Fractures

Question 1

Define a fracture

Answer 1

A break in the continuity of bone

Question 2

Define a comminuted fracture

Answer 2

A complex fracture pattern that involves 2 or more bone fragments at the fracture site

Question 3

Define displacement

Answer 3

The extent to which the 2 sides/ends of a fracture have shifted/moved from their normal position

Question 4

Define angulation

Answer 4

The angle by which one fragment of bone has moved in comparison to its previous position

Question 5

Define a compound fracture

Answer 5

A fracture which is open to the external environment through a tear or a laceration in the overlying skin or mucosa

Question 6

Define a pathological fracture

Answer 6

A fracture that occurs in an area of bone that has been critically weakened due to a disease process e.g. cancer, osteoradionecrosis, a very large cyst, MRONJ

Question 7

What is another term for a compound fracture?

Answer 7

Open fracture

Question 8

What do you call a fracture of the bone that does not lead to exposure to the external environment?

Answer 8

Simple fracture

Question 9

The incidence of facial injuries is triphasic, what does this mean?

Answer 9

Facial injuries are most likely to occur at 3 different peaks in life. This includes:

Children under the age of 5
Young adults in their late teens/early 20s
The elderly (above 75)

Question 10

What are the 3 most common causes of facial injuries?

Answer 10

Road traffic accidents
Assaults
Falls

Question 11

List some factors that influence the incidence of facial injuries

Answer 11

Age
Gender (2x more likely in boys than girls)
Socioeconomic status (almost 2x more likely)
Country and regions within a country

Question 12

List the mechanisms of injury

Answer 12

High energy injuries (RTA, high speed collision with a car as a pedestrian, ejection from car from passenger seat during high speed collision). Result in a lot of energy being transferred into the patient.

High energy penetrating injuries (military grade rifles, shot guns)

Low energy injuries (punch to the face, head clashes, simple falls from small heights e.g., tripping over your feet)

Low energy penetrating injuries (stab wound with a knife, air rifle shot)

Bite injuries

Question 13

Which type of injury poses a high risk of gross contamination of tissues

Answer 13

Gun shot wounds from a military style, hunting rifle/shot gun

This is due to the way ballistic injuries occur. They tend to suck material in from the outside e.g., patient’s clothing being sucked into the wound. Because of the way the energy wave passes through the soft tissue, we can get an enormous amount of soft tissue disruption from a small entry wound.

Question 14

If a patient presents with a facial injury, what is the likelihood that they’ll also have a brain injury?

Answer 14

45%

Question 15

If a patient presents with a facial injury, what is the likelihood they’ll also have an associated chest injury?

Answer 15

33%

Question 16

If a patient presents with a facial injury, what is the likelihood that they’ll also have an associated abdomen/pelvic injury?

Answer 16

15-20%

Question 17

If a patient presents with a facial injury, what is the likelihood that they’ll also have an associated cervical spine injury?

Answer 17

7%

Question 18

If a patient presents with a facial injury, what is the likelihood that they’ll also have an associated long bone injury (fractured arm/leg)

Answer 18

5%

Question 19

When a patient presents with a facial injury, how should you initially approach them?

Answer 19

Undertake ABC assessment to identify any life threatening airway, breathing or circulation issues that require immediate management.

Ask the patient to open their mouth to assess for any dental injuries that require immediate management e.g., avulsed, displaced teeth

Question 20

A patient presents to your practice with a tripod fracture of the zygoma. There is a deep laceration to the cheek on the same side. In your initial examination, what are you going to do?

Answer 20

Undertake an ABC assessment

Assess for any associated injuries e.g.
Brain injuries - could rapidly stop the patient’s breathing if severe.
Chest injuries e.g. cracked rib, lung contusion, pneumothorax with a collapsed lung - could disrupt the patient’s breathing and potentially the airway.
Abdominal/pelvic injuries - important to consider as there are large vessels in the abdomen space. An injury in this region could therefore lead to significant internal bleeding that is not apparent from the outside. Loss of blood may be so severe it becomes life-threatening
Cervical spine injuries
Long bone injuries

Ask the patient to open their mouth to assess for any dental injuries requiring immediate management

Question 21

Why is angulation important to consider when assessing fractures?

Answer 21

Important in determining how much mobility a fracture may cause a patient, because if the bone isn’t at the angle it is supposed to be at, it won’t be at the correct length and therefore the bone will not be able to move as it is designed to.

Question 22

Fractures in the tooth bearing regions of the mandible are most likely to be what type of fracture?

Answer 22

Compound/open fracture.

Any fracture involving the teeth bearing regions of the mandible will likely cause tearing of the mucosa

Question 23

List some conditions that can cause a pathological fracture

Answer 23

MRONJ
Osteoradionecrosis
Cancer
A very large cyst

Question 24

List some of the bones of the mid face

Answer 24

Nasal bones (e.g. lateral nasal bones, nasal septum)
Lateral wall of the maxilla
Lateral wall of the zygoma
Floor of the orbit

Question 25

Some of the bones in the mid face are <1mm thick in some areas. What bones are likely to have this feature?

Answer 25

Lateral wall of the nose
Nasal septum
Lateral wall of the maxilla

Question 26

Define an exophthalmos eye in the context of fractures

Answer 26

A fracture of the eye socket can cause a reduction in the volume of the orbit. This reduction in volume can lead to the eye sticking further forwards than is normal (bulging eye)

Question 27

Define an enopthalmous eye in the context of fractures

Answer 27

A fracture in the eye socket can cause an increase in the volume of the orbit. This increase in volume can cause the eye to sink into the orbit, sticking further backwards than is normal (sunken eye)

Question 28

What issue could arise in the jaw of a 70 year old patient following a lower arch clearance?

