## 3 Results  
Data from CBCT examinations of 8012 teeth in 1553 patients (671 males, 882 females) between 12 and 78 years (mean \(\pm\) standard deviation (SD) = 34.68 \(\pm\) 13.18) were analyzed retrospectively. CBCT images of 633 patients were excluded and 920 patients (4012 teeth) were included. The distribution of the evaluated parameters is presented in Figure 3.  
The prevalence of PRGs was slightly higher in males (98 patients, 25.3%) compared to females (119 patients, 22.4%). However, a chi-square test of independence revealed no statistically significant difference between genders in terms of PRG prevalence (\(p\) = 0.347). In the patient-level analysis of PRG distribution, unilateral cases were observed in 59 patients (27.2%), while bilateral cases were more prevalent, observed in 158 patients (72.8%). A chi-square test revealed a statistically significant difference between unilateral and bilateral distributions (\(p\) < 0.001). When analyzed by gender, unilateral distribution was slightly higher in females (6.77%) compared to males (5.93%), while bilateral cases were more frequent in males (19.33%) than in females (15.6%). However, a chi-square test revealed no statistically significant association between gender and the unilateral/bilateral distribution (\(p\) = 0.335) (Table 1). \begin{table}
\begin{tabular}{c c c c} \hline
**Gender** & **Patients Examined** & **Patients with PRG** & **Unilateral** & **Bilateral** \\ \hline Female & 532 & 119 (22.37\%) & 36 (6.77\%) & 83 (15.6\%) \\ \hline Male & 388 & 98 (25.26\%) & 23 (5.93\%) & 75 (19.33\%) \\ \hline Total & 920 & 217 (23.59\%) & 59 (6.41\%) & 158 (17.17\%) \\ \hline \(p\) value & - & 0.347 & 0.335 & \textless{}0.001 * \\ \hline \end{tabular}  
* Statistically significant association between the occurrences of unilateral versus bilateral PRG manifestations in patient base analysis (\(p\) < 0.001).  
\end{table} 
Table 1: Distribution of PRG according to gender and unilateral/bilateral manifestation. Figure 3: (**a**) Groove type distribution; (**b**) groove localization; (**c**) affected tooth type; (**d**) unilateral vs. bilateral (patients); (**e**) PRG prevalence by gender. In our study, the chi-square test conducted to evaluate the distribution of PRG across different tooth types revealed a statistically significant association between tooth type and the prevalence of PRGs (\(p<0.001\)). Chi-square analysis revealed a statistically significant difference in the prevalence of unilateral and bilateral PRGs at the tooth level (\(p<0.001\)). The bilateral PRG was markedly more common than the unilateral PRG across all examined teeth. Chi-square analysis showed no significant association between tooth type and bilaterality (\(p=0.708\)) (Table 2). The initial chi-square test revealed a non-homogeneous distribution of groove types associated with PRGs (\(p<0.001\)). Type 1 grooves were the most prevalent, observed in 299 teeth (71.5%). A post hoc analysis using Bonferroni correction confirmed that the prevalence of Type 1 grooves was significantly higher compared to Type 2 (67 teeth, 16.0%, corrected \(p<0.001\)), Type 3A (45 teeth, 10.8%, corrected \(p<0.001\)), and Type 3B (7 teeth, 1.7%, corrected \(p<0.001\)). This dominance was further validated by comparing Type 1 grooves to all other types combined, showing a significant difference (\(p<0.05\)). In contrast, chi-square analysis revealed no significant association between tooth type and groove type (\(p=0.091\)) (Table 3). A chi-square test revealed that the localization distributions were statistically significant (\(p<0.001\)). Midpalatal grooves were found to be the most prevalent localization type overall, with a statistically significant predominance. Pairwise comparisons showed that midpalatal grooves were significantly more frequent than mesial grooves (\(p=0.0379\), Bonferroni-corrected), and both midpalatal and mesial grooves were significantly more frequent than distal grooves (\(p<0.001\), Bonferroni-corrected).