28.1 Trauma Assessment and Fractures of Permanent Teeth

1. Clinical Assessment and Emergency Triage

Systematic Trauma History

An accurate trauma history must establish three essential variables:

1. When did the injury occur? Elapsed time directly dictates the survival of periodontal ligament (PDL) cells in avulsions and the choice of vital pulp therapy versus pulpectomy in crown fractures.
2. Where did the injury occur? Identifies environmental contamination (e.g., soil, asphalt), determining whether tetanus prophylaxis is required.
3. How did the injury occur? Evaluates the force and vector of impact. Blunt impacts against soft tissues increase the suspicion of alveolar or mandibular fractures, while high-velocity impacts against hard surfaces cause crown or root shattering. It also directs the clinician to search for tooth fragments embedded in lacerated lips, cheeks, or tongue.

Neurological and Head Injury Screening

Prior to intraoral inspection, every trauma patient must be screened for cranial and intracranial trauma. The clinician must check for:

• Loss of consciousness (even momentary).
• Post-traumatic amnesia (retrograde or anterograde).
• Nausea, projectile vomiting, or severe persistent headache.
• Lethargy, confusion, slurred speech, or blurred/double vision.
• Watery fluid discharge from the nose (cerebrospinal fluid rhinorrhoea) or ears (otorrhoea), or "raccoon eyes" periorbital bruising indicating base of skull fracture.

[!CAUTION] Immediate Emergency Referral: If any sign of intracranial injury, base of skull fracture, or altered consciousness is detected, dental treatment must be deferred immediately. Transfer the patient to the nearest hospital Emergency Department via emergency ambulance.

Clinical and Radiographic Examination

• Soft Tissue Inspection: Palpate and inspect lips, gingiva, and tongue. Any deep soft tissue laceration adjacent to a fractured or missing tooth must be palpated and radiographed at reduced exposure to detect embedded tooth fragments.
• Hard Tissue and Mobility Assessment: Evaluate each tooth for crown fractures, colour changes, displacement, and pathological mobility. Record percussion tenderness and sound (a high, metallic ankylotic note indicates lateral or intrusive luxation where the root is wedged into bone).
• Sensibility Testing: Test thermal (cold) and electric pulp testing (EPT). Note that traumatised teeth frequently yield false-negative responses for up to 3 to 6 months due to temporary pulpal neuropraxia; a non-responsive tooth in the acute phase is not an indication for immediate endodontic treatment unless accompanied by signs of necrosis.
• Radiographic Protocol (IADT Standard):
  • Parallel periapical exposure (90° direct vertical angulation).
  • Two eccentric periapical exposures (horizontal shift mesial and distal).
  • Maxillary or mandibular occlusal view to visualize root fractures and lateral luxations.

2. Hard Tissue and Pulp Injuries in Permanent Teeth

Hard Tissue Traumatic Injuries Hierarchy
  │
  ├── Enamel Infraction: Microcracks in enamel without tissue loss ──> Etch & resin seal
  │
  ├── Uncomplicated Crown Fracture: Involves enamel or enamel + dentine (No pulp exposure)
  │     └── Dentine within 0.5 mm of pulp? ──> Calcium silicate liner + composite restoration
  │
  ├── Complicated Crown Fracture: Enamel + dentine with pulp exposure
  │     └── Vital pulp? ──> CVEK PARTIAL PULPOTOMY (1–2 mm excised, MTA/Biodentine, composite)
  │
  ├── Crown-Root Fracture: Crosses CEJ into cementum ──> Fragment removal / extrusion / extraction
  │
  └── Root Fracture: Horizontal fracture of root dentine, pulp, and cementum
        └── Reposition coronal segment; flexible splint (4 weeks; up to 4 months if cervical)

Classification and Operative Protocols

The Cvek Partial Pulpotomy

First described by Cvek (1978), this is the treatment of choice for complicated crown fractures in children and adolescents, particularly in immature permanent teeth with open apices to facilitate apexogenesis (continued root elongation, dentinal wall thickening, and apical closure):

1. Administer local anaesthetic and place a rubber dam.
2. Wash the exposed pulp with sterile saline or 0.5% sodium hypochlorite.
3. Using a sterile high-speed diamond bur under copious water irrigation, amputate approximately 1.0 to 2.0 mm of the inflamed, superficial pulp tissue down to healthy, bleeding tissue.
4. Apply gentle pressure with a sterile cotton pellet moistened with saline for 1 to 2 minutes to achieve haemostasis.
5. Place a 1.5–2.0 mm layer of Mineral Trioxide Aggregate (MTA) or Biodentine directly over the amputated pulp stump.
6. Place a thin layer of resin-modified glass ionomer cement (RMGIC) over the calcium silicate material, followed by an immediate hermetic coronal composite resin restoration.
7. This approach achieves clinical and histological success rates exceeding 95%, preserving pulp vitality and allowing normal physiological completion of root development.

Healing Patterns in Root Fractures

Following repositioning and flexible splinting of horizontal root fractures, Andreasen described four distinct histological healing outcomes:

1. Healing with Hard Tissue (Calcified Tissue): Dentin and cementum union across the fracture line; the fracture line becomes indistinct. Excellent long-term prognosis.
2. Healing with Connective Tissue: The fractured surfaces are rounded and separated by a narrow band of intact fibrous connective tissue (similar to a PDL space). Favourable clinical prognosis; tooth remains stable and vital.
3. Healing with Bone and Connective Tissue: An alveolar bone bridge develops between the two fragments, separated by connective tissue. Typically observed when trauma occurs during active alveolar growth. Clinically stable.
4. Non-Healing (Granulation Tissue): Characterized by pulpal necrosis and bacterial infection of the coronal segment, while the apical segment almost invariably remains vital. Clinically presents with mobility, sinus tract, and radiolucency at the fracture line.
   • Management: Perform root canal treatment confined exclusively to the coronal segment up to the fracture line (obturating with an MTA apical plug). The vital apical segment must not be instrumented.