## 4 Discussion  
The results of our study revealed many canal types in conformity with [PERSON]'s classification, while some additional canal types were also detected. Thorough awareness of the root canal system and its anatomic deviations is mandatory for a positive endodontic treatment. This study determined the root canal morphology of MSPs in a Pakistani subpopulation. Previously, MSPs internal configuration has been testified to be highly variable [23; 24; 25; 26; 27]. According to a study by [PERSON] et al., single-rooted MSPs were found in 93% of the study sample, while the remaining study sample had two roots [28]. Another study on MSPs in China reported single roots in 92.5% of the samples while the remaining 7.5% of teeth had two roots, and no three-rooted MSPs were found in that study [19]. The outcomes of our study are in harmony with these former studies as 96.7% of MSPs had a single root whereas the remaining 3.3% had two roots. Additionally, no three-rooted MSP were found in our study. The canal numbers reported in the literature are variable for MSPs and various studies have reported different frequencies of the canals. [PERSON] et al. and [PERSON] et al. found a single canal in 27.7% and 48.66% of the samples, respectively, while 72.3% and 50.64% of the remaining samples had two canals, respectively [29; 30]. In our study, 73.3% of the samples had two canals while the remaining teeth had one canal. This finding is in accordance with these previous studies. Figure 14: Micro-CT image showing the middle third location of the isthmus. Figure 15: Micro-CT image showing the coronal third location of the isthmus. Canal configurations are also different, as reported by studies from other parts of the world. In a Saudi population, the canal configuration of type V was most predominant in MSPs, trailed by types IV, I, III, and II [9]. From Pakistan, a previous CBCT study reported that type I was the commonest root canal configuration, shadowed by type II [22]. In another study, about 39.93% of MSPs in a Spanish population had type I canal configuration trailed by type IV [31]. A previous study on the Turkish population also found the type I canal configuration to be most prevailing in MSPs [17]. In our study, the canal configuration of type 1 was most rampant, and this finding is in agreement with the outcomes of [PERSON] et al. [17], [PERSON] et al. [22], and [PERSON] et al. [31]. An accessory canal is a term used for small canals, which are found few millimeters apically [9]. It is believed that they are developed from breakage of the Hertwig epithelial root sheath (HERS), or during development, HERS grows around the prevailing blood vessels [32]. The number of accessory canals could be different, and their incidence does not follow a specific ethnicity pattern. In a previous similar study from Saudi Arabia, the incidence of accessory canals was 8% [9]. In contrast, our study revealed that 33.3% of the teeth had accessory root canals. An isthmus is an intercanal connection or crosswise anastomosis, which is a narrow ribbon-shaped communication containing pulp or pulpal derivative tissue between two root canals [3]. Its importance lies in the fact that it can act as a reservoir for bacteria, and roots that have two or more canals are highly likely to have an isthmus [23]. Our results showed that 13.3% of the samples had isthmuses, which is higher than 2%, reported in a study from Saudi Arabia [9]. On the other hand, it was lower than that reported by other studies conducted by [PERSON] et al. [23], [PERSON] and [PERSON] [24], and [PERSON] et al. [18], reporting isthmuses in 19%, 20.5%, and 30.8% of the samples, respectively. Apical delta is another important measure for successful endodontic treatment because of its ability to harbor microorganisms and difficulty getting debrided [23]. Our results revealed a higher number of apical delta (20%) compared to the study conducted by [PERSON] et al., who reported it to be 7% [9]. In an earlier study, [PERSON] et al.