Primary Tooth Trauma Leads to Developmental Disturbance of Permanent Dentition Traumatic Intrusion of Primary Teeth and Its Effects on the Permanent Successors: A Clinical Follow-Up Study

Background: Traumatic injury to primary teeth is a very common phenomenon as kids are often involved in facial trauma, and because the central incisors hold a prominent position in the facial profile. The standard of treatment is to extract the teeth if severely mobile or to leave them if stable. Of interest is the effect of the injury to the developing permanent dentition. These effects can range from hypoplasia, crown dilaceration, root angulation, sequestration of the permanent tooth germ, and disturbances in eruption. Objective: To evaluate the effect of trauma to primary teeth on the developing permanent dentition, and to specifically see if the type of injury to the permanent dentition is correlated to the age at which injury occurred. Design/Participants: This prospective study took place over a 7-year period; 78 patients had a total of 138 affected teeth. Methods: The patient demographics, type of injury, and type of post-traumatic sequela were recorded. Patients were followed with clinical examinations and radiographs until complete eruption of the permanent incisors. At the end of follow-up, developmental disturbances were recorded. These included enamel hypoplasia, hypocalcification, hypoplasia, discoloration, tooth malformation, and ectopic eruption pattern. Results: 93.47% of all intruded primary teeth were maxillary incisors; 36 teeth were extensively mobile and had to be extracted. Almost all remaining teeth had either partial or total spontaneous eruption, and 29.7% of these teeth developed necrosis, resorption, or ankylosis. Approximately 53.6% of the permanent successors (74 teeth in total) had developmental disturbances. These included hypoplasia, crown/root deformation, ectopic eruption, or a combination of these. Conclusion: The right central maxillary incisor was the most frequently injured primary tooth, and pulp necrosis was the most common consequence of intrusive injury. Severe injury to a primary tooth will result in a developmental disturbance to the permanent successor. Most commonly this will be enamel hypoplasia. There was no correlation between age of intrusion and frequency of subsequent development disturbances. Reviewer's Comments: The biggest concern parents have after their child suffers trauma is how the trauma will affect their teeth. This is a well done study that gives us a figure of approximately a 50% chance of developmental defect on permanent incisors. It is also important to note the high percentage of spontaneous re-eruption that occurs. The best treatment for intruded primary teeth is to leave them alone. (Reviewer-Ryaz Ansari, DDS).