Dear Editors,

The article “Dental changes evaluated with a 3D computer-assisted model analysis after long-term tongue retaining device wear in OSA patients” by Chen et al. [1] seems to leave many open questions.

I found the statement in the conclusion of the article “It was hypothesized that there might be two possible major mechanisms for the TRD induced side effects: one is the forward displacement of the tongue, which affects the anterior dental arch; and the second is the lateral pressure of the tongue affects the posterior arch” difficult to justify on the basis of the cases presented. The tongue has a profound effect on tooth position whether encased in a tongue-retaining device or not so this statement is not surprising but I fail to see how any hypotheses or conclusions can be drawn from the cases presented because the workflow protocol was so different in each instance. In fact, the conclusions probably could have been drawn without any case reports to substantiate them.

In addition, the article continually refers to “study models.” While this terminology is accepted in everyday conversation the fact is that a model is defined as having a different size than the original from which it is drawn. In other words, a “study model” is a representation of the dental arches that is either smaller or larger than the original dentition. The correct terminology in a scientific dental article is “study cast.” A small point to be sure but one that is necessary in a scientific paper.

There was a mention of a Rhinoceros Modeling Program without any explanation of what that is.

The article obviously was written for dentists but if I were a physician reading this article I would have been even more confused than I was. The use of acronyms became excessive and made the article extremely difficult to follow: “The AP relationship of the upper and lower arch was based on the same ORC as OB and OJ.” Using acronyms, even though these were defined earlier, forces the reader to continually track back to find the definitions of the acronym in question. Some acronyms are commonly known to dentists but not to physicians. In fact, some acronyms may be familiar to orthodontists but are not common to general dental practice (ORC, OP) and some are related to locality and the university involved (UBC). Sentences like “The first column in Fig. 4 exhibits the AW, CS, OB, OJ, and AP changes between the baseline and follow-up.” are just inordinately difficult to read logically. Sometimes just using the words makes the article substantially easier to read and understand.