Trauma To Baby Tooth

Trauma to the primary dentition: Not just a baby tooth

Outline:

Case presentations
Epidemiology
History taking
Examination

Diagnosis

- - Fractures
  - Luxations
Sequelae
General management strategies

We’ll start by presenting a few cases that demonstrate some of the consequences of primary tooth trauma. , then go through some background information, and finish with some key points about trauma management. We’ll start with patient A

He was referred to a private kids dentist with the chief complaint that his teeth haven’t come down properly”

Medical History

Outline:

Medical History:
- Fit & well
Dental History:
- Trauma at age 2 years
- Draining sinus from left lateral incisor region at age 7

in terms of his dental trauma history At age 2, the patient faceplanted at home, hitting his baby teeth against the edge of a table
His left baby central incisor was pushed in and wobbly
his right baby central incisor was completely knocked out
and his left lateral incisor was loose at the time of injury
He went to see his general dentist for assessment, and as per the dental trauma guidelines, he was correctly managed with no active treatment
5 years later, chronic, draining infection was noticed from his left lateral incisor tooth (click), which was subsequently extracted.

This shows the patient’s teeth on a presentation at age 11 – after being lost to follow up with his general dentist since the time of his primary tooth trauma
the upper right central incisor demonstrates a well-localized deficit in the volume of enamel
the upper left central incisor shows a well-defined opacity in the tooth’s surface…
And a combination of hypoplastic and hypomineralised defects are visible in the upper left lateral incisor, circled in red. it is easier to see the extent of the defects in this crown when compared to the normal tooth on the patient’s right (highlighted in green)
these defects are caused by a disturbance to the tooth’s crystalline structure during the time of formation and are all recognized consequences of trauma to the primary dentition. They can result from the force of impact of the baby tooth itself, or by a localized infection, that occurs as a sequelae of the primary tooth injury.

From this angle, you can see more clearly the hypoplastic defects, with the linear area of missing enamel and the area of orange discoloured enamel – caused by the avulsion of the successor primary tooth
you can also see a bite problem caused by the displacement of the permanent left incisor relative to the bottom teeth, which has resulted as a consequence of the baby incisor being pushed up into the developing crown of the permanent tooth.

This image shows another view of the left permanent central incisor circled in red, which we can see is not positioned correctly in comparison to the contralateral incisor in green.
We can see more clearly from this radiograph, that this malalignment has resulted from an abnormal bend which has developed in the crown of the tooth. This is called a dilaceration.
Dilaceration of the permanent tooth is another well-documented consequence of primary tooth trauma

- you can see the defects of enamel,
- dilaceration of the left CENTRAL incisor,
- AND severely dilacerated and malformed left LATERAL incisor, which has an associated infection around its rootThis is a full mouth x-ray of the same patient, which provides a nice summary of all the primary tooth trauma sequelae evident in his permanent teeth

This image represents the chronology of permanent tooth mineralization
We know from our trauma history that this patient had a substantial knock to the baby teeth at age two
This case is an excellent illustration of the significant consequences that the trauma sustained to the primary teeth HAS on the permanent teeth developing in the jaw at the time of injury.
The complications this patient encountered, including developmental defects and eventual loss of his infected lateral incisor tooth are all recognized sequelae of trauma to the primary dentition –
Highlights the importance of encouraging regular dental to follow up from the time of primary tooth injury until the eruption of the successor permanent tooth

This is an x-ray of patient B at the time of her initial dental trauma. After a fall at 5 years of age, her right primary lateral incisor was knocked out, and the upper central incisors were pushed forward and upward.
At the time of injury, these teeth were appropriately managed with no active treatment, as per the dental trauma guidelines. The nature of the injury, and all relevant clinical findings were accurately documented and the patient was scheduled for routine to follow up until the eruption of the permanent incisors.