Answer 28

Once all teeth in the lower arch have been removed, the edentulous ridge will resorb over the years. This can eventually leave a very thin mandible (pencil thin) that is prone to fracture, especially as elderly patients are more likely to experience fall injuries.

Question 29

What challenges could arise in the management of 75 year old edentulous patient who has fallen, causing a bilateral mandible fracture?

Answer 29

As the patient is edentulous, over the years, the alveolar ridge will have resorbed, leaving a pencil thin mandible known as an atrophic mandible.

An atrophic mandible will often break through the thinnest portion of itself. This makes management very challenging as it will be difficult to find a place to put a sufficiently large plate onto the bone in order to fix the bone in place.

As a result, fractures of the edentulous atrophic mandible can be quite unstable. This instability is made worse by the action of muscles which act to further displace the fracture

The masseter, temporalis and lateral pterygoid muscles at the back will be pulling the condyle and ramus upwards. Whilst the mylohyoid, hyoid and digastric muscles at the front will be pulling the chin point downwards. This will result in a fracture that is very unstable and acts as a bucket handle, with an area at the front which can swing down

Question 30

Where there is an atrophic and bilateral mandibular fracture, how do certain muscles act to make the fracture unstable?

Answer 30

Some muscles (masseter, temporalis, lateral pterygoid) will be pulling parts of the mandible upwards, whilst others (hyoid, mylohyoid, digastric) will be pulling parts of the mandible (chin point) downwards. This will lead to instability of the fracture site at the front, with it acting like a bucket handle and swinging down

Question 31

Why could a fracture of the zygomatic arch cause trismus?

Answer 31

Bones within the zygoma region are very close to the muscles e.g., the temporalis muscle runs underneath the zygomatic arch.

And so if you have a zygomatic arch fracture, it can impinge on the temporalis muscle to cause trismus.

Question 32

Which fracture pattern could also result in trismus?

Answer 32

Zygomatic arch fracture

Question 33

Why could a fracture of the (bony) orbital floor make it difficult to look upwards?

Answer 33

The extraocular muscles are very close to the bone.

A fracture of the bony orbital floor often leads to a trap door of bone and fat. Some of the extraocular muscles e.g., the inferior rectus muscle located below the eye, could herniate through this trap door and become trapped in the area.

As a result, when a patient tries to look upwards, the muscle below the eye is essentially trapped and will become shortened (cannot act within its full range of motion anymore). The patient will consequently experience diplopia (double vision) on an upwards gaze

Question 34

Which fracture pattern could also result in diplopia on an upwards gaze?

Answer 34

Fracture of the bony orbital floor

Question 35

Why may a fracture cause altered sensation/numbness?

Answer 35

Nerves can run through bone. If a fracture occurs in an area where a nerve runs, the nerve may also become damaged

Question 36

A patient presents with a facial injury, reporting lower lip and chin numbness on the LHS. What is the likely cause and why?

Answer 36

Fracture of the mandible that has occurred in front of the lingula. The inferior alveolar nerve runs through this area, supplying sensation to the lower lip and chin. If there is a fracture in this region, the inferior alveolar nerve may be damaged.

Question 37

How may a fracture of the bony orbital floor affect sensation? Why does this occur?

Answer 37

A fracture in this region will cause numbness down the side of the nose, the cheek and the upper lip on the affected side.

This is because the IO nerve runs through the floor of the orbit. Where the IO nerve runs along a fractured part of the bone in the orbital floor, it can become damaged

Question 38

Define retrobulbar haematoma

Answer 38

Collection of blood behind the eye ball

Question 39

Which fracture pattern could cause a retrobulbar haematoma? What are the implications of this presentation?

Answer 39

Mid face/orbital floor fractures

As blood can collect behind the eye ball, it can lead to an obstruction. This will result in a build up of pressure. This build up of pressure won’t stop the arterial blood supply to the eye (arterial blood will still be able to travel past the obstruction). But it will stop the venous drainage from the tissues/retinal veins.

This will cause a lot of congestion in the retina that will result in pain. And if left untreated for too long, it can cause the retina to die and the patient to become permanently blind

Question 40

What are the 4 most common sites for a mandibular fracture (in order of % incidence)

Answer 40

Condyle (30%)
Body of the mandible (25%)
Angle of the mandible (25%)
Parasymphyseal and mental region (15%)

Question 41

Which areas of the mandible are likely to result in closed fractures? Describe one issue with closed fractures in the context of their management

Answer 41

Condyle
Coronoid process
Ramus
Posterior angle of the mandible

It will be difficult to access these fractures during treatment

Question 42

Which areas of the mandible are likely to result in compound fractures? Describe one issue with compound fractures in the context of their management

Answer 42

Anterior angle of the mandible
Body of the mandible
Parasymphyseal and mental region

All these areas of the mandible are closely associated with teeth. These are teeth bearing regions and so the fracture that results in these areas is likely to be an open fracture (with a tear/laceration into the oral mucosa).

Although, these fractures are therefore more likely to become infected, it will be easier to access them during treatment (via the mouth)

Question 43

Why does the mandible have limited mobility?

Answer 43

2 condyles that fix the mandible in place (with the rest of the skull)

Question 44

Why are mandibular fractures often bilateral?

