This study compared the effects of conventional complete dentures (CD) and single-implant mandibular overdentures (SIO) on the oral sensorimotor ability, masticatory function, and nutritional intake of elderly people with severely resorbed alveolar ridge. No difference was observed in the nutritional parameters, except for a decreased ingestion of sodium after SIO insertion. The oral sensoriomotor ability was similar between groups and, concerning masticatory performance, a significant increase was observed after SIO insertion as well as regarding opening and closing velocities during masticatory function.

In general, it is a well-designed study which addressed an interesting and original research question that is clearly justified by what is already know about the topic. The novelty relies on the assessment of the oral sensorimotor ability, which adds new information to the topic. Methods are described clearly and there are enough details that allow the replication of the study. Authors reported that the current observational study included participants of a previous clinical investigation and references on the details of the original methods were provided. Variables were clearly defined and methods to measure these parameters (OSA, PM, chewing movements and nutritional intake) seems appropriate.

The discussion is very informative and well-constructed, in which results are explored from multiple angles and are interpreted properly with the use of pertinent references. Study limitations are clearly mentioned and suggestions for future studies are recommended based on existing limitations and gaps observed by the authors. The conclusions answer clearly the aims of the study and are supported by the study results.

However, some issues needs to be addressed to improve clarity and interpretability:

Major points in the article which needs clarification:

1. The title is informative and adequate, but it is not possible to identify the study design. I suggest the authors to include it.

2. Abstract: The study type is not mentioned and the description of the implant placement is also missing. The authors only mentioned that "dentures were later converted to single implant overdenture", which is insufficient to conclude that an implant was inserted.

3. Some information seems not to be essential in the introduction section, such as the second paragraph as a whole. This paragraph interrupted the flow of ideas. I recommend it to be excluded or reused in the discussion section, if pertinent. Information regarding the content of this paragraph is somehow mentioned at the 5th and 6th paragraphs of the introduction section.

4. It is not clear how the random selection of the pair of geometric forms were carried out. Did the authors use a specific random number generator? I suggest the authors to specify it in order to improve transparency.

5. Did authors consider the use of the STROBE guidelines to enhance transparency of the research report? There is no mention about it in the manuscript and also no checklist was included as a supplementary file. I strongly recommend authors to do it and to check throughout the manuscript if all aspects of the STROBE checklist are included in the paper.

6. Authors mentioned that the study sample participated in a previous clinical study and reference for it was provided (Amaral et al., 2018). After checking the reference and consulting the trial register stated in the original study (#RBR-3kgttj), I did not find any mention of the current outcomes assessed at the manuscript under review. Did the authors create another specific register for the current study? In addition, I suggest the authors to mention references of what was already published from the original register, in order to avoid selective reporting.

Minor points that need attention:

1. In the introduction section, Important references regarding 2-implant overdentures and single-implant overdentures were not mentioned by the authors, especially systematic reviews on treatment effects and international consensus that recommended the 2-implant overdenture as the standard of care for edentulous individuals. I suggest authors to include them.

2. In table 1 the meaning of the parameter “X50” must be included at the table footnotes. Also, Figure 1 presents some problems that should be managed by the authors: a) it presents low quality and it is difficult to read its content; b) the meaning of “CD” and “SIO” must be included in the footnotes; c) the meaning of the asterisk included in the upper right image should be explained in the figure description; d) the lower right figure presents incomplete labels of its columns.

3. The authors report that OSA test responses and response times did not differ according to the conventional CD and presents some data, but no p value was included. I recommend authors to include it.

Final considerations: I recommend the publication of this manuscript in the journal because its content is pertinent to the journal’s scope and it adds new knowledge to the topic. In my opinion, it presents high priority for publication but it is important that authors address all the requested considerations.