How to manage a patient with a traumatically displaced primary incisor

Traumatically displaced primary incisor

Incidents of primary incisors displaced as a result of trauma caused by impact occur most often when a child's gross motor skills and coordination are still under development.

The younger the child, the more likely that total tooth displacement will occur, as opposed to tooth/root fracture. The pediatric alveolus by nature tends to be more elastic and will preferentially yield to the force of impact, resulting in total tooth displacement.

Presentation

Population

Pre- and school-aged children. Generally, the sequelae of primary incisor displacement injuries become less significant as the child enters the mixed dentition stage.

Most common site of occurrence

Maxillary central incisor

Signs

• Primarily, the tooth will be visibly displaced from its normal position in the dental arch and may or may not demonstrate abnormal mobility.
• Secondarily, one may find evidence of:
  • Expansion or disruption of the local alveolar contours
  • Gingival laceration or other soft tissue injury with evidence of hemorrhage
  • Mucosal ecchymosis

Symptoms

• Pain severity may be child-dependent but young children may be reluctant to be examined, as tissue manipulation may cause the greatest discomfort.
• Altered tooth mobility
• Inability to eat or drink

Investigation

A calm, confident, and reassuring approach is important as parents may be upset and the injured child may be resistant to examination.

1. Inquire about the details of the incident (what, when, where, and how). Ask yourself whether this injury could be the result of child abuse. If yes, follow up with a report after emergency care is rendered, and inform the parents that you are doing so.
2. Determine if there are other injuries: reported loss of consciousness, vomiting, disorientation, or departure from the child's usual behaviour may all be indicative of cervical spine or closed head injury. Medical assessment may have to take precedence over dental injuries.
3. Complete a thorough medical history: note any pre-existing conditions, such as bleeding disorders, cardiac issues, and inadequate immunization. Tetanus prophylaxis is indicated if the child is not fully immunized and the wounds are obviously contaminated with dirt or debris.
4. Complete a thorough dental history to reveal the nature of any previous dental injuries or restorative treatments involving the same tooth. Prognosis of displaced tooth may be poorer if the tooth has had previous interventions or past trauma.
5. Perform a thorough intraoral and extraoral examination as soon as possible. If the child is upset or agitated, a knee-to-knee exam with the parent will be the best approach.
   1. Gently debride the peri- and intraoral areas with gauzes soaked in saline or diluted hydrogen peroxide. Take note of all soft tissue and hard tissue injuries.
   2. Palpate the alveolus in the area of the displaced tooth to feel for disruptions/prominence, if you suspect that the root tip has ruptured the labial plate or a greenstick or alveolar fracture has occurred.
   3. Reflect the lips fully away from the teeth to examine the gingiva and mucosa for lacerations, debris, and degloving injury.
   4. Determine if there are associated crown fractures and/or pulp exposures additional to displacement.
   5. Prescribe at least one periapical view that encompasses the area of trauma (maxillary occlusal).

Diagnosis

The spectrum of displacement (luxation) injuries includes:

• Extrusion: displacement in the axial direction, out of the alveolus; tooth highly mobile
• Intrusion: displacement in the axial direction, into the alveolus; tooth not mobile
• Lateral luxation: displacement in any direction but axial; tooth usually not mobile
• Avulsion: complete displacement

Concussion and subluxation are included in the spectrum of displacement injuries but for these injuries the tooth is not visibly displaced from its socket.

Differential Diagnosis

1. A fully intruded primary incisor may look like an avulsion; an occlusal radiograph can rule out or confirm this. If the tooth is not visible radiographically and not accounted for at the accident scene, then further assessment is needed to determine if the tooth has been swallowed or aspirated.
2. Primary incisors near exfoliation can mimic true displacement injuries as they may appear to be displaced from their normal arch position (due to lack of root support). The gingival attachment may bleed readily with relatively minimal trauma.

Treatment

In case of multiple tooth involvement, extensive gingival lacerations, degloving injuries involving the mucosa, alveolar segmental fractures, or difficult-to-manage child behaviour: refer the case to a specialist or hospital dental department.

The primary management objective is to minimize the damage to the developing permanent incisors.

Mild Displacements (<3 mm in any direction):  Conservative Management

• Attempt to manually reposition the tooth to relieve traumatic occlusion
• Soft diet
• Short-term analgesics

Depending on age, spontaneous repositioning can occur, especially if an anterior open bite exists.

Severe Displacements (>3 mm in any direction): Aggressive Management

Extraction should be performed, especially if there is:

• Occlusal interference
• Displacement of apex toward the developing permanent tooth
• Associated tooth fracture with pulpal involvement
• Well-established physiologic root resorption
• Minimal likelihood of compliance follow-up
• Parental preference to avoid possible negative sequelae

Postoperative advice

• Gentle brushing with soft toothbrush for remainder of the dentition
• Soft diet
• Analgesics
• Swabbing traumatized teeth with 0.12% chlorhexidine solution to minimize plaque accumulation (twice daily until regular tooth brushing is tolerated)
• Restricted use of pacifier (if applicable)
• Review of the signs and symptoms of infection if tooth left in situ: parent lifts the lip periodically to inspect the overlying soft tissues. Pain that develops after the healing period should be reported.

Inform the parents

• Mention the possibility of pulpal necrosis, swelling, fistula, crown discolouration, and ankylosis.
• Explain that some primary incisor displacement injuries may result in adverse sequelae in associated permanent incisor development and eruption.

Follow Up

• Clinical follow up may vary, but the usual format is 1 week, 1 month, 3 months, 6 months and 1 year.
• Radiographic follow up should be carried out at 6 months and 1 year, then annually until exfoliation.

THE AUTHOR

	Dr. Campbell is chief of dentistry, BC Children's Hospital, Vancouver, and clinical associate professor and director, graduate program in pediatric dentistry, University of British Columbia. Email: campbkar@dentistry.ubc.ca