managing dental injuries

8/10/2019 Managing Dental Injuries

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1.

The Dental-Trauma Patien t

Proper diagnosis of the dental-trauma patient must be done in a quickand accurate fashion. It involves a systematic approach to the

evaluation of the patient. If not done systematically, attention is firstpaid to the most obvious injury and other injuries are often not initially

identified.

The force or impact that caused injury to the teeth or mouth is oftensevere enough to cause concomitant injuries to the surroundingstructures, head, brain, neck, chest, or abdomen. Sometimes the

obvious injury is to the teeth and the patient is immediately brought tothe dentist. Subtle injuries to other systems may become obviousduring dental treatment. For example, a victim of a motor-vehicleaccident is thrown forward against the dashboard, displacing thevictim's anterior teeth, while also being restrained by a seat belt,

causing slow bleeding of the spleen that causes abdominal pain while inthe dental office.

This course will review all aspects of dental-trauma that might beencountered by a general dentist, dental specialist, or dental assistant.

The diagnosis and treatment of injuries to the teeth, jaws,temporomandibular- joints, and soft tissues are covered in detail. Thediagnosis of fractures of the bones of the jaws and face is included sothat all dentists treating trauma can identify these injuries and make

appropriate surgical referrals.

Figure 1: Dental injuriesrange from a single toothto complex injuries of the

teeth, bone and soft


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tissues. Thoroughextraoral, intraoral, and

radiographic examinationis needed

Examination o f the Dental-Trauma Patient

A thorough history and examination are necessary of the patient whohas suffered dental-trauma. Findings should be documented in the

records, for clinical reasons and for the fact that many injuries result inlitigation against the individual responsible for the injury.

History

A detailed history is important when the patient is first seen after an

injury. Questions should be asked to determine the cause of the injury,symptoms, possibility of concomitant injuries, and the medical historyof the patient before an accurate diagnosis and treatment plan can beestablished. Some of the questions that should be answered include:

General

When did the injury occur?Where did the injury occur?How did the injury occur?

Has there been any previous medical or dental treatment for this

injury?

Medical

Was there any loss of consciousness at the time of the injury? If so, forhow long?

Can you remember what happened before and after the injury?Do you have a headache?

Do you have nausea?Have you been vomiting?

Do you have double vision?

Do you have any injuries to other parts of the body from this accident?

Review medical history for serious illnesses, medications taken, andallergies.

Have you been vaccinated against tetanus? When?

Dental

Have the teeth been previously injured? When? Treatment performed?Treated by whom?

Do you have pain? Where?

Is there pain when biting teeth together?

Is there pain to heat, or to cold air or water?


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Soft tissue is visually examined for lacerations, ecchymosis, or swelling.Any lacerations should be explored to make sure they do not containfragments of teeth, bone, glass, dirt, grass, or other foreign material.This exploration can be performed after the wound is anesthesized in

preparation for closure. Examination prior to this would not be thorough

due to pain.

The integrity of the dental arch is assessed. Bimanual palpation of thealveolar processes and mandible is performed to rule out maxillary,mandibular, or alveolar-process fractures. The occlusion should be

checked.

The teeth are then evaluated for fractures, displacement, or otherinjuries. Mobility testing, percussion, and pulpal sensitivity testing

should be performed when possible.

Mobility testing determines the degree of loosening of individual teethor, in the case of alveolar fractures, several teeth. The degree of mobilityis an aid in determining the type of displacement injury and is recorded

on a scale of 1 to 3:

No mobility = 00 to 1 mm of horizontal mobility = 1

Greater than 1 mm of horizontal mobility = 2Axial mobility = 3

A mobility of 0 can indicate no injury, an intrusion injury, or, in the caseof postoperative examination, ankylosis. Percussion testing can be used

to determine between these.

Percussion testing with the handle of an examination mirror or othermetal handled instrument is used to determine tenderness to

percussion and the tone of percussion. Tenderness to percussionoccurs when there has been injury to the periodontal ligament.

Percussion tone of a tooth with an intact periodontal ligament will be alow, dull sound. Percussion of a tooth that is intruded or locked intobone will produce a high, metallic tone. A tooth that has developed

ankylosis will also produce a high, metallic tone.

Pulp-sensitivity testing, including cold and electric-pulp tests, should beperformed when possible to establish the condition of the

neurovascular supply to the injured teeth. While initial results may beinconclusive, they establish a baseline that can be compared with

follow-up examinations in subsequent months. Repeat mobility andpercussion testing, along with evaluation of tooth color, development ofswelling or fistulas, and radiographic changes, can help determine the

long-term health and status of the pulp.

With electric-pulp testing, placement of the electrode on the incisal edgeof the enamel, or in the case of crown fractures on the most incisal edge


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of enamel, produces the most reliable results. Teeth with incompleteroot formation and open apices respond inconsis

The Dental-Trauma Patienttently to electric-pulp testing, and testing primary teeth often is

inconclusive because of patient cooperation.

Radiographic Examination

After an initial clinical diagnosis is made, appropriate radiographs aretaken to further evaluate injuries.

With injuries to teeth, periapical radiographs are the most useful to lookfor root or crown fractures, displacement, and damage around the

periodontal ligament. They are also useful as a baseline to watch forlater changes of the root and pulp.

Standard occlusal radiographs are at times useful to check the integrityof the arch and to look for tooth or alveolar injuries. Occlusal films can

be used for lateral views of the anterior maxilla.

Panoramic radiographs are useful to evaluate injuries or fractures of themandible, maxilla, and alveolar processes. They are by far the bestscreening radiographs for these injuries, as they are able to show

injuries from the heads of the condyles to the symphysis.

For fractures of the mandible, other views are useful, including a PA

skull, oblique view of the mandible, and Towne's view. For fractures ofthe maxilla, Water's views are used. For more complex maxillary andmidface fractures, CT scans are useful.

2.

In ju ries to Permanent Teeth

Concussion and Subluxation

General Considerations

The least serious injuries to teeth are concussion or subluxation. Atraumatic impact to a tooth may cause a concussion or subluxation ofthe tooth without fractures or displacement of the tooth or alveolus.Hemorrhage and edema within the periodontal ligament space and

edema in the pulp may occur. The periodontal ligament remains intact


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with a concussion and, therefore, there is no mobility of the tooth. Withsubluxation, the periodontal ligament is torn and the tooth loosened.

Clinical examination shows considerable sensitivity to both vertical andhorizontal percussion. Bleeding from the gingival sulcus is generally not

present. Initially, both electric and cold vitality testing may show noresponse. No radiographic findings are present with either concussionor subluxation. With concussion, the tooth is attached normally to itsalveolar socket. With subluxation, the tooth is loosened in its socket,

although it is not displaced.

With both, swelling in the periodontal ligament space will cause thetooth to be in hyperocclusion, leading to the patient complaint that the

tooth is uncomfortable or painful to biting pressure.

Figure 2:Example of fractures of the enamel and dentin,along with pulpal exposure. Note the mucosal lacerationcontains the missing fragments of teeth.

Treatment

The immediate treatment for both concussion and subluxation injuriesinvolves treating the hyperocclusion caused by the edema and

hemorrhage in the periodontal ligament. This is done by selectiveadjustment of the opposing teeth so that the injured tooth will not

continue to be traumatized while the edema is resolving. The patient isalso advised to not occlude on or traumatize this tooth during healing.

Splinting of tooth with a subluxation injury is usually not necessary. Ifnecessary for patient comfort, the injured tooth may be splinted with an

acid-etched resin splint to the adjacent teeth for 2 weeks.

After initial healing, the tooth should be monitored at 1, 3, 6, and 12months post-injury for signs of pulpal necrosis or root resorption,

although these are rare. Clinical, vitality, and radiographic examinationsare performed at these visits.

Crown Fractures


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The most common traumatic injury to adult dentition is a fracture of thecrown of a tooth. A blow to the front of a tooth that exceeds the strength

of the enamel or of the enamel and dentin will cause a fracture. Slips

and falls, contact sports, vehicle accidents, and injuries from work toolsare common causes.

Fractures may be vertical, horizontal, angle mesial or distal, or may be ina coronal plane involving the entire lingual or facial surface. The

fractured segment may be dislodged, or the fracture can be incompletewith a fissure but no loss of tooth structure.

The amount of force required to fracture enamel or dentin is enough toalso cause concussion, subluxation, or displacement of the injured

tooth. These may affect the health of the pulp, even when there is not apulpal exposure.

Enamel Fractures

A fracture that involves only enamel will often initially cause discomfortto the patient due to the concussive injury that is often present.

Mesioincisal and distoincisal angles of an anterior tooth are the mostcommon locations for complete fractures of the enamel. The patient may

also complain of sharpness to the tongue or lips if the fracture iscomplete with a segment missing.

