Dental traumas are categorised according to the degree of severity of the injury, which in turn depends upon which tissue or tissues have been damaged and the extent of that damage.
TYPES OF DENTAL TRAUMAS
A tooth concussion is the mildest type of trauma/injury that can be inflicted on teeth. The fibres of the periodontal ligament may be strained and a few may be severed, but enough support remains to keep the tooth intact in the socket so that there is no measurable increase in mobility. The tooth might likely exhibit sensitivity to touch or diagnostic tapping; the gums around it might become slightly swollen, and may sometimes even bleed slightly. The neurovascular tissues in the dental pulp remain intact.
A subluxation can be considered as an aggravated concussion. There is greater damage to the periodontal ligament with more fibres, as well as some gingival capillaries, being severed or stretched. The tooth remains in place in its socket but a noticeable amount of movement can be elicited. Edema of the surrounding gingiva and interstitial bleeding from within the tooth-gum boundary (gingival sulcus) is evident. Pain is felt when the tooth is lightly touched or tapped; and there could be some slight damage to the neurovascular bundle of the pulp.
3) Extrusion or Extrusive Luxation
A luxation involves sufficiently severe trauma so as to dislodge the tooth. A luxation always involves at least partial (and sometimes total) rupture of the periodontal ligament as well as significant damage to or total severance of the blood vessels and nerve fibres of the dental pulp. Displacement of the tooth by just 5 mm or more decreases the probability of complete dental pulp recovery by about 50%.
In an extrusive luxation, the tooth is dislodged outwards away from the tooth socket in a direction generally parallel to the tooth root orientation. The tooth seems to have lengthened as part of the tooth root has been exposed. The alveolar bone in the tooth socket is usually not damaged.
4) Lateral Luxation
Lateral luxation is displacement of the tooth along any direction that is roughly perpendicular to the axial or longitudinal axis of the tooth. Fracture of the socket alveolar bone is always present in this type of luxation, and is quite common along the labial (lip) or palatal/lingual (palate/tongue) side of either jaw arches. There is partial or complete laceration of the periodontal ligament and pulpal neurovascular connections. The periodontal ligament on the side of the fracture undergoes traumatic compression.
5) Intrusive Luxation
In this type of luxation, a tooth is driven further into the alveolar socket. The alveolar bone is fractured and crushed (compressed). The periodontal ligament and the pulp blood and nerve connections are torn off and crushed, respectively. At times, the tooth becomes completely submerged into the jawbone, and might even penetrate the nasal cavity. Almost all intrusive luxations lead to pulpal necrosis.
In this type of dental trauma, the tooth is totally displaced out of the socket. If the tooth root has been fractured, a portion of the root might remain inside the socket. The pulp neurovascular supply and the root periodontal ligament are completely ruptured. Tooth loss is highly likely for this type of trauma. Even if the tooth is preserved and replanted, there is still the danger of the tooth not being recognised by the immune system and consequently rejected. A rejected replanted tooth will become fused to the bone (ankylosed) and then resorbed.
The time to replantation and the condition of the avulsed tooth are critical factors that determine the outcome of every case. The cells of the periodontal ligament that surrounds the tooth root are sensitive to mechanically induced damage, dehydration, and electrolyte depletion. In an emergency, an avulsed tooth should be very gently picked up by the crown and then immediately placed in a carton or plastic container that contains coconut water or milk. Washing or otherwise cleaning the tooth is not recommended. The patient and the avulsed teeth should then be sent to the dental clinic as soon as possible.
7) Broken Teeth
Broken teeth are dental traumas that involve damage only to teeth and usually do not involve dislocations. Teeth can be cracked, fractured, chipped, and torn off. The severity of a broken tooth injury is described according to the Ellis fracture classification system. This system assigns levels of severity based on whether the enamel, the dentin, and the pulp have been affected by the injury.
Broken teeth can involve only the enamel layer (Ellis Class I fracture), both the enamel and the dentin layers (Ellis Class II fracture), or the enamel and dentin layers and the pulp all at once (Ellis Class III fracture). Class I fractures are not medical emergencies and are easily managed with cosmetic dental treatments. Class II fractures on the other hand require either direct or indirect dental restorations since bacteria can easily proliferate within the dentin tubules. Class III fractures are true medical emergencies since bleeding and extreme pain are are commonly associated with this type of fracture. Infection of the pulp, gums, or jawbones can likely occur without prompt treatment.
According to increasing degrees of severity, broken teeth injuries include enamel infractions (also known as enamel craze or craze lines), enamel fractures, enamel-dentin fractures, crown-root fractures (without pulp involvement), enamel-dentin-pulp fractures, crown-root fractures (with pulp involvement), and root fractures.
Enamel infractions and enamel fractures are Class I fractures. Enamel-dentin and crown-root fractures without pulp involvement are Class II fractures; and lastly, enamel-dentin-pulp fractures, crown-root fractures (with pulp involvement) and root fractures are all Class III fractures.
Root fractures involve only the cementum, dentin, and pulp of the tooth root. These are relatively rare dental injuries that can be difficult to detect. Horizontal root fractures on the front teeth can be caused by direct impacts. The closer a horizontal root fracture is to the gum-line, the more likely it is that the tooth will be lost. Vertical root fractures on molars can result from clenching the teeth or from upwardly directed impacts to the lower jaw.
8) Alveolar Fracture
An alveolar fracture is a bone fracture of the alveolar ridge. The tooth socket may or may not be affected with this type of fracture. This is a serious bone fracture that can affect multiple teeth and, if it gets worse, can propagate throughout the entire mandible or maxilla.
9) Fracture of Mandible/Maxilla
This fracture is similar to an alveolar fracture but extends throughout the mandible or maxilla. This is a severe injury that requires immediate orthopaedic and/or oral-maxillofacial supervision.