Answer 44

The mandible is fixed at 2 points (by 2 condyles). This means that if there is a force applied to one part of the mandible (e.g. left parasymphyseal region), it will often result in forces also being applied to another part (e.g. right condyle or angle of mandible)

Question 45

Define Guardsmann fracture

Answer 45

A fracture of the chin point (symphyseal region) with associated bilateral condylar fractures

Question 46

Which other fracture pattern would you see in a patient who presents with a fracture of the chin point?

Answer 46

Bilateral condylar fractures

Question 47

When does a Guardsmann fracture occur?

Answer 47

Patient who has fallen flat on their face. All the energy from the force of the fall will be directed into the chin point, causing a fracture in the symphyseal region with an associated bilateral condylar fracture

Question 48

What kind of fractures patterns may occur in the zygoma following facial trauma?

Answer 48

Tripod fracture
Isolated zygomatic arch fracture

Question 49

The zygoma is attached to surrounding areas via 3 points. List these

Answer 49

1 limb of the zygoma connects to the frontal bone via the frontal zygomatic
suture.

Another limb is attached to the temporal bone via the zygomatic arch.

And the final limb attaches to the maxilla via the zygomatic buttress and the lateral wall of the maxilla and the orbital floor.

Question 50

Why do fractures of the zygoma tend to occur at 3 points?

Answer 50

The zygoma is attached via 3 points.

1 limb connects to the frontal bone through the frontal zygomatic suture.

Another limb is attached to the temporal bone through the zygomatic arch.

And the final limb attaches to the maxilla through the buttress and the lateral wall of the maxilla and the orbital floor.

Question 51

A footballer experiences a head clash injury during a match. There is a visible dent on the side of his face. What could this indicate?

Answer 51

An isolated zygomatic arch fracture

Question 52

What are Le Fort Fractures?

Answer 52

Particular fracture patterns that occur in the mid face.

3 types:
Le fort 1, 2, 3

Question 53

What could happen if a tripod fracture is not treated properly?

Answer 53

Profound cosmetic effect on patient’s appearance
Inability to see properly (diplopia etc.)

Question 54

Describe a Le Fort 1 fracture

Answer 54

A fracture of the maxilla, occurring above the apices of the upper teeth. Has the potential to involve the occlusion

Question 55

Describe a Le Fort 2 fracture

Answer 55

A fracture involving the maxilla and the nose. It will extend up through the zygomatic buttress into the orbital floor and involve the nose

Question 56

Describe a Le Fort 3 fracture

Answer 56

A fracture that involves the maxilla, nose, zygoma and the complete orbital floor. Very severe fracture type

Question 57

A patient presents with a mandibular fracture, how should you approach initial examination?

Answer 57

ABC to identify any life threatening that need to be managed before the dental injury itself.

Physical examination (E/O and I/O) using inspection and palpation-
During the inspection phase, we need to look for a bruised or bloodshot eye.
We then have to look for any bleeding and determine its source (nose, mouth or a skin laceration?).
Following this, we look for swelling/the presence of surgical emphysema.
We also assess for flattening of the face.
And we ask the patient to move their eyes to see whether there is any limited function to the eye or diplopia.

All of the above comprises inspection and allows us to determine diagnosis. Following inspection, we need to palpate the face to determine whether there’s been any nerve damage, secondary to the injury. (All 3 branches of cranial nerve V are tested) with a light touch sensation.

This leads to the completion of the E/O exam and we then move intra-orally-
We are looking for gaps/steps in the occlusion, gingival tears, new malocclusions following the injury.

Once the E/O and I/O examinations are complete, we need to conduct special investigations in the form of radiographs-
The type of radiograph chosen will vary depending on the type of fracture that we suspect.

Question 58

Why is it important to check the airway where a patient presents with a facial injury?

Answer 58

The mouth/face is integral to the airway. Very plausible that a patient with fractured facial/jaw injuries has airway problems, especially if the injury has led to a lot of soft tissue swelling that is compromising/obstructing the airway.

Very common for patients with a facial injury to also have a brain injury which results in complete or partial reduction of consciousness, making it difficult for the patient to support their own airway

Question 59

Why is it important to check the airway where a patient presents with a mandibular fracture?

Answer 59

The mouth/face is integral to the airway. Very plausible that a patient with fractured facial/jaw injuries has airway problems, due to swelling.

The floor of the mouth has a very good blood supply. It’s possible to get a lot of bleeding quite quickly into the floor of the mouth following a fractured mandible. This can cause the floor of the mouth to swell up, moving the tongue up and back and in turn, causing a potential airway problem.

Very common for patients with a facial injury to also have a brain injury which can result in complete or partial reduction in consciousness, making it difficult for the patient to support their own airway

Question 60

Why is it important to check breathing when a patient presents with a facial injury?

Answer 60

33% of patients with a facial injury will also have a chest injury that could impede breathing and potentially affect the airway

Very common for patients with a facial injury to also have a brain injury (45%) which can result in complete or partial reduction in consciousness, making it difficult for the patient to support their own airway and therefore breathe adequately

Question 61

Why is it important to check the circulation when a patient presents with a facial injury?

Answer 61

The head and neck have a very good blood supply. This provides a very rapid healing potential. But also means that patients with head and neck injuries can lose a lot of blood leading to circulatory issues that can become life threatening

Question 62

What is circumorbital ecchymosis?

Answer 62

Bruising around the eye following an injury. Otherwise known as a black eye

Question 63

What is a subconjunctival haematoma?

Answer 63

Blood over the sclera of the eye, following a facial injury. Otherwise known as a bloodshot eye

Question 64

Describe what a subconjunctival haematoma without a posterior limit is. What does this appearance indicate about the injury the patient has sustained?

