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Measuring Maxillary Posterior Tooth Movement: A Model Assessment using Palatal and Dental Superimposition
Published on: February 23, 2024
Root resorption after orthodontic intrusion and extrusion: an intraindividual study
Guangli Han1, Shengfu Huang, Johannes W Von den Hoff
1Department of Orthodontics, School and Hospital of Stomatology, Wuhan University, People's Republic of China.
The Angle Orthodontist
|February 2, 2006
Summary
Tooth intrusion causes significantly more root resorption than extrusion. Clinicians should monitor susceptible patients for root resorption during orthodontic treatment, as individual variations exist.
Area of Science:
- Orthodontics
- Dental Research
- Biomaterials
Background:
- Root resorption is a common side effect of orthodontic tooth movement.
- Understanding the differential effects of intrusive and extrusive forces is crucial for minimizing iatrogenic damage.
Purpose of the Study:
- To compare the incidence and severity of root resorption following continuous intrusive versus extrusive forces in the same individuals.
- To quantify root resorption using scanning electron microscopy and visual scoring.
Main Methods:
- Maxillary first premolars in nine patients were subjected to continuous intrusive or extrusive forces (100 cN) for eight weeks.
- Control teeth from six patients were used for comparison.
- Root resorption was assessed quantitatively (percentage of resorbed surface area) and qualitatively (visual scoring) via scanning electron microscopy.
Main Results:
- Root resorption predominantly occurred at the apical root surfaces in both intrusive and extrusive groups.
- Intruded teeth exhibited significantly more root resorption compared to control teeth (P = .006).
- Mesial and distal root surfaces showed significantly more resorption in intruded teeth (5.78%) versus extruded teeth (1.28%) (P = .004).
Conclusions:
- Tooth intrusion results in approximately four times greater root resorption than extrusion.
- Individual variability in root resorption is substantial.
- Clinicians must be aware of the potential for root resorption, even with extrusion, in susceptible patients.
