Permanent Trauma: Intrusion

Question 1

Describe tooth intrusion.

Answer 1

Axial impact displaces the tooth axially into the alveolar bone. The tooth is immobile and percussion will give an ankylotic sound (not recommended).
Extensive injury to the pulp and periodontium.

Question 2

Why is diagnosis more challenging in mixed dentition?

Answer 2

Intrusion can mimic a tooth in the process of erupting. Can be helpful to ask patient/parent if they think the tooth looks shorter or if they have recent photos to compare to.

Question 3

Radiographic appearance of intruded tooth.

Answer 3

PDL space appears to have disappeared.

Question 4

Why is healing following intrusion complicated?

Answer 4

Extensive PDL injury can lead to progressive external root resorption (ankylosis) and pulp damage creates a high risk of inflammatory resorption.

Question 5

What is the most important factor when deciding a treatment for an intruded tooth?

Answer 5

Tooth maturity.
- Immature root formation, can expect spontaneous re-eruption, 50% chance of pulp necrosis
- Complete root development, 100% chance of pulp necrosis

Question 6

Treatment of intruded immature tooth.

Answer 6

• Allow spontaneous eruption (passive repositioning)
• Monitor pulp status radiographically at 3, 4 and 6 weeks, and 6 months
• If resorption is seen: extirpate pulp and place non setting calcium hydroxide
• If there is no tooth movement after 3 weeks perform orthodontic repositioning

Question 7

Treatment of intruded mature tooth.

Answer 7

• Allow passive repositioning for mild cases, orthodontic repositioning required if there’s no movement 2-3 weeks later
• Elective pulp extirpation after 2 weeks and calcium hydroxide dressing for moderate/severe intrusions
• Permanent root filling once periodontal healing is established