## 3 Results
### Description of the Included Studies  
Only one study mentions a random patient sample, and the sample group sizes varied from 23 to 81 individuals [10]. Out of the 11 studies that were assessed, five contained sample groups solely comprised of female individuals [10; 11; 12; 13; 14; 15], another five studies analyzed samples with both male and female individuals [10; 16; 17; 18; 19], and only one study assessed an exclusively male group [20]. Four of the eleven studies specifically evaluated post-menopausal females [11; 13; 14; 15], one study evaluated acromegaly patients [20] and one study evaluated diabetic patients [20].  
Radiomorphometric analysis were used to assess BMD from CBCT images in several of the included studies. One author was involved in 3 studies [13; 14; 15] using the same sample comprised of 38 post-menopausal female patients. Although it is the same sample, the analyzes performed are from different bone zones and therefore were included as independent studies. The main results of both studies concluded that CBCT-derived radiographic density (RD) measurements of the body and ramus of the mandible and cervical vertebrae could help predict osteoporosis with an accuracy of 75% for lumbar vertebrae (LV) and 78.4% for femoral neck(FN) [15], accuracy of 90.8% for LV and 86.4% [13]. A strong correlation with LV and FN in trabecular bone structure of jawbones and odontoid process comparision, thus the authors concluded the dens-derived measures can accurately predict osteoporosis [14].  
The majority of the studies chose the lumbar spine as the preferred structure to assess BMD and to posteriorly compare the results to the CBCT of the mandibular cortical and cancellous bone. Four of the included studies compared the mandibular cortical bone with the lumbar spine DEXA obtaining an r value that fluctuated from 0.411 to 0.857 [12; 16; 17; 19; 20]. The highest correlation value that was observed among all the selected articles was of r = 0.924 and it was attained when comparing the cortical foramen and the femoral neck [17], in contrast, the lowest correlation value was observed between  
Figure 1: PRISMA flowchart diagram. This diagram represents all the information during the different phases, from identification, screnning and inclusion of studies.  
the distal epiphysis border of the radius and the femoral neck with an r = 0.17 [19]. In general, it was concluded that BMD presents lower values in osteopororotic groups when compared to osteopenia and/or control groups.  
Regarding the software used [16,17] of the eleven studies made no mention of the chosen software to analyze CBCT images. Three of the studies by the same author used the WhiteFox (r) Imaging v.3 (Atecon Group Ltd., Milan, Italy) software [13, 14, 15]. The i-Cat vision (Imaging Sciences International Inc., Hatfield, PA, USA) software was only used in oneof the studies [10]. Two out of the 11 studies assessed used Planmeca Romexis (Helsinki, Finland), another two [11,18] used the OnDemand 3-D Dental Software (CyberMed, Seoul, Republic of Korea) and only one studyused the Bonel 1.3.9 program, (U.S. National Institutes of Health, Bethesda, MD, USA) [19].  
FOV and voxel size are also important factors to take into account and two studies [16,17] did not provide any information about these variables. [PERSON] et al. [11] provided information regarding the FOV: 13 \(\times\) 14 cm and [PERSON] et al. [18] only provided information about the Voxel Size: 0.2 mm. Three studies [13, 14, 15] used values of FOV: 13 \(\times\) 15 cm and Voxel size: 0.25 mm. All other studies used different FOV and voxel values with one of these using FOV: 13 \(\times\) 15 cm and Voxel size: 0.25 mm [10], another using FOV: 8 \(\times\) 8 cm and Voxel size: 0.2 mm [12]; an additional one using FOV: 8 \(\times\) 8 cm and Voxel Size: 0.75 mm [19] and lastly, another one using FOV: 4 \(\times\) 4 cm and Voxel size: 0.4 mm [20]. Table 1 summarize the characteristics of the articles included.