Answer 64

A subconjunctival haematoma refers to a blood shot eye. This can occur in one of 2 ways which result in a slightly variable appearance. When the subconjunctival haematoma does not have a posterior limit, you cannot see the full limit of the haematoma, instead it appears to track forward.

This indicates a fracture of the orbit, where blood has begun to pool. This could be a fracture of the bony orbital floor or the medial, lateral or superior walls of the bony orbit. The blood that has arisen from the fracture of the orbit tracks forward underneath the conjunctiva.

Question 65

Describe what a subconjunctival haematoma with a posterior limit is. What does this appearance indicate about the injury the patient has sustained?

Answer 65

A subconjunctival haematoma refers to a blood shot eye. This can occur in one of 2 ways which result in a slightly variable appearance. When the subconjunctival haematoma has a posterior limit, you can see the full extent of the haematoma.

This indicates direct trauma to the eye ball. For example, someone poking the eye which has led to a collection of blood in the eye.

Question 66

Briefly summarise how to approach an E/O exam for a patient presenting with facial trauma

Answer 66

Inspection of the face for the following-
Circumorbital ecchymosis (bruising/black eye)
Subconjunctival haematoma (bloodshot eye)

Bleeding and its origin (nose, mouth, skin lacerations?)

Swelling or presence of surgical emphysema (palpation of swelling to determine this)

Flattening

Ability to move the eye in all directions, ability to look upwards and evidence of double vision

Skin sensation (asking the patient whether they are numb in any areas of the face, light touch palpation of the skin in all distributions of the trigeminal nerve which supplies sensation to all regions of the face, comparison of both sides of the face)

Question 67

What is surgical emphysema and which fracture causes an increased risk of it developing?

Answer 67

Refers to air collecting in the tissues where it shouldn’t be.

Patient will become very swollen. If the swelling is palpated, it will feel a lot like touching bubble wrap. We can feel the crackles as we palpate the air bubbles in the tissues.

Can often occur where patients present with fractured zygoma that involves the wall of the maxillary sinus (antrum).

Question 68

A patient who fell on the right side of their face presents to your clinic. There is evident skin lacerations and a lot of swelling on the right side of their face. As you palpate the skin to feel the bones, you pick up on a feeling similar to touching bubble wrap.

You ask the patient about the swelling. They tell you they suddenly became all puffed up after blowing their nose. What does this information tell you?

Answer 68

This could indicate a fractured zygoma that involves the maxillary sinus.

If patients have a fractured zygoma that involves the maxillary sinus, then blowing their nose leads to increased intra-nasal pressure as well as increased pressure in the sinus. This can blow air through the fracture into the tissues, leading to surgical emphysema.

So a patient who didn’t have much swelling before but suddenly does after blowing their nose and also presents with a presentation to the skin that feels similar to touching bubble wrap after a facial injury could have a fractured zygoma that involves the maxillary sinus and has led to surgical emphysema

Question 69

A patient presents with a flattened cheek following a facial injury. How do we pick up on a flattened appearance and what could flattening indicate about the injury?

Answer 69

Stand above the patient and behind them and look over the top of their forehead. Or stand at the patient’s feet with the patient on the bed and ask them to look up at the ceiling.

The body of the zygoma is responsible for the prominence of the cheekbone. If a patient is hit here and the zygoma goes back or in, then we get some flattening of the zygoma.

Question 70

A patient with a facial injury presents to your clinic. On an X-ray, you pick up on a blow out fracture. During the E/O examination, what would you likely have observed to support the X-ray findings?

Answer 70

A blow out fracture refers to a fracture of the orbital floor of the eye.

On asking the patient to move their eyes in all directions, the patient would struggle to move their eyes upwards. Instead the affected eye would look straight ahead whilst the unaffected eye would be able to look upwards.

The patient would also report double vision.

Question 71

A patient presents with a mandibular fracture. Why is it important to check the patient’s ability to feel sensation on the skin?

Answer 71

The inferior alveolar nerve runs through the mandible. Any fracture of the mandible, forward of the lingula and up to the mental foramen has the potential to damage the inferior alveolar nerve.

Lower lip and chin numbness is therefore a very common finding in patients with a fractured mandible.

Question 72

A patient presents with a facial fracture to your clinic. On inquiry, he reports numbness on one side of his nose, cheek and upper lip. What does this indicate about the fracture?

Answer 72

In patients with fractured zygomas, it’s very common to find numbness of the skin in that area.

This is because the IO (infraorbital) nerve, which is a branch of the maxillary division of the trigeminal nerve runs in the thin bone of the orbital floor and comes out anteriorly just above the roots of the premolars. This nerve supplies the sensation of the cheek, side of the nose, upper lip. If there is a fracture in the zygoma, this nerve may be damaged due to its location.

Question 73

A patient presents with a facial injury to your clinic. On inquiry, she reports forehead numbness. What does this indicate about the injury?

Answer 73

The injury likely involves the ophthalmic division of the trigeminal nerve.

The patient is likely to have a significant cranio-facial injury if she is experiencing forehead numbness as the ophthalmic division of the trigeminal is distributed in this area. It is likely it has been damaged as a result of the injury.

Question 74

Briefly summarise how to approach an I/O exam for a patient presenting with facial trauma

Answer 74

Inspect for-

Gaps in the occlusion (establish with the patient whether any teeth were missing prior to the injury, count the teeth to determine any missing teeth or whether the gap has been caused by a mandibular fracture that has sprung apart to create the gap between 2 teeth)

Gingival bleeding/bruising/tears (the springing apart of fractured fragments can cause these features)

Steps in the occlusion (also occurs as a result of fractured fragments springing apart, with one moving superiorly to the other)

Newly presenting malocclusion (not always easy to determine, need to ask the patient whether the way their teeth meet has changed). Often patients with a facial injury can present with open bites (anterior/posterior/lateral).

