Comparing the crown and root metric properties of double-rooted and single-rooted mandibular canine teeth

OBJECTIVES

To compare the crown and root metric properties of two- and single-rooted/multi-canal mandibular canines (MnCn) with single-rooted/single-canal MnCn.

METHODS

Cone-beam computed tomography images of 1000 patients (500 women and 500 men) with both right and left MnCn were analyzed. First, the root and canal morphologies of all teeth were examined. Then, the teeth were divided into three groups; (a) 2-rooted, (b) 1-rooted and multi-canals, (c) 1-rooted and single-canal. Crown lengths/sizes and tooth lengths were compared between the three groups. Statistical analyses were performed using Chi-square, one-way ANOVA, Welch, post hoc pairwise comparison, and independent sample t-tests. The significance level was set at 5%.

RESULTS

Of all the teeth, 2.35% were 2-rooted, and 6.3% were 1-rooted/multi-canal. The frequency of double roots was higher in women (p < 0.05). Double-rooted teeth had longer crown lengths but shorter tooth lengths than single-rooted teeth (p < 0.05). In 2-rooted teeth, buccal and lingual root lengths were similar, root bifurcation levels were mostly at the mid-root, and the mean distance of the bifurcation points of the canals to the cemento-enamel junction was 4.09 mm. Double-rooted teeth were mostly observed unilaterally.

CONCLUSIONS

Since 2-rooted MnCn do not differ significantly from other teeth in terms of crown sizes, it is not possible to differentiate between single- vs. double-rooted MnCn based on clinical examination.

Prevalence of three-rooted mandibular permanent first and second molars in the Saudi population

Introduction

This study aims to explore the frequency and factors affecting the prevalence of an extra root in the lower first and second permanent molars in the Saudi population.

Methods

Images of 379 Saudi patients who underwent CBCT for routine dental treatment were assessed. The CBCT images were evaluated on a 34-inch LED screen in a dark room and assessed by two examiners to count the prevalence of an additional root in the lower molars. Laterality and the gender factors were used to analyze that prevalence. Percentages represent categorical variables; Fisher’s exact test and Chi square test were also used for the categorical variables.

Results

In the lower first molars, the prevalence of extra root in female patients was 5.7%, 3% in male patients and the overall prevalence was 3.05%; in lower second molars, the prevalence was 1.81% in female patients and 3.04% in male patients with an overall prevalence of 1.48%. A statistically significant difference was fond in the existence of an additional root with regard to laterality, to be more common on the right compared to the left side for both mandibular molars. The extra root prevalence was statistically significant in female patients at the first molar compared to male patients (p < 0.05).

Conclusion

The overall of extra roots prevalence in the lower first and second molars in the Saudi population are 3.05% and 1.48%, respectively. Consideration and identification of this variation is essential to ensure successful endodontic treatment.

Case reports and clinical guidelines for managing radix entomolaris

Knowledge about the external and internal anatomy of the tooth is essential for successful dental practice. Anomalies in the tooth are often encountered which poses difficulties in dental treatments. As like any other tooth, mandibular first molars are also prone for anatomic malformations. One such anatomic variation is the presence of extra root distolingually. This distolingual root is called radix entomolaris (RE). The presence of an additional root can lead to difficulties during endodontic therapy. This article is a report of two cases describing the management of the first mandibular molars with an RE and clinical guidelines for its management.