This is an interesting concept related to facial pain. This study is adding information related to the understanding of facial pain. However, a link to the clinical setting is missing. Thereby, the English has to be revised by a native English speaker.

Running title: This is not a new pain monitor, because it is already published by Mozanski et al.

Abstract: Methods: you state that all data are analyzed by the paired sample t test, however, in the paper you state that also the independent t test was used.

Introduction • In the introduction is also stated that an objective monitoring method for pain is not yet developed. However, Mozanski et al. did it already. I agree that an objective measurement method would add new information in facial pain. Please add some relevant information about this. • You describe the 3-step and combination therapy; it is unclear what is meant by this. • Thereby, it is unclear why you add information about the use of analgesics to underpin your objective of this study. • Background information of thermal change and its relation to pain is missing. • In the sort of objective of the study you write: .. and to prevent it from being exacerbated. This is not described as result or even the discussion of this paper. • Please describe a clear objective and the end of your introduction. • In total: a clear hourglass writing stile is missing in this introduction.

Methods • Volunteers were from ASA1-2 groups. This is an inclusion criteria. So describe clearly you exclusion and inclusion criteria • It is a pitfall that pain is not an exclusion criteria. • Explain more clearly your power calculation and use a reference related to the used method. • The firma and location are missing related to the Testo 885 and its software. • In the text is not stated that NLS-1 is at the right side and NLS-2 at the left side. • Make a separate paragraph for statistics. • It is unclear what you mean by independent groups related to the independent t-test

Results • What is meant by BI, DI, and AI? • “Statistically significant increases (*p<0.05, Ωp<0.05) were…” one p-value is enough and * and Ω should not be used in the text. • In figure 3 the change in colour tones are not visible.

Discussion • Start the discussion with the answer to your research question. All information related to pain and temperature change should be written down in the introduction. • There is not a good discussion related to the literature which is done with subjective measurement outcomes. • Thereby, a link to the clinical setting is missing.