## 4 Discussion  
The PDATL questionnaire has been recently introduced in two studies [6; 7], where functional health and body image impairment related to negative depression, anxiety, and stress emotional states described in the well-established DASS questionnaire and to personal behavioral traits described in [PERSON] short-form questionnaire. They aimed at providing replacement options for tooth loss through a patient-centered treatment. The present study adds significant additional validation by confirming the inter-relationship between the variables and highlighting the PDATL scale's good properties as an outcome measure for prosthetic interventions where tooth loss has occurred. A three-factor solution was revealed where the first factor was linked to functional health, including trouble speaking, trouble eating, and dietary changes, which are the primary operational concerns related to denture wearing and chewing on artificial tooth units. The second and third factors were related to body image; however, the second factor referred to an inner sense of body dissatisfaction, while the third factor to an outer sense of negative body image, which entailed an emotional-behavioural component that also affected relationships with others. The correlation matrices indicated removing pain/discomfort because of tooth loss. Discomfort/pain appeared not to be critical for identifying functional problems related to conventional partial and complete dentures for both data sets. Thus, we pulled out that question since it was not loaded by most participants in study 1-NKUA and all participants in study 2-AUTH. Likewise, we removed the question on the difficulty of relaxing as the participants of both studies at most significant percentage did not worry about that perception. Both questions were discarded by PCA when the 9-item questionnaire and additional analyses after the removal of these items led to a 7-item, more concise version with a similar excellent internal consistency (i.e., 0.89 to 0.92 for the study 1-NKUA and 0.90 for study 2-AUTH). The shortened version of the scale highlighted the participants' lower disturbance of tooth loss, as displayed by the variability of the responses rating. The nationwide sample from both studies constitutes an asset as the same cultural and environmental factors influence them. Those common factors indirectly reinforced existing behavioral attitudes, personality traits, and eating habits. They were also influenced comparably by receiving treatment with removable partial and complete dentures under identical clinical protocols in university settings. Additional data quality was that all participants chewed on artificial tooth units; therefore, the samples of the two studies were considered parallel in function and mainly regarding eating and dietary habits. The higher percentage range of rare or no functional problems observed in the study 1-NKUA could be attributed to the lower total number of complete denture wearers and the inclusion of partially dentate participants who retained some of their natural teeth. In addition, since the participants were motivated patients who sought treatment for their tooth loss, the DASS statements revealed no severe negative emotional symptoms, and the results were similar in both data settings. However, tooth loss was acknowledged as a critical factor of distress in their life. That fact seemed to be compensated by the good quality denturespeople received at university clinics, where the protocols were well established within the student curricula. The present theoretical model offers ground for calculating summary scores for each item subset, differentiating amongst different groups, and confirming longitudinal response changes in future studies. An additional advantage raised was its shortened content which can readily be displayed by telephone interview to assess functional disturbances and how they affect denture wearers' behaviors, interactions, and relationships within the close or broader environmental settings.