Tooth Fractures

• Crown Fracture (Uncomplicated; No pulp exposure)

Crown Fracture

Crown fracture involving enamel and dentine without pulp exposure are called uncomplicated crown fracture by Andreasen and Class 2 fracture by Ellis. These may include incisal-proximal corners, incisor edges or lingual chisel type fracture in anterior teeth and cusps in posterior teeth.'

Incidence

It is very common and accounts for 1/3rd of all dental injury.

Biological Consequences

This Occurs Only

• If only enamel is involved – minimum consequences and complication.

• If dentine is exposed – a direct pathway exists for noxious stimuli to pass through dentinal tubule to the pulp. Pulp may remain normal or chronic pulpal inflammation may occur. It depends on factors like proximity of fracture to the pulp, surface area of exposed dentine, length of time between trauma and treatment and any injuries to the pulpal blood supply.

Diagnosis

• Clinical examination with a mirror and explorer.

• Determination of status of pulp and periradicular tissues by the routine examination procedures.

• Crown Fracture (Complicated; with pulp exposure)

Crown fracture involving enamel dentine and pulp

Crown fracture involving enamel, dentine and pulp are classified as complicated crown fracture by Andreasen and Class 3 fracture by Ellis and Davey.

Incidence

Incidence compared with all types of dental injuries is about 2-3%.

Biological Consequences

A complicated crown fracture if left untreated will always result in pulp necrosis. Bacterial contamination of pulp prevents healing and repair unless exposure is covered. Initial reaction is hemorrhage at the site of pulp wound. Followed by a superficial inflammatory response resulting in either a destructive or proliferate reaction.

Diagnosis:

 It can be made by clinical observation. It is important to evaluate the condition of the pulp.

• Crown Root Fractures

In these fractures enamel, dentine and cementum are involved; pulp may or may not be involved.

Incidence: 

Andreasen reported a 5% incidence of total dental injuries. If crack tooth syndrome and vertical fracture of endodontically treated teeth are also included the total incidence will be higher.

Biological Considerations: 

These are same as complicated or uncomplicated fractures. In addition, periodontal complication are present because fracture may encroach attachment apparatus.

Diagnosis: 

These fractures results in complains of pain on manipulation. Fragments are easy to move and bleeding from periodontal ligament or pulp fills the fracture lines. 

Direct light and transillumination is an effective way of diagnosing these fractures.

• Root Fractures

Root fractures involve the roots only, that is cementum, dentine and pulp.

Root fracture

Incidence: 

These accounts for less than 3 % of all dental trauma.

Diagnosis: 

As these fractures are mostly diagonal in angulation they are often missed radiographically. One additional film angulation of 45 degrees when combined with standard 90 degree reveals most of the traumatic fractures.

Luxation Injuries

These include impact trauma ranging from minor crushing of periodontal ligament and neurovascular supply to the pulp to more major trauma such as total displacement of teeth.

Incidence: Tooth luxation (extruding avulsion) is comprising the largest group of injuries in classification of dental trauma ranging from 30-40%.

There are 5 kinds of luxation injuries:

• Concusion: There is no displacement or mobility. It is characterized by sensitivity to perscussion only.

• Subluxation: There is no displacement but there is increased mobility and sensitivity to percussion.

• Lateral Luxation: Injury may result in displacement of tooth labially, lingually, distally or mesially. This condition is often very painful particularly when tooth is moved into premature occlusion due to trauma.

• Extrusive Luxation: Displacement of a tooth axially in coronal direction results in partial avulsions. Tooth is highly mobile and continuously traumatized by contact with opposing teeth.

• Intrusive Luxation: A tooth may be pushed into its socket resulting in a very firm almost ankylosed tooth.