***Fractures, resorption and toothwear

Question 1

Describe the need to take radiographs in a situation where trauma has occurred

Answer 1

• When a patient presents following trauma, clinical evidence alone does not indicate the damage that has occurred

Radiographs detect:
• root fractures
• fracture of the alveolar process
• luxation injuries 
• post injury pathological change

Question 2

Discuss the type of radiographs you would take for a fracture

Answer 2

• PA’s, BW’s, OPG’s & lateral cephs may not clearly show facial fractures
• Specialised techniques & scans such as CT may be necessary to detect many facial fractures

Question 3

Briefly describe a cleft lip and palate

Answer 3

• Incomplete fusion of medial, lateral and maxillary nasal processes
• Presentation varies from mild cleft lip only to extensive bilateral complete cleft lip and palate
• Cause unknown

Question 4

Describe concussions

Answer 4

Description
• Trauma to the supporting structures of the tooth
• No displacement or mobility

Radiographic appearance
• Normal

Question 5

Describe root fractures

Answer 5

Radiographic appearance
• Radiolucent lines separate the fragments
• Apical portion remains in place while coronal portion is displaced

Question 6

Describe alveolar fractures

Answer 6

Radiographic appearance

• Radiolucent line in bone
• Apex of the root is not attached to the bone

Question 7

Describe subluxation

Answer 7

Description
• Tooth is mobile
• Tooth is NOT displaced
• There may be bleeding around the gumline and the tooth is sensitive to the touch

Radiographic appearance
• No abnormalities
• Pulp tests can indicate damage

Question 8

Describe extrusive subluxation

Answer 8

Description
• Entire tooth is displaced, partially out of the socket

Radiographic appearance
• Apical portion of the socket is empty

Question 9

Describe lateral luxation

Answer 9

Description
• Tooth displaced laterally
• Fracture of the alveolar bone plate
• Tooth is immobile

Question 10

List the radiographic technique suited to straight fractures

Answer 10

Paralleling angle

Question 11

List the radiographic technique suited to angled fractures

Answer 11

Bisecting angle

Question 12

List the steps required when a concussion occurs

Answer 12

• PA via paralleling technique
• Radiographic review in 6 to 8 weeks - increased PLS, periapical radiolucency
• Monitor pulp vitality
• Refer to DO

Question 13

List the steps required when a crown/root fracture occurs.

Answer 13

• 2 PA’s: 1 paralleling technique and 1 bisecting angle
• Radiographic review in 6 to 8 weeks - increased PLS, periapical radiolucency
• Monitor pulp vitality
• Root fractures: refer to DO for repositioning, immobilisation and RCT

Question 14

List the steps required when an alveolar process fracture occurs.

Answer 14

• To distinguish from a tooth fracture, two radiographs will need to be taken with different vertical angulation
• If the bone is fractured, then the fracture will move in relation to the angulation. If it was the tooth only, then the fracture will not move
• Refer to DO for repositioning and immobilisation
• Radiographic review to ensure healing and to detect pathological changes

Question 15

List the steps required when a subluxation fracture occurs.

Answer 15

• Initial PA
• Refer to DO for immobilisation (repositioning if extrusive)
• For intrusive luxation, orthodontic extrusion is required
• Radiographic review & connective tissue healing & detect pathological changes

Question 16

List the steps required when an avulsion fracture occurs.

Answer 16

• Store tooth in saliva or milk
• PA & Occlusal films
• Refer to DO
• Reimplantation, immobilisation, antibiotic cover & tetanus prophylaxis
• Post radiographic &clinical review

Question 17

List the effects of trauma to the primary dentition on permanent dentition

Answer 17

• Effects may involve hypomyelination
• Whitish or brownish defects
• Crown dilacerations
• Dilacerations of the root, incomplete root formation
• Malformation resembling an odontoma
• Ectopic eruption

Question 18

Define resorption and list the types of resorption

Answer 18

Resorption: Tooth resorption is the removal of tooth structure by ‘clastic’ cells

Types:
Physiological resorption

Internal inflammatory resorption

External inflammatory resorption

Pressure resorption

Replacement resorption

Question 19

Describe physiological resorption. List the impact of malpositioned permanent successors.

Answer 19

Causes:
• NOT pathological
• Resorption of the roots of primary teeth

Radiographic appearance:
• Starts at the apex of the root/s
• As the permanent tooth erupts the resorption progresses coronally

Impact of malpositioned permanent successors:
• Resorption may not occur normally and the primary tooth may be over-retained

Question 20

Describe internal inflammatory resorption and its causes.

Answer 20

Causes 
• Dentine resorption due to pulpitis
• Caries
• Tooth surface loss
• Trauma
• Pulpal treatment

Radiographic appearance
• Radiolucency within the pulp chambers/ root canals

Question 21

Describe external inflammatory resorption, and possible causes.

Answer 21

Causes:
Inflammation of the PDL due to:
• Trauma (ortho appliances)
• Periapical infection

Radiographic appearance
• Occurs outside of tooth (not in pulp, dentine or enamel)
• Apical loss of root, indicated by blunting

Question 22

Describe pressure resorption

Answer 22

Surrounding structures may undergo resorption due to malposition of a unerupted or partially erupted tooth

Question 23

Describe replacement resorption

Answer 23

• Replacement of the tooth by bone
• Occurs following extensive damage to the cementum
• Seen most often following reimplantation of an avulsed tooth
• Early replacement resorption is evident by the loss of the lamina dura, making it difficult to distinguish between tooth and bone

Question 24

Describe the radiographic appearance of tooth wear

Answer 24

• Appear as radiolucent lesions superimposed on the teeth
• Attrition can result in shortened crowns or thin enamel on incisal edges and cusp tips
• Seen more clinically than radiographically

Question 25

Describe intrusive luxation

Answer 25

Description
• Tooth is forced back into socket
• Not mobile

Radiographic appearance:
• Partial disappearance of the PLS