CHAPTER 16: DENTAL TRAUMA

ppt / sas

maxillary incisors

most frequently injured teeth in the primary dentition

2-4 years → peak age for injuries to the primary teeth

crown fractures → are the most common injuries to the primary teeth

battle sign

bruising of the mastoid region; is associated with base-skull fracture

anatomic risk

vector: maxillary incisors are the most frequently injured teeth.

vulnerability: protruding incisors (class II malocclusion) increase trauma risk by 2-3x

primary vectors

indirect trauma → blows to the chin

automobile accidents → major cause of dental injuries

pacifier use → deflects force, causing displacement rather than fracture

primary incisor

lower crown-to-root ratio (less leverage resistance against impact forces)

spongy bone & highly resilient (absorbing impact by allowing the tooth to move rather than crack)

primary teeth luxate (displace) far more often than they fracture when compared to permanent teeth.

permanent incisor

dense alveolar bone

higher crown-to-root ratio firmly anchor the toothh (making coronal fracture the path of least resistance during impact)

routine pulp vitality testing

is NOT reliable in the primary dentition due to patient age and reporting capability. Instead, rely on percussion:

2 reasons to percuss:

• sensitivity in response to percussion gives information about the extent of damage to the apical tissues

• the sound in response to percussion is also an important indicator of the likelihood of ankylosis

radiographic baseline

3 weeks: periapical radiolucencies (necrosis) become detectable

6-7 weeks: inflammatory root resorption ankylosis or becomes visible.

6 months: wait if asymptomatic

1 month: postoperative

all traumatized teeth should be radiographed to assess:

• stage of root development

• injuries to root and developing structures

ellis & davey fracture classification I

presents smooth sharp edges

simple fracture involving enamel only

tx: restore primarily for esthetics or smooth to prevent soft tissue irritation.

ellis & davey fracture classification II

extensive fracture involving considerable dentin, but the pulp is intact

tx: requires covering exposed dentin to prevent pulpal irritation

ellis & davey fracture classification III

extensive fracture exposing the dental pulp

appears as a red dot or bleeding point

tx: requires immediate endodontic intervention or extraction.

ellis & davey fracture classification IV

necrotic tooth

ellis & davey fracture classification V

complete loss of the clinical crown or avulsion

ellis & davey fracture classification VI

root fracture

ellis & davey fracture classification VII

displaced tooth

ellis & davey fracture classification VIII

crown fracture

ellis & davey fracture classification IX

pediatric traumatic injuries

cervical or partial pulpotomy

management for class III crown fracture with vital pulp + thin root dentin (open apex) to preserve vitality

complete pulpectomy (fill with resorbable paste)

management for class III crown fracture with necrotic or neglected pulp

immediate extraction

management for class III crown fracture with massive resorption or follicle at risk to protect permanent bud

remove loose fragment & perform pulpotomy on main stable fragment

management for crown-root fracture (split tooth) with shallow splitting (supracrestal)

extract both fragments; unrestorable

management for crown-root fracture (split tooth) with deep splitting (creates periodontal pocket)

2 ways to determine fracture depth in crown-root fracture / split tooth

shallow splitting → supracrestal

deep splitting → creates periodontal ocket

apical fragment rule

never attempt to surgically dig out or retrieve a retained apical root fragment

surgical intervention risks catastrophic damage to the succedaneous permanent tooth bud

the fragment must be left alone to undergo physiologic resorption

concussion

clinical presentation:

• NOT mobile. NOT displaced

• tender to biting and percussion

PDL status:

• PDL absorbs impact and is inflamed (leaves the tooth tender to biting pressure and percussion)

radiographic findings:

• normal

• no changes

management:

• no tx

• monitor pulpal condition

• soft diet meticulous hygiene

subluxation

clinical presentation:

• LOOSENED, but NOT displaced

• bleeding from gingival crevice

PDL status:

• PDL damaged but attachment remains largely intact.

radiographic findings:

• widened pdl space

management:

• monitor, soft diet

• chlorhexidine application

intrusion

clinical presentation:

• tooth is DRIVEN INTO ITS SOCKET

• compressed pdl and crushed alveolar socket

management:

• if the root of the primary tooth is pushed against the crown of the permanent incisor, it may severely damage the developing tooth bud → immediate removal of the primary tooth to relieve the pressure and minimize damage

• intruded incisors that do not pose a risk the permanent teeth can be left to spontaneously reerupt

extrusion

clinical presentation:

• ELONGATED from socket

• increased mobility, central dislocation

pdl status:

• pdl is severely torn

• high risk of ischemia

radiographic findings:

• increased periapical radiolucency / apical gap

management:

• reposition and splint

• extract based on severity and apex closure

lateral luxation

clinical presentation:

• displaced labially, lingually, or laterally

• pdl is torn, alveolar bone is contused or fractured

management:

• mild: allow spontaneous repositioning

• severe: reposition and splint (7-14 days), initiate endodontic therapy, or extract if labial bone is heavily fractured.

lingual luxation

clinical presentation:

• crown moves palatally (often interfering with occlusion)

