## 3 Results
### Correlations between Variable
However, among the great number of the existing devices, only a few scanners meet the requirements for clinical use. For comparing the practical accuracy, [PERSON] et al. [47] used a high-accuracy industrial \"line-laser\" scanner (Faro) to evaluate two types of non-contact scanners using \"stereophotography\" (edMD), and \"structured light\" (FaceScan) technologies, in patients with facial deformities and found both scanners to be suitable for clinical use. An in vitro assessment of four scanners--EinScan Pro, EinScan Pro 2X Plus using Shining Software, iPhone X, using the Bellus3D Face Application and Planmeca ProMax 3D Mid--was performed by [PERSON] and [PERSON] [50], using a face model, printed from polylactic acid, with marked reference points. Different measurements were performed in x, y and z axes, between the reference points and compared to the values obtained by using a digital caliper. None of the four devices used were recommended for measuring the depth of more than 2 mm, the accuracy of a 3D scanner being affected by the scanning length and pattern of scanning [50]. However, the validity of the use of mobile phones as data collection devices for dental diagnosis and treatment purpose, in a clinical setting, was not previously assessed. In the present study, the \"Reference\" or \"Gold Standard\" measurement was the contact measurement method, very classical and commonly used in medical research, in agreement with previous studies [47; 51], despite the touching deformation error of facial soft tissue for a real person. Therefore, the reference for OVD measurement was considered the clinical measurement between Sn-Gn using a digital calliper. For assessing the validity of the use of facial scanning, four anthropometric measurements were used to evaluate the degree of agreement between contact measurements performed on subject faces and measurements performed digitally, on facial scanning. Ten subjects were evaluated, according to the sample size calculation and the in vivo study performed by [PERSON] et al. [47]. The results obtained are promising; a strong agreement between all measured parameters was registered (Figure 5). The 3D.obj file obtained through facial scanning can be stored on the patient's virtual file and also can be stored by the patient's itself for future use in oral rehabilitation and in preserving OVD through life, as proposed by the present study. Moreover, the measurements on the facial scanning file could overcome the drawback caused by the touching deformation of the skin when clinical measurements are done. Moreover, cephalometric files with landmarks marked could be superimposed over the facial scanning, in computer-aided design (CAD) software, as shown in Figure 4a. The anthropometric landmarks could be set more precisely and OVD could be measured and preserved through life in patient's medical record. However, an important aspect in complex oral rehabilitation is the restoration of lost OVD. Therefore, the correlation between clinical anthropometric and cephalometric measurements was assessed on 150 dentate subjects, considering the clinical measurements using a digital calliper as the \"gold standard\". Among the contact measurements, Sn-Gn distance with teeth contact was considered, as reference OVD and correlated to the other anthropometric measurements (Sn-Gn in rest position,Sn-PM in OVD and RVD, Pu-Ch_r and Pu-Ch_l in OVD) and cephalometric measurements (LFH\({}^{*}\) and ML'FH). For the cephalometric evaluations, the mean OVD reference value for our study group was \(62.47\pm 6.77\), similar to [PERSON]'s findings in an Arabian population [52]. OVD was strongly correlated to RVD, 92%, being in agreement with other research findings [9; 10; 11; 12]. A prediction formula of the difference between RVD and OVD (OVD = 0.9505 RVD-0.3316, Table 4) was calculated, instead of the usual clinical relationship of just subtracting 4 mm (OVD = RVD-4 mm) [18]. For the mean values, a difference of 3.6 mm was determined between RVD and OVD, for our group.