Question 75

A patient presents with a facial fracture to your clinic. He complains that the way his teeth meet has changed. On I/O examination, you notice an anterior open bite. What could this indicate about the fracture?

Answer 75

An anterior open bite quite commonly occurs following bilateral fractures of the mandibular condyles.

Question 76

Once an E/O and I/O exam are conducted following a facial injury, what is the next step a dentist should take?

Answer 76

Special investigations i.e. radiological examinations to confirm the suspected diagnosis and determine the severity of the fracture

Question 77

2 different radiographs taken at 2 different angles are the standard special tests carried out to confirm the diagnosis and determine the severity of the fracture. Why is this method used?

Answer 77

If we take an X-ray in one direction and the fracture has moved in a plane parallel to our line of vision, then it’s quite possible to miss a fracture.

Taking 2 radiographs also allows us to accurately assess fracture displacement and angulation.

Different fractures show up differently on different radiographs.

Question 78

What are the 2 radiographs often taken together for a mandibular fracture?

Answer 78

OPT

PA (posterior-anterior) view of the mandible (good for condyle and angle of mandible fractures)

Question 79

List all of the imaging that can be conducted for a mandibular fracture

Answer 79

OPT

PA view of the mandible

CT scan (if extra detail required)

Question 80

Which type of imaging should be used if we suspect condylar fractures and want to assess the condyles specifically?

Answer 80

CT scan

Reverse Towne’s view

Question 81

What is a Reverse Towne’s view taken for? How is it taken?

Answer 81

To look specifically at the condyles.

Patient will stand in front of the X-ray machine with their head pointing down and the X-ray comes up from above at 30 degrees.

Question 82

List the types of imaging that can be used if we suspect a fracture of the mid face?

Answer 82

Occipito-menton view

CT scan

Reverse Towne’s view?

Question 83

What is the Occipito-menton view taken for? And how is it taken?

Answer 83

Fractures of the mid face

The X-ray beam will come from the occiput (back of the patient’s head) down to the menton which is the patient’s chin. These are taken at different angles (15 and 30 degrees or 30 and 45 degrees)

Question 84

What can we see on an Occipito-menton view?

Answer 84

Fluid level- a sinus should be well aerated and dark on radiographic imaging but if a fracture has led to bleeding, a radiopaque region with a straight horizontal superior border indicating a meniscus (of a fluid level) may be seen. This area represents blood within the sinus, often seen in fractures involving the maxillary sinus

Infra-orbital margin- irregularities/kinks in the appearance of the infra-orbital margin which should normally appear as a nice and smooth thin layer of bone, could indicate a fracture of the bony orbital floor

Zygomatic buttress- could observe a break in the continuity of the bone in this area as a result of a fracture involving the body of the zygoma

Zygomatic arch- could observe a break in the continuity of the bone as a result of a fracture in the zygomatic arch

Question 85

What type of imaging is useful for isolating the zygomatic arch where an isolated zygomatic arch fracture is suspected? How is it taken?

Answer 85

Submento-vertex view

X-ray beam goes from underneath the chin to the very top of the skull which isolates the zygomatic arches

Question 86

What is the gold standard imaging technique for mid face fractures, once diagnosed? Why?

Answer 86

CT scan

Give much more detail with a lot more information about angulation/displacement.

Can be used to create a 3D reconstruction of the fracture

Question 87

Name the 4 phases of bone healing

Answer 87

Inflammatory

Proliferative

Bone callus formation

Remodelling

Question 88

Briefly describe the inflammatory phase of bone healing

Answer 88

After a bone breaks, there is some haemorrhage into the area. With that haemorrhage comes some inflammation because a bone injury will damage the soft tissues and hard tissues and this process of tissue damage will be recognised, instigating an inflammatory response. As a result, we get some bleeding into the fracture site followed by some inflammation. This will occur just after the fracture occurs (on the day of injury up until 2 weeks)

Question 89

Briefly describe the proliferative phase of bone healing

Answer 89

At this stage, fibroblasts will begin to proliferate and macrophages begin to move in and devour debris and dead cells. As the inflammatory phase reduces in its intensity, the proliferative phase takes off and we get some deposition of fibrous tissue around the fracture, leading to the formation of a soft callus. The purpose of this fibrous tissue is to stabilise the fracture to stop it moving around so much.

Occurs between 2 to 6 weeks following the fracture

Question 90

Briefly describe the bone callus formation phase of bone healing

Answer 90

Once the fibroblasts have proliferated, we then get differentiation of the osteoblasts and osteoclasts. The osteoblasts begin to produce bone matrix and the fibrous healing tissue (soft callus) gets reinforced with bone callus to actually unite the bone ends. At this stage, we have a hard callus forming.

Occurs 6 weeks from injury

Question 91

Briefly describe the remodelling phase of bone healing

Answer 91

During the bone remodelling process, the bone/hard callus will reduce in size and the actual bone ends will be remodelled so that they can unite to become a whole bone again.

Occurs about 6 months post-injury. Takes a long time to be completed, around 1-2 years for the bone to start looking normal again.

Question 92

Describe one feature that indicates that fracture healing hasn’t occurred properly

Answer 92

In general, especially within the head and neck region, there is usually sufficient strength of the injured bone by about 6 weeks following the injury. If there isn’t sufficient strength in the fractured bone by 6 weeks post-injury, then the fracture healing hasn’t occurred properly.

