12. Diseases of the teeth - oligodontia, polyodontia, brachygnathia, pulpitis.

What does diphyodont mean?

Having two sets of teeth: deciduous (baby) teeth and permanent teeth.

What does brachyodont mean?

Having teeth with roots that are longer than the crowns, and crowns covered with enamel.

What does anelodont mean?

Having teeth that do not grow continuously.

What is the deciduous dental formula for dogs?

2(i 3/3, c 1/1, pm 3/3) = 28 teeth

What is the permanent dental formula for dogs?

2(I 3/3, C 1/1, PM 4/4, M 2/3) = 42 teeth

What is the deciduous dental formula for cats?

2(i 3/3, c 1/1, pm 3/2) = 26 teeth

What is the permanent dental formula for cats?

2(I 3/3, C 1/1, PM 3/2, M 1/1) = 30 teeth

Which teeth are known as the carnassial teeth?

The last upper premolar (PM) and the first lower molar (M).

What are the structures of the tooth and tissues surrounding the tooth?

1. Gingiva

2. Margin

3. Sulcus

4. Crown

5. Cementoenamel junction

6. Root

What is the gingiva?

The soft tissue that surrounds the teeth and provides a seal around them.

What is the gingival margin?

The edge of the gingiva where it meets the tooth surface.

What is the gingival sulcus?

The space between the tooth and the surrounding gingiva.

What is the crown of a tooth?

The part of the tooth above the alveolar bone. Consists of enamel, dentin and pulp.

What is enamel?

The hard covering of the tooth crown, the hardest substance in the body.

What is dentine?

The bulk of the tooth surrounding the pulp cavity, similar to bone.

What is the pulp chamber?

The inner part of the tooth containing nerve and vascular tissue.

What is the cementoenamel junction?

Where the crown enamel meets the root cementum.

What is the root of a tooth?

The part of the tooth within the alveolar bone.

Consists of: periodontal ligament, cementum, apical foramen, furcation

What is the periodontal ligament?

The connective tissue surrounding the root that attaches it to the tooth socket.

What is cementum?

The hard tissue forming the surface of the root.

What is the apical foramen?

The opening(s) at the root tip for nerves and blood vessels.

What is the furcation?

The space between the roots of the same tooth.

What are examples of types of abnormalities causing diseases in teeth?

1. Abnormality on dental lamina and tooth gems

2. Abnormality in hard dental tissues

What are examples of disorders caused by abnormalities in dental lamina and tooth gems?

1. Disorders in number

2. Tooth size

3. Tooth shape

What are examples of disorders of tooth number?

1. Increase

   1. Hyperdontia/polydontia

2. Decrease

   1. Anodontia

   2. Hypodontia

   3. Oligodontia

   4. Pseudohypodontia

What is hyperdontia/polydontia?

An increase in the number of teethafter shedding of deciduous teeth due to retention.

In which breeds is hyperdontia common and what is a potential complication?

Brachycephalic breeds, with potential loss of alveolar bone around the roots.

What is anodontia?

Complete or partial absence of teeth.

What is hypodontia?

Missing 1-3 teeth.

What is oligodontia?

Missing more than 4 teeth.

What is pseudohypodontia?

Two teeth sharing one root/root bud.

What are examples of tooth size abnormalities?

1. Microdontia

2. Macrodontia

3. Ectodermal dysplasia

4. Impacted teeth

5. Embedded teeth

What is microdontia?

Smaller than normal teeth.

What is the difference between absolute and relative microdontia?

1. Absolute microdontia is when the teeth are small for the breed. Normal size of dog, but increased interdental space

2. Relative microdontia is when the teeth seem small due to adjacent teeth being larger than average or because of tooth malformation or an oversized dental arch.

What is macrodontia?

Larger than normal teeth.

What is ectodermal dysplasia?

A condition causing small, conical teeth.

What are impacted teeth?

Teeth that are prevented from erupting due to a physical barrier (trauma, positioning in alveolus).

What are embedded teeth?

Unerupted teeth due to a lack of eruptive force.

What are examples of abnormalities in tooth shape?

1. Gemination

2. Fusion

3. Concrescence

4. Dilaceration

5. Dens invaginatus/dens in dente

6. Supernumerary roots

7. Enamel pearls

What is gemination (in tooth development)?

A single tooth bud attempting to divide, resulting in a tooth that appears doubled but has a single root.

What is fusion (in tooth development)?

Two tooth buds fusing to form one tooth. Share pulp/root canals

What is concrescence?

Fusion of teeth by cementum only.

In which breeds is concrescence more common?

Brachycephalic breeds.

What is dilaceration?

A sharp bend or curve in the root or crown of a tooth.

What is dens invaginatus/dens in dente?

A tooth within a tooth, caused by enamel folding inwards during development.

What are supernumerary roots?

Extra roots on a tooth.

Which teeth are most commonly affected by supernumerary roots?

Third molars.

What are enamel pearls?

Small nodules of enamel found on the root surface, often at the neck of the tooth.

What problems can enamel pearls cause?

Food entrapment and inflammation.

What can abnormalities in hard dental tissues cause?

1. Structural defects of teeth

2. Abnormalities in the jaw

What are examples of structural defects in the teeth?

1. Amelogenesis imperfecta

2. Enamel hypoplasia

3. Enamel hypocalcification

4. Enamel hypomaturation

What is amelogenesis imperfecta?

A hereditary condition causing enamel defects.

What can cause amelogenesis imperfecta?

Vitamin deficiencies, epitheliotrophic viruses, hypocalcaemia, excessive fluoride ingestion, local infection, trauma, or idiopathic causes.

What is an example of a jaw abnormality?

Brachygnathia

What is brachygnathia?

A congenital malformation involving shortening of the maxilla (brachygnathia superior/prognathia - underbite) or mandible (brachygnathia inferior/hypognathia - overbite).

What is pulpitis?

Inflammation of the dental pulp.

What does the dental pulp contain?

Nerves, blood vessels, and connective tissue.

What can cause pulpitis?

Bacterial infection (secondary to tooth decay), trauma, thermal insult, and periodontitis.

What are the clinical signs of pulpitis?

Increased sensitivity to hot and cold, pain, decreased appetite, discoloured teeth.

What are the two types of pulpitis?

Reversible and irreversible.

What is reversible pulpitis?

Inflammation where the pulp can recover if the irritant is removed.

What is irreversible pulpitis?

Inflammation where the pulp is irreversibly damaged and cannot recover.

What usually happens to a tooth with irreversible pulpitis?

It usually requires extraction, although it can sometimes remain in the alveolus with few problems.

Complete pulpectomy, vital pulpotomy

What material is used to close cavities after the removal of exposed pulp?

Dental composite resin (with UV to harden)