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 Abstract
Dental injury is a distressing event, often causing psychological
as well as physical problems, since it normally involves the
highly visible front teeth. In addition, the treatment of such
injuries involves economic costs in both the short and the long
term.
These injuries range from minor fractures of the enamel to
more major damage involving the displacement or avulsion of
teeth.
In most dental trauma a rapid and appropriate treatment can
lessen its impact from both an oral health and an aesthetic
standpoint.
In this review of traumatic injuries (Dental Hard Tissue Fractures)
in the permanent dentition, we will describe the classification
of, assessment of and treatment strategies for managing such
injuries; As well as methods of minimizing complications and
preventive strategies.
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Introduction
Dental trauma is invariably distressing and painful for the
patient, and a challenge for the clinicians to manage in
such a way as to give the best possible opportunity of a
good, aesthetically pleasing, medium to long term clinical
outcome (1).
Epidemiological studies reveal that the majority of dental
injuries involve the anterior teeth, especially the maxillary
central incisors. Uncomplicated crown fracture is the most
frequent type of trauma.
The mandibular central incisors and the maxillary lateral
incisors are less frequently involved (2, 3).
Dental trauma can vary from a minor enamel chip to
extensive maxillofacial damage involving the supporting
structures and displacement, or avulsion, of teeth, causing
psychological as well as physical problems, since it normally
involves the highly visible front teeth (4). Could you imagine
the devastating effect on appearance and self-image a
broken or missing front tooth has on teenagers and young
adults?.
Dental trauma may be inflicted in a number of ways: contact
sports, motor vehicle accidents, fights, falls, eating hard
foods, drinking hot liquids, and other such mishaps. As
oral tissues are highly sensitive, injuries to the mouth are
typically very painful (5).
In most dental trauma a rapid and appropriate treatment can
lessen its impact from both an oral health and an aesthetic
standpoint (5, 6).
Several barriers may reduce the optimum management of
dental trauma. These include the clinician’s knowledge and
skills, financial considerations, and time constraints. Access
to care is crucial, since dental trauma often requires prompt
treatment (5).
When a player breaks a leg they are carried off the field,
transferred to hospital where the fracture is treated. The
delay of several hours is considered acceptable and does
not appear to affect the medical outcome.
Studies published more than 20 years ago however show
that if a tooth is knocked out, delaying treatment by 15
minutes reduces the chances of tooth survival by nearly
50%; Time is critical! Reducing delay between the time
of injury and primary care dramatically increases tooth
survival / retention reducing post-injury complications and
professional costs (7).
As dental injury is usually part of a multi-injury presentation
it is often not noticed or is ignored at the time of
presentation. The lay public, teachers, first aid providers
and medical practitioners appear reluctant, and have great
difficulty, in managing these injuries due to a lack of useful
information and the inadequacy of existing first aid kits.
Minimal treatment delay is crucial for the long-term success
of treating permanent teeth that have been knocked out.
Attempting to locate a dental practitioner in the event
of dental injury is impractical (many injuries occur on
weekends and after surgery hours when locating a dental
practitioner may be difficult) causing further delay severely
compromising the success of subsequent dental care (7).
Surveys amongst English physical education teachers and
school nurses found that despite first aid instruction, 57%
did not know what to do if a permanent tooth was knocked
out. More than 80% lacked the confidence and training
to manage if a permanent tooth was knocked out. Dental
injury is often managed by well-meaning but dentally
inexperienced staff relying on first aid kits containing no
relevant instructions or materials for managing this type of
injury (8, 9).
Suitable temporary care ensures the success of subsequent
professional dental care and reduces post-injury
complications keeping professional costs low. First aid areas
and dental practitioners are not often close to the accident,
readily located or immediately accessible (7).
Guidelines are needed to assist dentists as well as other
health care professionals in delivering the best care possible
in the most efficient manner. It is very important to promote
public awareness and to educate the population at greatest
risk for dental injury. Therefore, this paper includes basic
information on assessment of and treatment strategies for
managing dental injuries, as well as methods of minimizing
complications and preventive strategies. The correct
application of this management immediately following the
trauma should improve short and long-term outcome (3).
Classification of Dental Injuries
The World Health Organization, or WHO, developed a
classification for dental traumatic injuries that is descriptive,
easily understood and gaining international acceptance.
