**4.2 Visualization of root fractures**

Vertical root fractures (VRF) are a type of fractures that extend along the major axis of the tooth. If the diagnosis is not carried out, progressive destruction of the periodontal ligament and alveolar bone occurs which can influence the prognosis of adjacent teeth and future restorations. However, VRF may not produce any signs or symptoms such as pain or discomfort from chewing. Therefore, it is important that VRFs be diagnosed as quickly as possible. The prevalence of VRFs in several populations has been reported between 2 and 5% and depending on the literature reviewed; the percentage of endodontic and fissured teeth varies between 3 and 30%. The highest incidence occurs between 40 and 60 years [25]. The most common teeth where it occurs are lower molars and upper premolars [26]. One third of the VRFs are radiographically detectable, usually when the beam is perpendicular to the fracture line or the granulation tissue separates fragments [27]. (**Figure 3a** and **b**).

Mesio-distal fractures are almost impossible to detect with normal radiography [28]. The most effective in vivo diagnostic method of an LRF is surgical exposure of the fracture, and visual inspection under magnification with the help of staining. Edlund et al. examined 32 teeth in 29 patients, which gave symptoms of a VRF, with CBCT and subsequent surgical exploration; the results showed a high correlation between the diagnosis through CBCT and direct visualization, which confirms numerous in vitro studies that support the validity of CBCT in the diagnosis of VRF [29].
