## 1 Introduction  
The position of the mandibular condyle in the glenoid fossa is of great practical importance in dentistry, since many researchers consider it to be the main criterion for projecting prosthetics or orthodontic rehabilitations. There are various opinions upon the correct position of the condyle in the space of the articular fossa: several authors believe that the heads should be centered on the glenoid fossa [1]; others individuate it in a forward position, close to the articular tubercle [2; 3]; some other researchers collocate condyle in the distal and upper position during their rehabilitation (reference position) [4]. Finally, some researchers consider that the condyle can be located at any position, which is finally defined by normalization of masticatory muscle tone [5]. Condylar positional changes might also be related to condylar shape alteration; for example, previous studies show that condyle with osteophyte formations are located significantly more antero-inferiorly in the glenoid fossa at interocclusal position than reference position [6]. It is reasonably believed that one of the causes of intra-articular pain is compression of the bilaminar zone caused by uncorrected position of condyle [7], and one of the manifestations of this condition is a radiologically-diagnosed decrease in the upper and posterior width of the joint space. Thus, from a therapeutic point of view, if joint space is increased, allowing smoother condylar translation beyond the disc surface, irregularities and positional abnormalities disappear [7]. Thus, repositioning of the mandibular condyle can eliminate adverse symptoms caused by compression of the bilaminar zone, such as joint pain and/or noises [6]. The intra-oral splint is an important device to achieve this new condylar/fossa relationship while inducing muscle relaxation [8; 9; 10], as it changes occlusal vertical dimension in a not-definitive way, thus being a guide for the following prosthetic/orthodontic rehabilitation, representing a mandatory general step of the entire rehabilitative procedure. In a recent systematic review, [PERSON] et al. analyzed the clinical methods to detect mandibular repositioning and a new occlusal vertical dimension, depending on clinical judgment. This review identified two main streams to determine the occlusal vertical dimension: with the first method, the initial vertical dimension of the natural dentition is transferred to the new dentures mainly by intra-oral measurements, profile tracing, and cephalometric analysis. The other method relies on mandibular rest position, facial aesthetic appearance, swallowing pattern, craniofacial landmarks measurements, cephalometric analysis, phonetics, and existing dentures. The authors underline that all these available techniques have merits and are helpful for routine clinical use. However, they are empirical in nature, controversial, and lack the scientific support. Further, the main conclusion of the review is that no single accurate method exists for occlusal vertical dimension determination. Their study observed that, in general, all the available clinical techniques have merits and are helpful for routine clinical use, no matter what kind of approach is adapted, but they also have significant limitations that should be considered [11]. Therefore, beyond the clinical procedures, a previsualization of the positions of the condyle--in the habitual intercuspation, and after therapeutic repositioning--certainly allows a more justified and rational choice for the clinician. Thus, a suitable strategy for carrying out mandibular repositioning remains a visualization of the condyle in the glenoid cavity, which can be obtained with cone beam computed tomography (CBCT), which allows to reliably assess the shape, volume, and position of the condyle head, as well as glenoid fossa [12; 13; 14; 15; 16; 17]. In this scenario, mobilizing digital technology and CBCT 3D images could allow the acquisition of crucial details.