13. Fracture of the teeths. Extraction of the teeth. Endodontia, exodontia. Local analgesia of the head in dog.

What causes tooth fractures?

1. Trauma to the tooth, often from chewing hard objects.

2. Concussion: causes oedema → ↑ pressure in cavity, ↓ blood flow to pulp → ischaemia & necrosis

Which tooth is most commonly affected by fractures?

Upper P4

What factors affect the prognosis of tooth fractures?

1. The location of the fracture (more cranial fractures have a poorer prognosis)

2. Age of the animal (older animals have slower healing and increased susceptibility to infection).

What are the classifications of tooth fractures?

1. Crown fracture and cup

2. Enamel infraction (EI) / enamel fracture (EF)

3. Uncomplicated crown fracture (UCF)

4. Complicated crown fracture (CCF)

5. Uncomplicated crown-root fracture (UCRF)

6. Complicated crown-root fracture (CCRF)

7. Slab fracture: slice of crown separates from side of tooth, often exposing pulp cavity - often 108/208 (last maxil. PM)

8. Root fracture (RF)

9. Luxation injury: concussion, subluxation, extrusive luxations, intrusive luxations, avulsions

What are the three levels of treatment for tooth fractures?

Primary, secondary, and tertiary.

What does primary level treatment involve?

Replanting avulsed teeth and stabilising luxated teeth.

What does secondary level treatment involve?

1. Monitoring condition of pulp and supporting structures clinically and radiographically.

2. Endodontic therapy in situations where pulp is not expected to survive.

3. Definitive restorations of teeth w/ crown fractures in which primary treatment goal was to protect pulp.

What does tertiary level treatment involve?

Addressing complications from primary and secondary treatment.

What are the clinical signs of tooth fractures?

Issues with food prehension and ptyalism (excessive salivation), facial swelling.

How are tooth fractures diagnosed?

History, dental examination, and radiography.

How are crown fractures treated?

1. Endodontic considerations to protect the pulp (calcium hydroxide or MTA lining)

2. Extraction if the pulp is necrotic (especially in animals up to 10 months old).

How are root fractures treated?

1. Repositioning of the coronal segment (4-6 weeks)

2. Tooth extraction if pulp necrosis occurs

3. Antibiotics for complications like fistula formation.

What is exodontia?

Tooth extraction.

How can exodontia be divided?

1. Deciduous teeth extraction

2. Permanent teeth extraction

When are deciduous teeth extracted?

If they are still present after 6 months of age. Often done at the time of neutering.

Why are retained deciduous teeth a problem?

They can cause insufficient space for permanent teeth, leading to abnormal positioning.

How are deciduous teeth extracted?

Using torsional and lateral movements due to their single roots.

When are permanent teeth extracted?

In cases of tooth rot, root abscess, fracture, resorptive lesions, loosening, and periodontal disease.

What instruments are used for tooth extraction?

Elevators and extraction forceps.

What is the purpose of using elevators in tooth extraction?

To release the tooth from the gingiva and initiate haematoma formation within the socket → prevents bleeding.

What are extraction forceps used for?

Remove the tooth from the alveolus after loosening/rupturing the gingival attachment

How are single-rooted permanent teeth extracted?

Using torsional and lateral movements.

How are multi-rooted permanent teeth extracted?

Using lateral movements only, or by separating the roots with a drill and extracting them individually.

What are considerations when extracting canine teeth?

1. The risk of mandibular fracture due to the thinness of the mandible in that area.

2. Do not use rotation during final extraction → high risk of puncturing nasal cavity

What is the surgical protocol for canine tooth extraction?

1. A flap is cut in soft tissues to expose the alveolar bone of canine tooth. (Local anaesthesia can be administered in mental or infra-orbital foramen – limit post-op pain)

2. Exposed alveolar bone is removed by chisel or diamond drill to expose the tooth.

3. Force is applied to lingual side to extract tooth, flap is sutured to cover exposed canal – prevent infection and fistula formation

What are complications of canine tooth extraction?

Bleeding, damage of vessels or unerupted teeth, gingival laceration, oronasal fistula, local infection

What is endodontia?

