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Etiology of Salivary Duct Stenosis (Parotid Duct Stricture - Submandibular Duct Stricture)

Return to: Salivary Duct Stenosis (or click for more detail: Diagnosis / Classification / Management

Salivary duct stenosis is a common cause of obstructive sialadenitis - with a stricture defined as a narrowing in the duct sufficient to cause impairment to smooth outflow of saliva (Ngu 2007).

Ngu et al identified among 1362 sialograms done over a 10 year period for patients referred for recurrent salivary swelling and evidence for salivary obstruction. Among the 877 sialograms showing evidence of benign intraductal obstruction 198 (22.6%) identified ductal strictures in the absence of stones 642 (73.2%) or mucus plugs 37 (4.2%). the main presenting symptoms included swelling of the gland with 'meal-time syndrome'

Causes of Ductal


(Koch 2012, 2017

Kopec 2013)


up to 26.8% / 29.6%


up to 16.7% / 18.5%

Bruxism or cranio-manidbular disorder

up to 5.2%

Dental Prosthesis

1.45 %


up to 3.7% - 5.1%




13.8% / 5.2 - 12.9%




Hypothesized Causes of Stricture (Ngu 2007)

Epithelial ductal injury due to calculi
Recurrent infection
Minor trauma

  A. Trauma

      1.  Surgical manipulation of oral cavity

      2. Intra-oral dental xrays - (Kieliszak 2015)

  B. Sialolith

  C. Autoimmune disorders

  D. Viral and bacterial infection

  E. Radiation (I131, External beam)

  F. Pneumoparotitis (Goates AJ, Lee, Dan et al 2018)

  G. Unknown


Koch M, Iro H. Salivary duct stenosis: diagnosis and treatment. Acta Otorhinolaryngol Ital. 2017 Apr;37(2):132-141. doi: 10.14639/0392-100X-1603. PMID: 28516976; PMCID: PMC5463521.

Koch M, Iro H, Kunzel J, et al. Diagnosis and gland-preserving minimally invasive therapy for wharton’s duct stenoses. Laryngoscope 2012; 122: 552-8

Kopec T, Szyfter W, Wierzbicka M, et al. Stenoses of the salivary ducts-sialendoscopy based diagnosis and treatment. Br J Oral Maxillofac Surg 2013;51:e174-7

Nahlieli O, Shacham R, Yoffe B, Eliav E. Diagnosis and treatment of strictures and kinks in salivary gland ducts. J Oral Maxillofac Surg 2001;59: 484–490; discussion, 490–492. 

Plonowska KA, Gurman ZR, Humphrey A, Chang JL, Ryan WR. One-year outcomes of sialendoscopic-assisted salivary duct surgery for sialadenitis without sialolithiasis. Laryngoscope. 2019 Apr;129(4):890-896. doi: 10.1002/lary.27433. Epub 2018 Aug 27. PMID: 30152080.

Lee LI, Pawar RR, Whitley S, Makdissi J. Incidence of different causes of benign obstruction of the salivary glands: retrospective analysis of 493 cases using fluoroscopy and digital subtraction sialography. Br J Oral Maxillofac Surg. 2015 Jan;53(1):54-7. doi: 10.1016/j.bjoms.2014.09.017. Epub 2014 Nov 11. PMID: 25445390.

Ngu RK, Brown JE, Whaites EJ, Drage NA, Ng SY, Makdissi J. Salivary duct strictures: nature and incidence in benign salivary obstruction. Dentomaxillofac Radiol 2007;36:63–67

Kieliszak CR, Shokri T, Joshi AS. Acquired Wharton's duct stenosis after dental radiographs treated with sialendoscopy. BMJ Case Rep. 2015 Apr 26;2015:bcr2014209117. doi: 10.1136/bcr-2014-209117. PMID: 25917069; PMCID: PMC4422927.

Gillespie MB, Intaphan J, Nguyen SA. Endoscopic-assisted management of chronic sialadenitis. Head Neck 2011;33:1346–51.

Goates AJ, Lee DJ, Maley JE, Lee PC, Hoffman HT. Pneumoparotitis as a complication of long-term oronasal positive airway pressure for sleep apnea. Head Neck. 2018 Jan;40(1):E5-E8. doi: 10.1002/hed.25003. Epub 2017 Nov 17. PMID: 29149468.