Evaluation of detrimental effects of impacted Mandibular third molars on adjacent second molars – A retrospective observational study

Relationship between the Status of Third Molars and the Occurrence of Dental and Periodontal Lesions in Adjacent Second Molars in the Polish Population: A Radiological Retrospective Observational Study

“…Subsequently, the presence of M3s may lead to the appearance of caries on the distal surface of M2s [ 25 ]. The prevalence of caries on the distal surface of mandibular M2s, associated with a semi-erupted M3, ranged from 7% to 32% [ 26 , 27 , 28 , 29 , 30 , 31 , 32 ]. A large longitudinal study with a 25-year follow-up reported a relative risk ratio (RR) of 2.53, which meant that patients with erupted M3s were at 153% greater risk of caries on the distal surface of M2s in comparison with subjects missing M3s [ 33 ].…”

“…ERR was associated with mechanical or inflammatory factors such as dental trauma, chronic periodontitis, pressure resulting from orthodontic appliances, cysts, benign or malignant tumors, and close proximity to an unerupted tooth [ 39 ]. Previous studies analyzing the ERR of M2s due to M3s, which used panoramic imaging or apical radiographs, reported prevalence varying between 0.3% and 24.2% [ 24 , 28 , 40 , 41 , 42 , 43 ]. In the present study, the prevalence of ERR was 2.28% when M3s were present and increased to 6.62% in case of partially impacted M3s.…”

“…Another study reported an increased plaque index and bleeding on probing (BOP) around adjacent M2s [ 48 ]. The presence of N-M3s was indicated as a potential risk factor for the development of periodontitis in adjacent M2s [ 27 , 28 , 32 , 49 ]. N-M3s were correlated with a probing pocket depth (PPD) of at least 5 mm (OR 6.7) and BOP (OR 4.0).…”