## 4 Discussion
### Ethnic and Geographic Differences  
Ethnic and geographic variation may also influence prevalence. For example,  
* [PERSON] et al. (1981) found no significant difference in PRG prevalence between White and Black populations [11]. * [PERSON] et al. (2022) and [PERSON] et al. (2023), conducting studies in Chinese and Brazilian populations, respectively, reported prevalences of 8.4% and 21.67% [19; 23]. While this may suggest potential regional differences, it is important to note that. [PERSON] et al. (2023) found no significant racial differences within their Brazilian cohort, indicating that other factors such as sample size, methodology, or population-specific anatomical traits might account for these variations. In our study, the prevalence of PRGs was slightly higher in males (25.3%) compared to females (22.4%), but this difference was not statistically significant (\(p\) = 0.347). This aligns with studies such as [PERSON] et al. (1981), [PERSON] et al. (2019), and [PERSON] et al. (2018), which also found no significant gender differences [11; 30; 32]. However, [PERSON] et al. (2011) and [PERSON] et al. (2022) reported a significantly higher prevalence in males [23; 35], while [PERSON] et al. (2014) observed a female predominance in coronal grooves [36]. These variations may stem from population-specific genetic or developmental factors, as well as methodological differences like sample size or imaging techniques. Bilateral grooves were significantly more prevalent than unilateral grooves at both the patient level (72.8% vs. 27.2%, \(p\) < 0.001) and the tooth level (82.3% vs. 17.7, \(p\) < 0.001). This pronounced bilateral tendency contrasts with some earlier studies, such as [PERSON] et al. (2023) and [PERSON] et al. (2022), which reported higher unilateral prevalence [24; 37]. However, [PERSON] et al. found that 45% of grooves were bilateral, and [PERSON] et al. (2019) reported a higher bilateral prevalence of 62.2%, aligning more closely with our findings [29; 30]. Furthermore, [PERSON] et al. (2022) observed bilateral PRGs in 93.3% of teeth associated with bone loss, highlighting the importance of thorough bilateral assessment [23]. The consistent bilaterality in our study suggests a unique epidemiological pattern influenced by developmental or genetic factors. Unlike in vitro studies [3; 8; 38], where detection of bilateral manifestation is impossible, CBCT enabled accurate three-dimensional assessment. In our study, a chi-square test revealed no statistically significant association between gender and the unilateral/bilateral distribution (\(p\) = 0.335). [PERSON] et al. also reported observations of bilateral PRGs in both males and females but did not statistically analyze the relationship between gender and unilateral/bilateral presentation [23]. These findings collectively suggest no clear gender-related pattern in PRG distribution. Chi-square analysis showed no significant association between tooth type and bilaterality (\(p\) = 0.708). The higher prevalence of bilateral PRGs in lateral incisors is likely due to their larger representation in the sample. Regarding groove types, our study identified Type 1 grooves as the most prevalent (71.53%), followed by Type 2 (16.03%), Type 3A (10.77%), and Type 3B (1.67%). This distribution aligns with [PERSON] et al. (2019) and [PERSON] et al. (2022), who reported Type 1 as the dominant groove type (65.3% and 69.2%, respectively) [30; 39], and [PERSON] et al. (2022), who found Type 1 in 58.3% of cases [21]. These findings underscore the clinical importance of Type 1 grooves and suggest that they should be a focus of diagnostic and treatment strategies. [PERSON] et al. (2011) and [PERSON] et al. (2022) highlighted the clinical significance of rarer groove types, such as Type 3B, which are linked to severe periodontal complications and complex root anatomy [17; 23]. [PERSON] et al. (2022) further emphasized the anatomical variability of grooves, with micro-CT revealing deeper points in certain groove types, particularly Type 3B [28].