## 4 Discussion
examined 166 Bangladeshi subjects' CT scans and compared them with world data [17]. They investigated seven parameters of STM, shape and morphology of the ST [17]. Analysis of ST morphometrics was in total agreement with the current study [17]. [PERSON] [13], [PERSON] [22], and [PERSON] et al. [23] traced lateral cephalospor to determine and compare the shapes, sizes, and bridging of the ST in individuals with different skeletal patterns. In contrast to the present study, they measured only three parameters: the length, anteroposterior diameter and depth of ST; all three parameters were consistent with our study [13; 22; 23]. [PERSON] et al. analyzed lateral cephalometric radiographs of 180 subjects and estimated the size, shape and dimensions of the ST among three different skeletal classes [24]. They reported that no significant difference was found in linear dimensions of ST between the genders and different skeletal groups [24]. However, the liner dimensions were greater and inconsistent with the current study [24]. [PERSON] et al. evaluated 210 Saudi subjects for shape and size of sella turcica using CT [25]. They measured anteroposterior dimension, length, depth and volume of ST; the first three parameters (except the last parameter) were consistent with the current study. The volume of ST was not measured in the current study [25]. [PERSON] et al. analyzed 175 lateral cephalometric radiographs for ST size and morphology in three skeletal malocclusions [26]. They estimated length, depth and anteroposterior diameter of ST using cephalometric software 'Vista Dent' [26]. Except for the length, the remaining two parameters of the ST were consistent with our study [26]. [PERSON] et al. investigated 159 CBCT volumes for estimation of ST dimensions in three different craniofacial skeletal patterns [15]. They divided ST into right and left regions and included nine parameters for estimation of ST dimensions. Their results were inconsistent with the current study [15]. This inconsistency could be related to several factors, such as age of the subjects (18-40 years), gender, genetic factors and measurement method employed [15]. [PERSON] et al. studied 300 lateral cephalograms for the linear dimensions and morphology of ST in cleft and non-cleft subjects [27]. They observed normal dimensions of length, depth and diameter in non-cleft subjects, which was in agreement with the current study [27]. [PERSON] and [PERSON] investigated lateral cephalograms and OPGs of 123 cleft subjects from Kingdom of Saudi Arabia for ST morphometrics, bridging, and associated anomalies [14]. All seven parameters measured in four groups--bilateral cleft lip and palate (BCLP), unilateral cleft lip and palate (UCLP), unilateral cleft lip (UCL), and unilateral cleft lip and alveolus (UCLA)--were in accordance with the current study except the non-cleft group; also, the BCLP group exhibited smaller values when compared with other groups [14]. Most of the previous studies employed two-dimensional conventional imaging, which has its own limitations such as superimposition of other cranial bones, landmark identifications and tracing errors. This could be one of the factors responsible for the differences in the measurements of STM [14; 20; 28; 29]. This study employed advanced three-dimensional CBCT imaging, which allowed effective three-dimensional viewing of the SOS and ST free of superimpositions [4; 8; 12; 15; 18; 19]. CBCT can accurately spot the position of the impacted maxillary canines. The location of the impacted tooth plays an important role in determining the feasibility of the surgical approach and the proper direction for the application of orthodontic forces [8]. A few drawbacks of this study could be that it studied the subjects from a single-center Saudi population and also did not compare with global data. The difference in STM morphometrics could be due to different evaluation methods employed. Future studies could involve a wider, multi-center sample size and compare with global data involving many populations.