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

Comparison of the distribution of the Bartholin and/or Rivinus salivary ducts assessed with magnetic resonance-sialography in patients with ranula and in healthy subjects

Background

The distribution and drainage of the sublingual gland ducts have various patterns that might be related to sublingual gland-related diseases, including ranula. This study aimed to elucidate the characteristics of the distribution of Bartholin and/or Rivinus ducts in patients with ranula using magnetic resonance (MR) sialography.

Methods

In this retrospective cross-sectional study, the distributions and drainage patterns of sublingual gland ducts on MR sialography were classified in 74 subjects without sublingual gland-related disease as confirmed by both medical history and clinical examination and 15 patients with ranula, respectively. All patients had visited Kyushu Dental University Hospital from July 2015 to June 2022 to undergo MR imaging. Data on the distributions and drainage patterns of the sublingual gland ducts, including the characteristics of the Bartholin and/or Rivinus ducts, were then statistically compared between subjects without sublingual gland-related disease and patients with ranula. The images were assessed by an experienced oral and maxillofacial radiology specialist certified by the Japanese Society for Oral and Maxillofacial Radiology. The distributions (five groups) and drainage patterns (three patterns) of the sublingual gland ducts on MR sialography were classified in reference to previous studies, with some modifications in all subjects without sublingual gland-related disease and patients with ranula.

Results

A significant difference in the distribution of the ducts (P<0.001), with a low number of patients exposing an undetected canal or Rivinius duct, was found in the group of patients with ranula (P<0.05). Regarding drainage patterns, no patient with ranula presented a Rivinius duct only. A significant difference in the drainage patterns of the sublingual gland ducts on MR sialography was observed between subjects without sublingual gland-related disease and patients with ranula (P=0.001).

Conclusions

The present results suggest that the distribution of the sublingual gland ducts, mainly, the Bartholin duct, may be related to ranula formation. These findings also demonstrate that MR sialography contributes well to preoperative evaluation and is effective for assessing the complex excretory distribution of the sublingual gland ducts.

A retrospective study of magnetic resonance sialography imaging applied in the prognostic evaluation of chronic obstructive parotitis

Background

Magnetic resonance sialography (MRS) can be used to clearly examine the main duct of the parotid and is widely applied in the diagnosis of chronic obstructive parotitis (COP). However, there are few studies on the classification, treatment options and prognosis of COP using MRS.

Methods

Clinical and imaging data were retrospectively collected from 41 patients with COP between January 2010 and December 2020 at the Ninth People's Hospital affiliated with Shanghai Jiao Tong University School of Medicine. All patients underwent MRS and were treated with intraductal irrigation. The patients were divided into 2 groups according to the presence or absence of symptomatic relapse during the 6-month follow-up period. The imaging features of parotid MRS included three parts: gland volume, stenosis classification and dilatation classification. The location/length of dilatation, the widest diameter of the dilated duct, and the condition of the branch ducts were also recorded and compared between the groups.

Results

A mean of 14.8±12.3 irrigations were performed. There were 15 patients with recurrence and 26 without recurrence. There was no significant difference in the parotid volume (P=0.460), stenosis grade (P=0.738) or maximum diameter of dilatation of the branch duct (P=0.723) between the recurrence and non-recurrence groups. Statistically significant differences were found in dilatation classification (P=0.009), length of dilatation (P=0.043), condition of the branch ducts (P=0.017) and dexamethasone use (P=0.031).

Conclusions

MRS is an available diagnostic and grading modality for COP. The imaging features and classification of the parotid main duct in MRS could be helpful for treatment selection. Patients who accept irrigation could be less likely to experience recurrence with a low dilatation grade and no branch duct dilatation.

Special Issue-"Diseases of the Salivary Glands"

Salivary glands (SGs) are of the utmost importance for maintaining the health of the oral cavity and carrying out physiological functions such as mastication, protection of teeth, perception of food taste, and speech [...].