## 1 Introduction  
Dental caries is a multifactorial disease that initiates with demineralization of the teeth [1]. Untreated caries progress to involve the pulp [2], a condition that requires root canal treatment (RCT). The outcome of a successful RCT depends on knowledge of the morphology of a tooth, which can affect cleaning, shaping, and obtin three-dimension (3-D) [3]. The incapability to detect, debride, and shape root canals is one of the most common reasons for the failure of endodontic treatment [4]. The occurrence of anatomic deviations in the root canal morphology offers a significant challenge to dental practitioners [5]. Improper endodontic treatment eventually gives space to microorganisms that can enter the canal and cause endodontic failure [6]. Henceforth, appropriate skills are required to properly treat teeth with complex root canal systems [7]. Researchers have used various techniques to observe the inner and outer anatomy of the tooth, such as conventional radiographs, modified radiographic techniques, cone beam computed tomography (CBCT), and microcomputed tomography (micro-CT) [8]. Among these techniques, the use of micro-CT to study the tooth morphology gives high-quality details in 3-D and can be used for quantitative as well as qualitative analysis (3). Additionally, scan thickness of micro-CT is less than computed tomography (CT); therefore, it could produce high-definition (HD) images with minimum destruction of the samples [9].  
The morphology of the root canal could be different in people with different racial backgrounds [9]. The knowledge obtained from various racial regions could help in locating and negotiating root canals in an ideal way [3]. The maxillary second premolar (MSP) is one of the most challenging teeth for endodontic treatment as it has shown significant variations in its root canal configuration, as shown in previous studies [5; 10; 11]. This tooth usually presents with one or two root canals, but occasionally, a third canal is also found [12]. However, the majority of the studies in the literature have reported a higher incidence of two root canals [13; 14]. The MSPs mostly have a single root; however, two roots and three roots are also observed. Maximally premolars (first or second) having three roots are regarded as \"ridiculous premolars\" or \"small molars\" [15; 16]. Concerning the root canal configuration of MSPs, its incidence varies among different populations. An earlier study from Turkey [17] reported Vertucci's type-I canal configuration [18] to be most prevalent in MSPs as it was found in 77.6% of the teeth. Another study reported type-II Vertucci's canal configuration to be most commonly found in their study (present in 43.3% MSPs) [19]. It should also be noted that MSPs also present with diacetated canals (merged or independent) [20]. Therefore, in the light of the abovementioned evidence, it can be said that MSPs pose anatomical challenges in root canal navigation and treatment. Knowledge on MSP anatomy could prove to be valuable, as it would aid dental practitioners in performing successful endodontic treatments, reducing the incidence of endodontic failures.  
There is a deficit of studies in the literature from Pakistan that have studied the morphology of MSPs root canals. Three previous studies that were reported from this region studying the morphology of the same tooth have used clinical examination aided by conventional radiography and CBCT [14; 21; 22]. To the best of our understanding, no studies in the literature from this region exist that have utilized micro-CT to appraise the root canal morphology of MSPs. Therefore, the current study was aimed at evaluating the morphology of the MSPs root canal and to compare it with an already established root canal morphology classification system.