External root resorption of second molars caused by impacted third molars: CBCT characteristics

Area of Science:

• Dentistry
• Oral and Maxillofacial Surgery
• Radiology

Background:

• External root resorption (ERR) is a pathological process affecting teeth.
• Impacted third molars are a known risk factor for ERR in adjacent teeth.

Purpose of the Study:

• To characterize cone-beam computed tomography (CBCT) findings of external root resorption (ERR) in second molars linked to impacted third molars.
• To identify factors influencing ERR severity and occurrence.

Main Methods:

• Analysis of 69 second molars with ERR caused by impacted third molars in 52 patients.
• Utilized CBCT to evaluate impacted third molar characteristics (position, angulation, proximity) and their correlation with ERR extent in adjacent second molars.

Main Results:

• Mandibular second molars were most affected by ERR.
• Nearly half of ERR cases extended to the pulp chamber, with 24.6% communicating with the oral cavity.
• Complete bone impaction of third molars correlated with deeper ERR, and oral communication with ERR sites increased pain.

Conclusions:

• Low-level and complete bone impactions of third molars are significant contributors to ERR in second molars.
• ERR sites communicating with the oral cavity pose a high risk of infection.