First Report of Sublingual Gland Ducts: Visualization by Dynamic MR Sialography and Its Clinical Application

Round 1

Reviewer 1 Report

Thank you for giving me the opportunity to review this interesting article describing the us of MR sialography for evaluating the sublingual ductal anatomy. Although MR sialography has become widely used for evaluating parotid/submandibular ductal anatomy/disease, this has not been widely adopted for the evaluation of sublingual ductal anatomy/pathology. Therefore, this has the potential of providing added benefit to an under imaged area of the head and neck.

See attached file for several English grammatical changes.

The materials and methods section states that the Mann-Whitney U test was used to asses for differences between the adult and elderly volunteers. However, I do not see any of the results from the statistical analysis in the results section. You need to include the Mann-Whitney U test results along with the corresponding p values.

Comments for author File: Comments.pdf

Author Response

1. We revised the several English grammatical changes in all text, as suggested by the reviewer. In concrete, we deleted the words, “, including ours,” and “function” (Introduction section, page 1, lines 37-38). We revised the two sentences (Introduction section, page 2, lines 45-47). We revised the two sentences (Results section, page 4, lines 138-142). We revised the two sentences (Figure legend in Results section, page 5, lines 148-152). We revised the three sentences (Results section, page 6, lines 175-180). We revised the two sentences (Figure legend in Results section, page 6, lines 183-185). We revised the sentence (Figure legend in Results section, page 6, lines 187-188). We revised some sentences (Discussion section, page 7, lines 203-227). We revised the sentence (Discussion section, page 8, lines 252-257).

2. We added P values according to Mann-Whitney U test in Results section (page 5, lines 156-170).

Reviewer 2 Report

I thought the paper was nicely written describing practical anatomic and functional imaging of the salivary glands. The only minor edit I would suggest is about the wording used lines 67-68 ..."such as the parotid and submandibular ducts..."

Author Response

1. We added the new Table 1 on the data relating to the subjects engaged in the study　(Materials and Methods section, page 2, lines 69).

2. We added the introduction about usefulness of MR sialography for diagnosis of Sjögren’s syndrome and other diseases including our previous reports (Introduction section, page 1, lines 38-42).

Reviewer 3 Report

• This is a very interesting and clear article that describes, for the first time, the MR-sialography as a tool to evaluate the morphology and function of  sublingual gland ducts. Moreover the authors underline the potential use of the MR-sialography in the dental, medical, and biological fields. There are some limitations in this  study, evidenced by the authors themselves, including the low number of subjects engaged , especially as regards the patients.The originality of the study can be appreciated although further investigations are needed to define the diagnostic and applicative importance of these methods from a pathological point of view.
• I would like to suggest to report the data relating to the subjects engaged in the study in a table, in order to immediatly highlight all the parameters evaluated in the study.
• The diagnosis of Sjögren’s syndrome involves clinical symptoms, serum tests for antibodies, radiological examinations and biopsy of the minor salivary gland. Imaging tests commonly used to facilitate the diagnosis include, X-ray sialography, salivary scintigraphy and various magnetic resonance imaging techniques (MRI). Nowdays, MR sialography detects peripheral ducts dilation in parotid glands with unmatched spatial resolution, while X-ray sialography technique is invasive for the patient. For this reason, it would be interesting improve the introduction explaining  in detail this technique, and its implications in other diseases.

Author Response

1. In the present study, we paid attention to the possibility of visualizing sublingual gland ducts using dynamic MR sialography and its clinical application. Therefore, we could not elucidate the classification of the drainage of the sublingual glands in the respective Bartholin's ducts or/and just ducts of rivinius. However, we should try the classification of their drainage patterns. In addition, we should try to elucidate the presence of a Bartholin's duct may be related to ranula formation as next stage. We added the sentence mentioned above in the revised manuscript (Discussion section, page 8, lines 251-257).

Reviewer 4 Report

This is a fascinating paper. The idea is of importance to those of us who manage sublingual gland disease. The authors are credible. The paper is well-written. 

I do think it should be reviewed by a radiologist who has experience in MRI sialography. 

I have a couple of comments from a clinical point of view:

1) Did the authors identify Bartholin's ducts or just ducts of rivinius. There has been a classification of the drainage of the SLG and there is a credible hypothesis that the presence of a Bartholin's duct may be related to ranula formation. 

2) Can the authors classify the drainage pattern by the data they obtained from this group?

IN other words: 

Patterns:

1. Ducts of rivinius only (and what is the range of number of these)

2. Ducts of rivinius with Bartholin's separate

3. Bartholin's duct only

4. Ducts of rivinius which drain into Bartholin's

5. Bartholin's draining into SMG duct vs. directly into Floor of mouth

6? Other combinations

3) Also, was there any consistency in patients or in other subjects when left and right sides were compared in terms of above?

Author Response

1. We revised the title as “First report of sublingual ducts visualization by dynamic MR sialography and its clinical application”.
2. We revised the sentence, as suggested by the reviewer (Discussion section, page 7, lines 203-204).

Reviewer 5 Report

Possibility of visualizing sublingual gland ducts 2 using dynamic MR sialography and its clinical 3 application

The authors introduce the dynamic MR sialography technique for the sublingual gland in adults, elderly and in disease of the sublingual gland area. This was previously considered impossible due to technical limitations.

In short, this technique provides a useful contribution to the armamentarium of salivary gland imaging. Especially, in some cases of sublingual gland disease, this might be the key to optimal diagnosis of non-straight forward disease and pre-operative planning for difficult recurrent ranula cases.

Compliments to the authors.

A suggestion for the title:

“Introduction of sublingual ducts visualization by dynamic MR sialography and its clinical application”, or: “First report of sublingual ducts visualization by dynamic MR sialography and its clinical application”

One small remark regarding line 201:

“So far, the reason why the sublingual gland ducts, which are so thin and short that they could not be visualized even on MR images, was that no attention was paid to their visualization.”

The authors probably mean:

“So far, the reason why imaging of the sublingual gland ducts, which are so thin and short that they could not be visualized even on MR images, was that no attention was paid to their visualization”. This however is a non-argument. They in fact say: it has not been done, because nobody paid attention to doing it. They might want to state:

“So far, the reason why the sublingual gland ducts, with their thin and short size have not been visualized before even on MR images, was that it was considered technically impossible.”

Author Response

1. We revised the title as “First report of sublingual ducts visualization by dynamic MR sialography and its clinical application”.
2. We revised the sentence, as suggested by the reviewer (Discussion section, page 7, lines 203-204).