<prompt> The diagnostic method of submandibular sialolithiasis isUSGSialographyPlain X-rayCT scan  <response>: Ans. c Plain X-rayRef: Bailey and Love 27th Edition Page 780 MC cause of Submandibular duct obstruction is Stones in Gland and Duct. 80 stones are radio opaque and hence X ray is diagnostic. 80 of salivary stones are seen in Submandibular duct. Stones distal to Lingual nerve Beyond 2nd Molar - Duct lay opening and stone removal is enough 