Related Experiment Video
Updated: Sep 13, 2025
Author Spotlight: Enhancing Dental Pulp Research with Improved Mouse Models
Published on: October 27, 2023
Outcomes of Permanent Tooth Intrusion; Pulp Necrosis, Ankylosis and Tooth Loss
Brittany M Schweiger1,2, Hancong Tang3, Janice A Townsend1
1Division of Pediatric Dentistry, The Ohio State University, Columbus, Ohio, USA.
Background/Aim:
The aim of this study was to examine the timing of pulp necrosis, ankylosis, and tooth loss in intruded permanent teeth based on the stage of root development, degree of intrusion, and initial treatment.
Materials And Methods:
In this retrospective study of intruded permanent teeth between 2013 and 2021, data from 112 teeth in 77 patients were reviewed. Kaplan-Meier survival analyses and Cox Proportional Hazards Model were conducted to compare hazards and time to necrosis, ankylosis, and tooth loss (extraction or decoronation) in different groups.
Results:
Majority of the patients (N=64, 84.4%) were 6-11 years old and male (N=46, 59.7%). The mean age was 8.8 years (Standard Deviation = 2.6) and the median age was 8 years old. Fifty-nine teeth (52.7%) were immature, and 53 teeth (47.3%) were mature. Two years post-injury, mature teeth, teeth with severe intrusion, and surgically repositioned teeth were more likely to experience necrosis (survival probabilities 11%, 17% and 13% respectively). The hazard of pulp necrosis in mature teeth was significantly higher than in immature teeth (HR = 4.30, p < 0.001). Two years post-injury, mature teeth, severely intruded teeth, and surgically repositioned teeth were more likely to experience ankylosis (survival probabilities 47%, 55% and 42% respectively), but the differences were not significant in Cox regression analysis. Two years post-injury, mature teeth, severely intruded, and surgically repositioned teeth were more likely to experience tooth loss (survival probabilities 55%, 57% and 55% respectively). The hazard of tooth loss was significantly higher in moderate and severe intrusions compared to mild intrusion (HR = 16.85, HR = 13.92, p = 0.01 respectively).
Conclusions:
The results indicate that the risk of pulp necrosis, ankylosis, and tooth loss increased with mature apex, increasing degree of intrusion, and surgical repositioning. Cox proportional hazard models showed significant associations between pulp necrosis and mature root development, and between tooth loss and degree of intrusion.
Related Concept Videos
01:21Tooth Anatomy
The Crown, Neck, and Root
The visible part of the tooth is referred to as the crown. It's covered by enamel, the hardest substance in the human body. The crown is uniquely shaped for each type of tooth, allowing for different functions such as cutting, tearing, or...
01:15Teeth
In the bud stage, the tooth germ (an aggregation of cells) starts to form in the developing jawbone. During the cap stage, the tooth germ differentiates into enamel organ, dental papilla, and dental sac, which will later develop into the tooth's enamel, dentin...
01:26Aneurysm III: Interprofessional Care
01:29Blood and Nerve Supply to the Bones
Nutrient Artery
The nutrient artery is the main blood vessel that enters the diaphysis via the nutrient foramen. While most long bones have only one nutrient foramen, large bones, such as the femur, may have two. This...
01:30Aneurysm I: Introduction
01:22Sutures of the Skull
Sutures are immobile joints between adjacent bones of the skull. The narrow gap between the bones is filled with dense, fibrous connective tissue that unites the bones. The long sutures located between the skull bones are not straight but instead follow irregular, tightly twisting paths. These twisting lines tightly...