavity

• centre of the tooth

• also known as pulp chamber

Where is pulp cavitty found?

enters the root canal by fine canals known as the apical delta at root apex

Whatt does the pulp cavity contain? (3)

• nerves

• lymphatics

• blood capillaries

Pain/conditions related to the pulp cavity

• when inflamed it will be painful

• overheating from scaling/polishing can result in pulp necrosis

Location of pulp cavity

Inside the root is referred to as root canal

Roots

• may be more than one root and furcation angle is where they diverge

• end of the root is known as the apex

Two roots

Bifurcation

Three roots

Trifurcation

How much of the tooth is the root? (2)

• 60-70%

• generally one and a half time longer than the crown

Periodontal ligament (2)

• made of collagen fibres, responsible for suspending tooth in sockets

• has both a good nerve and blood supply

What does the periodontal ligament do? (2)

• attaches the tooth to the alveolus

• allows movement of tooth

Cementum

Softer than enamel and dentine

Cementum and Periodontal Ligament (2)

• covers root surface and allows attachment of periodontal ligament

• has no direct blood supply, but can repair and be remodelled from vessels within periodontal ligament

Gingival sulcus

very shallow groove between gingiva and tooth

Free gingiva (2)

• covers alveolar bone

• protects nerve of each tooth

How is gingival sulcus measured?

periodontal probe

Gingival sulcus - dog (2)

• small dogs = 1mm depth

• large dogs = 3mm depth

Gingival sulcus

cats = 1mm depth

Mesial

surface facing towards the sagittal midline

Distal

surface facing towards the rear of the mouth

Buccal/Labial

surface facing the cheek and/or lips

Lingual/Palatal

surface facing tongue (mandibular teeth) or palate (maxillary teeth)

What are incisors used for?

used for grooming and shearing

Incisors

small with single root

How many incisors do cats/dogs have?

6 maxilla & mandible

Canines

large with single root

How many canines do cat/dogs have?

2 maxilla & mandible

What are canines used for?

used for tearing and grasping

Premolars/Molars have…

multiple roots

What are premolars used for and why?

sharp edge used for shearing

How many premolars do dogs have?

8 maxilla & mandible

How many premolars do cats have?

6 maxilla & 4 mandible

What are molars used for and why?

large and used for crushing

How many molars do dogs have?

4 maxilla & 6 mandible

How many molars do cats have?

2 maxilla & mandible

What is special about lagomorph anatomy?

Aradicular hypsodont teeth

What are aradicular hypsodont teeth?

Continuously growing roots

Problems that occur with aradicular hypssodont teeth? (3)

• cause problems in jaw bones as crown leaves

• blocked tear ducts

• tooth root abscesses

Veterinary care for lagomorphs (2)

• dentals normally keep teeth in correct position/shape

• CT necessary for tooth extractions

What isn’t necessary for lagomorph dental? (2)

• rarely full tooth extraction

• scale and polish

How many incisors do lagomorphs have?

2 maxillary & 1 mandibular

How many canines do lagomorphs have?

0 maxillary & mandibular

How many pre-molars do lagomorphs have?

3 maxillary & mandibular

How many molars do lagomorphs have?

3 maxillary and 2 mandibular

Deciduous teeeth and lagomorph

Not a concern as they drop out a few days after birth

Rodents (2)

• hypsodont teeth

• often seen in practive for tooth re-shaping

Bearded dragons

• suffer from dental disease

• can have scale and polish