Fractures and trauma

Classification of dentoalveolar injuries

Injuries to dental hard tissues and pulp

  • Enamel infraction – incomplete crack of enamel, no loss of tooth structure
  • Enamel fracture – loss of tooth structure involving enamel only
  • Enamel dentine fracture – loss of enamel and dentine, pulp not involved
  • Complicated crown fracture – crown fracture involving pulp
  • Complicated crown root fracture – enamel, dentine, cementum involved and pulp exposed
  • Uncomplicated crown root fracture – pulp not exposed
Ellis and Davey's classification of tooth fracture

Injuries to periodontal tissues

  • Concussion – injury to tooth supporting structure. Pain on percussion and no bleeding or displacement
  • Subluxation – increased tooth mobility due to traumatic injury to PDL tissues, no displacement
  • Extrusive luxation – partial displacement from socket
  • Intrusive luxation – intrusion into socket with socket fracture
  • Lateral luxation – displacement in horizontal plane with fracture of alveolar socket
  • Avulsion – complete displacement of tooth from socket

Injuries to alveolar bone

  • Comminution of alveolar socket wall
  • Fracture of alveolar socket wall – fracture confined to lingual/palatal or facial socket wall
  • Fracture of alveolar process ± alveolar socket
  • Fracture of basal mandibular or maxillary bone ± alveolar socket

Other injuries

  • Soft tissue injuries – laceration, imbedding foreign body in lips
  • Swallowing/inhaling avulsed tooth
  • Iatrogenic injury:
    • During extraction damage to adjacent teeth, fracture of associated jaw
    • Perforate root apex or side of root during endodontic treatment

Radiographic investigation

  • Two x-rays perpendicular or in different angles in vertical plane (IOPA, USO)
  • OPG
  • CBCT
  • Chest/abdomen x-ray if tooth aspirated/swallowed
  • Reproducible views for follow up evaluation

Classification of mandibular fractures

Anatomical site of fracture and associated radiographic investigation

Anatomical sites of mandible

1. Condylar neck:

NB: Intracapsular fracture of bone → Bleeding within joint cavity (hemarthrosis)→ Bone fragments with high osteogenic potential → Organization of hematoma within joint → Conversion to fibrous tissue → Then to bone (Ankylosis)

2. Coronoid process:

3. Ramus:

4. Angle

5. Body:

6. Canine region:

7. Symphysis:

Nature and complexity of fracture

  • Simple fracture – no communication with external environment, not breached overlying skin/mucosa
  • Compound fracture – communication with external environment, due to break in overlying skin and mucosa
  • Comminuted fracture – several broken bone fragments
  • Complex fracture – involves injury of vital structure eg. nerve, major blood vessel, joint
  • Greenstick fracture – in children, one side of cortex is broken and opposite side is spared

Etiological agent

  • Trauma
  • Iatrogenic – during extraction or enucleation of large cyst
  • Pathologic – neoplasm, cyst, osteomyelitis
  • Contrecoup fracture – fracture due to indirect force

Effect of action of muscles of mastication:

  • Favourable/unfavourable
  • Horizontal/vertical

Midfacial fractures

Le Fort fractures

Le Fort I

  • Horizontal force delivered above the level of teeth (to the maxilla)
  • Bilateral detachment of alveolar process and palate
  • Involves pterygoid process of sphenoid bone
  • ± Nasal septum
  • Unilateral or bilateral
  • The fracture separates the maxilla from pterygoid plates and nasal and zygomatic structures
  • Clinical:
    • Extraoral:
      • Swelling of upper lip
      • Soft tissue laceration
      • Open mouth due to displaced dentoalveolar portion epistaxis
    • Intraoral:
      • Malocclusion
      • Mobile dentoalveolar portion
      • Dull sound on percussion
      • Ecchymosis of maxillary buccal sulcus

Le Fort II

  • Pyramidal subzygomatic fracture of the maxilla
  • Separation of maxilla and attached nasal complex from the orbital and zygomatic structures
  • Clinical:
    • Extraoral:
      • Ballooning of face
      • Lengthening of face
      • Circumorbital ecchymosis
      • Subconjunctival hemorrhage
      • Epistaxis
      • Diplopia
      • Enophthalmos
      • CSF rhinorrhea
      • Step deformity in lower border of orbit
      • Intact zygomatic bone and arch
    • Intraoral:
      • Malocclusion
      • Anterior open bite
      • Mobility of the maxilla
      • Ecchymosis of sulcus

Le Fort III

  • High level suprazygomatic fracture of central and lateral parts of face
  • Most severe
  • Extensive soft tissue injury
  • “Floating” component is almost entire face
  • Clinical:
    • Extraoral:
      • Ballooning of face
      • Lengthening of face
      • Bilateral circumorbital ecchymosis – “racoon eyes”
      • Bilateral subconjunctival hemorrhage
      • Flattening of cheeks
      • Epistaxis
      • Diplopia – due to edema, hematoma, restrictive motility disorder (mechanical), cranial nerve injury
      • Enophthalmos
      • CSF rhinorrhea
    • Intraoral:
      • Malocclusion
      • Anterior open bite
      • Mobility of the maxilla, mandibular interference
      • Ecchymosis of sulcus
      • Obstructed airway – soft palate rests on posterior dorsum of tongue

Zygomatic complex fractures

Zygomatic complex fracture

Naso-orbito-ethmoid (NOE) complex fractures

Naso-orbito-ethmoid (NOE) complex fractures
  • Signs and symptoms:
    • Occular injury
    • Epiphora
    • Saddle nasal deformity – pushed between the eyes
      • Reduced nasal projection and height
      • Flattened nasal dorsum
      • Septal deviation/dislocation
    • Cerebrospinal fistula
    • Airway obstruction
    • Epistaxis
    • Frontal sinus involvement
    • Telecanthus – Increased distance between inner corners of the eyelids (medial canthi), while interpupillary distance is normal. Occurs due to displacement of bone fragments
  • Examination:
    • Airway
    • Anosmia (loss of smell)
      • CSF rhinorrhea
      • Loss of dorsal support
    • Ocular examination
    • Ophthalmology consultation
    • Intercanthal distance: Rule of thirds: intercanthal distance equal palpebral fissure width
      • Female: 32-33mm
      • Male: 33-34mm
  • Complications of NOE fractures:
    • Facial deformity
    • Telecanthus
    • Epiphora
    • Anosomia
    • Meningitis
  • Management:
    • Reattatchment and repositioning of the medial canthal tendon is key. Restore intercanthal distance
    • Nasolacrimal duct repair
    • Plating bone pieces
    • Transnasal wiring
    • Primary bone grafting for dorsal nasal support
    • Soft tissue adaptation
    • CSF leak – chemoprophylaxis to prevent disease

Objectives of fractures

  • Establish occlusion
  • Anatomic reduction
  • Ensure continuity with bone
  • Esthetic

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