Evidence map›Paper›PMID 40325295›Full record

SynthesisEuropean archives of paediatric dentistry : official journal of the European Academy of Paediatric Dentistry2025

Root anatomy and canal configuration of primary molars: a systemic review and meta-analysis.

Q Wen, Y Wang, H Ren, X Chen, J Zheng, L Ge, Y Zhao

Abstract readSystematic ReviewMeta-Analysis
PubMed Publisher
In one paragraph

Synthesis in European archives of paediatric dentistry : official journal of the European Academy of Paediatric Dentistry, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 4 papers.

0numbers the graph read from it
0cells of the map it votes in
4citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

4 citing papers in PubMed.

  1. Article
  2. Article
  3. Article
  4. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors.

Q Wen *First Clinical Division, Peking University School and Hospital of Stomatology, National Center for Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Research Center of Oral Biomaterials and Digital Medical Devices, 37A Xishiku Street, Xicheng District, Beijing, 100034, China.
Y Wang *State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & West China Hospital of Stomatology, Sichuan University, Chengdu, 610064, China.
H RenDepartment of Pediatric Dentistry, Peking University School and Hospital of Stomatology, National Center for Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Research Center of Oral Biomaterials and Digital Medical Devices, No.22, Zhongguancun South Avenue, Haidian District, Beijing, 100081, China.
X ChenFirst Clinical Division, Peking University School and Hospital of Stomatology, National Center for Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Research Center of Oral Biomaterials and Digital Medical Devices, 37A Xishiku Street, Xicheng District, Beijing, 100034, China.
J ZhengFirst Clinical Division, Peking University School and Hospital of Stomatology, National Center for Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Research Center of Oral Biomaterials and Digital Medical Devices, 37A Xishiku Street, Xicheng District, Beijing, 100034, China.
L GeDepartment of Pediatric Dentistry, Peking University School and Hospital of Stomatology, National Center for Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Research Center of Oral Biomaterials and Digital Medical Devices, No.22, Zhongguancun South Avenue, Haidian District, Beijing, 100081, China.
Y ZhaoDepartment of Pediatric Dentistry, Peking University School and Hospital of Stomatology, National Center for Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Research Center of Oral Biomaterials and Digital Medical Devices, No.22, Zhongguancun South Avenue, Haidian District, Beijing, 100081, China. yumingzhao70@sina.com.

Funding

National Natural Science Foundation of China 82401050the Beijing Natural Science Foundation 7212135Youth Foundation of Peking University School of Stomatology PKUSS20220113
6 · The paper itself

Abstract

purposePrecise knowledge of root and canal morphology in primary teeth is critical for endodontic success, yet existing studies are fragmented and lack synthesis. This systematic review and meta-analysis addresses this gap by investigating the distribution of root numbers, canal configurations, and root lengths in human primary molars, while exploring possible influencing factors.

methodsA literature search was conducted through PubMed, ScienceDirect, Web of Science, the Cochrane Library, and China National Knowledge Infrastructure (CNKI) up to September 2023. Retrospective studies using patients' cone-beam computed tomography (CBCT) data or cross-sectional studies utilizing computed tomography (CT) or CBCT on extracted primary molars reporting on the root canal morphology of primary molars were included. Study quality was assessed using a modified Newcastle-Ottawa Scale. A meta-analysis was performed to estimate the proportions of root and canal numbers and calculate the mean values of root lengths. Forest plots were used to present the results.

resultsThe search strategy identified 799 records. After screening abstracts and full texts, 30 studies met the inclusion criteria. Of these, 2 studies had a high risk of bias, 23 a moderate risk, and 5 a low risk. The meta-analysis revealed that primary maxillary first molars were predominantly three-rooted (80.2%) with three canals (96.9%), while primary maxillary second molars were primarily three-rooted (89.7%) with three or four canals (84.4% and 14.7%, respectively). Primary mandibular first and second molars typically had two roots with M2D2 being the most common canal type, though the former showed high variability in canal configurations. Root lengths were also analyzed. Subgroup analysis indicated that heterogeneity may be influenced by country and data source, while no significant differences were associated with imaging techniques.

conclusionsPrimary maxillary molars are predominantly three-rooted with three canals, while primary mandibular molars typically had two roots with four canals. Variations in root anatomy and canal configuration should be considered during endodontic treatment of primary teeth. High heterogeneity and methodological inconsistencies limit the current evidence, highlighting the need for future research to address contributing factors to heterogeneity and to develop standardized methods for assessing root and canal morphology in the primary teeth.

trial registrationPROSPERO registration no. CRD42023414536 on 2023.04.

Indexed as

Dental Pulp CavityMolarTooth, DeciduousTooth RootCone-Beam Computed TomographyHumansCone-beam computed tomographyMeta-analysisMolarPrimary teethRoot canal

Identifiers

PMID40325295

What OpenQuestion holds

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.