, Chicago, IL, USA). Statistically significant differences were evaluated using the chi-square test, with significance set at P<.05. RESULTS The numbers and percentages of mandibular premolars directly and molars evaluated in this study population are shown in Table 2. Table 2 Number and percentage of mandibular premolars and molars in study population. Mandibular first premolars and second premolars In total, 790 teeth (99.9%) were detected to have a one-rooted mandibular first premolar. Only one tooth (0.1%) had a two-rooted mandibular first premolar. The overall occurrence of the roots between female and male participants and the occurrence on the left side and the right side did not display any significant difference (P>.05; Table 3 and and44).

Table 3 Classification of permanent mandibular premolars and molars by root number and topology (right and left side). Table 4 Classification of permanent mandibular premolars and molars by gender. In addition, 784 mandibular second premolars were one-rooted (99.4%), and five second premolars (0.6%) were two-rooted teeth. There were no significant differences between females and males regarding the overall occurrence of the roots (P>.05). Likewise, the occurrence on the left side and the right side did not show any statistically significant difference (P>.05; Tab. 3 and and44). Mandibular first molars The majority of first molars (77.4%) had one mesial and one distal root (Table 3 and and4).4). One hundred sixty-two mandibular first molars (22.3%) had DL roots, and two first molars (0.3%) were one-rooted teeth.

The bilateral incidence of three-rooted mandibular first molars was similar between male (n=28) and female subjects (n=25; P>.05; Table 5). Regardless of gender, the overall occurrence on the left side and the right side showed a statistically significant difference (P=.011). The right mandibular first molar (tooth n=90, 13.5%) had a higher incidence of being a three-rooted tooth when compared with the left side (tooth n=59, 8.9%). Table 5 Analysis of gender distribution in unilateral and bilateral cases of (1) mandibular first molars with two distal roots in patients having bilateral mandibular first molars, (2) mandibular second molars with two distal roots in patients having both mandibular … Mandibular second molars Most mandibular second molars (54.5%) were two-rooted teeth with one mesial and one distal root; 2.

3% of the second molars had three roots having one DL root, and one tooth (0.1%) had three roots with two mesial roots. In total, 293 teeth (41.3%) had Entinostat C-shaped roots (Table 3 and and44). The bilateral incidence of a three-rooted mandibular second molar having one DL root was similar between females (n=2) and males (n=2; Table 5). The right mandibular second molars (tooth n=6) had a similar incidence of being a three-rooted tooth when compared with the left side (tooth n=7).