Classification and morphology of middle mesial canals of mandibular first molars in a southern Chinese subpopulation: a cone-beam computed tomographic study

Abstract

Background Cone-beam computed tomography (CBCT) was employed to study the morphology and curvature of middle mesial canals (MMCs) of mandibular first molars (MFMs). Methods CBCT scanning was performed on MFMs of 1100 patients. Patients' images that met the inclusion criteria were divided into group A (< 40 years old) and group B (≥ 40 years old) for further study. The images were used to study the incidence of MMCs at different ages, measure the curvature of MMCs in the mesiodistal and buccolingual directions using the Schneider method, and observe the anatomical morphology of the mesial root canal system. All statistical analyses were performed by using SPSS 21.0 software. Quantitative data were presented as mean ± standard deviation. Student’s t-test was used to calculate the statistical significance. P < 0.05 was considered statistically significant. Results In 875 patients, 1750 MFM images met the inclusion criteria. Among these cases, 158 MFMs contained an MMC, yielding an incidence rate of 9.03%. The incidence rate of MMCs was 11.22% in group A and 6.61% in group B, and this difference was statistically significant (P < 0.05). The curvature in the mesiodistal direction was 29.39 ± 8.53° in group A and 26.06 ± 8.50° in group B, and this difference was also significant (P < 0.05). The curved regions in groups A and B were often located in the middle 1/3 of canal. No significant difference in the distance between MMC orifices and mesiobuccal canal orifices or mesiolingual canal orifices was noted (P > 0.05). The most common mesial root canal morphological type was type II (3-2) (53.80%). Conclusion The incidence of MMCs in MFMs declined as age increased. The canal systems of MMCs were varied and complex, mainly exhibiting an obvious mesiodistal curve. CBCT is an outstanding method to help guide root canal therapy. *Yeqing Yang and Buling Wu have contribute equally to this article.

Vertucci’s root canal configuration of 11,376 mandibular anteriors and its relationship with distolingual roots in mandibular first molars in a Cantonese population: a cone-beam computed tomography study

“…CBCT may be considered if the clinician suspects the presence of multiple root canals. The accuracy of CBCT is much higher than that of periapical radiographs [ 30 , 31 ].…”

A systematic review and meta-analysis of the prevalence and global distribution of middle mesial canals in mandibular molars identified by CBCT

“…As mentioned above, no meta-analysis was performed on age and its relation with the prevalence of MMC because of the insufficient data and heterogeneity of the most included studies regarding age. However, some studies reported that the prevalence of identifiable MMC decreases as age increases [ 8 , 46 ]. Therefore, the prevalence of identifiable MMC could be related to secondary dentin deposition [ 58 ].…”

Incidência do canal médio-mesial em primeiros molares inferiores através de Tomografia Computadorizada Cone Beam

“…A importância da TCFC na endodontia, especialmente para a localização e estabelecimento da anatomia do canal MM em primeiros molares inferiores, está demonstrada nos resultados apresentados. Isso também está demonstrado em inúmeros estudos revisados (La et al, 2010;de Toubes et al, 2012;Chavda & Garg, 2016;Versiani et al, 2016;Tahmasbi et al, 2017;Srivastava et al, 2018;Tomaszewska et al, 2018;Honap et al, 2020;Kuzekanani et al, 2020;Weinberg et al, 2020;Xu et al, 2020;Yang et al, 2020) que utilizaram a TCFC como critério de avaliação isoladamente, ou em comparação com outros métodos.…”

“…Em relação ao gênero, nesse estudo, não houve diferença estatisticamente significante na incidência entre mulheres e homens o que também foi constatado em outros estudos (Huang et al, 2010;Nosrat et al, 2015;Tahmasbi et al, 2017;Srivastava et al, 2018;Xu et al, 2020;Yang et al, 2020). (Nosrat et al, 2015;Chavda et al, 2016, Versiani et al, 2016Tahmasbi et al, 2017;Srivastava et al, 2018;Weinberg et al, 2020;Xu et al, 2020).…”

“…Dentre os dentes pesquisados, os molares inferiores têm sido alvo de algumas pesquisas que destacaram uma enorme variação anatômica (Aminsobhani et al, 2010;Kuzekanani et al, 2020;de Toubes et al, 2012;Srivastava et al, 2018;Versiani et al,2016;Weinberg et al, 2020;Xu et al, 2020;Yang et al, 2020) podendo apresentar inúmeras configurações e quantidade de canais radiculares.…”