Incomplete fractures may be difficult to diagnose and may be vertical,horizontal, or angled. A light beam directed parallel to the long axis of

the tooth may help visualize the fracture.

Immediate treatment for enamel-only fractures is aimed at providingrelief of the sharpness for the patient by smoothing any rough edgeswith a water-cooled high-speed diamond. Teeth with incomplete or

complete fractures have been traumatized and should be taken out ofocclusion with a diamond by adjusting the opposing occlusion.

Several weeks after the injury, definitive repair of the tooth can beperformed. If a small portion of enamel is missing, the tooth can berecontoured by selective grinding with a diamond in a high-speed

handpiece. If it is larger, an acid-etched composite restoration can beperformed at this time.

All complete and incomplete fractures of enamel should be monitoredfor evidence of pulpal necrosis. Clinical, vitality, and radiographic

examinations should be made at 1, 3, 6, and 12 months. After that, thetooth should be examined annually.

Enamel and Dentin Fractures


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Fractures that extend through the enamel and dentin cause the patientsensitivity to temperature or to chewing due to the exposed dentin.Concussive injury may also be present, causing symptoms. Such

fractures may expose the pulp to oral bacteria via open dentinal tubulesbetween the dentin and pulp.

Immediate treatment is to protect the exposed dentin without causingfurther damage to the pulp. The fractured enamel and dentin are cleanedusing a moist cotton pellet and then dried with air blown indirectly over

the fracture. Cover the exposed dentin with eugenol-free calciumhydroxide, such as Dycal. Acid-etch the enamel and rinse with water for

20 seconds before restoring the tooth with composite. Do so withoutusing rotary instruments for additional preparation in order to prevent

further injury to the pulp. Build up the composite in such a way thatfurther rotary smoothing is not necessary and make sure the tooth is

slightly out of occlusion.

The injured tooth can be permanently restored 6 to 8 weeks later afterclinical, vitality, and radiographic examination shows no evidence of

pulpal or periapical changes. It should then be monitored at 3, 6, and 12months post-injury, then annually for several years to watch for pulpal

changes.

Fractures Into the Pulp

Fractures that extend into the pulp will cause sensitivity or pain to

chewing or temperature changes. Pulp exposure is usually visible.Treatment is determined depending on whether the root is completely orincompletely developed, the size of the exposure, time since exposure,

and final restoration needs.

For teeth with completerootformation that have a pinpoint exposurethat has been present for less than a few hours, a pulp cap with calciumhydroxide can be considered. This will allow new dentin to bridge over

the exposure site, preserving the uninflamed, vital pulp.

Clean the fractured enamel and dentin using a moist cotton pellet, dry

with air blown indirectly over the fracture, and cover the exposed dentinwith eugenol-free calcium hydroxide, such as Dycal. Acid-etch the

enamel and rinse with water for 20 seconds before restoring the toothwith composite. Avoid additional preparation using rotary

instruments in order to prevent further injury to the pulp. Build up withcomposite material and make sure the tooth is slightly out of occlusion.

Final restoration of a tooth with pulp capping should be delayed for 6 to8 weeks. With healing, a dentin bridge may be seen on radiographs.Clinical, vitality, and radiographic examination should be performedprior to final restoration to check for signs of pulpal necrosis, canal

hypercalcification, and internal resorption. A root-canal would beindicated if any of these were present.


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Continue to monitor a pulp-capped tooth after the final restoration.Clinical, vitality, and radiographic examination should be performed at 3,

6, and 12 months post-injury, then annually for several years.

If a completely formed tooth has a pinpoint exposure and has also been

displaced, pulp capping is a poor choice since the pulp likely has beenalready damaged from the apical end. Root-canal therapy should beconsidered from the start and the tooth treated with the protocol for

displaced teeth. Also, teeth with inflammatory or degenerative changesfrom previous injuries, as indicated by reparative dentin narrowing the

pulp cavity, should have root-canal therapy.

If a tooth with complete root formation has an exposure greater thanpinpoint or has indication of previous trauma, standard root-canaltherapy should be performed instead of pulp capping. Many times

restorative considerations will also make this necessary to allow for a

crown retained by a post and core.

The pulp can be extirpated, the canal shaped, enlarged, and filled withgutta percha in one appointment. Since these injuries are oftenemergencies worked into a full schedule, a pulpectomy can beperformed on an emergency basis with final cleaning and filling

accomplished at a subsequent appointment. Permanent restoration ofthe injured tooth can also be done at this time.

Teeth with incompleterootformation are treated somewhat differently.Pulp capping with calcium hydroxide, as described above, and the

placement of a temporary restoration are recommended for pinpointexposures that occurred within a few hours of the time of treatment.

This provides a seal that allows for a reparative bridge of dentin.

A partial pulpotomy is recommended for pinpoint exposures presentover a few hours and for larger exposures that occurred less than 24

hours before treatment. To be successful, the calcium hydroxidedressing must be placed in contact with healthy pulp that is not

inflamed. This allows for continued apposition of the dentin in thecoronal region of the tooth apical to the pulpotomy site.

Under local anesthesia, a water-cooled high-speed handpiece with adiamond bur is used to remove the pulp and adjacent dentin to a depthof approximately 2 mm below the level of the exposure. This should bedone intermittently for brief periods and should be supplemented withcopious irrigation with saline or water to avoid heating up the pulp and

dentin.

Ultimately, the amount of pulp tissue removed is determined by thehealth of the pulp. If the remaining pulp is inflamed, as indicated by

continued bleeding of the stump of the pulp for over 5 minutes,

additional pulp tissue should be removed. All inflamed superficial pulpmust be removed so the calcium hydroxide is in direct contact with


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healthy pulp. After removal of 2 mm of pulp tissue, allow severalminutes for hemostasis to occur. Stop bleeding that occurs for morethan 5 minutes by placing saline-moistened cotton pellets that havebeen squeezed almost dry over the bleeding pulp tissue and then

holding pressure for 3 to 5 minutes. Should bleeding continue after this,

additional pulpal tissue should be removed.

Once bleeding has stopped, a hard-setting, eugenol-free calciumhydroxide, such as Dycal, is placed over the stump of the pulp and the

remaining exposed dentin. Temporarily restore the tooth with acid-etched composite resin as described above.

A traditional pulpotomy removing the pulp down to the level of thecervical line is necessary for a pulpal exposure that has been present

for over 24 hours. It is performed in the manner just described, makingsure to keep the diamond bur cooled well with water. The powdered

form of calcium hydroxide may be easier to apply to the stump of thepulp given the increased depth present. It can be placed in the access

cavity with an amalgam carrier and a rounded instrument used to gentlyplace it in contact with the pulpal tissue, taking care not to pack it into

the pulp. Dycal or other hard-setting, eugenol-free calcium hydroxide isthen placed over the powdered calcium hydroxide and the tooth

temporarily restored.

Injured teeth with incomplete root formation that have been treated withpulp capping or pulpotomy should not be permanently restored for atleast 6 to 8 weeks. They should then be monitored for pulpal necrosis,

internal resorption, or hypercalcification of the canal with clinical,vitality, and radiographic examination at 3, 6, and 12 post-injury and

then annually thereafter.

Root Fractu res

Root fractures can be either isolated to the root or can include a fractureof the crown that extends into the root. Isolated-root fractures are

relatively rare, while crown-root fractures are common.


Isolated-rootfractures typically involve maxillary central incisors withcomplete root formation and are caused by a horizontal impact to the

crown from the front. This impact moves the tooth palatal, resulting in afracture at some level of the root. The alveolar process may also be

fractured in these injuries, especially if the fracture is in the mandibularincisor region. Fights and impacts by foreign bodies (baseball bats,

tools, etc.) are the usual cause of this type of root fracture.

Root fractures in the apical and middle thirds of the root are usuallyoblique with the apical edge of the fracture being on the labial. Fractures


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in the coronal third are also oblique, with the apical edge being on thepalatal. If a root fracture is displaced, the coronal fragment is lingual and

may be extruded.

A frontal impact from falls, motor-vehicle accidents, bicycle accidents,

and impacts from foreign bodies are the usual cause of crown-rootfractures. Beginning supragingivally on the labial surface, the fractureline extends in an oblique course below the gingival crest to the palatal

side, usually exposing the pulp.

Diagnosis

Isolated-Root Fractures

Tenderness on biting pressure is the main complaint of a patient with anisolated-root fracture. Clinically, the crown may be displaced lingually

and may be slightly extruded, although the more apical the fracture theless displacement there will be of the crown. Bleeding of the gingivalsulcus may be present. After a root fracture, the injured tooth may not

immediately respond to electric-pulp testing or to cold.

