Root Morphology Of Mandibular Premolars Research Articles

Internal Morphological Variability of Mandibular Premolars in North Indian Population

Aims: The current study aims to investigate the root canal morphology of root canals of mandibular premolar teeth via cone-beam computed tomography (CBCT) among a sample of the north Indian population.
 Study Design: Retrospective observational study.
 Place and Duration of Study: Department of conservative dentistry and endodontics.
 Methodology: A total of 240 CBCT images were examined in the study. The Mandibular premolars were identified, and canal configurations were classified according to vertucci classification. Root canal configurations were investigated using a chi-square test.
 Results: Of the total 240 Mandibular premolars, vertucci type I was found in 86.66% in Mandibular first premolars followed by type v (8.33%) and type iv (5%). Vertucci type I was found in 96.6% in Mandibular second premolars followed by type v (1.66%), type iii (0.8%) and type viii (0.8%).
 Conclusion: The root morphology of Mandibular premolars in the north Indian population demonstrated a high degree of variability. However, the clinician should be aware about the possible anatomic variations of these teeth and their relationship with the adjacent anatomic structures while planning and performing endodontic, restorative, periodontal, and surgical procedures.

Canal configuration and root morphology of mandibular premolars using cone-beam computed tomography in a Korean population.

This study aimed to investigate the anatomy of mandibular premolars from two perspectives-the canal configuration and radicular grooves-using cone-beam computed tomography (CBCT) in a large Korean population. CBCT images of mandibles acquired from March 2018 to December 2019 for dental treatment were randomly selected. In each image, the root canal of premolars was classified into 8 types according to the canal merging or diverging pattern and the number of apical foramens. The presence and the location of radicular grooves were also assessed. Statistical analysis was performed. A total of 1463 first and 1448s premolars from 732 patients (390 males, 342 females, mean age of 36.1years) were evaluated. A single canal with one foramen predominated in both first (85.7%) and second (99.5%) premolars, while complete or partial multi-canals accounted for 14.3% and 0.5% of first and second premolars, respectively. The prevalence of radicular grooves was significantly higher in first premolars (13.2%) than in second premolars (0.5%) and in males (4.3%, n = 119) than in females (2.5%, n = 73). Although most premolars were complete single canals, the first premolars showed a relatively higher number of complex canals compared to the second premolar. In addition, radicular grooves in mandibular premolars were significantly more common in male patients. When planning the endodontic treatment of mandibular premolars, clinicians should be aware of their morphologic complexity, especially in the first premolar of male patients.

Double Roots of Mandibular Premolar in Full-mouth Periapical Films.

To evaluate the incidence of two-rooted mandibular premolar morphology using full-mouth periapical film series in a Chinese population, with particular emphasis on bilateral incidence, so as to provide a clinical anatomical basis for root canal treatment in mandibular premolars. A total of 2015 patients who underwent dental treatment and had full mouth periapical radiographs at the Peking University School of Stomatology from April 2011 to April 2012 were enrolled in this study. Three experienced dentists reviewed the patients' periapical films and classified the root morphology of mandibular premolars bilaterally. The incidence of unilateral and bilateral double roots were recorded and calculated, including confirmed and suspected bucco-lingual root types. In terms of the morphology of two-rooted mandibular first premolars, of the 2015 cases with complete root formation, two-rooted first premolars were detected in 120 cases, with a total number of 159 teeth. According to the number of teeth, the overall incidence of double roots was 4.03% (159/3972). In terms of the morphology of two-rooted mandibular second premolars, of the 2015 cases with complete root formation, two-rooted second premolars were detected in 24 cases, with a total number of 33 teeth. According to the number of teeth, the overall incidence of double roots was 0.85% (33/3880). The roots of mandibular premolars display specific morphological patterns. Based on a large sample, we observed and calculated not only the occurrence rate of bucco-lingual and mesio-distal double roots in first and second mandibular premolars, but also the incidence of unilateral or bilateral double roots within the same mandible. These findings could provide useful information on the anatomical structure of mandibular premolars for endodontic, prosthodontic and surgical procedures, and could improve the quality of treatment and reduce complications.

Root morphology of mandibular premolars in 40 patients with Turner syndrome

To analyse root morphology of mandibular premolars in 40 females with Turner syndrome. All patients aged 18-50 years (mean+/-SD: 26.2+/-6.22) were clinically and cytogenetically diagnosed and divided into three groups according to karyotype: I-with 45,X (n=19); II-with 46,X,i(Xq) and other structural changes of this chromosome (n=8); III-with mos45,X/46,XX and other mosaic karyotype (n=13). The control group consisted of 30 healthy women aged 20-50 years (mean+/-SD: 31.52+/-5.21) who underwent dental treatment at the Department of Conservative Dentistry and Department of Periodontology and Oral Mucosa Diseases, Medical University of Gdańsk, Poland. The root morphology of mandibular premolars was studied based on orthopantomogram X-ray images. The results were analysed using chi-square test with Yates's adjustment. Separate mesial and distal root canals and separate root apices were noted on orthopantomograms in patients with Turner syndrome. Two-rooted mandibular first premolars were observed in 34% of cases in group 45,X (group I), in 31% of cases in the group with structural aberrations of chromosome X (group II) and in 31% of cases with mosaic karyotypes (group III). Two-rooted mandibular second premolars were observed in 39% cases in group 45,X and in 31% of cases in the group with structural aberrations of chromosome X and in 35% of cases with mosaic karyotypes. This type of root morphology was not observed in the control group. No significant difference was found between the three groups of Turner syndrome. Highly significant differences in root morphology of mandibular premolars between patients with Turner syndrome and a population control group were found.

Effect of 45,X/46,XX mosaicism on root morphology of mandibular premolars.

The effect of X chromosome mosaicism on root morphology of mandibular premolars was studied in 14 females with 45,X/46,XX chromosome constitution. Occurrences of two-rooted premolars and the morphology of the roots were examined from orthopantomograms. Six (43%) of the 45,X/46,XX mosaics had two-rooted mandibular premolars. Two-rooted first premolars were found in four (29%) and second premolars in three (21%); in one, all four mandibular premolars were two-rooted. The results indicate that the frequency of two-rooted mandibular premolars was similar in 45,X/46,XX mosaics and in 45,X females, and in both groups significantly higher than in normal 46,XX females. Compared with 45,X females, the 45,X/46,XX mosaics showed a slight tendency toward more simplified root morphology in the first premolars. The findings suggest that the presence of normal 46,XX cells among the defective 45,X cells does not affect the development of the mandibular premolar roots. Furthermore, the results do not support the earlier proposal that the presence of normal 46,XX cells in 45,X/46,XX mosaic individuals would be reflected in gradual normalization of dental development.

Root morphology of mandibular premolars in human 45,X females

The teeth of 87 Finnish 45,X females, 60 of their first-degree relatives and 87 normal females were examined. The presence of separate mesial and distal root canals and separate root apices was noted from orthopantomograms. Of the 45,X females, 40 (or 46%) had lower premolars with separate root canals; 30 individuals in first and 28 in second premolars. The number of first and second premolars with separate mesial and distal root canals was 40 and 43, and of those also showing separate apices, 28 and 21 respectively. Three of the female relatives and two of the normal females had premolars with separate mesial and distal root canals. The differences between the 45,X females and the two control samples were highly significant ( p < 0.001; Fisher exact test). The findings indicate increased molarization of the premolars in 45,X females; this contrasts with the earlier observation of a tendency to reduced crown morphology. The present outcome supports the hypothesis that the X chromosome has gene(s) involved in the regulation of root morphology.