Displaced Tooth

Trauma to the teeth may result in fractures, avulsions, or displacements. Injury to primary teeth more often results in displacement of teeth rather than fractures. Maxillary and mandibular incisors are the most commonly displaced primary teeth.[1]

A typical cause is a directed force sufficient to overcome the bond between the affected tooth and the periodontal ligament within the cradling alveolar socket. Displacement may be in the form of subluxation, intrusion into the alveolar socket, or extrusion from the socket with tearing of the apical neurovascular bundle. All these forces may lead to pulp necrosis and apical abscess formation.[2]

Causes of tooth displacement include the following:

• Unknown (17%)

• Altercations (17%)

• Contact sports (15.9%)

• Motor vehicle collisions (10.8%)

• Motorcycle accidents (10.4%)

• Ice hockey (2.3%)

In children, the most common cause of displacement injuries to primary teeth (up to 44.8%) is a fall while walking or running.[3]

United States data

Dental displacement is the most common injury to primary dentition.[4]

International data

A study conducted in Sweden showed that approximately 7% of all physical injuries involved the oral cavity. In patients aged 0-19 years, 9% of all injuries involved the oral cavity. More than 50% of physical trauma in child abuse cases occurs in the head and neck region. During the Korean War, 3000 maxillofacial injuries occurred.[5]

Sex- and age-related demographics

Male-to-female ratio is 2-3:1.

Average age of injury is variable. In youths, falls and sporting activities account for the majority of injuries. In the later teenaged years, motor vehicle collisions (MVCs) and assaults account for the majority of injuries.

Morbidity/mortality

Trauma to the teeth is not life threatening; however, associated maxillofacial injuries and fractures can compromise the airway. Morbidity to the teeth may be individualized to primary and permanent teeth.

Almost half of teeth with luxation injuries become necrotic after 3 years.

• Primary teeth - Failure to continue eruption, color changes, infection, abscess, loss of space in the dental arch, ankylosis, injury to the permanent teeth, abnormal exfoliation

• Permanent teeth - Color changes, infection, abscess, loss of space in the dental arch, ankylosis, resorption of root structure, abnormal root development[6]

Complications

Complications of tooth displacement include the following:

• Tooth loss
• Cosmetic deformity
• Infection

For excellent patient education resources, visit eMedicineHealth's Oral Health Center. Also, see eMedicineHealth's patient education articles Broken or Knocked-out Teeth and Toothache.

Constant or spontaneous pain in traumatized teeth may indicate injury to the pulp, periodontal ligament, or supporting bone.[7]

Lateral displacement

Tooth may be mobile or firm but is displaced facially or lingually.[7]

Axial displacement[7]

• Extrusion injury: Patient may complain of mobility or malaligned teeth.

• Intrusion injury: Patient may complain of pain; patient has malalignment or no sense of mobility. This type of displacement has the worst prognosis.[8]

Inspection

Evaluate surrounding soft tissue area for laceration, discoloration, ecchymosis, and embedded foreign bodies (eg, chipped teeth). Use of radiographs to locate tooth fragments inside the lip is appropriate.[9, 10, 11]

In cases of tooth crown fractures, checking the lip for possible tooth fragments is important. Manual palpitation and radiographic screening of the affected lip help with detection of any foreign objects.[9, 10]

When checking displaced tooth, ensure that the soft tissue is not removed or scraped from the tooth prior to reimplanation.[9]

Evaluate teeth for fractures, chips, and other deformities. Embedded tooth fragments may lead to chronic infection or fibrosis.[9]

Palpation

Evaluate if tooth is mobile or if an entire segment is mobile.[9]

If possible, have patients bite down to further localize suspected area.

Percussion and sensitivity

Percuss tooth with a tongue blade to evaluate sensitivity.[9]

Sensitivity to thermal stimuli may help to indicate status of the pulp. Lingering pain to temperature indicates irreversible pulpitis. Short duration of pain (< 5 seconds) indicates better recovery potential for the pulp.

Tooth displacement can often be viewed radiologically. Lateral and axial extrusive displacements may reveal widened periodontal ligament spaces. Axial intrusion displacement may reveal a blurred periodontal ligament.[12]

Obtain 4 films (maxillary anterior and 3 periapical films from various angles) to evaluate a dental fracture or displacement. In the emergency department, because such specialized films often are not available, use a limited facial series and a Panorex to evaluate maxillary and mandibular fractures, foreign bodies, and displacement. A Panorex can be used to assess mandibular fracture.

Use a periapical film to view foreign objects, such as tooth fragments, within lacerated soft tissue.

Illumination can be used to visually identify fractures within the tooth, if present.

Provide adequate pain management, tetanus vaccination, and ensure proper follow-up care.[10, 11, 13, 14]

Document arrangements for follow-up care with a dentist.

Consult a dental or oral maxillofacial surgeon for splinting.

Subluxation or extrusion injury

A dentist should adjust and splint.[15]

Intrusion injury

A tooth should be allowed to re-erupt. Dentoalveolar ankylosis of a primary tooth hinders eruption of the succedaneous permanent tooth.

• Intruded primary teeth: Allow teeth to re-erupt before possible repositioning.

• Intruded adult teeth: Allow re-eruption then stabilize.

A study investigated differences in the periodontal outcomes of palatally displaced canines (PDC) exposed with either an open or a closed surgical technique. The study concluded that there is a periodontal impact when a unilateral PDC is exposed and aligned, however, this impact is small and unlikely to have clinical relevance in the short term.[16]

Antibiotics are not truly indicated for displacement unless clinical signs of infection are present. Analgesics are indicated for pain relief.

Class Summary

Therapy must cover all likely pathogens in the context of the clinical setting.

Penicillin VK (Veetids, Beepen-VK, Betapen-VK)

Inhibits biosynthesis of cell wall mucopeptide and is effective during active replication. Inadequate concentrations may produce only bacteriostatic effects.

Erythromycin (EES, E-Mycin, Ery-Tab)

Alternative for patients who are allergic to penicillin. Due to possible GI irritation, advise patients to take with food/milk if GI upset noted.

Inhibits RNA-dependent protein synthesis possibly by stimulating the dissociation of peptidyl tRNA from ribosomes. Inhibits bacterial replication.

Amoxicillin (Amoxil, Polymox, Trimox)

Interferes with synthesis of cell wall mucopeptide during active replication, resulting in a bactericidal activity against susceptible bacteria.

Class Summary

Pain control is essential to quality patient care. Analgesics ensure patient comfort, promote pulmonary toilet, and have sedating properties that benefit patients who have sustained trauma.

Oxycodone and acetaminophen (Percocet)

Drug combination indicated for relief of moderate to severe pain. DOC for patients who are hypersensitive to aspirin.

Hydrocodone bitartrate and acetaminophen (Vicodin ES)

Drug combination indicated for relief of moderate to severe pain.