Trauma

Question 1

What can happen to the pulpal tissue following trauma?

Answer 1

The pressure inside the pulp can increase.

If the pulpal tissue pressure increases to 31mmHg or above (more than the apical arteriolar pressure - 30mmHg), then this can result in lack of blood flow to the pulp leading to pulpal necrosis.

Question 2

How long does root formation normally take?

Answer 2

~3 years

Question 3

What happens if the dental pulp of a permanent tooth if it becomes necrotic before the root is fully developed?

Answer 3

There will be arrested root development.

Question 4

Describe a scenario following dental trauma where a non-vital tooth may become revascularised?

Answer 4

If the dental pulp becomes non-vital due to the apex being moved through the bone by trauma shearing off the apical blood vessels

• In this case it is possible for new vital tissue from the PDL to grow in through the apex, replacing necrotic tissue (this takes about 3-4 weeks to completely fill the pulp chamber).

Question 5

What would prevent a tooth from undergoing re-vascularisation following dental trauma?

Answer 5

If the tooth is heavily infected

Question 6

What is the most common complication of dental trauma?

Answer 6

Pulpal necrosis

Question 7

Before classifying trauma, what is it important to check for?

Answer 7

1. Any skeletal injuries - including cranial injuries, alveolar injuries, maxilla/mandible
2. Potential aspiration
3. Any suspicion of non-accidental injury
4. Any soft tissue injuries
5. Any dental (tooth injuries)
6. Any periodontal injuries

Question 8

What skeletal injuries might occur during trauma?

Answer 8

Cranial injuries
Alveolar injuries
Maxilla/Mandible injuries

Question 9

What questions should you ask the patient regarding head injuries following dental trauma?

Answer 9

1. Any history of LOC?
2. Was the incident witnessed?
3. Is the child acting ‘out of character’?
4. Any history of nausea/vomiting?
5. Visual disturbances?
6. Amnesia?

Question 10

What soft tissue injuries may be seen following dental trauma?

Answer 10

Grazes/lacerations
Contusions (bruises)
Inclusion of foreign bodies - e.g. gravel, tooth fragments

Question 11

What are the 7 different classifications of tooth injury following trauma?

Answer 11

1. Enamel Infraction (incomplete crack)
2. Enamel fracture
3. Enamel dentine fracture (uncomplicated)
4. Enamel dentine pulp fracture (complicated)]
5. Crown root fracture without pulp involvement
6. Crown root fracture with pulp involvement
7. Root fracture (cervical or mid 1/3)

Question 12

List the 4 different types of periodontal injury that can occur as a result of dental trauma?

Answer 12

1. Concussion (bruised)
2. Subluxation (loosened)
3. Luxation (displaced - extrusive, intrusive, or lateral)
4. Avulsion

Question 13

What clinical findings may be apparent in a patient who has experienced an extrusive luxation injury to their periodontium following dental trauma?

Answer 13

The tooth appears elongated and is excessively mobile
Sensibility tests will likely give negative results
Radiographically increased PDL space apically

Question 14

What clinical findings may be apparent in a patient who has experienced a concussion injury to their periodontium following dental trauma?

Answer 14

No displacement
No mobility
No radiographic abnormalities
TTP

Question 15

What clinical findings may be apparent in a patient who has experienced a subluxation injury to their periodontium following dental trauma?

Answer 15

No displacement
TTP
Increased mobility
Bleeding from gingival crevice
Sensibility test may be negative initially - transient pulpal damage
Radiographic abnormalities are usually NOT found

Question 16

What clinical findings may be apparent in a patient who has experienced an intrusive luxation injury to their periodontium following dental trauma?

Answer 16

Immobile tooth
Percussion may give a high, metallic (ankylotic) sound
Sensibility tests will likely give negative results
Radiographically:
- The PDL may be absent from all or part of the root
- The CEJ of the intruded tooth sits more apically than in the adjacent non-injured teeth (sometimes this can be apical to the bone margin level)

Question 17

What clinical findings may be apparent in a patient who has experienced a lateral luxation injury to their periodontium following dental trauma?

Answer 17

Immobile tooth
Percussion usually gives a high, metallic (ankylotic sound)
Fracture of the alveolar process present
Sensibility tests will likely give a negative response
May be an occlusal interference
Radiographically - widened PDL (best seen on eccentric or occlusal exposures)

Question 18

Following intrusive and lateral luxation injuries of primary teeth, what is extremely important to check and why?

