LAUSR

We would like to thank Mr. Özden for his interest in and comments on our article and the Editorial Board for providing us with the opportunity to respond. First of all, Numerical Rating Scale (NRS) is a widely used tool for musculoskeletal pain intensity assessment. There is a large body of studies examining the psychometric properties, cut-off points, minimal clinically important change and minimal detectable change of NRS [1–5]. Majority of these studies identified the cut-off point for mild to moderate pain as 4–5 [3–5]. Taking into consideration the previous studies, our study also classified NRS as 0, 1–3 and ≥ 4 [3, 6]. However, determining the cut-off values of any outcome measure is beyond the scope of this study. Facial Disability Index (FDI) was developed in 1996 for assessment of disabilities of patients with facial nerve disorders [7]. Although, as also pointed out by Mr. Özden, its cross-cultural adaptation and validation study had not been published by the time of the conduct of this study, it has been applied in a number of studies on the Turkish population [8, 9]. Both of these studies can be accepted as indicators of clinical validation of FDI. In addition, all of the patients in our study understood all of the items. None of the patients had any ambiguity or difficulty in understanding questions, which represents good face validity. In the meantime, Özden et al. have already demonstrated its validity in the case of Turkish population and they also stated that no part of the questionnaire needed to be adapted to Turkish culture [10]. Therefore, using FDI before its cross-cultural adaptation study affects neither our results nor the quality of the study. Finally, as this study was designed as a longitudinal study, use of comparison methods for sample size estimation is not appropriate [11]. In addition, relatively small size of the sample was already mentioned as one of the limitations of our study.[12]. Following the completion of this study with 20 patients; a power analysis was performed with G Power V.3.1.7 (University of Kiel, Kiel, Germany) and the power of the study was calculated as 0.805 with 20 patients, one group, three repeated measures, with non-centrality parameter of 10.58 and type 1 error rate of 0.05. Although the larger sample size would be better, the desired power was achieved.