Prevalence and predictive parameters of external root resorption caused by retained wisdom teeth

Area of Science:

• Dentistry
• Oral and Maxillofacial Radiology
• Dental Imaging

Background:

• Retained third molars (M3) are frequently associated with external root resorption (RR) of adjacent second molars (M2).
• Accurate diagnosis of RR is crucial for treatment planning and preventing complications.
• Panoramic radiography (PAN) is a common initial imaging modality, but its sensitivity for detecting RR may be limited.

Purpose of the Study:

• To estimate the prevalence and severity of external root resorption (RR) caused by retained third molars (M3).
• To compare the diagnostic sensitivity of panoramic radiography (PAN) and cone beam computed tomography (CBCT) for RR.
• To identify predictive factors associated with the development and severity of M2 root resorption.

Main Methods:

• Retrospective cross-sectional analysis of 367 patients with both PAN and CBCT imaging.
• Predictor variables included patient age, gender, M3 inclination, retention depth, and M2 contact level.
• Outcome variable was M2 root resorption, graded using established criteria, with subgroup analyses based on PAN findings.

Main Results:

• CBCT revealed RR in 20% of M2 adjacent to retained M3, whereas PAN suggested RR in less than 5%.
• Predictive factors for increased RR severity included mesial inclination of M3, older patient age, and deeper M3 retention.
• CBCT identified RR in cases where PAN showed no pathology.

Conclusions:

• PAN demonstrates poor performance in diagnosing external root resorption associated with third molars.
• CBCT is a more sensitive tool for detecting RR, particularly in cases of mesioangulated and deeply retained M3 in older patients.
• Findings support considering CBCT for surgical planning of third molar extraction when RR is suspected or when PAN is inconclusive.