Predicting and preventing root resorption: Part II. Treatment factors

Area of Science:

• Orthodontics
• Dental Radiology
• Periodontology

Background:

• External apical root resorption (EARR) is a common consequence of orthodontic treatment.
• Identifying specific treatment factors associated with EARR is crucial for clinical management.
• Radiographic assessment is key to detecting and quantifying EARR.

Purpose of the Study:

• To identify orthodontic treatment factors most strongly linked to external apical root resorption detectable on periapical radiographs.
• To analyze the association between tooth movement, treatment duration, and EARR in patients undergoing fixed edgewise therapy.

Main Methods:

• Retrospective analysis of 868 patient records from experienced private practice clinicians.
• Measurement of horizontal and vertical root apex displacement of maxillary central incisors using cephalometric radiographs.
• Comparison of EARR incidence based on extraction patterns (no extraction, premolar extraction) and treatment variables.

Main Results:

• First premolar extraction therapy was associated with significantly more EARR compared to non-extraction cases.
• Treatment duration and horizontal incisor apex displacement showed a significant correlation with EARR.
• No significant association was found between EARR and bracket slot size, archwire type, elastics, or expansion methods.

Conclusions:

• Clinicians should exercise caution with extraction therapy for overjet correction, especially when prolonged treatment times are anticipated.
• Significant variations in EARR prevalence exist among different orthodontic practices, highlighting the importance of individual clinician awareness.
• Minimizing horizontal incisor movement and optimizing treatment duration are key strategies to mitigate EARR risk.