Lessons learned from unintended sublingual sialography: imaging anatomy, technical considerations, and diagnostic implications

A Single Institution Cadaveric Study on Anatomical Variation of the Sublingual Gland Duct

The purpose of this study was to conduct a cadaveric dissection study on the anatomical variation of the sublingual (SLG) excretory ducts and dictate an improved understanding of the anatomical communication between the SLG duct and submandibular (SMG) ducts. This study is carried out by standardized dissection of anterior floor of mouth in 6 formalin-fixed adult cadavers in Silent Mentor Workshop University Malaya in August 2020. The cadavers had no trace of scars, adhesions, signs of trauma or operation. SMG duct opening was identified lateral to the lingual frenulum through a papilla in the floor of mouth behind the lower incisor tooth. A horizontal incision line was done over floor of mouth just lateral to the opening. SMG duct and SLG was traced and skeletonized. Any presence of major duct arising from the SLG and its communication with SMG duct were investigated. We found there are 3 patterns of SLG excretory duct variants; (1) One major (Bartholin’s) duct which open independently at its own orifice adjacent to the orifice of the Wharton’s duct of SMG. (2) One major (Bartholin’s) duct which joined into the Wharton’s duct of SMG. (3) Absent of a major duct arising from SLG. The overall mean diameter of SLG ducts were 1.3 ± 0.41 and the mean length of SLG ducts were 18.5 ± 6.55. The overall mean diameter of SMG ducts was 2.6 ± 0.74 and the mean length of SMG ducts were 46.5 ± 6.57. Excretory ductal system of SLG showed great variations, not only between the different cadavers but also within the different sides of the same cadaver. Awareness of potential anatomical variations can aid in the accurate diagnosis and treatment of patients with salivary gland pathology as well as help surgeons reveal potential risk factor and avoid complications during surgical procedures in the floor of mouth.

Radiocontrast Dye Extravasation During Sialography

Objective:

Evaluate the pathophysiology of contrast extravasation.

Methods:

Two hundred fifty-five sialograms at the University of Iowa from 2008 to 2016 were reviewed.

Results:

Twelve sialograms (4.7% of total) were identified with main ductal extravasation. In each case, ductal stenosis as a diagnosis was supported by clinical history and the finding of difficulty in advancing the cannula into the duct during sialography. In all but 1 case, extravasation occurred at the distal duct with no further imaging of the ductal system. Each of the 5 cases treated with sialendoscopy with or without gland resection confirmed stenosis. Ultrasound evaluation of 5 of the cases detected ductal dilation in 4 (80%). Six of 11 computed tomography scans done before the sialogram were interpreted as normal with indirect evidence for ductal stenosis (duct dilation) reported in only 1. All extravasations were associated with either stricture alone or stricture with stone (1 case).

Conclusion:

Radiocontrast extravasation from the main duct during sialography is highly associated with the presence of ductal stricture. In our experience, the inability to fill the ductal system with radiocontrast is a useful sialographic finding that correlated closely with anatomic abnormality rather than technical error. The frequent finding of extravasation of radiocontrast supports the use of water soluble contrast.

Imaging of sialadenitis

Sialadenitis is an inflammation or infection of the salivary glands that may affect the parotid, submandibular and small salivary glands. Imaging findings vary among unilateral or bilateral salivary gland enlargement, atrophy, abscess, ductal dilation, cysts, stones and calcification. Imaging can detect abscess in acute bacterial suppurative sialadenitis, ductal changes with cysts in chronic adult and juvenile recurrent parotitis. Imaging is sensitive for detection of salivary stones and stricture in obstructive sialadenitis. Immunoglobulin G4-sialadenitis appears as bilateral submandibular gland enlargement. Imaging is helpful in staging and surveillance of patients with Sjögren’s syndrome. Correlation of imaging findings with clinical presentation can aid diagnosis of granulomatous sialadenitis. Post-treatment sialadenitis can occur after radiotherapy, radioactive iodine or surgery.

Imaging of sialadenitis

Sialadenitis is an inflammation or infection of the salivary glands that may affect the parotid, submandibular and small salivary glands. Imaging findings vary among unilateral or bilateral salivary gland enlargement, atrophy, abscess, ductal dilation, cysts, stones and calcification. Imaging can detect abscess in acute bacterial suppurative sialadenitis, ductal changes with cysts in chronic adult and juvenile recurrent parotitis. Imaging is sensitive for detection of salivary stones and stricture in obstructive sialadenitis. Immunoglobulin G4-sialadenitis appears as bilateral submandibular gland enlargement. Imaging is helpful in staging and surveillance of patients with Sjögren's syndrome. Correlation of imaging findings with clinical presentation can aid diagnosis of granulomatous sialadenitis. Post-treatment sialadenitis can occur after radiotherapy, radioactive iodine or surgery.

Imaging of sialadenitis

Sialadenitis is an inflammation or infection of the salivary glands that may affect the parotid, submandibular and small salivary glands. Imaging findings vary among unilateral or bilateral salivary gland enlargement, atrophy, abscess, ductal dilation, cysts, stones and calcification. Imaging can detect abscess in acute bacterial suppurative sialadenitis, ductal changes with cysts in chronic adult and juvenile recurrent parotitis. Imaging is sensitive for detection of salivary stones and stricture in obstructive sialadenitis. Immunoglobulin G4-sialadenitis appears as bilateral submandibular gland enlargement. Imaging is helpful in staging and surveillance of patients with Sjögren’s syndrome. Correlation of imaging findings with clinical presentation can aid diagnosis of granulomatous sialadenitis. Post-treatment sialadenitis can occur after radiotherapy, radioactive iodine or surgery.