A retrospective case series illustrating a possible association between a widened hilum and sialolith formation in the submandibular gland.

OBJECTIVE: The purpose of this study was to explore any association between anatomical variances in the ductal system and sialolith formation using sialoendoscopy and acrylic resin replication of the ductal system.
METHODS: A retrospective study of 372 submandibular gland sialoendoscopies was performed to review the findings of the submandibular gland duct anatomy. Using sialoendoscopy and replicated casts, a high rate of hilar widening was noted in patients with submandibular sialolithiasis.
RESULTS: Sialolithiasis was detected in 326 of the patients who presented with obstructive symptoms. Around 67% (285/426) of the stones were located in the distal third of the ducts or at the hilum of the submandibular gland. During the sialoendoscopic procedure, the anatomy of the ductal system was examined and 285/326 (87.4%) of the hilums were noted to be widened like a basin. The anatomy of the duct from the replicated casts demonstrated a treelike structure and the basin-like widening of the hilum was found in all the excised submandibular glands.
CONCLUSION: Using sialoendoscopy, a high number of patients presenting with sialolithiasis in the submandibular gland seem to have an anatomical variance in the hilar region. The reproduced ductal system from excised glands also demonstrated this abnormal widening of the hilum. Although further studies need to be performed, we try and explain why there is such a high prevalence of hilar widening in patients with submandibular sialolithiasis.