Moving the crown gently in an anterior-posterior direction to look formobility will often allow the examiner to discover the location of the

fracture and to differentiate between a root fracture, crown-root fracture,and displaced tooth. The closer the fracture is to the crown, the more

mobile the coronal fragment will be.

A periapical radiograph should be taken to evaluate any tooth thatsustained significant trauma and can be important in the diagnosis of a

root fracture. It can be difficult to see a fracture on a radiograph,however.

To be visible on radiographs, the central x-ray beam cannot deviatevertically from the plane of the fracture by more than about 15 to 20degrees. If it does, the fracture will show up as an elliptical double

fracture instead of a single oblique fracture.

If immediate displacement of the apical and coronal fragments has notoccurred the fracture may not be visible. If chewing forces, edema, orgranulation material cause separation of the fragments, subsequent

radiographs may show the fracture.

When a fracture does not show on radiographs despite a strong clinicalsuspicion that one exists, additional periapical radiographs should betaken at different angulations from the initial exposure. Increase the

vertical angulation of one radiograph by 15 degrees more than the initialradiograph and decrease the other by 15 degrees from the initial

radiograph.

Crown-Root Fractures


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Tenderness on biting is also the main complaint of a patient with acrown-root fracture. A supragingival fracture line is frequently presenton the labial surface to clinical examination. The coronal fragment may

be slightly extruded and moving it anterior-posterior may be painful.Usually, it is not tender to apical palpation. Gingival bleeding may be

present from the sulcus.

Since the oblique fracture line is perpendicular to the central x-ray beamand the lingual aspect is often not displaced, a crown-root fracture can

be difficult to diagnose on a radiograph.

Immediate Treatment

Isolated-Root Fractures

When an isolated-root fracture occurs apical to the gingival attachment

and there is no separation or mobility of the coronal fragment, the toothis taken out of occlusion by adjusting the opposing teeth. No splinting is

necessary; however, the patient is cautioned to avoid biting down onthis tooth.

If there is separation between the apical and coronal fragments,regardless if it is in the apical, middle, or coronal third of the root, the

coronal fragment is aligned to its properposition by digital manipulation under local anesthesia. This is usuallyaccomplished easily. If resistance is encountered, it is usually causedby interference from displaced bone fragments. These bone fragments

should be repositioned before attempting further realignment of thecoronal fragment.

Once the coronal fragment is clinically aligned with the apical fragmenta periapical radiograph should be taken to confirm proper position. The

tooth is then immobilized using a firm, acid-etched resin splint or asimilar passive splint that can be applied without displacing the coronal

fragment.


Under local anesthesia, the coronal fragment is separated from theperiodontal attachments and removed. The depth of the fracture cannow be better evaluated. Extraction of the remaining root is indicated

when the fracture extends below one-third of the clinical root.

If the fracture does not extend below one-third of the clinical root,consider restoration of the tooth. Smoothen rough supragingival and

subgingival edges and treat dentin or pulpal exposures as you would acrown fracture. If there is a pulpal exposure, and a root-canal is

necessary, it can be completed at this time, or a pulpectomy can be

performed with gutta percha filling at a later time.


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Finally, a temporary restoration that has supragingival margins isplaced. The fractured coronal segment can be used as a temporaryrestoration by bonding it with acid-etched resin to adjacent teeth.

Definitive Treatment

Isolated-Root Fractu re

The injured tooth should be splinted for 3 months. The splint is thenremoved and the tooth evaluated. If the coronal fragment is still mobileand there is no indication of pulpal necrosis, the splint can be replaced

for an additional 1 to 2 months, making sure the tooth is taken out ofocclusion by selective adjustment to the opposing tooth. After the

additional splinting time, if the coronal fragment is still mobile and thereis still no evidence of pulpal necrosis, it may be permanently splinted to

the adjacent teeth.

Monitoring of the fractured tooth should be done at 3 weeks, 6 weeks, 3months, 6 months, and 12 months from the time of the injury. Clinicalexam should evaluate the color of the crown, palpation of the facial

aspect of the alveolus overlying the root,vitality testing with electric-pulp testing and cold testing. Mobility

testing, percussion, and periodontal probing should be checked whenthe splint is removed to evaluate for pulpal necrosis or a periodontal

fistula.

Pulpal necrosis may occur only in the coronal fragment or in both thecoronal and apical fragments. Should it occur, treatment options include

extraction or endodontic therapy. The determining factor is the extentand prognosis of the endodontic therapy and the patient's desire. Whenonly the pulp of the coronal fragment is necrotic, only this portion needsto be cleaned, shaped, and filled. The apical fragment does not require

endodontic treatment. When both the coronal and apical segments havepulpal necrosis, both should be treated. If it is not possible to gain

access to the apical fragment, a root-canal is performed on the coronalfragment and then the apical fragment is surgically removed.


Definitive treatment of crown-root fractures involves gaining subgingivalaccess to the fracture for proper preparation of the margin of the finalrestoration. Several options are available depending on the depth and

position of the fracture including gingival and/or osseous recontouringsurgery, orthodontic extrusion of the root, or a combination of the two.

Orthodontic extrusion is preferable if recontouring surgery wouldrequire removal of bone or gingival tissue on the labial, or if the fracture

is greater than 2 mm below the level of the bone.


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When the pulp is vital at the time of the injury, the tooth should bemonitored clinically and radiographically for pulpal necrosis at 3, 6, and

12 months post-injury and annually for several years.

3.

Displacement o f Permanent Teeth

The most common tooth injury after crown or root fractures isdisplacement of teeth from their alveolar socket. Teeth may be displaced

in laterally (posterior, anterior, medial, or lateral), apically (intruded),partially avulsed (extruded), or completely avulsed. Maxillary anterior

teeth, especially central incisors, are the most common teeth displaced,followed by mandibular incisors.


Neurovascular In jury and Pulpal Necrosis

The blood and nerve supply to a tooth enters via the neurovascularbundle that enters through the apex. When a tooth is displaced from itsalveolar socket the neurovascular bundle is damaged to some degree. If

the apex is displaced more than 5 mm, there is definite damage andimmediate root-canal therapy will be necessary. If it is displaced lessthan 5 mm, damage may occur or the neurovascular bundle may be

stretched without damage. Such teeth need to be monitored clinicallyand radiographically for pulpal necrosis, with root-canal therapy

indicated only if necrosis occurs.

Teeth with roots that have an open apex and are not completely formedhave a chance of revascularization without the need for endodontictherapy. The embryonic-dental papilla contains a capillary network that

is receptive to revascularization instead of several distinct vesselsfound in teeth that have completed their development. If

revascularization is not adequate, the pulp may become fibrotic orcalcified.

Per iodontal Ligament In jury and Resorpt ion

Attaching the tooth to the alveolus, the periodontal ligament is also

damaged when a tooth is displaced. In some cases, there is tearing ofthe periodontal-ligament fibers on only one side of the tooth, although


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usually all of the ligaments are torn. Damage to the periodontal ligamentcan lead to external resorption of the root surface.

After an injury, both the periodontal ligament and cementum aresensitive to damage from desiccation when out of the mouth,

temperature change, contamination and manipulation. With minordamage to the periodontal ligament or when a tooth is rapidly replantedafter an injury, the periodontal ligament may successfully reattach to the

cementum, and with small cemental tears reversible resorption of theroot surface may occur.

Unless the tooth is rapidly replanted into the socket, the periodontalligament and cementum are irreversibly damaged and will not reattachnormally. Instead, ankylosis occurs with the bone fusing directly to the

root surface. Areas of bare cementum will lead to ankylosis.

When irreversible root or periodontal ligament damage occurs, there isprogressive replacement of the root by bone, called replacement

resorption. Occurring over months to years, replacement resorption isgradual and asymptomatic and no inflammation is present.

Radiographically, the normal radiolucent space of the periodontalligament is not present.

Replacement resorption is usually progressive; however, sometimes itmay be transient. That is, some teeth that are totally ankylosed and

immobile may become mobile to some degree later as small islands ofankylosis break away due to function over time. Normal attachment over

the rest of the surface of the root maintains the tooth in the socket.

External-inflammatory resorption is much more rapid than replacementresorption. Sometimes there is significant resorption of a tooth in a

matter of weeks. Thought to be due to the products of pulpal infection,inflammation is extensive and the resorption can be seen on a

radiograph as a radiolucent area.

Timely root-canal therapy to remove the infected pulp can prevent orhelp stop external- inflammatory resorption. With displaced teeth,

extirpation of the pulp and debridement should be performed once thetooth is stable, generally within 2 to 4 weeks. Calcium hydroxide shouldbe used to temporarily fill the canal. It can be replaced every 3 months if

external-inflammatory resorption continues. Final filling of the canalwith gutta percha should be delayed for up to 12 months, as the lateralcondensation puts considerable pressure on the healing periodontal

ligament tissues.

