Dentoalveolar Trauma 6

Question 1

What are root fractures?

Answer 1

Defined as fractures involving dentin, cementum, and pulp.

Question 2

How common are root fractures?

Answer 2

Relatively uncommon injury making up only about 0.5 - 7% of injuries to permanent teeth and 2 - 4% of injuries to primary teeth

Question 3

How do root fractures occur?

Answer 3

Usually frontal impact such as fights and objects striking teeth.

Fracture can occur in different places depending on the direction and distribution of the force

More commonly oblique.

Question 4

What concurrent injuries accompany root fractures?

Answer 4

Coronal fragment may be concussed, subluxated, extruded, laterally luxated, or avulsed.

Apical fragment often has intact PDL and pulp.

Pulp in coronal fragment may be stretched or lacerated at the fracture line. Rupture and/or compression of the PDL. Root surface may be exposed if the coronal fragment is displaced.

Question 5

How are root fractures classified?

Answer 5

Apical

Middle

Coronal subdivided into subcretal or supracrestal.

Coronal fragment injury should also be named accordingly.

Question 6

How are root fractures diagnosed?

Answer 6

History

Clinical observation (coronal segment may be mobile or displaced, bleeding from the gingival sulcus, may have crown discolouration, may be tender to percussion)

Radiographs

Pulp sensibility testing.

Question 7

Why is pulp testing done for root fractures?

Answer 7

To assess the risk of healing complications. Positive initial pulp test response indicates significantly reduced risk of pulp necrosis.

Initial pulp test is necessary to assess pulp status at subsequent review appointments.

Question 8

How many radiographs should be taken for root fractures?

Answer 8

Minimum 3 PAs, 1 occlusal and 1 - 2 PAs of opposite arch

This is to diagnose all the injuries.

Question 9

Which radiographs are best for apical third, middle third, and coronal third root fractures?

Answer 9

Middle + Apical = occlusal

Coronal = Bisecting angle PA.

Some root fractures are not evident initially

Question 10

Is CBCT useful for root fractures?

Answer 10

No, Not of practical value and unnecessary more radiation.

CBCT can identify injuries to the alveolar bone.

Question 11

How does the tooth respond to root fractures?

Answer 11

Healing of calcified tissues

Interposition of connective tissue

Interposition of bone and connective tissue

Interposition of granulation tissue

Question 12

When does healing of calcified tissues occur?

Answer 12

Most likely when no, or little displacement of the coronal fragment

Question 13

How does healing of calcified tissues occur?

Answer 13

Internal repair of dentine. Usually rounding can be seen in peripheral fracture edges.

Pulp canal calcification is often seen over time

Question 14

How does interposition of connective tissue occur? When does this occur?

Answer 14

Occurs when coronal segment has been displaced and pulp has been severely stretched or severed completely. PDL cells dominate healing in the fracture line leading to connective tissue repair. (pulp may repair or revascularize if no bacteria are present)

Pulp canal calcification is seen over time

Question 15

How does interposition of bone and connective tissue occur?

Answer 15

If fracture occurs before completion of alveolar growth the coronal fragment erupts normally while the apical fragment stays in the same position and can get rounding of peripheral fracture edges.

Pulp canal calcification occurs over time

Question 16

How does interposition of granulation tissue occur?

Answer 16

If the pulp in the coronal fragment necroses and becomes infected, granulation tissue forms in the fracture line in response to the infection. (Similar to apical periodontitis from an infected RCS)

No union between fragments

May be some inflammatory resorption leading to widening of the foramen and the fracture line.

Question 17

What is the prognosis like for the pulp followign root fracture?

Answer 17

It is very good. Necrosis rate is lower at 26%.

A study of 13 teeth that were incompletely developed there were no lost teeth, external resorption, ankylosis, bone loss, nor pulp necrosis.

In fully developed teeth, Bone loss was seen most commonly in coronal 3rd fractures. Middle third fractures had small percentage of bone loss. Apical third had no bone loss.

Question 18

What factors affect the prognosis of root fractures?

Answer 18

Age

Stage of root development

Mobility of coronal fragment

Displacement of the coronal fragment

Diastasis between fragments

Treatment provided

It is difficult/impossible to generalize.

Question 19

What is the rate of pulp canal calcification that was observed following a root fracture?

