Intrusion injuries of primary incisors. Part III: Effects on the permanent successors

Resident’s Name: Anna Haritos Date: August 8, 2008
Article title: Intrusion injuries of primary incisors. Part III: Effects on the permanent successors
Author(s): Diab, M et al.
Journal: Quintesscence International
Volume (number): 31: 377-384
Month, Year: 2001
Major topic: primary tooth trauma in relationship to permanent tooth
Minor topic(s): none
Type of Article: literature review
Main Purpose: to evaluate common etiology and progression of primary intrusion, particularly in relation to development of permanent successors
Overview of method of research: Review of the literature
Findings: 44% of intruded, discolored teeth demonstrated damage to their successors. Only 3 mm of hard tissue exists between the primary incisor and its successor; In younger patients, this barrier may be mostly/only fibrous connective tissue. Younger children are more susceptible to permanent tooth damage from primary incisor intrusion as the successor crown does not complete formation stage until age 3. The permanent tooth can also be traumatized during its mineralization stage. Intrusion of a primary incisor that results in the root heading palatally (crown labially) is a bad intrusion as is more likely to impinge on toothbud; an intrusion resulting in the root headed labially and the crown palatally has a much better prognosis for the toothbud. As long as you can achieve good follow-up, it is better to let the tooth re-erupt spontaneously rather than extract. In the permanent teeth, yellow-brown spots suggest introduction of blood products during enamel matrix formation. White spots indicate hypomineralization. Other changes in permanent teeth come from movement of the ameloblasts as they lay down enamel, resulting clinically in pits, grooves, and/or altered shape. If the trauma occurs at age 2, a crown dilaceration may appear in the permanent tooth. When the trauma occurs between the ages of 2-5, root malformations may be present in the permanent tooth.
Key points/Summary: intrusive displacement of primary incisors is associated with pulpal and periodontal structure damage and possible fracture of alveolar bone. The trauma to the pulp may result in discoloration of the tooth and/or pulpal necrosis and infection. If the periodontal ligament is severely injured, ankylosis of the primary tooth may occur. The latter can cause delayed or ectopic eruption of the permanent successor.
Assessment of article: Very good review of what can happen to permanent tooth following primary tooth intrusion