Four-Rooted Maxillary First Molars: A Systematic Review and Meta-Analysis

Anatomic relationship between the root apex of maxillary molars and maxillary sinus in the presence of antagonist teeth: A Kwak's method with divisions

OBJECTIVE

The purpose of the study was to evaluate the proximity between the root apices of maxillary molars and maxillary sinus floor using cone-beam computed tomography (CBCT) in the southern Turkish subpopulation.

DESIGN

For the study, 246 CBCT images were analyzed. The absence of antagonist teeth was excluded. Kwak's types III and V were detailed with three divisions. Division M; the penetration of the mesial root only, Division D; the penetration of the distal root only, and Division MD; the penetration of both buccal roots. The distance between the maxillary sinus and the root apices was measured. Student's t-test, one-way ANOVA, and chi-square were used for statistical analysis.

RESULTS

The penetration of maxillary molars was 24.40%. The highest prevalence belonging to Type I. Division MD was 44.35% for Type III and 40.42% for Type V. Division M was higher than Division D. The distances between the sinus and root apices were 1.35-2.41 mm in Type I. The distance decreased with age (p < 0.05).

CONCLUSION

Both buccal root penetration into the sinus was higher than the single root penetration. The distance of the second molar root apices to the sinus was closer than the first molar. One-quarter of the first and second molars were inside the sinus. A greater likelihood of penetration of the root apices into the sinus with increased age.

Endodontic Treatment of a Maxillary First Molar With Two Separate Palatal Roots: A Case Report

Maxillary first molars exhibit considerable anatomical variation, with a single palatal root being the most common occurrence, while two palatal roots are notably less frequent. This case report details the endodontic treatment of a maxillary first molar with two separate palatal roots. It highlights the critical importance of recognizing these anatomical variations and their unique challenges during endodontic procedures. This report emphasizes the essential role of advanced diagnostic methods, such as cone-beam computed tomography, and the use of microscopic techniques in identifying and treating such cases.

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

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.