Answer 19

38. 5% after 1 year
39. 1% after 3
40. 1% after 10

Question 20

What problems sometimes arise after root fractures?

Answer 20

Bone loss is the most common. Rarely ankylosis and replacement resorption after 10 years.

Question 21

How common is healing with hard tissue, connective tissue, and granulation tissue in incompletely and completely developed teeth following concussion/subluxation, extrusion, and lateral luxation?

Answer 21

Incomplete:

Subluxation/concussion = 100% hard tissue

Extrusion = 50:50 Hard tissue, connective tissue

Lateral luxation = 100% Hard tissue

Complete:

Subluxation/concussion = 75% hard tissue, 20% connective, and 5% Granulation

Extrusion = 5% hard tissue, 50% connective tissue, and 45% granulation tissue

Lateral luxation = 8% hard tissue, 60% connective tissue, and 32% granulation tissue

MORE GRANULATION TISSUE IN COMPLETE.

Question 22

How common is pulp canal calcification in root fractures?

Answer 22

Most common in apical third fractures

Common in coronal third root fractures

Less common in middle third

Question 23

Which root fractures are managed conservatively and which are critical?

Answer 23

Depends on fracture position:

Apical, middle and coronal sub-crestal fracture = Manage conservatively.

Supra-crestal = Critical case.

Question 24

How are root fractures managed in apical middle and coronal sub-crestal root fractures?

Answer 24

Reposition coronal fragment if dispalced

Stabilise with wire/composite splint (rigid) longer splinting period is better than smaller

Review PDL and pulp healing (If no signs of pulp necrosis continue to review for as long as possible)

Do not start root canal treatment unless there are signs of pulp necrosis.

Question 25

What is the aim of initial management of root fractures?

Answer 25

To stabilize the fragments to provide the ideal environment for healing with calcified tissue.

Question 26

If pulp is necrotic after reassessment what should be done?

Answer 26

Several options: The coronal fragment can be RCTed individually.

Entire tooth RCT

Coronal RCT + Remove apical root.

Question 27

If pulp is necrotic after reassessment what should be done?

Answer 27

Several options: The coronal fragment can be RCTed individually. (Preferred method)

Entire tooth RCT

Coronal RCT + Remove apical root.

Question 28

How would coronal fragment only RCT be done?

Answer 28

It is the preferred method.

If early necrosis: Coronal fragment is treated as a tooth being RCTed and then apexification is done with Ca(OH)2 or an MTA plug is placed.

If necrosis and infection occur later: PCC usually narrowed the canal and so normal RCT can often be done.

Question 29

When should both the apical and coronal fragments be RCTed?

Answer 29

When the apical third also shows signs of pulp necrosis

Question 30

Why is RCT of the entire tooth not recommended?

Answer 30

Difficult to control debris, bacteria, tissue materials, etc at the fracture line.

This method generally has a poor prognosis. It is better to just remove the apical fragment and excess materials.

Question 31

When is it recommended to do RCT + surgical removal of the apical fragment?

Answer 31

Rarely required since apical fragment is not usually affected by the trauma and rarely develops pulp necrosis.

However most cases are due to treatment problems after extrusion of materials into the fracture site.

Question 32

How are root fractures managed in coronal supra-crestal root fractures?

Answer 32

Depends on fracture posiition. Usually difficult and not feasible and depends on if there’s enough tooth structure for a post, core, and crown.

This is similarly managed to crown:root fracture.

Coronal fragment is removed and RCT done followed by post, core, crown. Crown lengthening surgery may be needed or orthodontic extrusion.

Alternately remove entire tooth and replace with prosthesis.

Question 33

What factors should be considered before ortho extrusion/Perio surgery for post, core, crown?

Answer 33

Several factors including:

Root:Crown length ratio

Emergence profile (Width of root: Width of crown)

Amount and strength of remaining tooth structure (Ferrule)

Occlusion

Aesthetics

Perio condition

Parafunctional habits

Etc

Question 34

How does emergence profile affect tooth restorability?

Answer 34

If there is excessive taper and so the root is too narrow when extruded, this will force the crown to be overcontoured leading to problems down the line.

Question 35

How long is extrusion wire used for management of supracrestal root fracture and complicated root fracture?

Answer 35

Used until it is high enough into the mouth and then kept for 3 months until PDL fibers reorganize.