Significant ankylosis can occur when an injured tooth has been out ofthe mouth long enough for periodontal ligament damage to occur. In

children, such teeth do not erupt, leaving a tooth out of occlusion that

cannot be moved with orthodontic therapy. In adults, ankylosed teeth


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remain in position and function well, although they may be difficult toremove should extraction become necessary.

Physio logy of Tooth In jur ies

Trauma to the teeth may fracture a tooth, displace a tooth, or separate orcrush the supporting bone, periodontal ligament, or gingiva.

When teeth are separated from their periodontal ligament attachment,such as during an extrusion injury, there is a tearing of collagen fibersand intercellular material with limited damage to adjacent cells. Wound

healing can occur rapidly since cells are not damaged.

Intrusion injuries, however, cause crushing of the supporting tissueswith extensive damage to adjacent cells and intercellular material.

Before the injured tissues can heal, these damaged tissues must beremoved by macrophages and osteoclasts, which delays healing byseveral weeks.

Immediately after an injury, there is bleeding from damaged bloodvessels with subsequent clotting and hematoma formation. Neutrophilsmigrate to the area to attack microorganisms that can cause infection.

Macrophages digest damaged cells and foreign bodies. The injured areais then revascularized giving blood supply to ischemic tissue andforming new tissue in areas with tissue loss. Endothelial cells and

fibroblasts then move into the injured area.

When a simple luxation-type of injury occurs to a tooth, new collagenfibers form within a week to repair the severed periodontal-ligament

fibers. By the second week, the fibers have healed sufficiently to givethe periodontal ligament about two-thirds of its normal mechanical

strength.

When the vascular supply to the pulp is severed, new blood vesselsbegin to grow within 4 days following the injury and, in teeth with open

apices (greater than 1 mm), they grow at a rate of 0.5 mm per day.

In injuries that severely damage the periodontal ligament, such ascrushing injuries or desiccation following avulsion, root resorption mayoccur due to the loss of the layer of cementoblast and epithelial rests of

Mallassez on the root surface. This loss allows macrophages andosteoclasts to remove damaged cementum and periodontal ligament

from the surface of the root.

This can lead to complications of wound healing, including resorption ofthe root. Resorption depends on the eventual exposure of dentinaltubules, whether the pulp is sterile and ischemic or necrotic and

infected, and presence or absence of vital cementoblast adjacent to theinjury.


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Resorption can be surface resorption, inflammatory resorption, orreplacement resorption. In surface resorption, macrophages and

osteoclasts resorb the surface of the root in response to damage of theinnermost layer of the periodontal ligament, forming a shallow, curveddepression on the root. If the adjacent cementoblast layer is intact and

the damage does not extend into a dentinal tubule, the area ofresorption is repaired by deposition of new cementum and Sharpey's

fibers.

If the resorption has extended through the cementum exposing dentinaltubules, inflammatory resorption can occur. Bacterial toxins from

infected pulp or dentinal tubules are transmitted via dentinal tubules tothe area of resorption and the periodontal ligament. Inflammation in the

periodontal ligament and continued osteoclastic activity causesresorption of the lamina dura and of the adjacent bone. This resorption,

left untreated, will continue until the root-canal is exposed. If treated

with root-canal therapy, the removal of the bacteria will stop theresorptive process and bone or cementum will fill in the cavity formed

by resorption.

With extensive damage to the innermost layer of the periodontalligament, replacement resorption may occur. With replacement

resorption, healing from the periodontal ligament produces cementumand Sharpey's fibers at the same time that healing from the adjacent

bone of the alveolar socket wall produces bone from bone-marrow cells.This can create a progressive ankylosis, making the tooth part of the

bone remodeling process.

Spl int ing Methods

Figure 3: Semi-rigid splint madefrom orthodontic wire and acid-

etched bonding material.

Splints are used to stabilize displaced teeth. The injured teeth aresplinted to adjacent teeth. After one week of splinting, displaced teethare reasonably stable and the splint is left in place for 10 to 14 days to

allow for gingival reattachment. Prolonged splinting has been shown topromote ankylosis by preventing normal function of the tooth that

fractures small areas of fusion of bone to cementum.


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Semirigid splinting is assumed to assist healing of the periodontalligament, but this has not been definitely proven. Rigid splinting doesnot seem to promote healing, and in cases of prolonged splinting in

injuries with extensive damage it seems to promote ankylosis.

Semirigid resin splints, constructed of orthodontic wire and acid-etchedbonding material, provide stability while at the same time allowing

functional motion to prevent ankylosis. These are normally used for asingle displaced tooth when treatment is in a dentist's office.

Figure 4:An Erich-arch bar used as a rigidsplint is wired to the displaced tooth andto several teeth on each side using 24-

gauge wire.

An Erich-arch bar may be used when bonding techniques are notavailable, such as in many hospital emergency rooms. A segment of

arch bar is cut long enough to include the displaced tooth and at leasttwo teeth on either side. It is then attached circumdentally to each toothusing 24-gauge stainless steel wire. It is a rigid splinting technique, notallowing for functional motion of the injured tooth. Erich-arch bars arealso used with many displaced alveolar fractures and with fractures of

the mandible or maxilla.

Other techniques that can be used if nothing better is available includean Essig splint or periodontal-packing material.

Lateral Displacement (Lu xat ion) of Permanent

Teeth

A common injury is a horizontal displacement of a tooth due to a blow tothe crown. Most often this is an anterior tooth and the tooth is displaced

posterior, displacing the crown of the tooth posterior and the rootanterior through the labial alveolar plate.


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Maxillary central and lateral incisors are often affected. Common causesinclude a fall, a blow to the teeth from being punched by a fist, and

sports injuries. Mandibular incisors are displaced often due to bicycleaccidents, such as hitting an object and being thrown over the

handlebars.

In such an injury, the neurovascular bundle is severed, some fibers ofthe periodontal ligament are torn, and some on the palatal aspect of the

tooth are compressed, and the alveolar bone may be fractured.

History and Diagnosis

The injury is usually obvious to the patient, who will complain that thetooth has been "knocked back." The patient may complain that the teeth

don't come together or that the displaced tooth occludes before theothers. There will be pain when touching the displaced tooth and

surrounding structures. Bleeding may occur, but this stops quickly andusually is not a problem by the time the patient is seen by the dentist.

Clinical exam will show the crown to be displaced, often lingually, withthe tooth firmly locked into the displaced position. There is little or no

mobility of the tooth. The apex of the tooth can be palpated on the labial.Vitality testing shows no response to cold or electric-pulp tests. A

hollow or metallic sound is produced from percussion testing.

A radiograph should be taken to rule out root fractures. With a laterally

displaced tooth, it will show widening of the periodontal-ligament space.It may show an increased space at the apex if the radiograph was takenat an oblique angle to the normal horizontal angulation of the tooth. Ifthe tooth has been displaced mesial or distal, there may be a widened

periodontal-ligament space on the opposite side.

Immediate Treatment

Local anesthesia is used to anesthetize the region before repositioningthe tooth. Then, steady digital pressure is applied to the tooth to

reposition it into normal anatomical position. Pressure is applied to the

lingual surface of the crown pushing it labial, while pushing the apexlingually with pressure on the labial mucosa over the displaced apex ofthe root. Once the apex is pushed back through the fenestration in thelabial plate, pressure is placed in an apical direction to seat the tooth

firmly in the socket.

If a tooth is displaced in a position other than posterior, use the samedigital manipulation technique to reposition it into proper position.Evaluate the occlusion to make sure the tooth is properly aligned.

Bone fragments that can be palpated on the labial or lingual should be

repositioned with digital pressure. Any lacerations to the gingival aresutured at this time.


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An acid-etched semirigid splint should be placed to immobilize the toothas described previously. A rigid splint, such as a wire splint or Essig

splint may be used if bonding material is not available (for example, in ahospital setting.) Be sure to adjust the occlusion by selective grinding of

the opposing tooth so that the splinted tooth is not in hyperocclusion.

A tooth displaced over 5 mm that cannot be completely repositionedmay be moved with orthodontic repositioning after the bone has healed.


Three weeks after the injury, a periapical radiograph is taken. If it showsno loss of marginal-bone support for the tooth, the splint can be

removed.

For a resin and wire splint, the splint is removed by using a high-speedfissure or diamond to remove the wire from the resin. Care must be

taken to avoid excessively manipulating the repositioned tooth, so asnot to cause its displacement. Support the incisal edge of the tooth

while grinding the splint off. After the wire is removed from the tooth,smoothen the excess resin, but avoid additional manipulation for

several weeks for further healing to occur before removing it at all.

If the 3-week radiograph shows loss of marginal bone, the splint shouldbe left in place for another 5 to 8 weeks from the time of injury.

