Sequelae of Trauma to Primary Teeth and Its Management

Introduction

Classification of Trauma to Primary Teeth

1. Hard tissue and pulp injuries - Infraction, uncomplicated crown fracture, complicated crown fracture, crown-root fracture, root fracture
2. Periodontal tissue injuries - Concussion, subluxation, extrusive luxation, lateral luxation, intrusive luxation, avulsion
3. Supporting bone injuries - Comminution, fracture of alveolar socket wall, fracture of alveolar process
4. Gingival/oral mucosa injuries - Laceration, contusion, abrasion

Sequelae of Trauma to Primary Teeth

• (A) The traumatized primary tooth itself
• (B) The permanent successor tooth germ

A. Sequelae in the Primary Tooth

1. Pulp Necrosis and Infection

• Most common long-term sequela
• More frequent after luxation injuries (especially intrusion and avulsion) than crown fractures
• Manifests clinically as: discolouration, sinus tract (parulis), spontaneous pain, swelling, pathological mobility
• Radiographically: periapical rarefaction, internal or external root resorption, failure of normal root resorption pattern

2. Pulp Canal Obliteration (PCO) / Calcific Metamorphosis

• Occurs in 20-25% of luxated primary teeth
• Results from pulp survival with reparative dentinogenesis obliterating the canal
• Clinically: yellowish discolouration of crown (in permanent teeth it is yellow-brown; in primary teeth it may appear grayish)
• Management: monitor; no treatment needed unless signs of pulp necrosis develop

3. Inflammatory Root Resorption

• Sequel to pulp necrosis + bacterial contamination
• External inflammatory root resorption - stimulated by infected pulp tissue
• Internal inflammatory resorption - from pulp breakdown products
• Distinguished radiographically: external affects root surface, internal appears as a "balloon" within the canal

4. Replacement Resorption (Ankylosis)

• Occurs when PDL is destroyed (especially after avulsion or intrusion)
• Root is replaced by bone; tooth becomes ankylosed
• Clinically: high (metallic) percussion tone, lack of physiologic mobility, infraocclusion over time
• Relevant in primary dentition as it may prevent normal exfoliation and impede eruption of permanent successor

5. Root Fracture

• Less common; more common in older primary teeth with partially resorbed roots
• Coronal fragment may become necrotic; apical fragment may remain vital
• Management: if coronal fragment is mobile and displaced, remove it; leave apical fragment for natural resorption

6. Crown Discolouration

• Pink discolouration - Internal resorption (blood breakdown products)
• Gray/Black discolouration - Pulp necrosis (hemosiderin/hematin deposits in dentinal tubules)
• Yellow discolouration - Pulp canal obliteration
• Gray discolouration alone (without clinical/radiographic pathology) may resolve spontaneously in ~25% of cases

7. Gingival/Alveolar Injuries

• Lacerations of attached gingiva and oral mucosa
• Loss of alveolar bone with severe intrusion or avulsion injuries

B. Sequelae in the Permanent Successor

• Age of child at injury (younger = worse, as permanent germ development is incomplete)
• Type of injury (intrusion and avulsion have highest risk)
• Severity/direction of displacement

1. White Spot Lesions / Diffuse Enamel Opacities

• Milder disturbance of ameloblast activity
• White, chalky opacities on enamel surface
• Seen after concussion, subluxation, extrusion

2. Demarcated (Circumscribed) Enamel Hypocalcification

• Well-defined white, yellow, or brown opacities
• Represent localized disturbance of matrix mineralization
• Common after lateral luxation and intrusion

3. Enamel Hypoplasia

• Structural defect with physical loss of enamel (pitting, grooves)
• Permanent disruption of ameloblast differentiation
• Seen after severe injuries (intrusion, avulsion) especially in children under 2 years
• Collectively, enamel defects (Turner's hypoplasia / Turner's tooth) are the most common type of developmental disturbance

4. Crown Dilaceration

• Angulation between the crown portion and root portion of the permanent tooth
• Occurs when the calcified crown is displaced and root formation continues at an angle
• Can cause eruption failure or ectopic eruption
• Most common with intrusion injury at age < 2 years

5. Root Dilaceration

• Angulation deformity involving the root
• Occurs later in development (when root is forming)
• Lateral bending of root - impairs eruption

6. Odontome Formation (Compound/Complex)

• Very rare
• Severe early trauma (in infancy) may disrupt the tooth germ architecture completely
• Leads to disorganized calcified mass instead of a tooth

7. Partial or Complete Arrest of Root Formation

• Severe injury at time when root is actively forming
• Short, blunt, or completely absent roots

8. Sequestration of the Permanent Tooth Germ

• The developing tooth germ is destroyed entirely
• Results in absence (missing tooth) of the permanent successor
• Most severe sequela

9. Eruption Disturbances

• Ectopic eruption (labially displaced, palatally displaced)
• Delayed eruption
• Premature eruption (stimulated by early loss of primary tooth)
• Eruption failure (especially with ankylosis of successor or severe dilaceration)

Key evidence (Folmer et al., 2025 - Int J Paediatr Dent, PMID: 40038884): In a retrospective cohort of 206 patients, the risk of developing sequelae in permanent successors was more than 7 times greater in traumatized vs. control groups. Hypoplasia and malformations were most common in the 0-2 year group and were strongly associated with intrusion, lateral luxation, and avulsion. Demarcated and diffuse opacities occurred across all age groups.