Question 93

List the requirements of bone healing

Answer 93

Reduce the fracture

Restore the length of bone

Restore the angulation of bone

Hold the bone in the correct position for at least 6 weeks

Prevent excessive movement

Allow some physiological stress to encourage bone remodelling

We need to think of the bone as a spacer between 2 joints. The joints are the important feature here. They need to be the right distance apart in order for the muscles to work properly. They also have to have the correct angulation. The joints are essentially designed to work at a particular angle, so if the bone doesn’t heal in the right position, to the right length and it doesn’t heal with the correct angulation, the joints aren’t going to work properly, and in turn, the muscles aren’t going to work properly. This will leave the patient with a disability because of the fracture healing incorrectly.

Once we have the bone healing to the right length and the correct angulation, we then have to hold it in position (usually for about 6 weeks until the bone develops a hard callus and has sufficient strength). We need to hold it in the correct position, prevent excessive movement but at the same time, allow some physiological stress, as we know bone healing is encouraged by a little bit of stress (not necessarily movement) applied across the joint

Question 94

List the priorities when treating facial fractures e.g., mandibular fractures, midface fractures etc.

Answer 94

Restore function (correct occlusion).
If we know the patient’s occlusion is correct, then we have a decent indication of the bone (mandible, jaw joints/TMJ etc.) also being in the correct position and angulation. So when we plate or splint jaw fractures, we need to correct the occlusion and then hold the occlusion in the correct position whilst the fracture heals.

Restore function (eyesight).
Zygoma/mid face fractures can lead to issues with eyesight. When fixing these fractures, we need to think about the eyesight and consider possible muscle entrapment, retrobulbar haematomas etc. that may be impairing eyesight or lead to permanent blindness in the long term.

Restore appearance

Question 95

Generally, what 2 methods are used to treat fractures?

Answer 95

Splinting

Plating

Question 96

List the principles of fracture management

Answer 96

Speed-
How quickly can the patient get back to normal function?

Safety-
How safe is the technique?

Stability-
How well is the fracture going to be held in the correct position?

Mobility-
Is there a little bit of physiological stress being applied across the fracture in order to encourage callus development and the remodelling process? A little bit of mobility across the fracture will enable this

Question 97

List the 4 treatment options for managing facial fractures

Answer 97

Conservative management
Leave and monitor

Manipulation under anaesthesia (MUA)
Involves moving the bone back into the correct position

Intermaxillary fixation
Teeth are wired or held together in the correct occlusion with the use of elastic bands

Plating / Open Reduction Internal Fixation (ORIF of a fractured bone)

Question 98

Describe the advantages and disadvantages of plating a fracture, in the context of the 4 principles of fracture management

Answer 98

Involves an operation, with a risk of a scar and potential for nerve damage. If the patient has medical problems, there’s also a potential for GA complications (for a lot of elderly people, there is a host of medical issues they may already have). Therefore, relatively less safe than other methods such as splinting.

But the patient will be able to start using the area a lot quicker.

We will also be able to establish that the fracture has been united in the correct position almost immediately after placement of the plate.

Extremely stable due to the rigidity of the titanium plate, but not as mobile. This is because the whole rationale for putting a titanium plate across a fracture is to hold the 2 fractured ends of bone in position whilst the fracture heals, so there’s going to be reduced opportunity for physiological stress to be applied across that fracture

Question 99

Define a greenstick fracture

Answer 99

Where a bone has fractured but the fracture doesn’t involve both cortices, so the fracture is not displaced

Question 100

Which fracture pattern would conservative management be indicated for?

Answer 100

Greenstick fracture (where the bone is broken but doesn’t involve both cortices, so the fracture is not displaced)

Question 101

Which fracture pattern would MUA be indicated for?

Answer 101

Condylar fractures

Zygomatic arch fractures

Question 102

How is MUA used to treat a zygomatic arch fracture?

Answer 102

An incision is made in the hairline.

We then dissect down onto the external temporal fossa. This fossa is incised through.

Then an instrument is passed down deep to the fossa, which will cause it to go deep to the zygomatic arch. This instrument can be used to lever the zygomatic arch out into position. As a result, the arch usually clicks out into position.

No splinting or plating involved. The bone is simply pushed into position and stays there

Question 103

Which fracture pattern would plating / ORIF be indicated for?

Answer 103

Comminuted fracture of the zygoma

Orbital floor fractures

Mandibular fractures

Maxillary fractures

Condylar fractures

Question 104

What can we use to repair orbital floor fractures?

Answer 104

Orbital floor mesh, made out of titanium to hold the bony orbital floor in the correct position, at the correct length and angulation whilst it heals

Question 105

What can we use to repair a fractured zygoma?

Answer 105

Plating / ORIF
Mini plates can be used to hold the zygoma bone in very precise positions whilst it heals

Question 106

We can use several methods to repair a condylar fracture. Describe each.

Answer 106

Intermaxillary fixation.
Involves manipulating the bone back into the correct position, by holding the patient in the correct occlusion with their teeth together using either wires or elastic bands. Needs to be kept this way for at least 6 weeks to allow hard callus formation and sufficient strength of bone at the fracture site.

Very often, condylar fractures will produce a malocclusion. If we correct the occlusion, we can ensure we have the bone (mandible, jaw joints/TMJ) in the correct position, length and angulation, allowing the fracture to heal properly.