Check the radiograph for signs of external-inflammatory resorption. Ifresorption is occurring, root-canal treatment should be startedimmediately. Use calcium hydroxide to temporarily fill the canal for thefirst 6 to 12 months before permanently obturating the canal with gutta

percha.

If there are no signs of external-inflammatory resorption in a tooth with afully developed root and closed apex, and the tooth was displaced morethan 5 mm, root-canal therapy should be performed as soon as possible.Again, use calcium hydroxide to temporarily fill the canal for the first 6

to 12 months before permanently obturating the canal with gutta percha.

A tooth with a fully developed root that was displaced less than 5 mmand that has no signs of external-inflammatory resorption should beclinically examined at 3, 6, and 12 months after the injury. Check for

signs of pulpal necrosis or external-inflammatory resorption withradiographic and clinical testing, including evaluation of color of thecrown, percussion, palpation, mobility, and electric- and cold-vitality

testing. If there is a periapical radiolucency present or there are clinicalsigns of a non-vital tooth, standard root-canal therapy is performed with

permanent gutta percha obturation. Temporary filling with calciumhydroxide is not needed.


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If a tooth has an incompletely developed root with open apex, noendodontic therapy is performed unless there are signs of pulpalnecrosis. Monitor the tooth monthly with radiographic and clinical

examinations until there is evidence of continued root growth or pulpalnecrosis. If pulpal necrosis occurs, endodontic therapy is started

immediately using calcium hydroxide as a temporary filling material for6 to 12 months before permanent obturation with gutta percha.

After 12 months, if the apex is still not closed adequately, continuetemporarily filling with calcium hydroxide until apexification occurs,

closing the apex so that a permanent filling can be performed.

A displaced tooth that cannot be completely repositioned may be movedwith orthodontic repositioning. If it was displaced over 5 mm, start root-canal therapy with temporary calcium hydroxide filling before beginning

orthodontic movement. If it was not displaced over 5 mm, orthodontic

movement may be started as soon as the splint is removed. The tooth isstill monitored for pulpal necrosis and external-inflammatory resorptionduring orthodontic movement. Should either occur, root-canal treatment

may be initiated during orthodontic treatment.

Extrusio n o f Permanent Teeth

A blow to the crown of a tooth from an angle oblique to the long axis ofthe tooth partially displaces (extrudes) it from its socket. The

neurovascular supply is severed, as is most of the periodontal ligament.

Some gingival fibers on the palatal may be intact.


The patient will complain that the tooth is "knocked loose," or that theteeth don't come together properly. The tooth may be extruded and may

occlude before the other teeth.

Clinical exam will show the tooth to be elongated, loose, and oftendisplaced lingually. The tooth is non-vital to testing with cold- and

electric-pulp tests. Percussion is not necessary, although it would causea dull sound. Radiographic exam will show an increased periodontal

space in the apical region of the socket.

Immediate Treatment

After administration of local anesthesia, slow, steady apical pressureshould be applied to the crown of the tooth to reposition the tooth in thesocket. The pressure will displace the clot that was formed in the apex

of the socket.

Once the tooth is repositioned, an acid-etched semirigid splint shouldbe placed to immobilize the tooth as described previously. A rigid splint,


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such as a wire splint or Essig splint may be used if bonding material isnot available (for example, in a hospital setting.)

Adjust the occlusion by selective grinding of the opposing tooth so thatthe splinted tooth is not in hyperocclusion. The splint is left in place for

3 weeks.


If the tooth was displaced more than 5 mm at the time of the injury andhas a complete root, then immediate root-canal therapy should be

started using calcium hydroxide as a temporary filling material for 6 to12 months before permanent filling. If the tooth was not extruded 5 mm,it can be monitored for signs of pulpal necrosis or external inflammatory

resorption, as discussed in the lateral displacement section.

At three weeks after the injury, a periapical radiograph is taken toevaluate whether or not external-inflammatory resorption is taking

place. If so, root-canal therapy is immediately started, using calciumhydroxide as a temporary filling for 6 to 12 months before permanent

obturation with gutta percha.

An extruded tooth with an open apex and incomplete root formationshould not have root-canal treatment unless there are signs of pulpal

necrosis or external-inflammatory resorption. If either occurs,endodontic therapy is started immediately using calcium hydroxide as a

temporary-filling material for 6 to 12 months before permanentobturation with gutta percha. After 12 months, if the apex is still notclosed adequately, continue temporarily-filling with calcium hydroxideuntil apexification occurs, closing the apex so that a permanent filling

can be performed.

Intru sion of Permanent Teeth

A blow along the long axis of a tooth will force the tooth into the alveolarprocess, causing severe damage to the periodontal ligaments and

neurovascular bundle. The alveolus is fractured or crushed. External-inflammatory root resorption and loss of marginal alveolar bone is

common.


The patient will relate a history of trauma, causing impaction or "loss" ofthe tooth. An intruded tooth may be partially visible or may be

completely intruded into the socket and not visible, causing the patientto think it was "knocked out."

The shortness of the crown in adult dentition is an indication thatintrusion has occurred. The tooth is usually not mobile, not sensitive to


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percussion, and does not respond to vitality testing with cold- orelectric-pulp testing. Percussion may produce a metallic sound.

If the tooth is not present on clinical examination, a periapicalradiograph should be taken to determine if the tooth is avulsed or

intruded. If it is intruded, it will radiographically be displaced and theperiodontal-ligament space will be missing apically.

A maxillary-central incisor may also be completely intruded with its rootprotruding through the alveolar process and into the floor of the nose.

This can be determined by examination of the nares.

In mixed dentition, it may be more difficult to determine if the tooth isintruded or is just erupting, as the tooth will not be mobile. The child orparent may be able to determine if the tooth is in the pre-injury position.Tooth height can be compared to the height of the adjacent non-injured

tooth. Percussion may help in the determination. An erupting toothshould have a dull sound, while an intruded tooth may have a metallic

sound.

Immediate Treatment

An intruded tooth with incomplete-root formation will usuallyspontaneously reerupt and no treatment is required for this tooth. It

should be monitored clinically and radiographically to make sureeruption is occurring.

The exception is if the tooth has perforated the floor of the nose. In suchcases, the tooth should be repositioned with forceps and then stabilizedwith an acid-etched wire and resin splint, as described previously. The

splint should be left in place for 2 weeks.

It is unpredictable whether a tooth with complete-root formation willspontaneously reerupt. Therefore, the best treatment is to extrude the

tooth with orthodontic treatment over a period of 3 to 4 weeks. As soonas possible after any swelling has subsided, this treatment may be

started. If the tooth is completely submerged, surgical exposure may be

needed and a bonded bracket placed.

Again, if the tooth has perforated the floor of the nose, it should berepositioned with forceps and stabilized with a splint.


Intruded teeth are at high risk for pulpal necrosis and external-inflammatory resorption due to the severe injury to the neurovascular

supply and to the periodontal ligament. They must, therefore, bemonitored closely.


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A tooth that was intruded enough that it required surgical repositioningshould have the splint removed in 2 weeks and then have endodontictherapy started immediately. The tooth is opened, the pulp extirpated,

and the canal cleaned. Calcium hydroxide is placed as a temporaryfilling for 6 to 12 months at which time a permanent gutta percha filling

is placed.

If an intruded tooth with a complete root and closed apex is extrudedwith orthodontic therapy, it should be opened and the pulp extirpated at

two weeks post-injury. Calcium hydroxide is placed as a temporaryfilling for 6 to 12 months at which time a permanent gutta percha filling

is placed.

A tooth that had incomplete-root formation and was not treated whenthe injury occurred should be clinically evaluated 3, 4, and 6 weeks after

the injury, and then radiographically at 3-, 6-, and 12- month intervals,

watching for signs of spontaneous re-eruption, pulpal necrosis, orexternal-inflammatory resorption.

Should a radiograph show a periapical radiolucency or signs of externalresorption of the root, endodontic therapy should be instituted

immediately. The canal should be opened, debrided, and temporarilyfilled with calcium hydroxide. It should be reopened, cleaned, and

repacked with calcium hydroxide at 3-month intervals for 6 to 12 monthsbefore permanent obturation with gutta percha. After 12 months, if the

apex is still not closed adequately, continue temporarily filling withcalcium hydroxide until apexification occurs, closing the apex so that a

permanent filling can be performed.

Avuls ion o f Permanent Teeth

Avulsion is the complete traumatic removal of a tooth from its socket,usually from a frontal horizontal (straight-on) impact, such as from a fallor being hit in the mouth. It occurs most often in younger patients whohave elastic periodontal ligaments. Avulsion almost always occurs withmaxillary-central incisors. Mandibular teeth and other maxillary teeth are

rarely affected.

