## 4 Discussion
The focus of the proposed PDApp software, on the other hand, is on predicting whether or not the molar will erupt in the future from information provided by experts and not limited to molar angulation. Our application combines the measurement of third molar angulation in relation to the occlusal plane with the radiological retention coefficient (RCC) calculated by performing linear measurements [20]. Taken together, angular and linear measurements increase the precision of the tool. We consider the lack of retromolar space at least as important as the angulation of the third molar itself. Nonetheless, [PERSON] el al. [14] also found that 17% of third molars with adequate retromolar space still failed functional eruption. We attempted to automate the prediction of third molar eruption with the aim of reducing the time required to obtain an analysis, improving the accuracy of identifying eruption status, and reducing errors due to clinician subjectivity. The results indicated that PDApp is an easy clinical tool for identifying the status of eruption or retention of the mandibular third molar based on panoramic radiograph images. In order to overcome the limitations of the current work, we will conduct further studies on a larger number of panoramic radiographic images, with more types of third molars and not only those that are mesioangulated (i.e., vertical and distoangular), and images of non-Caucasian patients will be needed to allow generalizing the results. Third molar eruption is a complex multifactorial process and neither factors involved in the process are completely understood nor the worldwide rate of occurrence known. Third molar impaction is much more likely in the mandible than the maxilla, and mesioangular impaction is the most frequently orientation type of impaction [29]. The PDApp was developed for a single center population and should be warranted to test its use in a larger population to assess the generalizability of the results obtained. Therefore, validation of this tool that could predict eruption status over time for patient populations would be widely used. The most common treatment for third molars is exodontia, and information on the eruption or non-eruption status (retention) of these teeth is essential to estimate the potential need for treatment for the individual patient and also at future dental population-based studies for economic analysis. This information would be valuable when the results of population-based oral health surveys included radiographic examination and prediction of eruption status. Thus, according to [PERSON] et al. to ensure consistency between clinical and radiographic findings, dentists must check the panoramic on the same day and confirm the identification of teeth in clinical examination [39]. The clinical relevance of our tool lies in individualized patient counselling. Before surgery, the patient is informed about the course of life of his third molars including future status of eruption. Clinicians treating young adults know if third molars have erupted or are not yet erupted years before the eruption. PDApp not only records the eruption status at the time of taking the panoramic images but also the potential final status of third mandibular molars.