Plating / ORIF
2 plates placed across the fracture to hold it in position. Involves an operation (risk of post-operative scars, GA complications and damage to the facial nerve which could lead to the development of facial weakness post-surgery)

Question 107

List the 2 methods of treating condylar fractures

Answer 107

Intermaxillary fixation

Plating / ORIF

Question 108

In the context of the 4 principles of fracture management, list the advantages and disadvantages of using intermaxillary fixation to treat condylar fractures

Answer 108

Involves manipulating the bone back into the correct position, by holding the patient in the correct occlusion with their teeth together using either wires or elastic bands. Therefore, relatively safe as it does not involve surgery which comes with the risk of post-operative scars, GA complications, nerve damage etc.

But the patient needs to be held in the correct occlusion for at least 6 weeks to allow hard callus formation and sufficient strength of bone at the fracture site. This will have potential ramifications for the patient’s nutrition and OH (could amplify caries)

If elastic bands are used to hold the teeth in the correct position, a little bit of mobility is possible allowing some physiological stress to be applied across the TMJ/jaw joints to encourage hard callus formation and bone remodelling.

Can be a stable technique but not as stable as plating

Question 109

In the context of the 4 principles of fracture management, list the advantages and disadvantages of using plating / ORIF to treat condylar fractures

Answer 109

2 plates placed across the fracture to hold it in position in an operation

Not without risk, involves an operation that could lead to post-operative scarring, GA complications or nerve damage. As we are working very closely to the facial nerve in this area, we would need to warn patients that there’s a risk of developing facial weakness post-surgery due to facial nerve proximity.

We can be sure almost immediately that the bone is in the correct place, length and angulation after plate placement. The patient can begin to use the area relatively quickly as a result

Very stable and rigid as a titanium plate is used to hold the fracture fragments together

Very little mobility as the whole premise for putting a titanium plate across a fracture is to hold the 2 fractured ends of bone in position whilst the fracture heals, so there’s going to be reduced opportunity for physiological stress to be applied across that fracture

Question 110

Describe the potential issues with treating a fracture in a patient with an atrophic, edentulous mandible

Answer 110

Surrounding muscles will pull the fractured fragments in awkward directions. At the back, the temporalis, masseter and lateral pterygoid muscles are pulling up and at the front, the strap and mylohyoid muscles are pulling down.

This means that atrophic mandible fractures are by definition unstable, as a result being very difficult to treat.

Very challenging to find an area to place a plate on sometimes. The plates that go onto mandibles need to be quite sturdy, which means that they need to be large but if the mandible is very thin, then sometimes it’s very difficult to get a plate that is strong enough and will sit against the bone rather than away from the bone

Question 111

List the methods for treating a bilateral fracture of an edentulous atrophic mandible. Describe each

Answer 111

Placement of a large reconstruction plate.

Rather than having the plate span the individual fractures on either side of the mandible, we have the plate going all the way around the mandible from one side to the other. This plate is big and chunky in order to ensure that we can counter the unhelpful forces from the muscles at the back and at the front

Gunning splint (where a patient has C/C dentures and no teeth of their own)
Involves taking both dentures and grinding away the anterior teeth entirely to make a feeding hole. The dentures are then placed back into the patient’s mouth and wired in place using circum-maxillary wires to hold the upper denture in place (up onto the maxilla) and circum-mandibular wires to hold the lower denture in place (down onto the mandible). These wires go through the mandible and maxilla in order to hold both dentures in their respective places. The upper denture is then wired to the lower denture to hold the patient in the correct occlusion and ensure the mandible, jaw joints/TMJ heal at the correct position, length and angulation

Question 112

In the context of the 4 principles of management, list the advantages and disadvantages of using a reconstruction plate to treat a bilateral fracture in an atrophic edentulous mandible

Answer 112

Relatively quick way of managing a fracture because we can restore the shape of the mandible within an hour or so.

In terms of safety, it is not so safe as it involves a big operation, with a likely post-operative scar on the patient’s neck as well as potential GA complications or nerve damage.

Likely to be very stable.

But one of the issues with placing a reconstruction plate on the mandible is that we don’t get any mobility and over time, the mandible can end up getting even thinner because the physiological stress that we need in order to maintain the bone is shielded from the mandible, by the plate. As a result, the plate in the long term can cause eventual problems rather than solving them

Question 113

In the context of the 4 principles of fracture management, list the advantages and disadvantages of treating a bilateral fracture of an edentulous atrophic mandible with a Gunning splint

Answer 113

Not an ideal way of managing atrophic edentulous mandibles that have fractured.

Relatively safe in terms of not having to expose the patient to a long procedure but the wires placed through the maxilla can actually pull through the bone as the maxillary bone is relatively thin and weak. Unless we get this absolutely right, we often get poor healing of mandibular fractures in this circumstance.

Not a great lot of stability with this approach

But there will be mobility across the fracture allowing some physiological stress to be applied across the jaw joint/TMJ to encourage hard callus formation and bone remodelling

Question 114

List the methods we can use to treat a fracture of the mandible

Answer 114

Plating / ORIF (osteosynthesis plates arranged in a very particular order)

External fixation (useful technique where there has been very high energy injuries with a lot of contamination or missing pieces of bone. Holds fractures in position using external tools/plates whilst they heal over the course of 6 weeks or so)

Question 115

What is external fixation? When is it indicated

Answer 115

A method of treating mandibular fractures, where there has been very high energy injuries with a lot of contamination or missing pieces of bone.

Old fashioned. Holds the fracture in position using external means (plates etc.) whilst it heals over the course of 6 weeks or so

Question 116

A patient presents to your clinic with a facial injury. On I/O inspection, you can see that the patient has a malocclusion with an evident shift in their lower midline. On taking an X-ray, you notice a radiolucent line across the left condyle. How will you treat this patient?

Answer 116

Patient has a condylar fracture.