The neurovascular supply and periodontal ligament are torn from thetooth, creating a non-vital tooth. If the tooth is reimplanted soon after

the injury, it may reattach and be a functional tooth. If it is notreimplanted within 2 hours, the body may treat it as a foreign body and

rapid resorption may occur, causing loss of the tooth.


The long-term prognosis of an avulsed tooth depends on the length of

time out of the socket and the contamination or damage to the rootsurface. Determine the mechanism of injury, when the accident


25/87

occurred, how long the tooth has been out of the socket, and what hasbeen done with it in the interim. How has it been stored? Has it been

cleaned?

The length of time the tooth has been out of the mouth has a bearing on

the prognosis. The longer it has been out, the greater the chance thatthe root will have external-inflammatory resorption. Teeth that are out of

the mouth for 30 minutes or less have a 10% chance of externalresorption. At 30 to 60 minutes, there is a 50% chance, and at 2 hours

there is a 90% chance.

Examine the avulsed tooth and the remaining socket. Check the toothfor fractures, contamination, and presence of completely or

incompletely formed apex. Evaluate the periodontal ligament. Is it intacton the root surface or has it been disturbed by trauma or a previous

attempt to clean the tooth? Evaluate the root for fractures and a

radiograph taken if a fracture is suspected.

Examine the socket to check for fractures of the alveolus, intact buccaland palatal bone, and evidence of advanced-periodontal disease. If a

tooth is to be reimplanted, the alveolus should be reasonably intact andthe socket free of periodontal disease.

General guidelines suggest that a tooth should not be reimplanted if ithas been avulsed for over 2 hours since the long-term survival is low.

Still, there may be times to consider reimplantation in these cases.Sometimes, parents may prefer or insist on trying reimplantation, even if

the prognosis is not good. Even if the tooth is lost 2 to 4 years later,growth and development of the alveolus may allow for a better

prosthetic result or implant site. A tooth that has been out of the socketfor over 5 hours has almost no chance of success.

Immediate Treatment

When possible, immediate treatment should begin before the patient isbrought to the dental office, ideally within minutes of the accident. Teeth

that are reimplanted by the patient or parent have a better chance of

survival than those that are left out until the patient can arrive at thedentist's office.

When informed by telephone of the injury, the dentist should advise thepatient to clean the tooth by holding it by the crown and washing the

root with cold water taking care not to touch the root surface withanything except water. The root should not be scrubbed by any

mechanical means. After the tooth has been cleansed it should beplaced back into the socket, reimplanted with a back and forth rotation,then held in place with finger pressure or by biting on a cloth while the

patient is immediately brought to the dental office.


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If the tooth cannot be reimplanted or the patient or parents are unwillingto try, the tooth should be kept moist while being transported with thepatient to the dentist. This is best accomplished by placing it in normal

(physiologic) saline, salt water (1/2 tsp salt in 8 oz glass of water), ormilk. If not available, the tooth can be kept moist in a wet towel, plastic

wrap, or water, although this is not as satisfactory as milk or saliva. Ifnothing else is available, it can be held in saliva in the mouth in thebuccal vestibule or under the tongue, although there is a risk of the

patient swallowing the tooth with this method.

Once the patient reaches the dental office, the avulsed tooth should beplaced in normal saline solution while the history is taken, and

examination of the tooth and patient performed. The tooth should berinsed with normal saline until any dirt or debris is removed. Be sure to

include the open apex of an incompletely formed tooth. If needed, debristhat cannot be washed off can be removed with an instrument, such as

cotton pliers, or gently with the corner of a gauze sponge moistened insaline. Handle the tooth only by the crown.

Flush and suction the clot from the socket before reimplanting the tooth.Push apically with digital pressure to seat the tooth firmly in the socket.

If resistance is met, remove the tooth and place it in saline whilereevaluating the socket to make sure any debris or obstruction is

removed. In cases where the buccal plate has been compressed, it mayneed to be gently expanded by placing a flat instrument, such as a

straight elevator, into the socket and pressing in an anterior direction.This is not often necessary.

Figure 5: Oral view of avulsed teeth # 8and 9. If the avulsed teeth are not presentwith the patient, the differential diagnosis

must include intrusion of the teeth.

Figure 6: Care must be taken withavulsed teeth to not damage the

periodontal ligament during handling orcleaning and to keep them moist before

reimplantation. Note fractures of the teethin addition to avulsion.


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Figure 7: Reimplanted teeth stabilized withErich-arch bar. Wire over incisal edge is to

maintain tooth in apical position.

Figure 8: Periapical radiograph ofreimplanted teeth after endodontic therapy,

with arch bar still in place.

If a tooth had been reimplanted prior to being seen by the dentist, aradiograph can be taken to check for fractures and the adequacy of the

reimplantation. If it appears that the tooth was rinsed and cleaned beforereimplantation and it is properly seated, it may be splinted withoutremoval. If not, remove it, placing it in saline, while debriding and

rinsing the socket. Then reimplant the tooth into the socket.

Once the tooth is seated in the socket, check the occlusion to make surethe tooth is in proper position. Some dentists take a radiograph to verify

the position in the socket; however, this is usually evident by clinicalexamination.

Immobilize the tooth by placing an acid-etched resin and wire splint or

Essig splint, as described in previous chapters and suture any softtissue lacerations. Relieve the occlusion so that the tooth is slightly out

of contact during the healing phase.

Prophylactic-antibiotic therapy should be started. If not allergic,penicillin VK 500 mg, two immediately and then one every 6 hours for

ten days, is generally used. If the wound or tooth was contaminated withsoil, administration of tetanus toxoid is recommended and the patientshould be referred to the patient's personal physician, or immediate-

care center.



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29/87


It is estimated that trauma to primary teeth occurs in up to 25 to 30% ofyoung children. Many injuries are minor, going undetected by parents,

although they may require future treatment.

Injuries to primary teeth occur primarily to the anterior teeth, especiallythe deciduous maxillary-central incisors. Younger children, aged 1 1/2 to2 1/2 years old, have the highest incidence. This corresponds to the timethe child is learning to walk and run. Frequently, the injury is caused byfalling on the edge of a table, falling off a bed, or out of a stroller, or by

tripping over toys, sidewalks, or steps. As children get older, theincidence of these types of injuries to primary teeth decreases. Motor-vehicle accidents cause serious injuries to primary teeth and the facial

bones, especially if the child is not in a properly restrained car seat.

Injuries to the primary teeth may also be caused by child abuse. In theUnited States, estimates are that hundreds of thousands of children areabused every year. Child abuse should be suspected if there are injuries

to primary teeth along with other facial injuries to the oral cavity, face,and head. Often, abuse is repetitive and the incidence of injury occurs

over time. Dentists are morally and legally obligated to report suspectedcases of child abuse to authorities.

Treatment decisions regarding injured primary teeth are based onseveral factors. The extent of the injury is a main factor. Often, children

sustain injuries to multiple-primary teeth at the same time. Avulsion,root fractures, crown fractures, and displacement may all be present inthe same patient. Behavior and cooperation of the child is another factor

in treatment decisions. At best, very few children under the age of 2years are able to be good dental patients. After an injury, these young

patients are scared, in pain, and are not cooperative or normal. Theability of the child to cooperate with examination and treatment affects

the treatment plan. The parent's wishes and concerns about thetreatment affect treatment decisions too, as well as their willingness,

ability, and cooperation to help manage behavior.

Given the complexity of the injury, patient behavior, and parentalwishes, ideal treatment may not be possible for difficult problems and

compromises may be necessary.

History and Clinic al Examinat ion

In evaluating an injured child, a good history of the accident isimportant. When the accident occurred; the mechanism of injury (fall,motor-vehicle accident, etc.); whether teeth are broken, displaced, or

avulsed; the presence of lacerations or bleeding from the mouth or face;

and whether there was a loss of consciousness or a head injury theseare some of the facts that need to be determined. It can be difficult to


30/87

ascertain the exact mechanism of injury from the child if the accidentwas not witnessed by an adult. Medical history, including medications

taken, should be reviewed.

In many falls, the child strikes not only the mouth, but also the skull.

Should there be any indication of concomitant trauma to the head,especially if there was a loss of consciousness at the time of the injury,

the child should be seen by a physician or emergencyhospitalpersonnel to rule out head injury.

The clinical exam is sometimes difficult due to the lack of cooperationfrom the child. Starting with an extraoral exam, the patient is checked

for lacerations and abrasions; facial bones and mandible are palpated torule out fractures. Palpation of the mandibular condyles is important, ascondylar fractures occur most often when the chin or anterior mandiblesustains a blow from the front, the same mechanism that causes injury

to primary teeth. The occlusion and alignment of the arches should beexamined. Teeth should be evaluated for injuries, including fractures,pulpal exposure, displacement, or avulsion. Examination should be

gentle, especially with regards to percussion and mobility testing, aspain from the examination can upset the child and make him or her

uncooperative. Electric-pulp testing is not useful as it is unreliable inyoung children and in recently injured teeth. Lip, tongue, and gingival

lacerations are common with pediatric injuries to the mouth, so a goodsoft tissue examination of the oral cavity is important.