Acceptance of this system would benefit both patients
and the profession by allowing a better understanding of
various traumatic injuries and the selection of appropriate
treatment. Additionally, universal application of this system
would improve reporting to insurance carriers and for
research purposes. The WHO system was slightly modified by
Andreasen and Andreasen to clarify variations in the original
WHO categories of luxation and intrusion. In this review the
WHO classification will be used because of its broader scope
and international acceptance (10,11, 12).
The Mechanism of Dental injuries
The mechanism of injury and timeline are particularly
important aspects of the history because they define the
risk of associated injuries and available treatment options.
The exact mechanisms of dental injuries are likely unknown
and without experimental evidence, but injuries can be
the result of either direct or indirect trauma. Direct trauma
occurs when the tooth itself is struck. Indirect trauma is seen
when the lower dental arch is forcefully closed against the
upper, e.g. blow to chin. Direct trauma implies injuries to
the anterior region, while indirect trauma favours crown or
crown-root fractures in the premolar and molar regions as
well as the possibility of jaw fractures in the condylar regions
and symphysis (2).
Assessment of Traumatic Dental Injuries
Traumatic injuries are unexpected and inconvenient. A
thorough examination is essential in arriving at an accurate
diagnosis, selecting appropriate treatment and predicting
prognosis, but the time such an examination requires
is often not available. Consequently, it is essential that
we be prepared to assess such patients both rapidly and
comprehensively. Often, the patient not only has a physical
injury, but also is in emotional distress, which further
complicates the process. Use of a checklist or form that
encourages a systematic and thorough assessment should
minimize the clinician’s omission of key information (11,
13).
Trauma assessment should include: - medical history,
clinical examination, radiographic examination and, ideally,
photographic documentation (14)..
Classification of Dental Injuries
ENAMEL FRACTURE
Involves enamel only and includes enamel chipping
and incomplete fractures or enamel cracks.
C R O W N F R A C T U R E W I T H O U T P U L P A L
INVOLVEMENT
An uncomplicated fracture involving enamel and
dentin; no pulpal exposure.
CROWN FRACTURE WITH PULPAL INVOLVEMENT
A complicated fracture involving enamel, dentin and
exposure
or the pulp.
ROOT FRACTURE
Fracture or root only-cementum, dentin and pulp. Also
referred to as “horizontal root fracture.”
CROWN-ROOT FRACTURE
Tooth fracture that includes enamel, dentin and root cementum,
and may or may not include the pulp.
LUXATION
There are several subcategories of this type or injury:
Concussion. The tooth is sensitive to percussion but
has not been displaced and is not abnormally mobile.
Subluxation. The tooth has increased mobility but has
not been displaced.
Lateral luxation. The tooth has been displaced and
may be very firm.
Extrusive luxation. The tooth is very mobile because of
partial displacement out of the socket.
Intrusive luxation. The tooth has been forced apically
and is firmly embedded in bone.
AVULSION
Complete displacement of a tooth from its socket.
FRACTURE OF THE ALVEOLAR PROCESS (MANDIBLE
OR MAXILLA)
Fracture or comminution of the alveolar socket or the
alveolar process; if the
fracture involves a tooth socket, the blood supply to
the tooth pulp may be
compromised.
*Based on the World Health Organization system.
(Box, “Classification of Dental Injuries”)
History
The medical history should provide sufficient information
regarding the patient’s ability to receive treatment for the
injury. The injury history should document several important
pieces of information:
a) The time of injury, which may influence both the treatment
choice and prognosis;
b) The place of injury, which may determine issues of
liability;
c) How the injury occurred, as knowledge of the nature of
the force or blow can guide the clinician in broadening the
scope of the examination;
d) Why the injury occurred— whether it is something that
is likely to reoccur, whether future injury can be prevented,
and therefore whether treatment should be ambitious or
transitional;
e) Any history of injury to this tooth, which can be important
in interpreting radiographic findings, determining treatment
and prognosis, and ascertaining any possible history of
abuse;
f ) Whether the patient has been treated elsewhere before
coming to the dental office (14).
Neurologic Evaluation
Early diagnosis of neurologic injury is crucial to preventing
subsequent pathology. When a patient arrives with dental
trauma, begin by evaluating the entire craniofacial complex.
If approached logically in a systematic order, the course of
neurologic assessment of a patient with traumatic dental
injuries can be achieved in a short time. If neurologic damage
is suspected, immediate medical referral is indicated, as
impending neuropathologic crises of secondary injury may
be prevented with definitive early care (15, 16).