The patient returned for routine follow up at age 7. We can see that the position of the left central incisor has spontaneously corrected with time from the initial presentation, as is often the case
Although there is a wide variation from child to child, we usually expect the permanent front teeth to come into the mouth at around 7 years of age. As this patient’s baby front teeth were still firmly in place, another x-ray was taken to check for any associated pathology.
Resorption of the baby tooth usually moves progressively from the tip of the root down towards the crown. As we can see from the patient’s x-ray, the resorptive process is progressing abnormally, with the entire length of the roots still present. This leads to a delay in their exfoliation and prevents the permanent teeth from erupting normally.

Because the baby teeth were not resorbing normally, there were extracted to eliminate any further obstruction and allow the normal growth of the permanent central incisors.

These images highlight the importance of regular clinical and radiographic follow up after primary tooth injuries similar to those sustained by patient B
Without appropriate review following the injury to the primary teeth, the failed exfoliation of these teeth has not been detected and managed in a timely fashion
Therefore, the baby teeth have been over-retained – causing a delayed and malpositioned eruption of these permanent teeth – and obstructing the eruption of this tooth altogether- leading to these rather unsightly traffic jams!
These patients are now likely to require extensive and expensive! orthodontic treatment to correct the alignment of their permanent teeth.
Advice to parents on the importance of regular dental follow up after primary tooth trauma could have helped to detect these missed milestones of exfoliation. Timely detection of the issue could have allowed for appropriate early intervention – as was carried out for patient B.

disturbance to the right permanent incisor

We will now move on to the third case. This is a child with a clear disturbance to her right permanent incisor.

But she was referred initially at age 5 looking like this (click) with a missing primary tooth that has always been missing
- Medical history
  - Fit and healthy
- Dental History
  - Fallen from her bed on her face at age 6 months
  - Reviewed by ED, no treatment carried out
  - parents report:
    - no primary teeth present in the oral cavity at the time of trauma
    - Left primary central incisor erupted at 8 months of age, the right primary central incisor never erupted.
    - consulted a general dental practitioner → advised waiting for the eruption of the right primary central incisor
  - referred to a specialist paediatric dentist at age of 5
- Dental history revealed that at 6 months of age before the teeth had even begun to erupt, the child had a fall and a significant bleed from the mouth
  She didn’t have a dental assessment, because of course, there were no teeth at the time.
  
  But then we took a radiograph…

…And discovered that the tooth had been there all along! It had never been able to erupt after that injury even though the remaining teeth came through. And now you can see, there is damage to the permanent tooth resulting from this injury which stresses the importance of proper dental evaluation, even when there seem to be no teeth involved.

Here we can see in panel (a) the anterior region of the maxilla where the primary maxillary right central incisor is clinically missing, and there is a bony-like hard projection on the buccal aspect of the alveolus.
In panel b, at the time of surgery, we can see the inverted primary tooth that has been sitting in the gum pressed up against the developing permanent tooth.
Panel C shows the buccal and palatal views of the extracted primary tooth,
The image in panel(d) was taken at the clinical follow up at age 7 showing unusual morphology of the permanent successor
panel (e) shows a close-up view of the permanent maxillary right central incisor with an indentation of the tooth-like form,
panel(f) shows the reconstruction of the indentation that resembled the crown of the primary tooth
the last 2 panels show the facial and palatal views of the permanent maxillary right central incisor tooth after restorations to restore shape, function and colour

Epidemiology of Primary Tooth Trauma

1 in 3 children sustain an injury to the primary dentition
There is no significant difference in sex distribution
Peak age is just as they are starting to run around, in the 2-4-year-old age groups.
And obviously, the teeth that are going to get hurt most are the top front teeth

Infants take about 2000 steps in an hour and fall about 17 times

(Adolph et al. 2012)

Australian study:

The incidence rate of 20 TDI per 1000 individual per year in children aged 6-12

(Stockwell 1988)

True prevalence difficult to calculate

Depending on attendance for treatment
Minor injuries are not seen

The true prevalence is actually very difficult to calculate because most of the studies look at hospital and dental presentations which immediately means they have selected the more serious injuries and the minor injuries have been overlooked. Most studies also rely on

parental recall. A lot of minor injuries are not seen by parents or they might be forgotten about and sometimes even major injuries get forgotten about. We have here cases that have presented with odd things happening to their permanent dentition and when we ask the parents about history of trauma, parents report they can’t remember any trauma, but when we look back through clinical notes there is actually a documentation of the trauma that the parents have completely forgotten about.