The branch of dentistry concerned with the pathophysiology and treatment of conditions affecting the pulp and periapical tissues.

What are the indications for endodontic treatment?

Pulp exposure, pulpitis, and pulp necrosis.

What are some causes of pulp problems?

Trauma, caries, periodontal infections, iatrogenic pulp exposure, developmental abnormalities, crown height shortening, and incomplete root canal development.

What are the components of an endodontic diagnosis?

1. Extra-oral exam

2. Intra-oral exam

3. Clinical tests (peri-radicular, pulp vitality tests, periodontal exam)

4. Radiography.

What are some extra-oral findings in endodontic cases?

Facial asymmetry, swelling, redness, sinus tracts, and tender or enlarged lymph nodes.

What are some intra-oral findings in endodontic cases?

Discolouration, inflammation, ulceration, swelling, sinus tracts, fractures, abrasions, erosions, caries, and plaque/calculus.

What are some peri-radicular tests?

Percussion and palpation.

What are some pulp vitality tests?

Cold test, heat test, electrical pulp testing, and test cavity for blood supply.

What are the limitations of radiography in endodontic diagnosis?

1. Pathological vital pulps are not visible

2. Necrotic pulps may not show early changes

3. Inflammatory process must involve alveolar bone to be visible.

What radiographic changes can be seen in periapical disease?

Apical loss of lamina dura and radiolucency at the apex.

What does endodontic treatment depend on?

1. The ability of the dental pulp to survive after exposure, which depends on the presence of mesenchymal cells (odontoblasts)

2. Size and time of exposure

3. Degree of concussive shock

4. Tooth localisation.

How can healing be improved in endodontic cases?

With local or systemic anti-inflammatories or direct pulp capping.

What are the steps of endodontic treatment?

X-ray to determine vitality of teeth → access canal with sterile endodontic burr → place a small file (pin) and x-ray to access length → clean (with file), disinfect and dry canal → place endodontic sealer (resin based, zinc oxide, calcium hydroxide) → obturate canal with gutta percha to seal the root canal → restore the access site with composite, harden with UV light

What is the purpose of local analgesia in dental procedures?

To manage pain.

What are the different nerve blocks used in dental procedures?

1. Rostral maxillary nerve block (n. infraorbitalis) (A)

2. Caudal maxillary nerve block (palatine branches of n. maxillaris) (B)

3. Mandibuloalveolar nerve block (inferior alveolar branch of n. mandibularis) (E)

4. Rostral mandibular block (n. mentalis). (D)

   

What area does the rostral maxillary nerve block (infraorbital) anaesthetise?

From the 3rd premolar rostrally, including adjacent tissues and bone.

Where is the injection site for the rostral maxillary nerve block?

Caudally along the alveolar bone at the 2nd premolar towards the infraorbital foramen (located between 3-4th premolars).

What area does the caudal maxillary nerve block anaesthetise?

The maxilla, palate, upper teeth, nose, and upper lip.

Where is the injection site for the caudal maxillary nerve block?

1. Extraorally: ventral to the zygomatic arch, caudal to the lateral canthus, perpendicular to skull, after reaching bone surface, inject.

2. Intraorally: wide mouth opening, perpendicular to the palate dorsal to the 2nd molar.

What area does the mandibuloalveolar nerve block anaesthetise?

Lower teeth and lower lip.

Where is the injection site for the mandibuloalveolar nerve block?

Palpate angular process of mandible → insert needle 0.5cm rostral to angular process. insert needle 1.5cm dorsally against medial surface of the ramus mandibulae to feel for margin of mandibular foramen → inject into mandibular foramen

What area does the rostral mandibular block (mentalis) anaesthetise?

Rostral to the mental foramen.

Where is the injection site for the rostral mandibular block?

Into the mental foramen, located below the medial aspect of the 2nd premolar.

What is the most dangerous risk with teeth extraction?

Damage to the mandible

What is brachygnathia?

Shortened jaw

Superior: shortened maxilla

Inferior: shortened mandible

Are sutures necessary after tooth extractions?

Yes

What anaesthesia should be used before extractions?

Nerve blocks