Risk factors for external root resorption of maxillary second molars associated with third molars

Area of Science:

• Dentistry
• Oral and Maxillofacial Radiology
• Diagnostic Imaging

Background:

• External root resorption (ERR) associated with maxillary third molars (M3s) is a significant clinical concern.
• Accurate diagnosis of M3-associated ERR is crucial for appropriate treatment planning.

Purpose of the Study:

• To evaluate the diagnostic performance of panoramic radiography versus cone-beam computed tomography (CBCT) for detecting M3-associated ERR.
• To identify risk factors for M3-associated ERR detectable on panoramic images.

Main Methods:

• A retrospective study included 397 maxillary M3s from 247 patients.
• Diagnostic accuracy was compared between panoramic images and CBCT using the chi-square test.
• Logistic regression analysis identified risk factors for ERR based on panoramic findings and dental records.

Main Results:

• Panoramic imaging demonstrated a diagnostic accuracy of 0.79 for M3-associated ERR compared to CBCT (P<0.05).
• Superimposition of M3s onto second molars (M2) significantly increased ERR risk by approximately 33 times (P<0.05).
• Impacted M3s exhibited a 5-fold higher risk of ERR compared to erupted M3s (P<0.05).

Conclusions:

• Panoramic radiography is a reasonably accurate tool for diagnosing M3-associated ERR.
• M3 superimposition on M2 is the most critical risk factor for ERR, suggesting CBCT may be indicated in such cases.
• M3 impaction is also a significant risk factor requiring careful clinical examination.