Examination
Extraoral examination should rule out facial bone fractures
and should include a thorough assessment of soft tissue
injuries. Lacerations of the lips and intraoral soft tissues must
be carefully explored for tooth fragments and other foreign
bodies. The occlusion and temporomandibular joints also
should be assessed.
The patient’s periodontal status can influence the clinician’s
decision to attempt any heroic measures in instances of luxation or avulsion injuries. The teeth and their supporting
structures need to be examined carefully—not only the
obviously injured tooth, but adjacent and opposing teeth
as well (14, 17, 18)..
Documentation
Record all findings such as fractures, infractions, color
changes and pulp exposure. Describe luxation injuries in
terms of direction and degree of displacement. Note any
mobility of teeth and of the alveolar process. Percussion
helps identify traumatized teeth (14)..
Pulp testing
Pulpal status may be determined by symptoms, history,
and clinical tests. Pulp testing immediately after trauma can
produce a high incidence of false-negative responses; it can
provide a baseline measurement for readings taken during
follow-up appointments (17, 19)
Radiographs
Radiographs are examined for fractures of bone or teeth and
stage of development. Radiographs obtained at the time of
injury not only assist in arriving at a correct diagnosis but
also serve to establish a baseline for monitoring changes,
both positive and negative, throughout the healing period.
It is important to use multiple exposures and standardized
techniques to ensure maximum detection of injuries as well
as accurate identification of injury type (2, 17, 18, 20)..
Photographs
Taking clinical photographs is encouraged as an additional
means of documenting injuries for insurance and legal
reasons, as well as establishing a clinical record for
monitoring patient and treatment progress (14, 18, 20)..
Evaluation
At the conclusion of the assessment, it is important for the
clinician to step back and evaluate whether the clinical and
radiographic findings are consistent with the history of the
injury provided by the patient or by whomever accompanies
him or her—a parent, caregiver, spouse or friend. If what
has been related as the cause of the injury is not congruent
with the clinical findings, the clinician’s index of suspicion
regarding abuse must be raised (14)..
Hard Tissue Fractures, Treatment Guidelines
Fractures of teeth and alveolar bone-
Infraction
Uncomplicated crown fracture
Complicated crown fracture
Crown-root fracture
Root fracture
Alveolar fracture.
Diagnosis and emergency management
Infraction
Definition: Incomplete fracture (crack) of the enamel without
loss of tooth substance. oss anatomic and radiographic
appearance; craze lines apparent, especially with transillumination.
Treatment objectives: To maintain structural integrity and
pulp viability. Periodic recalls are necessary as the energy
of the blow may have been transmitted to the periodontal
tissues or the pulp. Fracture of enamel may be either
smoothened or repaired with composite resin and splinting
if there is associated mobility.
General prognosis: The prognosis for enamel fracture is
very good. The likelihood of pulp canal obliteration or pulp
necrosis occurring is low for both enamel infractions and
enamel fractures (2, 12, 18, 20, 21).
Crown Fracture – Uncomplicated
Crown fractures comprise about 75% of injuries to
permanent teeth.
Definition: An enamel fracture or an enamel-dentin fracture
that does not involve the pulp (Fig 1).
Diagnosis: Clinical and/or radiographic findings reveal a loss
of tooth structure confined to the enamel or to both the
enamel and dentin (Fig 2-A) (22).
Treatment objectives: To maintain pulp vitality and restore
normal esthetics and function. Injured lips tongue, and
gingival should be examined for tooth fragments. For small
fractures, rough margins and edges can be smoothed. For
larger fractures, the lost tooth structure can be restored (Fig
2-B) (22).
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Fig. 2 A Enamel Fracture – before treatment
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General prognosis: The prognosis of uncomplicated crown
fractures depends primarily upon the concomitant injury to
the periodontal ligament and secondarily upon the extent
of dentin exposed (Andreasen & Andreasen, 2000). Optimal
treatment results follow immediate assessment and care
(18, 22).
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Fig. 2 B Enamel Fracture -
after treatment
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Crown Fracture – Complicated
Definition: An enamel-dentin fracture with pulp exposure
Diagnosis: Clinical and radiographic findings reveal a loss of
tooth structure with pulp exposure (22).
Treatment objectives: To maintain pulp vitality and restore
normal esthetics and function. Injured lips tongue, and gingiva should be examined for tooth fragments.