Most often:

Within and around the home
Due to falls

The energy of impact:

Low velocity (resilient surface) →damage to surrounding tissue (displacement)
High velocity (hard surface)🡪 bits breaking off the teeth

Home is actually a very dangerous place to be and most of the injuries occur at home falling over or falling down from stuff.

From what we know the energy of impact significantly determines the outcome of the injury with low-velocity impacts tending to cause displacement and damage to surrounding tissues. High-velocity impact on hard surfaces tends to cause bits to break off the teeth.

Risk Factors

These are some of the risk factors associated with dental trauma.

Protruding upper incisors (>3mm)
The deep vertical overlap between upper and lower teeth
Resting lip apart posture

(Bastone et al. 2000 & Bonini et al. 2012 & Goettems et al. 2012)

Challenges

Trauma to primary teeth naturally means we are dealing with very young children, most of which is their first dental visit. They are often very anxious and stressed which leads them to be uncooperative. Parents are also anxious, stressed and impatient as they have usually been waiting in ED for a long time as dental injuries are usually put down an as low priority.

anxious patient and parents
stressful
age
pain
fear
urgent care needed
first dental visit

Medical & Dental History

We need to know if there are any medical complications. we want to know the details of when, where, why and how this injury has occurred so that we can get a correct diagnosis and treatment. But this also goes to the prognosis of the injury and helps us deal with any insurance claim and medico-legal issues.

medical complications
details of injury sustained (when, where, how, previous injuries, pain)
enables correct diagnosis
ensures correct treatment
prognosis of injury
insurance claim
medico-legal reasons

Examination

Every dental injury is a head injury.

It is important to note that every dental injury is a head injury,
So it is very important that each child that has presented for an emergency assessment also has an appropriate head injury assessment.
Thankfully usually minor but needs to be properly assessed.

Extra-oral Examination

We are going to look at all of these things because we need to make sure we have identified the full extend of the injury, to document them and to be able to provide an appropriate diagnosis treatment recommendations and given indication of our prognosis.

facial asymmetry/ bony discrepancies
bleeding
bruising
lacerations
fractures
paraesthesia
visual disturbance
headache
CSF leak, nose/ears
trismus

Intra-oral Examination

We will carry out a comprehensive intra-oral examination.

It is worth checking if the child’s parents or caregiver have a photo of the child smiling prior to the injury. This can help us determine if the tooth has been displaced or not. Sometimes teeth are not all aligned but parents may have not paid attention and following a dental injury they assume the tooth has been displaced. Comparing the position of the tooth on a photograph prior to a dental injury can help with diagnosis.

bony discrepancies
bleeding/ contusion/abrasion
bruising
lacerations
occlusal discrepancies
pain
teeth position (previous photos)
teeth color
teeth mobility
teeth percussion?

Radiographs

We want to take radiographs from multiple angles because we are using intra-oral plain films. At this stage, 3-dimensional imaging is not a routine part of the initial dental assessment but we may look at CT or cone-beam CT in special cases.

Occasionally we may need to take radiographs of the soft tissue if we are looking for missing fragments in lacerations.

OPG is not a very good film for the screening of injury to the primary anterior dentition.

Intraoral plain films from different angles v.s. full mouth OPG
soft tissue radiographs if required

Fracture in Baby Tooth

We’ll now go through some of the injuries that are seen in the primary teeth, starting with fractures – or injuries to the dental hard tissues. These are less common than luxation injuries in the primary dentition owing to the elastic nature of the alveolar bone in young kids.

Based on the World Health Organisation accepted classification of traumatic dental injuries, these diagrams are adapted from the Dental trauma guide, demonstrate the various fracture injuries to the primary dental hard tissues, ranging from the least severe infraction injury.

Fracture in Baby Tooth

Enamel Infraction

incomplete fracture of the enamel without loss of tooth structure

Of particular note, even where there’s no apparent loss of tooth structure, you can see crack lines resulting from the trauma. These are a marker of injury in the tooth, which needs to be monitored by a dental practitioner.

