February 13, 2024
Traumatic injuries to the teeth can often be an emergency situation. The fracture of the tissues of the tooth and its surrounding structures can elicit a lot of pain and discomfort. Depending on the severity of the injury, the fracture of the tooth can either involve some or all the tissues of the tooth. Based on this, Roy Ellis in 1970 gave a classification for the various types of traumatic injuries that a tooth can suffer from. This classification can also help in planning the treatment for the affected tooth.
The classification given by Ellis can be broken down into nine categories.
Class I: Simple crown fracture with little or no dentin affected
This type of fracture is seen where only the enamel is affected with or without the involvement of dentin. Infraction of enamel or broken tooth fragments may be the cause of sensitivity for the patient. In most cases this is an uncomplicated tooth fracture with very good prognosis. A radiograph can help in determining the extent of fracture, whether the root is pushed within the bone and if any missing fragment is lodged in the surrounding soft tissues. Treatment involves restoring the broken fragment if available. Restoring the tooth surface with a composite resin is also a common treatment modality. A follow-up is required after 2 months and after 1 year to confirm the healthy state of the tooth and surrounding tissues with the help of radiographs.
Class II: Considerable loss of enamel and dentin with the pulp not affected
A tooth fracture involving the enamel and dentin usually has a favorable prognosis. If the broken fragment is preserved in water saline or milk, and is brought to the dentist within 20 minutes, then the fragment can be bonded back to the tooth. A radiograph can confirm how much distance is present between the pulp and dentin. If this distance is less than 0.5mm, then a layer of calcium hydroxide is placed, over which the tooth can be restored with composite resin or glass ionomer cement. The tooth needs to be kept on regular follow-ups up until 1 year.
Class III: Extensive crown fracture with loss of dentin and pulp exposure.
When there is loss of dentin due to trauma and there is an exposure of the pulp, the patient might complain of sensitivity to air, sweets, cold, etc. This is because the exposed pulp leads to the nerves and blood vessels of the tooth exposed to the external environment. In young patients where the roots of the tooth are yet to form completely, it is extremely crucial to maintain the health of the pulp. In such cases, depending on the severity of the fracture and if at all there is a luxation of the tooth, a pulpotomy or a root canal treatment is preferred. Pulpotomy involves removing the part of the pulp present in the crown and covering it with a suitable dressing material and restoring it eventually. A root canal treatment is a more extensive procedure that might be needed in case of an inflamed pulp. Here, the pulp is entirely removed from the roots and the crown. Later, following thorough cleansing and disinfection of the root canals, a biocompatible material is placed to fill up the root canal space and the crown of the tooth. The patients need to be on a follow-up every 2 months till 1 year. Bonding back the lost tooth fragment can be done depending on the amount of tooth structure lost and the healing status of the pulp.
Class IV: A tooth devitalized by trauma, with or without loss of tooth structure
A traumatic blow to the tooth can cause the blood vessels and nerve to rupture, leading to inflammation and subsequent discoloration of the tooth structure. Depending on the extent of this injury, a root canal treatment can be carried out. If there is considerable loss of tooth structure, then a post and core might be needed to retain the strength of the tooth. In this, the root canals of the tooth are filled with a rigid material called the post and the crown is restored with a core material, that takes support of the post. In order to treat a subluxated tooth, an orthodontic intervention may be needed, wherein the tooth is pushed out of the bone, to its rightful position in the oral cavity.
Class V: Teeth lost as a result of trauma
When the entire tooth is lost due to trauma, the tooth must be preserved in water, saline, milk or Hank's Balanced Salt Solution. Within 1 hour, the tooth must be replanted to have a good success rate. The tooth is cleared off all the debris and contamination before being repositioned in the oral cavity. The dentist will clean the socket with saline before repositioning the tooth. The tooth is positioned with slight digital pressure. A radiograph is taken to confirm the position of the replanted tooth. The tooth is then splinted with a flexible wire. Within 2 weeks, the tooth is reevaluated and a root canal treatment is initiated. In case the underlying bone is fractured as well, then a time period of 4 weeks is needed after splinting the tooth, before initiating the root canal therapy. Prognosis depends on how early the tooth was replanted and how it was stored when it was avulsed out of the socket.
Class VI: Root fracture with or without loss of crown structure
A fracture of the root an be diagnosed with multiple radiograph or with a CBCT. The direction and position of the fracture in the root determines its prognosis. Depending on the status of the pulp and the amount of crown structure lost, the tooth needs a pulpotomy or root canal treatment or post and core retention. The patient needs to be kept on a follow-up for each month till 1 year and later annually once for 5 years.
Class VII: Displacement of the tooth with neither tooth or crown fracture
This type of fracture can be sub-classified as concussion, subluxation, luxation and intrusion. Concussion usually does not require any treatment unless the tooth's pulp becomes necrotic or shows signs of tenderness upon percussion. Subluxation and luxation injuries can lead to the tooth being mobile and bleeding from the gums is commonly seen. The tooth needs to be splinted for a couple of weeks and must be monitored for at least 1 year. Intrusion is when the tooth is pushed further below the bony level. Upon percussing an intruded tooth, a metallic sound can be heard. The tooth needs to be pushed out with orthodontic treatment or surgically, and root canal therapy is done after it is repositioned. A corticosteroid-based medicament is needed to fill the teeth after the root canal treatment is done. The tooth is kept on a follow-up for at least 5 years.
Class VIII: Complete crown fracture and its replacement
In this type of fracture, there is total loss of the crown structure. The tooth needs surgical and orthodontic intervention for lengthening the crown. An endodontic treatment needs to be carried out, following which the tooth is restored with a porcelain fused metal crown.
Class IX: Traumatic injuries to primary teeth
Traumatic injuries to primary teeth should be managed cautiously, so as not to damage the tooth bud of the permanent tooth below the primary tooth. While most treatment modalities remain the same as that we saw in permanent teeth, complexity arises when the fracture involves the roots. In such cases, extraction of the loose fragments or the entire tooth might be needed. The parents should be reassured about the condition of the underlying successor tooth. Damage to the permanent tooth bud can occur in cases of intrusion or luxation injuries. There can be a change in the erupting path of the permanent tooth. Treatment is initially targeted towards repositioning the primary teeth. An orthodontic intervention might be needed for this. In any case, longer follow-up period with regular radiographic monitoring is needed to ensure a smooth eruption-shedding pattern.
Ellis classification thus helps in deducing the extent of the fracture and evaluating the treatment plan accordingly.