Radiographic examination of the injured teeth is important, but can bedifficult due to the lack of cooperation from the patient. The child may

need to sit in the parent's lap with the parent holding the film holder forthe patient. Adult-sized periapical film can be placed in a film holder andpositioned as if a maxillary or mandibular occlusal film was being taken.

Injured-primary teeth should be monitored over the long term for pulpalnecrosis and resulting abscess. Tooth color can be an indication of thestatus of the pulp. Some injured teeth will immediately change color due

to hemorrhage inside the pulp chamber. This will fade over time if thepulp maintains its vitality. If discoloration occurs late, it may be due to

pulpal necrosis or pulp chamber calcification.

Decomposition of the pulp in pulpal necrosis can turn a tooth variousshades of gray, sometimes almost black. Often the color change willoccur before there are clinical symptoms or radiographic changes.

Pulpectomy is indicated, although extraction is an alternative.

Primary teeth may turn yellow following a traumatic injury. This is areparative response in which secondary dentin develops in response tothe injury and obliterates the pulp chamber. The increased dentin showsthrough the relatively thin enamel of primary teeth to give them a yellow

color. Even though this is a pathologic response, no treatment isnecessary and these teeth will resorb naturally.


31/87

Concussion and Subluxation

As with a permanent tooth, a traumatic blow to a primary tooth maycause a concussion or subluxation without fracturing or displacing the

tooth or alveolus. Hemorrhage and edema within the periodontal-ligament space and edema in the pulp may occur. The periodontal

ligament remains intact with a concussion and, therefore, there is nomobility of the tooth. With subluxation, the periodontal ligament is torn

and the tooth loosened.

A concussion type of injury is common in children and the parents arefrequently not aware of the injury unless the child complains.

Clinical examination shows considerable sensitivity to both vertical andhorizontal percussion. Initially, both electric- and cold- vitality testing

may show no response. No radiographic findings are present with eitherconcussion or subluxation. With concussion, the tooth is attachednormally to its alveolar socket and not mobile. Bleeding from the

gingival sulcus is generally not present. With subluxation, the tooth isloosened in its socket, although it is not displaced, and some bleeding

may be present in the gingival sulcus.

No immediate treatment is needed for a concussive injury. The toothshould be monitored on a long-term basis to watch for the possibility of

pulpal necrosis, although this is not common.

Immediate treatment of subluxation injuries to primary teeth depends onthe mobility of the tooth. Usually, it is not very mobile and no treatmentis necessary. If the tooth is somewhat mobile, but not excessively so,

and the patient is cooperative, an acid-etched splint can be placed. Thetooth should be extracted if it is so mobile that it might fall out or there

is concern that it could be swallowed or aspirated. Primary teethsustaining subluxation injuries usually tighten up on their own. They

need to be periodically evaluated with clinical and radiographicexaminations to watch for pulpal necrosis.

C rown Fractures

Primary teeth are frequently fractured due to falls and other childhoodinjuries. Often, multiple teeth will be injured.

Enamel Fractures

A fracture of the enamel of a primary tooth requires no treatment otherthan smoothing out any rough surfaces with a diamond bur. It should

then be monitored for the remote possibility of pulpal necrosis.

Enamel and Dentin Fractures


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When only small amounts of dentin are exposed in a fractured tooth, allthat is necessary is to smooth out any rough edges with a diamond bur.

When larger amounts of dentin are exposed, an indirect pulp cap isindicated. Place calcium hydroxide, such as Dycal, over the exposed

dentin. Cover this with an acid-etched composite restoration. The tooth

should be monitored for future pulpal changes.

Fractures into the Pulp

When a fractured primary tooth has a pulp exposure that has beenpresent for less than 2 hours, a formocresol pulpotomy is indicated,

followed by a composite restoration or crown. A pulpectomy, filling thecanal with a zinc oxide and eugenol paste, is indicated if the pulp

exposure is present over 2 hours.

Root Fractures

Isolated-root fractures are not common in primary teeth, but they dooccur at any location on the root. Fractures in the apical one-third of the

root do not need treatment if the tooth is stable and not mobile.Extraction is necessary for teeth with fractures occurring in the middleor coronal thirds of the root if they are moderately or severely mobile.

Care should be taken in removing the apical fragment in order toprevent damaging the underlying follicle of the permanent tooth. It is

better to leave a fragment of root in the socket than to damage thefollicle. Resorption by the erupting permanent tooth will occur. If a root

fragment is left in place, it should be periodically monitored and the

parents informed of the decision.

Crown-root fractures extending to the cervical region of the crown aregenerally non-restorable and extraction is the treatment of choice.

Injuries to Primary Teeth

v Displaced Primary Teeth

Lateral Displacement


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Primary teeth will be displaced to the palatal if they receive an impact totheir labial surface and will be displaced to the labial if they receive an

impact from the palatal side, such as if the child were to hit the edge of atable with the mouth open. Displacement to the mesial or distal is alsopossible in severe injuries. In all cases, the teeth will be displaced and

mobile.

No treatment is necessary if the displacement is minor and the teeth arestable, as the teeth will usually tighten spontaneously. If there issignificant displacement, either extraction or repositioning with

splinting is indicated. If the child is cooperative, an acid-etched splintcan be placed after manually repositioning the tooth into proper position

and checking occlusion. The tooth should be monitored long term forpulpal necrosis. Extraction is best in cases of severe displacement,

fracture of the alveolar bone, or extrusion.

Intrusion

An impact on the incisal edge of a primary tooth may force it apicallyinto the pliable alveolar bone. The intrusion may be minor or the tooth

may be pushed completely into the socket. It may be forced directly intothe underlying follicle of the developing permanent tooth or may be

forced labial, missing the follicle.

When an injured tooth is clinically missing, a radiograph can determineif it is intruded or avulsed. Since treatment is determined by whether thetooth is labial or into the underlying follicle of the developing tooth, an

occlusal film can be used to take a lateral radiograph of the area todetermine its position.

If the tooth is labial to the developing tooth, it can be left alone toreerupt. Most often it erupts into normal alignment if it is the first time ithas been intruded. This generally occurs within 3 months and the toothmay remain vital or may develop pulpal necrosis. If it has not moved in 3

months, it should be extracted since ankylosis can occur impeding

eruption of the permanent tooth. Should subsequent intrusion injuriesoccur, the tooth does not generally reerupt and extraction should be the

treatment of choice.

A tooth that is intruded straight into the follicle of the underlyingpermanent tooth should be extracted to prevent damage to the

developing tooth.

Managing Dental Injuries

Extrusion


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Primary teeth that are extruded will be elongated, mobile, often rotated,and there will be bleeding around the gingival.

When extrusion is minimal, the tooth is stabile, and there is nointerference with the opposing occlusion, no treatment is necessary, as

it will tighten on its own. Repositioning or extraction can be performedon very mobile primary teeth that are extruded over a distance of one-

third the length of the crown.

With a cooperative child, repositioning is accomplished under localanesthesia by manipulating the tooth into proper position and splinting

it to adjacent teeth with an acid-etched resin splint.

Avu ls ion

Although avulsed primary teeth have been reimplanted, the prognosis is

poor and the recommended treatment is to not reimplant them. Thewound will quickly heal like an extraction site. Maintenance of space is

not a problem in the anterior arch and space maintainers are notadvised. However, a fixed or removable prosthesis may be placed for

esthetic reasons if parents wish replacement of the tooth.

Lacerations

Soft-tissue lacerations of the oral cavity and lips are common withpediatric injuries. Most are superficial and minor, requiring examination

and debridement without suturing. Tongue and lip lacerations may

require suturing depending on the depth and extent. Stripping of thelabial gingiva and mucosa on the maxillary or mandibular alveolus is acommon injury with falls. The wound should be debrided and irrigated

before reapproximating the tissue and suturing it in place.

5.

Acute-Temporomandibu lar-

Join t In jur ies


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Temporomandibular-joint (TMJ) disorders are a common problem which

dentists see on a regular basis. The term "TMJ" is a general term todescribe all of the specific disorders that may occur. Some start as

acute injuries, while others are caused by long-term mild problems thatprogressively get worse causing chronic disease.

Acute disorders of the temporomandibular-joint can be classified asthose arising in the joint itself or in the surrounding musculature. Acute-

joint disorders include traumatic posterior capsulitis, anteriordislocation of the disc without reduction (closed lock), sprained-capsular ligament, and dislocation of the mandible (open lock).

