The impact of maxillary non-impacted third molars on the distal alveolar bone of adjacent teeth using CBCT: a retrospective study.

OBJECTIVE: The purpose of this study was to find out how the maxillary non-impacted third molars (N-M3s) impact the distal region of alveolar bone of adjacent second molars (M2s).

SUBJECTS AND METHODS: The periodontal condition of maxillary M2s for which the neighboring M3s were missing (NM3-group) and those with intact N-M3s (NM3+group) was analyzed in a retrospective study. Using cone beam computed tomography (CBCT), we categorized the patients based on the presence or absence of periodontitis and measured the alveolar bone resorption parameters in the distal area of M2s.

RESULTS: A total of 135 patients with maxillary 200 M2s were enrolled in this retrospective study. Compared to NM3-group, the M2s of NM3+ group exhibited more odds of increasing alveolar bone resorption in the distal region (health: OR=3.60, periodontitis: OR=7.68), regardless of the presence or absence of periodontitis. In healthy patients, factors such as female gender (OR=1.48) and age above 25 years old (OR=2.22) have been linked to an elevated risk of alveolar bone resorption in the distal region of the M2s.While in patients with periodontitis, male gender (OR=3.63) and age above 45 years old (OR=3.97) serve as risk factors.

CONCLUSIONS: Advanced age, different genders, and the presence of N-M3s are risk factors associated with alveolar bone resorption in individuals with M2s. In addition, the detrimental effects of N-M3s in the population with periodontitis may be exacerbated. From a periodontal perspective, this serves as supportive evidence for the proactive removal of N-M3s.