Pulpal treatment alternatives for permanent teeth are direct
pulp capping, partial pulpotomy, and pulpectomy (start of
root canal therapy) (22).
General prognosis: The prognosis of crown fractures appears
to depend primarily upon a concomitant injury to the
periodontal ligament. The age of the pulp exposure, extent
of dentin exposed, and stage of root development at the
time of injury secondarily affect the tooth’s prognosis.
Optimal treatment results follow immediate assessment
and care (18, 22).
Crown/Root Fracture
Definition: An enamel, dentin, and cementum fracture with
or without pulp exposure.
Diagnosis: Clinical findings usually reveal a mobile
coronal fragment attached to the gingiva with or without
a pulp exposure. Radiographic findings may reveal a
radiolucent oblique line that comprises crown and root
in a vertical direction in primary teeth and in a direction
usually perpendicular to the central radiographic beam
in permanent teeth. While radiographic demonstration
often is difficult, root fractures can only be diagnosed
radiographically (22).
Treatment objectives: To preserve pulp vitality for continued
root development and restore normal esthetics and function
(14, 22).
The emergency treatment objective is to stabilize the
coronal fragment but the complicating feature is control of
soft-tissue bleeding.
Definitive treatment alternatives are to remove the
coronal fragment followed by a supragingival restoration
if the remaining tooth structure is adequate for retention
or necessary gingivectomy, osteotomy, or surgical or
orthodontic root extrusion to prepare for restoration. If
the pulp is exposed, pulpal treatment alternatives are
pulp capping, pulpotomy, and root canal treatment.
Other treatment options for mature teeth with crown-root
fractures include extraction and replacement with a bridge
or implant (14, 18, 22).
General prognosis: This type of dental injury is considered
one of the more complex types of injuries because of the
severity; the fracture may extend subcrestally and often the
pulp is exposed (20).
Although the treatment of crown-root fractures can be
complex and laborious, most fractured permanent teeth
can be saved (Andreasen & Andreasen, 2000).
Fractures extending significantly below the gingival margin
may not be restorable. (14, 22).
Root Fracture
Definition: A dentin and cementum fracture involving the
pulp (Fig 3).
Diagnosis: Root fractures occur in only 7% of dental injuries.
Horizontal root fractures occur in anterior teeth, and are
caused by direct trauma. Vertical root fractures usually occur
in molars, and may be caused by clenching or trauma to the
mandible. Vertical root fractures are more difficult to detect,
and may not be found until extensive tooth destruction has
occurred. A horizontal root fracture is classified based on
the location of the fracture in relation to the root tip (apex).
Horizontal root fractures may occur in the apical third,
middle third, or cervical third of the root. Tooth fractures are
often not apparent during a clinical examination, and can
usually only be diagnosed using appropriate radiographs.
Radiographs with at least two views are required for making
this diagnosis (20, 22).
Clinical findings reveal a mobile coronal fragment attached
to the gingiva that may be displaced. Radiographic findings
may reveal 1 or more radiolucent lines that separate the
tooth fragments in horizontal fractures (23).
Treatment objectives: To reposition as soon as possible and
then to stabilize the coronal fragment in its anatomically
correct position to optimize healing of the periodontal
ligament and neurovascular supply, while maintaining
esthetic and functional integrity (Andreasen & Andreasen,
1994) (22).
No further treatment is indicated, unless clinical or
radiographic evidence demonstrates development of pulpal necrosis (14).
The most important factor in the success and treatment of
a horizontal root fracture is the immediate reduction of the
fractured segments, and complete immobilization of the
coronal segment. Root fractures must be diagnosed before
the body tries to “repair” the problem, and before the blood
clot prevents apposition of the fractured segments. If more
than 24-72 hours have elapsed, it may be impossible to
obtain close apposition of the segments (23).
Treatment for horizontal root fractures consists of rigid
fixation (immobilization) in an attempt to get the cementum
and dentin to heal (23).
General prognosis:
The prognosis for teeth with horizontal root fractures is
usually good. Healing favors young, immature teeth, but,
properly treated, many teeth can recover from a traumatic
root fracture. It is important to differentiate between
vertical and horizontal root fractures. Vertical fractures,
splitting roots along their long axes, have a poor prognosis.