Management of Traumatized Primary Teeth

1. Avoiding harm to the permanent successor
2. Maintaining space and function
3. Minimizing distress to the young child

Management by Injury Type

1. Crown Fractures

2. Root Fractures

• Coronal 1/3 fracture: If coronal fragment is mobile - extract it. The apical fragment can be left to resorb.
• Middle/apical 1/3 fracture: If coronal fragment is stable - maintain and monitor. If signs of necrosis appear - extract coronal fragment.
• Splinting is generally NOT recommended in primary teeth (risk of ankylosis; child compliance is poor)
• Per Andreasen (IADT guidelines): extraction of coronal fragment when displaced with alveolar bone involvement

3. Concussion and Subluxation

• Concussion: No abnormal mobility; tender to touch. No treatment; soft diet; monitor with clinical and radiographic follow-up
• Subluxation: Abnormal mobility but no displacement. No repositioning required; soft diet 1-2 weeks; monitor

4. Extrusive Luxation

• Mild extrusion (< 3 mm): Allow spontaneous re-eruption OR reposition and monitor
• Severe extrusion (> 3 mm): Extract, especially if risk to permanent germ
• If tooth is retained: soft diet, monitor radiographically at 4 weeks, 3 months, 6 months

5. Lateral Luxation

• Important: The displaced primary root tip may now point directly toward the permanent germ
• If root apex is displaced toward permanent germ - extract immediately
• If apex displaced away from permanent germ and occlusion is not disturbed - may allow spontaneous repositioning
• Reposition only if it can be done atraumatically; otherwise extract

6. Intrusive Luxation

• Most common severe injury in toddlers (1-3 years); fall on outstretched arms / forward falls
• Crown appears shortened or has "disappeared into socket"
• IADT Guidelines (Malmgren et al.):
  • If intruded with apex displaced toward permanent germ: Extract immediately
  • If intruded palatally (toward palate, away from germ): May allow spontaneous re-eruption (especially in children < 3 years with primary teeth not fully developed)
  • Monitor clinically and radiographically at 1, 3, 6 months

7. Avulsion of Primary Teeth

• Primary teeth should NOT be replanted (unlike permanent teeth)
• Rationale:
  • Risk of ankylosis and subsequent damage to developing permanent germ
  • Risk of introducing infection
  • Procedure too distressing for young child
  • Tooth will exfoliate naturally in a few years anyway
• Management: Reassure parent; space maintainer is generally not required unless space loss is anticipated (especially if lost early, before age 4-5)
• Space maintainer (removable partial denture / "Pedo partial"): considered if multiple anterior teeth avulsed and speech/aesthetics/function are compromised
• Verify tooth was truly avulsed (not intruded) - take radiograph

Management of Sequelae

Pulp Necrosis / Infected Primary Tooth

• Pulpectomy + ZOE obturation: If tooth is restorable and is strategically important
• Extraction: If tooth is grossly destructed, has significant bone loss, or infection is spreading
• After extraction: assess need for space maintenance
• ZnO-Eugenol (ZOE) is the preferred obturating material - it resorbs along with the primary root

Pulp Canal Obliteration

• Monitor radiographically every 6 months
• No active treatment unless signs of infection appear

Discolouration

• Gray/black: investigate for necrosis; treat pulpally or extract
• Pink: suggest internal resorption; extract (risk of perforation is high)
• Yellow: PCO; observe

Ankylosis / Replacement Resorption

• If exfoliation delayed and permanent tooth erupting: extract the ankylosed primary tooth
• Risk: if not extracted, permanent tooth may become ectopically positioned

Complications in Permanent Successor

• White spot lesions/hypocalcification: microabrasion, bleaching, composite veneering at appropriate age (after full eruption)
• Enamel hypoplasia: composite restoration, porcelain laminate veneer (in adults)
• Crown dilaceration: depends on angulation; may require surgical exposure, orthodontic traction, or extraction and implant/prosthetic rehabilitation
• Odontome: surgical removal to facilitate eruption of permanent tooth

Follow-up Protocol (IADT Recommended)

Factors Affecting Prognosis of Permanent Successor

1. Age at time of injury: < 2 years = highest risk (crown is mineralizing; germ is very close to primary apex)
2. Type of injury: Intrusion > lateral luxation > avulsion > extrusion > subluxation > concussion
3. Severity and direction of displacement of primary root apex
4. Stage of permanent tooth development at time of injury
5. Prompt, appropriate management of primary tooth

Summary Table: Sequelae

Conclusion

• Andreasen JO, Andreasen FM, Andersson L. Textbook and Color Atlas of Traumatic Injuries to the Teeth, 5th ed.
• IADT Guidelines - Malmgren et al. 2012; updated guidelines available at dentaltraumaguide.org
• Folmer AM et al. (2025) "Sequelae in Permanent Dentition After Traumatic Dental Injury in the Primary Dentition." Int J Paediatr Dent. [PMID: 40038884]
• Laforgia A et al. (2025) "Paediatric dental trauma: insights from epidemiological studies and management recommendations." BMC Oral Health. [PMID: 39748355]