Fractures of the mandibular condyle can also injure thetemporomandibular-joint. These injuries will be discussed in the chapter

on fractures of the mandible.

v Temporomandibular-Joint Anatomy

The temporomandibular-joint is a synovial joint between the mandibleand temporal bone of the skull. The condyle of the mandible articulates

with the glenoid fossa and articular eminence or the temporal bone. Anarticular disc separates the glenoid fossa and condyle, forming an upper

and lower compartment. The condyle moves on the inferior surface ofthe articular disc within the lower compartment, while the superiorsurface of the articular disc articulates with the glenoid fossa and

articular eminence. As a synovial joint, synovial cells that line the tissueto the joint compartments produce synovial fluid that lubricates the joint

during function.

A deep depression on the inferior surface of the zygomatic process ofthe temporal bone, the glenoid fossa (also known as the articular fossa

or mandibular fossa), is where the condyle of the mandible, an oval-shaped head on the condylar neck of the mandible, articulates duringopening and closing hinge movements. On opening the mouth wide,

Managing Dental Injuriesthe condyle moves (translates) anterior and inferior along the articular

eminence (also known as the mandibular eminence, or articulartubercle) a bony prominence anterior to the glenoid fossa. During

protrusive movements, both condyles move forward together along theirrespective articular eminence. During lateral-excursive movements, the

condyle on the ipsilateral side of the movement stays in the glenoidfossa, while the contralateral condyle translates out of the fossa and

along the eminence.


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The articular disc is a biconcave, oval-shaped pad composed of flexiblefibrocartilage that lies between the mandibular condyle and glenoid

fossa. It is always considerably thinner in the central region than in theperiphery. It acts as a shock absorber and travels with the mandibularcondyle when it translates forward out of the glenoid fossa. The tissue

that continues posterior to the disc, called the retrodiscal pad, is a thicklayer of loose and vascularized connective tissue that is highly

innervated. This loose tissue allows for the anterior movement of thecondyle during protrusion and opening. It is stretched tight at full

protrusion. The vascularity of the retrodiscal pad allows for edema andswelling if injured. Anteriorly, the articular disc and capsular ligament

are fused and contain fibers of the lateral pterygoid muscle. The lateralpterygoid muscle inserts into the anterior aspect of the neck of the

mandibular condyle and also to the articular disc, pulling the disc andcondyle anterior during contraction.

The joint and articular cartilage are held in place by the capsularligament, the major ligament of the temporomandibular-joint. This

sleeve-like capsule is attached superiorly along the entire rim of thearticular eminence and glenoid fossa, inferiorly to the circumference of

the neck of the mandible, and attaches to the edges of the articular disc,holding it in place during movement of the mandible. It is reinforced

laterally by the temporomandibular ligament, a thickening of thecapsule, whose fibers run inferoposteriorly from the tubercle of the

zygomatic arch to the lateral and posterior portion of the condylar neckof the mandible. This ligament helps prevent posterior movement ordisplacement of the condyle, such as from a blow to the front of the

mandible, protecting the tissues behind the disc. Laterally and medially,the articular disc is attached independently to the lateral and medial

poles of the mandibular condyle.

Auxiliary ligaments, including the stylomandibular andsphenomandibular ligaments, restrict anterior motion of the mandible to

prevent it from being dislocated anterior to the articular eminence.

Traumatic-Pos ter ior Capsul i t is

Posterior capsulitis, also known as traumatic capsulitis or intracapsularedema, is an inflammation of the retrodiscal tissue following an injury tothe mandible. The tissues are highly vascular and innervated. An injury

caused by the mandibular condyle being forced posterior into thistissue causes inflammation and edema which is painful and displacesthe mandibular condyle. Non-traumatic causes of posterior capsulitis

include edema due to arthritic exudates and infection.

Diagnosis

A patient presenting with posterior capsulitis will report pain anddifficulty opening the mouth occurring shortly after an injury to the face


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Treatment is symptomatic in nature and the extent of treatment dependson the severity of the symptoms.

For many patients, all that is needed is explaining the problem andreassuring them that it is a temporary condition. They should eat soft

foods and avoid any further impact to the retrodiscal tissue until thesymptoms resolve, which may take several days. As the edema

subsides, the occlusion will return to normal.

If the symptoms are more severe, ice packs are used over the joint forthe first 24 to 36 hours. Ice can be placed over the affected

temporomandibular-joint for 5 minutes and removed for the next 15minutes, then repeated. After 2 to 3 days, moist heat is used instead of

ice.

Over-the-counter nonsteroidal antiinflammatory drugs are useful to treat

the pain and decrease the inflammation.

An ter ior Disc Dis locat ion Without Reduct ion

Figure 9: Manual reduction of an acuteanterior dislocation without reduction is

performed by placing the thumb on the secondmolar on the locked side and using steadyforce to distract the condyle downward and

medial.

The articular disc moves on with the head of the condyle on translationmovements to allow full opening of the mouth. If the ligaments that hold

the disc in position become stretched or loose, the disc can becomedislodged from its position superior to the condylar head and become

locked anterior to the condyle.

Spontaneous return to normal position upon opening the mouth iscalled anterior dislocation with reduction and is the common cause forclicking sounds in the temporomandibular-joint. It is common in about

half of the population.

Anterior dislocation without reduction, also called closed lock orcomplete anterior dislocation of the disc, is when the disc does not


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spontaneously reduce into normal position upon attempts to open themouth. The dislocated disc blocks the path of the condyle in translation

and it is not possible to open the mouth fully. The disc displacesanteriorly and medially due to the pull of the lateral pterygoid muscle

and it thickens or becomes folded.

Diagnosis

Anterior dislocations without reduction happen acutely and patients areimmediately aware of their inability to open their mouth wide.

Sometimes, there is a long history of anterior dislocation with reductionprior to the lock, and sometimes there is a history of joint clicking orsymptoms that were present initially, but resolved prior to the current

incident. Locking may be intermittent or permanent.

Often, an anterior dislocation without reduction happens without anyprevious history of temporomandibular problems. Sometimes the cause

is trauma to the mandible, particularly a blow from the front, whichforces the condyle posterior and the disc anterior. Opening the mouthwide, as in yawning, singing, or yelling, or when biting down on a hard

object, is frequently the cause. In other cases, the patient may go to bedfine, only to wake up and being unable to open the mouth.

Parafunctional habits, such as bruxism, may be the cause in theseinstances. The patient will be able to tell the dentist exactly when and

under what circumstances the injury occurred.

On clinical examination, limited oral opening is present. Generally, themaximum intrinsical distance is only 20 to 30 mm, and the mouth cannotbe forced open any wider by the dentist. Pain at rest is usually not

present unless there is also posterior capsulitis. On attempted openingor clenching, however, there may be pain over the preauricular area. On

opening and protrusion, the midline will deviate to the affected side.Lateral-excursive movement is normal towards the affected side and

limited toward the contralateral side (less than 6 mm) due to the medialposition of the disc.

Temporomandibular-joint radiographs are not usually needed to make

the diagnosis of anterior dislocation without reduction of the articulardisc. If taken, however, they will show that the condyle, instead of being

properly centered, is displaced posteriorly and superiorly within theglenoid fossa.

Differential diagnosis would include only those disorders withimmediate onset. The other diagnosis that has acute onset of sudden

limited opening of the mouth is myospasm of the elevator muscles. Witha myospasm of the elevator muscles, lateral-excursive movements ofthe mandible are not limited as they are with an anteriorly dislocated

disc without reduction.

Treatment


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Attempting to reduce (recapture) the dislocated disc is the immediatetreatment for an anterior-dislocated disc. On occasion, patients can dothis on their own by moving the mandible in side-to-side movements.

If this does not work, the patient should be asked to close the mouth so

that the teeth almost touch. The patient should then move the mandiblelaterally as far as possible away from the affected side. When the

mandible is in full lateral-excursive movement, the patient should thenopen the mouth as wide as possible. This motion will sometimes cause

the disc to self-reduce into proper position.

A manual manipulation by the dentist may be required if the above doesnot work. The goal is to reduce the disc into normal position. This

procedure tends to work on acute dislocations without reduction thathave been present for a short time, generally less than one week. In

such cases, the retrodiscal tissues are generally healthy and the disc is

not permanently distorted. Chronic dislocations or dislocations presentfor longer periods of time have a much less chance of being

successfully reduced. Adhesions to the disc or permanent distortion ofthe disc and stretching of the ligaments and retrodiscal tissue make this

procedure less predictable when the disc is chronically dislocated.

The factors that determine whether a manipulation procedure of anacute-disc dislocation will be successful include muscle spasms andthe position of the condyle. When the superior portion of the lateral-

pterygoid muscle is in spasm, as it often is when it is in pain, it pulls thedisc anterior and medial. It

managing dental injuries

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