## 4 Discussion
It should also be noted that there is an indication of a relationship between severity of the disease and the MCW value, with higher MCW values in type III OI. This is contrary to the study by [PERSON] et al., whose MCW value increased more and with greater variability for type IV [1]. Regarding the measurement of FD in the trabecular bone (ROI I and 2), it was observed that it was a constant in all the subjects, since they presented the same value in the whole sample and were excluded from the study. As in the study by [PERSON] et al. [25], the results presented were not statistically significant between types of OI with respect to trabecular bone, concluding that there are two factors that could explain this effect: the first is the probability that the trabecular bone does not reflect the microarchitecture of the jaw, as in other bones, and, further, that the main effect of antiresorptive drugs is on the width of cortical bone, with little effect on the thickness of the trabecular bone. This is also supported by the research of [PERSON] et al. 2014, whose results suggest that measurements in cortical bone are more reliable than measurements in trabecular bone in discriminating between patients with normal BMD and osteoporotic patients [19]. Consequently, in our study, the FD measurement in the basal cortical bone (ROI 3) had a slightly lower mean value in the group of OI children, but not enough to accept that FD differs between OI cases and cases with normal BMD. Even less likely is a correlation with the type or severity of OI suspected. As for the qualitative indices, SVE and MCI, statistically significant differences were found with respect to the presence or absence of OI, the severity of the disease, the intake of cycles of antiresorptive drugs, and according to age. In most of the sample, the SVE is thin and the MCI presents more cases of C2, followed by C1 and less present C3, whereas, in the study of [PERSON] et al. 2016, the SVE was mostly not thin as a consequence of the intake of several cycles of palmitonate, stating that mandibular cortical thickness increases after the first years of administration. In the present research, the SVE did not present statistically significant differences that allow us to differentiate the OI cases from the control group subjects, which we can justify by the fact that since it is a child population, the width of the lower mandibular cortex is thinner, especially in younger children, due to mandibular growth. However, there is an indicator of a possible relationship between the thinner SVE and the severity of the disease, mostly found in type I and III, respectively. In contrast, MCI does correlate with the presence of OI, with type C2 being much more frequent in the study group, while type C1 is much more common among children in the control group. Depending on the severity of the disease, C3 cases appear mostly within type II and IV compared to type I. Type C2 subjects are similar in both groups. The collection of a simple visual estimation (SVE) and the measurement of the mandibular cortical index (MCI), without the need to use sophisticated tools or programs, can suggest which will be the expected bone alterations in relation to antiresorptive treatment in children with OI, seen in serial panoramic radiographs over time [31]. The results obtained according to the intake of antiresorptive drugs show that there is no statistically significant evidence pointing to a relationship between the number of cycles administered to patients with OI and the mean values of the fractal dimension of the cortical bone and the mandibular cortical width. We find slightly lower values in these variables in the patients who had received more cycles in comparison with those who had ingested less or who had not received treatment directly.