Can be treated using intermaxillary fixation or plating / ORIF

Question 117

What specific risk does plating condyle fractures pose?

Answer 117

Post-operative facial weakness

Working very closely to the facial nerve in this area, therefore there’s a risk of developing facial weakness post-surgery

Question 118

Following treatment of zygoma/orbital floor fractures, why do we need to monitor the patient’s eyesight for 24-48 hours?

Answer 118

One of the issues with these fractures is the potential to form a retrobulbar haematoma (which can occur after the fracture has been treated).

We need to therefore spend a lot of time checking and rechecking on the patient’s eye sight, pain levels, visual acuity (24 to 48 hours post-operation).

As they are at risk of developing this following a fracture, we need to be vigilant, if this is not recognised or treated quickly, it can cause the patient to lose sight in the affected eye.

Question 119

You have treated an orbital floor fracture with an orbital floor mesh made out of titanium. What is the next step in the management protocol for orbital floor fractures?

Answer 119

As the fracture is in the orbital floor of the eye, there is a risk of a retrobulbar haematoma occurring even after treatment

We need to therefore spend a lot of time checking and rechecking on the patient’s eye sight, pain levels, visual acuity (24 to 48 hours post-operation).

As the patient is at risk of developing this following a fracture of the orbital floor, we need to be vigilant, if this is not recognised or treated quickly, it can cause the patient to lose sight in the affected eye.

Question 120

Describe the clinical features of a retrobulbar haematoma

Answer 120

Will look red, inflamed, bulbous (sticking out of the orbit more than the unaffected eye) and painful

Question 121

When an intermaxillary fixation technique is used to treat a fracture, why do we need to consider the patient’s nutrition and OH compliance post-treatment?

Answer 121

If the patient is in pain or if they’ve got limited mouth opening or even if their jaws are wired together, we need to think about how we’re going to get food/fluid into the patient to ensure adequate nutrition during management and healing of the fracture.

It is very tempting for patients to consume high sugar foods to intake the needed calories during fracture healing, however as dentists, we know this is not good for patients’ teeth. We therefore need to reinforce the importance of protective dietary habits and reduced frequency of sugary snacks/drinks

Intermaxillary fixation also acts a plaque trap. So patients’ OH tends to deteriorate around the area of intermaxillary fixation, which can cause gum disease/caries. This is amplified if the patient has a high calorific diet through high sugar consumption for 6 weeks.

Question 122

List the complications associated with fractures

Answer 122

Can be classified into 2 categories-

Complications that arise as a result of the fracture itself or its treatment. Includes-

Cosmetic e.g. post operative scar

Eyesight e.g. retrobulbar haematoma, muscle and fat entrapment

Nerve damage e.g. damage to the inferior alveolar nerve with mandibular fractures, damage to the facial nerve with condylar fracture plating / ORIF treatment

Scarring

Infection (always potential for infection inside fractures or around the fracture where a plate has been placed)

OR

Complications arising from problems with fracture union. Includes-

Malunion

Delayed union

Non-union

Question 123

Define malunion

Answer 123

Where the bone heals but is not at the correct length or angulation

Question 124

Define delayed union

Answer 124

Where the bone hasn’t healed after 6 weeks

Question 125

A patient who has been treated for a bilateral condylar fracture presents at your clinic for a review appointment. On the imaging you notice the condylar heads are angulated and displaced. You realise the condyles have healed at the incorrect position and angulation. What are the clinical implications of this for the patient?

Answer 125

If the condyles heal in the incorrect position and at the incorrect angulation, the dimensions of the posterior mandible are going to be incorrect, leading the patient to develop an anterior open bite.

A post-traumatic anterior open bite can be very difficult to manage

Question 126

What are the complications that could occur as a result of delayed union?

Answer 126

The plates that are put in when plating a fracture are good but have a limited life span. Usually fail after 20,000 stress cycles. As we use the mouth and lower jaw very often, 20,000 movements of the lower jaw/mouth (stress cycles) is actually not very long (just a few weeks). So if the fracture hasn’t healed after 6 weeks, then there’s a risk of the plate fracturing

The other issue that may occur is that the screws within the plates may pull out through the bone. The threads of the screws can be stripped or actively pulled out through the bone. Or if there’s a lot of inflammation around the area, with bone remodelling, the screws may become loose in the bone.

Delayed union IS therefore a problem, if there’s a delay in the fracture healing and there’s too much stress placed across those plates for too long a time, then the plates can fail, leaving us in a position where we need to retreat.

Question 127

What are the complications that could occur as a result of malunion?

Answer 127

Could lead to cosmetic and functional deformities where surrounding muscles do not work as they are supposed to or a post-traumatic anterior open bite develops

A lot of strain will be placed on the TMJ that isn’t designed to work at the incorrect angulation, which could potentially lead the patient to develop TMJ symptoms later on in life because of abnormal, unreasonable forces being applied across the joint

Question 128

Define non-union

Answer 128

A condition where the bone fragments don’t heal at all (do not heal together and unite as one bone)

Question 129

What are the complications that could occur as a result of non-union?

Answer 129

Mobile fracture

Bone will have no strength

Functional and cosmetic deformities

Question 130

What are the radiological features of non-union?

Answer 130

Ends of the fractured fragments will become rounded off and appear like they’re trying to heal but won’t be healing together

Will observe a radiolucent line between the fractured fragments

Question 131

In what situation can we get the development of pseudo-arthrosis or the development of a pseudo joint?

Answer 131

Where there is non-union, the ends of the bone heal or get rounded off but won’t unite (heal together) leading to the development of a pseudo joint