Answer 18

Must check which direction the root has been displaced in.

This is crucial as if the root has been displaced towards the permanent successor (palatally) then it could damage the permanent successor - must warn the parent that there is a risk that the permanent successor may already be damaged!

The root may be displaced away from the permanent successor.

Regardless of which way the tooth has been displaced, must monitor the affected tooth and allow for spontaneous repositioning.

Question 19

What must NOT be done to an avulsed primary tooth?

Answer 19

You must NOT re-implant it!!

This is because it can result in the need for significant treatment and can also put the patient at risk of aspiration of the tooth.

Question 20

Which type of force may result in a periodontal injury?

Answer 20

Relatively soft impact force - fist in an assault case, elbow in sports etc.

Question 21

Which type of force may result in a tooth injury?

Answer 21

Very hard impact force

Question 22

Name a few ways you can prevent dental trauma from occurring:

Answer 22

1. Overjet reduction
2. Mouthguard provision for contact sports

Question 23

How do you decide whether it is appropriate to extract a primary tooth following dental trauma?

Answer 23

Generally you would leave and monitor the tooth in most dental trauma cases.

However, if the injury appears problematic and there is infection/inflammation then it would be appropriate to extract the tooth.

(If in doubt refer to IADT Guidelines for Trauma Management)

Question 24

Following dental trauma, which special investigations should be carried out?

Answer 24

1. Trauma table:
   - including tooth, direct colour, transillumination colour, alveolar tenderness, sinus, TTP, mobility, percussion note, EPT, thermal test.
2. Radiographs:
   - generally an AOMax + PA

Question 25

If a patient following trauma presents to your practice with a tooth fragment, what should you do with it?

Answer 25

Place it in saline

Question 26

Regarding the patients MH what must you consider prior to re-implanting an avulsed permanent tooth?

Answer 26

Must consider if they are at risk of Infective Endocarditis.

Question 27

Following dental trauma, you observe that your patient has a step in their occlusion which they did not have previously.

What might this indicate?

Answer 27

This may indicate that there has been a fracture of the maxilla/mandible.

Question 28

What might result in the presence of a periapical radiolucency around the apex following dental trauma?

Answer 28

Inflammation as a result of bacterial invasion from a necrotic pulp

OR

Transient apical breakdown*

*Must be careful - if you see a small apical radiolucency at the apex following trauma it does not always indicate the need for endodontic treatment.

Question 29

How do you decipher radiographically whether a traumatised tooth is vital or not?

Answer 29

A tooth is likely non-vital if there is:
- Discontinued root development
- Pulpal obliteration
- PA radiolucency (although be aware that TAB can present as a PA radiolucency even though pulp is still vital)

Question 30

What is the purpose of splinting permanent teeth following dental trauma?

Answer 30

To stabilise teeth that have undergone injuries to the PDL until there is sufficient healing.

Ideally a splint should allow normal biological movement.

It should fit passively and apply no force to the teeth - do not use NiTi as this is active and will cause shape deformation of the splint.

Question 31

List radiographic signs of pulpal health following trauma?

Answer 31

1. No radiographic signs of PA inflammation/infection (apical radiolucency)
2. No shrinkage of the pulp chamber (pulpal obliteration)
3. No signs of root resorption
4. No signs of ankylosis
5. No signs of root fracture
6. Continued root development - compare to contralateral tooth

Question 32

If the tooth is pink after trauma, what might this indicate?

Answer 32

Fresh blood leaching into tissues

• This can be an early sign of pulpal necrosis

OR

• It can indicate internal resorption of the coronal 1/3 of the canal

Question 33

If the tooth is yellow after trauma, what might this indicate?

Answer 33

Indicates pulp obliteration - reactionary dentine being laid down in response to trauma.

Question 34

If the tooth is brown after trauma, what might this indicate?

Answer 34

Blood is oxidising to form hemosiderin

Question 35

If the tooth is grey after trauma, what might this indicate?

Answer 35

Pulpal necrosis

Question 36

Why are sensibility tests unreliable for testing vitality?

Answer 36

1. EPT and ECL tests only test nerve supply, they DO NOT test vascular supply.
2. Vital teeth that have been traumatised and vital teeth with incomplete root development are quite likely not to respond to pulp testing.
3. You have to rely on the patient to be honest with you - can give false positive responses.