Complicated Crown Fracture

a fracture involving enamel and dentin with loss of tooth structure and exposure of the pulp

Sometimes the injury is so severe that it goes right through the nerve of the tooth, which you can see protruding out of the crown in this poor young child. You can imagine how painful this type of injury must be, and illustrates the importance of timely dental assessment and management – even though its “just a baby tooth!” ☺

Root Fracture

fracture confined to the root of the tooth involving cementum, dentin and the pulp

Sometimes the break may not be clinically visible because its actually inside the gum. But here you can see the effect on the nerve of the tooth, due to the break in the middle of the root

this is why thorough dental assessment is important, so accurate diagnosis of the injury can be made.

Luxations

Luxations are displacements of the teeth, occurring as result of injury to the tooth-supporting structures

Luxation Injuries

More common than fractures in the primary dentition

As we mentioned previously, young children are much more likely to displace (or luxate) their teeth rather than fracture them, as their teeth are hard and their alveolar bone is soft and elastic. These injuries to the supporting structures can be equally significant,. Even if you haven’t knocked bits off the tooth, simply displacing the tooth can affect the blood supply to the vital internal structures.

This is a WHO approved categorisation of luxation injuries in the primary dentition, randing from the most minor , thorugh to the most severe avulsion injury

Intrusive Luxation

In toddlers, particularly kids under the age of three, this is a very common type of injury, where the tooth gets pushed up into the gum.
You can see the intimate relationship between the root of the injured baby tooth and the crown of the developing adult tooth.
And thinking back to the first case of Patient A, (click) its easier to imagine the mechanism of injury to the developing permanent tooth – as a result of this type of injury.

Sequelae of Primary Tooth Trauma

Complications in the primary dentition

colour changes

The most common sequelae after the injury to a primary tooth is bleeding in the nerve.
This colour change is essentially a bruise in the tooth, as would be expected after sustaining what can be a considerably forceful knock!

This is often just a transient change, as you can see in this case here:
This photo was taken at the time of trauma before the fractured upper left tooth was restored.
this is the tooth discoloured at a routine recall 3 years later
and returned to its normal colour at review last year
Whether transient or permanent, colour changes are not necessarily a problem. But they are an indicator that the tooth has had damage to the nerve and needs follow up to detect any late complications

Pulp Necrosis

Sometimes there’s a significant compromise to the blood supply of the tooth, which leads to pulpal necrosis. Here, you can see the characteristic presentation of a dental abscess is a gum boil.

Pulp Canal Obliteration

You can also get calcification of the internal structures of the tooth as a healing response, which is really only visible on an intraoral radiograph.
But These teeth are the ones most likely to fail to fall out when they should. This leads to the types of displacement you saw in the case of our introductory Patient B

permanent displacement after luxation
pathological root resorption

There can be many variations in the exfoliation sequence as a result of dental injuries.
Even teeth that appear to be asymptomatic still need to be appropriately followed up until they exfoliate or need to be extracted.

disturbances in physiological root resorption
premature tooth loss

Failure to do this can lead to these types of interferences to the eruption and positioning of the permanent tooth.

Prevalence of developmental disturbances in permanent successors ranges from 20% – 74%

(Andreasen & Andreasen 2007, Lenzi et al. 2015)

Influenced by:

age
type of injury

Due to the close anatomical relationship between the primary and permanent teeth, up to 3/4s of primary tooth trauma will result in developmental complications of the successor permanent tooth.
To give you an idea of just how easy it is for a knock to the primary tooth to damage the adult tooth developing in the bone…the distance from the tip of the root of the baby front tooth to the edge of the adult tooth crown ranges from 3mm at age 3 to less than 2 mm at age 6.
The rate of complications is impacted by age and stage of dental development and the TYPE and EXTENT of injury sustained.

enamel defects

The sequelae in the permanent teeth can range from simple enamel defects…

delayed eruption

to significant disturbances in the eruption sequence of the permanent teeth…

The partial or complete arrest of root formation

and interrupted or arrested root formation, …

Crown and Root Dilaceration

All the way through – to major disturbances in the formation of the crown and root, as you’ll also recall from our introductory Patient A.

