External root resorption in maxillary and mandibular second molars associated with impacted third molars: a cone-beam...

Area of Science:

• Dentistry
• Oral and Maxillofacial Surgery
• Radiology

Background:

• External root resorption (ERR) is a pathological process affecting teeth.
• Impacted third molars (M3s) are frequently associated with complications in adjacent teeth.
• Second molars (M2s) are particularly vulnerable to resorption due to their proximity to M3s.

Purpose of the Study:

• To determine the prevalence of ERR in maxillary and mandibular second molars (M2s) adjacent to impacted third molars (M3s).
• To identify specific risk factors contributing to ERR in these M2s.
• To compare the severity and location of ERR between maxillary and mandibular M2s.

Main Methods:

• Cone-beam computed tomography (CBCT) scans of 184 maxillary and 323 mandibular impacted M3s were analyzed.
• Variables assessed included patient age, gender, M3 impaction status, and ERR presence, severity, and location in M2s.
• Multivariate logistic regression was used to identify risk factors for ERR.

Main Results:

• ERR prevalence was 32.6% in maxillary M2s and 52.9% in mandibular M2s.
• Mesially angulated and deeply impacted M3s were significant risk factors for ERR in both M2 locations.
• Age over 25 years increased the risk of ERR in maxillary M2s; ERR was more severe in maxillary M2s.

Conclusions:

• External root resorption in M2s adjacent to impacted M3s is prevalent, especially in the mandible.
• Mesial angulation and impaction depth of M3s are significant risk factors for M2 ERR.
• Maxillary M2 ERR, though less prevalent than in the mandible, is often more severe and influenced by patient age.