Fortunately, they occur only rarely as a result of acute
trauma. Horizontal, infrabony fractures involve cementum,
dentin and the pulp. The prognosis worsens the further
cervically (towards the crown) the fracture has occurred. As
long as the fracture is infrabony with no communication to
the gingival sulcus and the patient exhibits meticulous oral
hygiene, appropriate treatment results in a high degree of
successful outcomes in both immature and mature teeth
(14).
Pulp necrosis in root-fractured teeth (approximately 25%)
is attributed to displacement of the coronal fragment and
mature root development. In permanent teeth, the location
of the root fracture has not been shown to affect pulp
survival after injury. Therefore, root fractures occurring
in either the tooth’s cervical third or apical third could be
treated successfully by stabilization of the repositioned
fragment (Andreasen & Andreasen, 2000) (14,22).
Dental bone fracture (alveolar process fracture)
Alveolar fractures are suspected when several
teeth move as a unit, when tooth displacement is
extensive, or in cases of occlusal misalignment (17).
Jaw fractures
These mainly result from high velocity impact as in road traffic
accidents, other accidents, and assaults. The immediate
concern is to preserve the airway. Assess all traumatised
patients along the lines of the advanced trauma life support
scheme (ATLS). Other immediate life threatening problems
include intracranial haemorrhage, severe haemorrhage
from other sites, and cervical spine damage.
During the secondary survey, inspect the head for lacerations
and leakage of cerebrospinal fluid. Associated bleeding may
further compromise the airway.
Jaw fractures alone, unless associated with a split palate
or gunshot wounds, rarely cause severe haemorrhage.
Bleeding from a ruptured inferior dental artery usually
stops spontaneously, but may recur if, for example, there is
traction on the mandible. Severe maxillofacial bleeding may
be tamponaded with craniofacial fixation. Bleeding can arise
from fractured nasal bones, in which case nasal packing may
be required. If bleeding recurs the damaged vessel must
be ligated. Definitive management of fractures, despite
frighteningly severe disfigurement, is not an immediate
priority, but debris such as fractured teeth, blood, and
saliva should be cleared from the mouth, and the tongue
may be controlled by a dorsal suture. An oropharyngeal
airway may be required. Involve the maxillofacial team early
on for treatment planning. Intubation may be necessary
in presence of substantial head injury, and inability to
intubate may necessitate surgical cricothyroidotomy, since
nasotracheal intubation is contraindicated (24).
Diagnosis
The alveolar bone, which supports the teeth, may experience
a fracture at the alveolar socket wall, the alveolar process,
or as a comminuted (shattered) fracture of the supporting
bone. Segmental fractures involve multiple teeth and their
supporting alveolar process (23).
The diagnosis of fracture is from the history, pain, swelling,
bruising (haematoma), bleeding (usually intraorally),
mobility of fragments (and crepitus), deranged occlusion,
paraesthesia or anaesthesia of nerves involved, and
radiographic signs.
Treatment of alveolar process fractures requires manually
repositioning the segment of displaced teeth back into
proper arch alignment (23).
Mandibular fractures
These are commonly owing to assault and are usually
simple and not associated with serious other injuries or
bleeding. If the is comminuted the tongue
could fall back and obstruct the airway, and this must be
prevented. Simple undisplaced fractures may occasionally
be treated conservatively with a soft diet if the teeth are not
damaged. If the fragments are excessively mobile, pain will
be substantial, and early fixation is the best management.
Most fractures are managed by open reduction and internal
fixation, usually with miniplates
(23)..
Conclusion
Most dentoalveolar trauma is preventable. It can be
prevented by the use of well fitting, properly constructed
mouthguards in any sport in which there is a risk of
sudden impact to the face. Routine use of seat belts in cars
can prevent the type of dental trauma that results from
forceful contact with the car’s steering wheel, dashboard or
windshield.
It should go without saying that anyone with injured
teeth should be seen by a dentist as soon as possible. But
meanwhile there is much that can be done at the scene of
the accident to provide immediate care and reduce the risk
of long-term complications.
Immediate care is the treatment of choice advocated by
dental schools, dental clinicians and their professional
associations for traumatic dental injury. In particular,
successful dental treatment for a permanent tooth, which
has been knocked out, is determined by the actions of those
at the scene of the accident not afterwards by the dentist.
The longer this time interval the poorer the likelihood of
long-term tooth survival.
When dental trauma receives timely attention and proper
treatment, the prognosis for healing is good. Subsequent
to the initial management of the dental injury, continued
periodic monitoring is indicated to determine clinical and
radiographic evidence of successful intervention.
References
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