Fused roots of maxillary molars: characterization and prevalence in a Latin American sub-population: a cone beam computed tomography study

Exploring the sex-associated differences in molars fused roots

BACKGROUND

Human sexual dimorphism is associated with many biological characteristics, including dental variables.

OBJECTIVES

To investigate if molars fused roots present sex-associated differences.

METHODS

Panoramic radiographs were used to investigate the frequency and distribution of permanent molars fused roots. Only patients with all first and second permanent molars were included. Third molars were not investigated. Any molar with roots fused apical to the usual furcal position were considered molar fused roots. Comparisons between males and females were performed using chi-square or Fisher's and Mann-Whitney tests and the established alpha was 5% (p<0.05). Sex-differential liability models were also proposed.

RESULTS

A total of 84 males and 86 females were included and 1360 molars were analyzed. Among them, 46 (26.06%) present at least one molar with fused root. Second maxillary molars were the most affected teeth. There was an association between sex and molars with fused roots. Females had a 3.4 higher chance to present fused roots than males (OR=3.4, CI 95% 1.6-6.8; p=0.0008). The female: male ratio of molars with fused roots was 2.5:1. The number of molars with fused roots ranged from 1 to 6 per patient, and the mean number of Females presented more molars with fused roots (mean = 1.01; standard deviation = 1.52) than males (mean = 0.31; standard deviation = 0.85) (p<0.05).

CONCLUSIONS

Molar fused root of permanent teeth presents sex-associated differences, in which females are more affected than males. Our results support sex-differential liability models for molars fused roots.

Prevalence of root fusion in canine maxillary second molar teeth using cone-beam computed tomography

This study evaluated the prevalence of root fusion in the right and left maxillary second molar teeth in dogs using cone-beam computed tomography (CBCT). A total of 180 dog CBCT scans, or a total of 360 maxillary second molar teeth, were analyzed in this study. Dogs were divided into weight categories of small (<10 kg), medium (10-25 kg), and large (>25 kg). Skull type (brachycephalic, mesocephalic, dolichocephalic) and sex were also recorded for each dog. Overall, 65% of maxillary second molar teeth had some type of root fusion. Of the teeth that had fusion, the only configuration represented was fusion of the distobuccal root with the palatal root. The most common root morphology overall (all dogs and both right and left maxillary second molar teeth included) was partial fusion (177/360, 49%). With the high prevalence of fused roots in maxillary second molar teeth in dogs found in this study, CBCT will help clinicians to more accurately assess a dog's anatomy and implications for treatment.

Assessment of C-Shaped Canal Morphology in Mandibular and Maxillary Second Molars in an Iraqi Subpopulation Using Cone-Beam Computed Tomography

Endodontic treatment is basically dependent on knowledge of the root canal anatomy. The goal of this study was to use cone-beam computed tomography (CBCT) imaging to examine the C-shaped canal configuration of mandibular and maxillary second molars in an Iraqi subpopulation. The prevalence and configurations of C-shaped canals were evaluated in 368 mandibular second molars and 369 maxillary second molars using CBCT scans. The effects of gender, age, and unilateral/bilateral on the presence of C-shaped canals were investigated. Chi-square and Fisher's exact tests were used to determine the level of significance (p ≤ 0.05), and kappa value was used to check reliability of results of the research. In mandibular second molars, the prevalence of C-shaped canals was 17.4%. The prevalence was significantly higher in females (23%) than males (10.4%) using the chi-square test. There is no significant difference in the prevalence of C-shaped canal depending on age and tooth position. The C2 type was the most common (56.3%). This prevalence did not differ with gender, age, or tooth position. In maxillary second molars, C-shaped canals were present in 7.9%. Type I (subtype C) (fusion of 2 root canals MB-DB) was the most common type of fused root (65.5%). There is no significant difference in the prevalence of C-shaped canal depending on the type of fused root, age, and tooth position. The majority of C-shaped canals in mandibular second molars were bilateral in both genders, but unilateral presence was more common in maxillary second molars in both genders. Within the limits of this study, C-shaped canals were found to be more common in mandibular second molars than in maxillary second molars in an Iraqi subpopulation.

Investigating prevalence of dental anomalies in Eastern Province of Saudi Arabia through digital orthopantomogram

Objective

The aim of this study was to investigate the prevalence of dental anomalies in the Eastern Province of Saudi Arabia using the digital Orthopantomography (OPG).

Methods

A retrospective radiographic study was performed in which digital OPGs of 1189 subjects, ages ranging between 7 and 65 years were reviewed, and 1104 fulfilled inclusion criteria. Statistical analysis was performed. The OPGs were reviewed for congenitally missing teeth, impactions, ectopic eruption, supernumerary teeth, odontomas, dilacerations, taurodontism, dens in dente, gemination and fusion.

Results

OPGs of 1104 patients with mean age 35.32 ± 16.63 were included. The total prevalence of developmental anomalies in this study was 36.3% (401/1104). Male and female subjects with anomalies were 133 (33.2%) and 268 (66.8%) respectively. The prevalence of dilacerated teeth 300 (30.2%), congenitally missing teeth was 246 (24.7%), supernumerary teeth 18 (1.8%), talon cusp and taurodontism were seen in one patient each 1 (0.1%). Of these, a total of 15 (1.5%) anomalies were noted in pediatric patients.

Conclusions

Dilaceration was the most prevalent anomaly (30.2%) in the studied sample followed by congenitally missing teeth (23.4%). Talon cusp, concrescence/fusion, and taurodontism were the least prevalent anomalies.