Related Experiment Videos
Association between impacted third molars and external root resorption on adjacent second molars based on cone-beam
Wenxuan Liu1,2,3, Ailin Liang4, Yanling Zhou1,2,3
1Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, No. 56, Lingyuan West Road, Guangzhou, 510055, China.
Background:
External root resorption (ERR) on second molars (M2s) is an undesirable type of pathological damage associated with adjacent impacted third molars (iM3s). Owing to its limited detectability on conventional radiographs, ERR may remain undiagnosed until irreversible damage has occurred. This systematic review aimed to quantitatively evaluate the association between iM3s and ERR on M2s via cone-beam computed tomography (CBCT).
Methods:
Six databases, including PubMed, Scopus, Web of Science, the Cochrane Library, Embase and ProQuest, were searched for relevant articles published prior to June 2025. Only human studies using CBCT to investigate iM3-related ERR on M2s were included. Methodological quality was assessed via the Joanna Briggs Institute Critical Appraisal Checklist. Meta-analyses were performed using random-effects model with heterogeneity assessed via RevMan software. Meta-regression analysis and the evaluation of publication bias were conducted using Stata software.
Results:
Twenty-six articles were included in this meta-analysis: Twenty-four had a low risk of bias. The quantitative synthesis demonstrated a 31% (95% confidence interval: 26% to 36%) prevalence of iM3-associated ERR on M2s. A higher prevalence of ERR was associated with mesioangular, horizontal or transverse inclination of iM3s and direct contact with the apical third of the M2 roots.
Conclusions:
Findings indicate that ERR on M2s is related to the contact between iM3s and the apical third of M2 roots. Mesioangular, horizontal, or transverse iM3 inclinations are significantly associated with higher ERR prevalence on adjacent M2s. This study identified key associated factors for ERR on M2s with iM3s, providing evidence-based suggestions for treatment plans of asymptomatic iM3s.
Registration:
PROSPERO: CRD42022332920.
Related Concept Videos
01:15Teeth
In the bud stage, the tooth germ (an aggregation of cells) starts to form in the developing jawbone. During the cap stage, the tooth germ differentiates into enamel organ, dental papilla, and dental sac, which will later develop into the tooth's enamel, dentin and...
01:21Tooth Anatomy
The Crown, Neck, and Root
The visible part of the tooth is referred to as the crown. It's covered by enamel, the hardest substance in the human body. The crown is uniquely shaped for each type of tooth, allowing for different functions such as cutting, tearing, or grinding food.