Crown-root fractures
Occurs when the force of impact exceeds the shearing strength of the hard dental tissues.
- Fracture initially follows the enamel rods of the labial surface of the crown and then takes an oblique course below palatal gingival crest
- May or may not involve the pulp
- The prognosis for a crown-root fracture is often poor as communication from the coronal portion of the fracture allows the ingress of oral bacteria down the fracture to the periapical tissues/pulp..
Management:
An accurate history and diagnosis is required, always suspect root fractures or crown-root fractures in mobile teeth, especially when the fulcrum of mobility appears more coronal than for a subluxation injury.
Radiographs are essential to assess the extent of the fracture, often two view are required at different angles as crown-root fractures can be difficult to spot if there is minimal displacement of the fractured segments.
Options
- Removal of coronal fragment and supragingival restoration - if the fractured segment is minimal in size and does not extend more than 2mm subgingivally.
- Removal of coronal fragment supplemented by gingivectomy and / or very rarely osteotomy
- Removal of coronal fragment and surgical or orthodontic extrusion of the root to move fracture surface to more optimal location (rarely performed)
- Extraction is often the best solution, especially if there is pulpal involvement