• apex is pushed labially → labial bone plate is fractured

management:

• reposition immediately before coagulum forms

• utilize intentional open bite (composite buttons on molars) to clear occlusion

• extract if severely displaced

labial root displacement

80% of cases are safe

clinical signs:

• palatal crown inclination

• hard swelling palpated in the labial vestibule

radiograph:

• tooth appears foreshortened and highly opaque

management:

• safe to preserve

• allow spontaneous re-eruption (typically begins within 2 to 6 months)

• monitor for rotation

palatal root displacement

dangerous

clinical signs:

• root is pressed directly against the developing permanent tooth bud

radiograph:

• tooth appears elongated

management:

• immediate extraction

• extract immediately to relieve pressure and minimize irreversible damage to the permanent successor

avulsion

clinical signs:

• the tooth is COMPLETELY DISPLACED from the alveolus

• pdl is severed

• fractures of alveolar bone may occur

general rule:

• avulsed primary incisors are NEVER replanted.

the biomechanical risk:

• complete displacement from the alveolus severs the pdl

• reinsertion forces the contaminated root or coagulum directly into the delicate follicle of the developing permanent successor, irreversibly irreversibly damaging it in up to 75% of cases.

next steps:

• account for the avulsed tooth immediately to rule out aspiration.

• if a well-meaning parent has already replanted the tooth at home, advise them of the extreme risk

• if retained, it requires splinting and immediate root canal treatment with resorbable paste to prevent rapid inflammatory resorption.

pathologic sequelae of trauma to the teeth

reversible pulpitis

coronal discoloration

infection of the periodontal ligament

pink / red discoloration

observed shortly after the injury may represent intrapulpal hemorrhage

early presentation:

• intrapulpal hemorrhage

• rupture of blood vessels causes extravasation of RBCs into dentinal tubules.

late presentation:

• internal resorption

• the coronal dentin is destroyed from within

• apical root can be left to resorb spontaneously if the crown is lost.

yellow discoloration

can be seen when the dentin is thick and the pulp chamber narrower than usual → condition termed as pulp canal obliteration

• pathology:

  • pulp canal obliteration (PCO)

  • accelerated deposition of thick dentin narrows the pulp chamber.

• pathology:

  • pathologic, but requires NO treatment.

  • monitor radiographically.

dark (gray / black)

RBC hemolysis, often indicates pulp necrosis.

when the pulp becomes necrotic or when pulpal hemorrhage occurs, red blood cells lyse and release hemoglobin—hemoglobin and its derivatives such as hematin molecules that contain iron ions, invade the dentin tubules and stain the tooth dark.

management:

• this color alone does NOT mandate extraction

• over 70% of asymptomatic dark primary incisors exhibit no radiographic pathology

• extract or treat endodontically ONLY if swelling, fistula, mobility, periapical radiolucency are present

internal resorption

can lead to root perforation

odontoclasts attack dentin from within due to chronic inflammation

external (atypical) resoprtion

apical half

coronal half remains unaffected.

• eventually:

  • apical half is completely resorbed.

  • root becomes short with a rounded apex.

• clinically resembles early natural exfoliation.

rapidly progressing (inflammatory)

extremely rapid destruction

related to necrotic pulp and inflamed pdl

requires immediate endodontic filling with resorbable paste

replacement external root resorption

aka: ankylosis

• results from irreversible PDL injury.

• alveolar bone directly contacts and fuses with the root.

• root is gradually resorbed and replaced by bone.

• more common in intruded primary teeth.

clinical result:

• tooth eventually becomes infraoccluded (below the normal occlusal level).

management:

• extract if it causes:

  • delayed eruption of the permanent tooth, or

  • ectopic eruption of the permanent tooth.

complications for the permanent dentition

enamel defects

follicle deflection

arrested development

space loss & ectopic eruption

arrested development

loss of pulp vitality at an early age halts dentin apposition, apposition, leaving the primary tooth with thin, fragile root walls.

follicle deflection

an infected, expanded primary follicle can physically push and deflect the permanent central incisor away from its normal eruption path.

enamel defects

permanent incisors succeeding infected primary teeth often present with enamel hypoplasia caused by the inflammatory cascade or over-instrumentation during primary endodontics

at-home care protocols

diet modification:

• maintain a strictly soft diet for 7-14 days to stabilize luxated or repositioned teeth.

topical disinfection:

• apply 0.2% chiorhexidine gluconate to the injured gingiva twice daily.

application technique:

• use a cotton-tipped applicator to swab the crevices

• do not use as a rinse to prevent the toddler from swallowing the solution while effectively disinfecting the torn pdl

monitoring & clinical alerts

vigilance for infection:

• return to the clinic immediately if facial swelling, red mucosal tracking, or a "pimple" (fistula) appears on the gums.

• watch closely for suddenly increased tooth mobility or expressions of chewing sensitivity.

reassurance on esthetics:

• warn parents that the tooth may transition to a dark gray or black color over the coming weeks.

• reassure them that color change without associated pain or swelling often requires monitoring only, not immediate surgical extraction.

practice question in sas