Management of trauma to the primary dentition

Very different to permanent tooth trauma management
Conservative
Extraction

ALL injuries need FOLLOW-UP

Management of trauma in the PERMANENT dentition is often a lot more involved at the acute stage
Trauma in the PRIMARY dentition however, is often managed much more conservatively.
After diagnosis and thorough documentation, minor injuries often require just a simple repair, or no active intervention at all.
More severe dental injuries will often require extraction of primary tooth at the time of trauma .
As we’ve seen in the previous slides, up to 75% of cases will have some long-lasting complication with the successor permanent tooth…
Therefore The most important point to note is that ALL primary tooth injuries need ongoing review until eruption of the permanent tooth, even in cases where the baby tooth is extracted.

Management of avulsion

confirm if primary or permanent tooth
- primary tooth: never replant
- permanent tooth: replant as soon as possible

Arguably the most important element of dental trauma assessment is that of avulsion injuries. It is of utmost importance for the first line assessor to determine if an avulsed tooth is primary or permanent.
Particularly in the mixed dentition stage, when children are transitioning from their baby to their adult set of teeth, this can prove challenging.

Avulsed primary teeth should be bid farewell and given to the tooth fairy, as attempting to replant these teeth may damage the developing adult tooth in the bone.
A permanent tooth avulsion however, has lifelong consequences for the child and requires very different management and Is incredibly time critical.
Timely action significantly improves the prognosis for the avulsed permanent tooth.
The prognosis for survival of avulsed permanent teeth replanted within 10 minutes of being knocked out is 90% at 5 years
- after just 60 minutes delay, this prognosis decreases drastically to just 10%.
obviously time taken for travel alone often exceeds 10 minutes, let alone further delays with queues and triaging. Therefore, the best first aid for avulsed permanent teeth is often carried out by the parent or even the child themselves at the site of injury.

Emergency first aid for avulsed PERMANENT teeth

Plan A

reposition into socket AS SOON AS POSSIBLE!
contact an emergency dentist as soon as possible

Plan B

protect the root in HBSS or milk

They should be encouraged to pick up the tooth, flick off any loose bits and put the tooth back into the socket
The replanted tooth can be supported by biting down on gauze, a handkerchief or even stabilized with aluminium foil while awaiting dental assessment.
theres a lot more emergency dental management that needs to be done, but if they can put the tooth back in at the site, their tooth will have a much better outlook for survival

There are some cases where you just cant put the tooth back in. The child may be hysterical, they may be unconscious or the bone might be crushed. In these cases, your fall back position is to put the tooth into something that will help to preserve the root. The tooth can do without the nerve, but it cant survive without the root!
In our hospital, we have access to Hanks Balanced Salt Solution which has a good evidence base to help preserve the delicate cells of the root for up to 24 hours before you loose root viability.
In a situation where you don’t have access to Hanks, then the tooth should be stored in humble old milk. It doesn’t matter if its full cream, skinny or half-half– this will preserve the root for a couple of hours, which could make all the difference for that child.

Since we cant expect all children to be THIS careful, all the time, some general considerations are important with regards to management of traumatic injuries in the primary dentition

Seatbelts
Helmets for bike riding
Supervision of pets
Mouthguards

Some common-sense points that go without saying to help reduce the RISK or SEVERITY of medical injuries … also apply to dental trauma.
And all children who play contact sports should be encouraged to wear a mouthguard

limited evidence for many treatment options
factors influencing treatment:
- child’s ability to cope
- time to expected exfoliation
- occlusion
importance of follow up

Like many things in medicine, some treatment options have limited evidence because they are less often seen injuries.
Factors to consider in the management of primary tooth trauma include:
- A child’s maturity and ability to cope with the emergency situation,
- the time to expected exfoliation of the injured primary tooth,
- and the influence of the injury on the child’s bite

With the risk of sounding like a broken record, you already know how we feel about dental follow-up!