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Review
. 2022 Mar 28:2022:9411076.
doi: 10.1155/2022/9411076. eCollection 2022.

Three-Rooted Permanent Mandibular First Molars: A Meta-Analysis of Prevalence

Nyan M Aung  1 , Kyaw K Myint  2
Affiliations
Review

Three-Rooted Permanent Mandibular First Molars: A Meta-Analysis of Prevalence

Nyan M Aung et al. Int J Dent. .

Abstract

Introduction: Although numerous amounts of high-level evidence were present, they solely emphasized the tooth-level prevalence of three-rooted permanent mandibular first molar. Global patient-level prevalence and bilateral symmetrical distribution of this type of teeth were needed to be tackled across the world. The research question was "What is the global prevalence of three-rooted permanent mandibular first molars?"

Materials and methods: In vivo epidemiological studies undergone with Cone Beam Computed Tomography (CBCT) were eligible. The proportions of the prevalence of three-rooted permanent mandibular first molars were presented in the forest plots by random effect model. The calculation was performed with MetaXL version 5.3. Subgroup analysis, sensitivity analysis, and publication bias method were also calculated.

Results: Seventy-two studies from 31 countries were selected for both qualitative and quantitative analyses. 26302 patients and 37994 permanent mandibular first molars were included in the analysis. 9% of permanent mandibular first molars all over the world demonstrated 3 roots. These three-rooted teeth were found in 10% of the world population, more than 45% of which revealed bilateral symmetry of that anatomy. Right-side dominance and no sexual dimorphism were seen in the distribution of three-rooted permanent mandibular first molars. Global tooth-level prevalence of Radix Entomolaris and Radix Paramolaris was 12% and 0.1%, respectively.

Conclusion: The prevalence of three-rooted permanent mandibular first molars (PMFMs) was influenced by different geographical locations across the world and also by widespread habitation of the Mongoloid descent. The authors postulate that globalization, together with blending among ethnicities, may have a great impact on the reduction or accentuation of the anatomical significance in some populations.

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Conflict of interest statement

The authors declare that they have no conflicts of interest.

Figures

Figure 1
Figure 1
Variations in the position of the third root of right PMFM: (a) distolingual position at which the third root stands from the lingual aspect of the distal root, (b) centrolingual position at which the third root is midway between mesial and distal roots at the lingual surface, (c) mesial-lingual position at which the third root branches from and lingual to mesial root, (d) mesiobuccal position at which the third root stems from buccal aspect of mesial root, (e) distobuccal position at which the third root rises from buccal to distal root, and (f) the third root that splits from the apical third of the mesial root.
Figure 2
Figure 2
Distal proximal view of right three-rooted PMFM showing various curvatures of the distolingual root.
Figure 3
Figure 3
Distal proximal view of right three-rooted PMFM showing variations in the size of the distolingual root.
Figure 4
Figure 4
Flow diagram of identifying, screening, and processing the studies.
Figure 5
Figure 5
Summary of research methodology of the included studies.
Figure 6
Figure 6
Global tooth-level prevalence of three-rooted PMFM.
Figure 7
Figure 7
Global patient-level prevalence of three-rooted PMFM.
Figure 8
Figure 8
Global patient-level bilateral symmetry of three-rooted PMFM.
Figure 9
Figure 9
Funnel plot of global tooth-level prevalence of three-rooted PMFM (Ι).
Figure 10
Figure 10
Funnel plot of global patient-level prevalence of bilateral symmetrical distribution of three-rooted PMFM.
Figure 11
Figure 11
Funnel plot of global patient-level prevalence of three-rooted PMFM.
See this image and copyright information in PMC

References

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