Location Matters for Proximal Hilar Submandibular Stone Removal: Position Relative to the Mylohyoid

To identify imaging predictors for successful sialendoscopy-assisted removal of proximal/hilar submandibular stones.

Retrospective cohort study of patients with sialolithiasis near the hilum of the submandibular gland (SMG). Two independent reviewers measured CT images for stone size, number, location relative to the mylohyoid, and distance from the inferior mandible.

Seventy-six patients were evaluated. Stones were located at the mylohyoid plane in 52 patients (68.4%), superior to the mylohyoid in 9 (11.8%), and inferior to the mylohyoid in 15 (19.7%). A combined transoral approach was required in 65 (85.5%) patients. Proximal/hilar SMG stones were successfully removed in 82.9% (n = 63), with higher removal rates in patients with stones located superior to the mylohyoid line (100.0%) compared to at (84.6%) or inferior (60.0%, p = 0.038). Shorter average distance between the inferior border of the mandible and the stone was associated with successful removal (p < 0.001). Maximum stone diameter was significantly larger in successful cases compared to unsuccessful cases (8.0 vs. 5.4 mm; p = 0.043). Stones visible with sialendoscopy (n = 55, 72.4%) were associated with higher successful removal rates than for stones not seen with sialendoscopy.

Gland preservation techniques for proximal/hilar submandibular sialolithiasis required proximal transoral incision in 85.5% of cases. Imaging characteristics, including stone position superior to or at the mylohyoid plane and larger stone size, were predictors of successful sialendoscopy-assisted transoral removal. Imaging findings can assist with surgical planning for proximal/hilar submandibular stones.