Sialolithiasis and its management in oral and maxillofacial surgery

sialolithiasis in oral and maxillofacial surgery.

1. SIALOLITHIASIS Dr ARJUN SHENOY PG STUDENT DEPT OF OMFS

2. INTRODUCTION Sialoliths are calcified structures that develop within the salivary gland or the ductal system. Men > women Rare in children 75% - single 3% - bilateral 1.2% -autopsy

3. GLAND WISE DISTRIBUTION 80-92% - submandibular gland. 6-20% - parotid. 1-2% - sublingual and the minor salivary glands. Submanibular – larger & intraductal Parotid – multiple, within the gland

4. SUBMANDIBULAR GLAND OCCURENCE Abundant calcium concentration Alkaline Ph Anatomic factors Wharton’s duct - longest - two sharp curves - small punctum

5. Composition Organic substances

6. INORGANIC

7. CHEMICAL COMPOSITION Chemical composition Microcrystalline apatite (Ca5[PO4]3OH) or Whitlockite (Ca3[PO4]) Brushite and weddellite

8. RECENT DISCOVERIES Scanning electron microscopy has demonstrated oval, elongated shapes, suggesting the presence of bacilli in sialoliths . A recent polymerase chain reaction study found bacterial DNA, mainly belonging to the Streptococcus genus ARCH OTOLARYNGOL HEAD NECK SURG/VOL 129, SEP 2003

9. PATHOGENESIS Multifactorial event Secretory disturbances & precipitation – inflammatory process Specific changes in structure of organic molecules – supportive frame formation Metabolic disturbances – alkalinity & precipitation

10. MICROLITHS Concrements detectable only microscopically Contain – calcium and phosphorus hydroxyl apatite organic secretory material necrotic cellular residues Generated - autophagocytosis of organelles that are rich in calcium .

11. Dyschylia - Disturbed salivary secretion & change in the composition Accumulation of organic substances & mineralisation of organic matrix Accumulation of calcium Increase in p H Decreases the solubility of calcium phosphates

12. PROGRESSION Secretory disturbances viscous secretions Microlith formation ductal obstruction Coaction of factors + participation of bacteria sialoliths Dyschylia & increasing microlith formation ascent of bacteria lead to a focal obstructive atrophy of the acinar cells secretory disturbances Journal of Oral Science, Vol. 45, No. 4, , 2003

13. OTHER FACTORS Infection Salivary dysfunction Ductal anamolies Foreign bodies Ductal epithelium metaplasia

14. SYMPTOMS Pain, swelling & discomfort Pain - meal time – severe with sour or acidic food Unusual taste Associated with infection – fever , purulent discharge & lymphadenopathy

15. CHARACTERISTICS The annual growth rate - 1 mm per   year Shape - round or irregular Size - 2 mm to 2 cm

16. GIANT SIALOLITH 72 mm in length and weighing 45.8 g The ability of a calculus to grow and become a giant sialolith depends mainly on the reaction of the affected duct. Rai and Burman . Giant Submandibular Sialolith . J Oral Maxillofac Surg 2009 .

17. TREATMENT MODALITIES Newer treatment modalities - extracorporeal short-wave lithotripsy and sialoendoscopy are effective alternatives to conventional surgical excision for smaller sialoliths . However, for giant sialoliths , transoral sialolithotomy with sialodochoplasty or sialadenectomy remains the mainstay of management.

18. HISTOLOGIC FEATURES Stratified & mineralized with metaplastic excretory duct cells Concentric laminated structures Acini infiltrated by lymphocytes Dialatation of duct Epithelium exfoliation

19. DIAGNOSIS History Clinical examination Bi-manual palpation Imaging

20. BIMANUAL

21. IMAGING Imaging

22. Conventional radiography Intra oral radiographs IOPA , Occlusal radiographs Extra oral radiographs Panaromic , PA skull projection Intraglandular and small stones can be missed. 20% of sialoliths   are radiolucent

23. Sialography "Gold Standard” Retrograde infusion of oil or water based contrast & the architecture of the salivary duct system is visualized radio graphically .

24. LIMITATIONS

25. Ultrasonography Non invasive, alternative method Stones > 2mm detected as echo-dense spots with a characteristic acoustic shadow.

26. MR Sialography Non invasive Acute infections Canulation not possible

27. COMPUTED TOMOGRAPHY Posterior of the duct Hilum of the gland Substance of the gland Radiation exposure Non invasive & do not require contrast media

28. SIALOENDOSCOPY Minimally invasive Diagnostic & therapeutic Small endoscope – light at end of flexible cannula

29. Differential diagnosis Phleboliths – radiolucent center Dystrophic calcification of lymph nodes – Cauliflower shaped Palatine tonsiliths - multiple & punctate Haemangiomas with calcifications

30. TREATMENT

31. Sialoendoscopy Small endoscope – optical fibres - irrigation or working ports Special devices – guide wire - balloon catheters - metal baskets - laser fibres Ductal dialation – lacrimal probe - balloon dialator

32. Sialoendoscopy – assisted Sialolithectomy Large sialolith Lithotripsy Fragmentation Types – intracorporeal - extracorporeal

33. Intracorporeal techniques Mechanical fragmentation Intracorpreal laser lithotripsy - Er : YAG - Ho: YAG Pneumatic lithotripsy

34. ARCH OTOLARYNGOL HEAD NECK SURG/VOL 129, SEP 2003

35. Extracorporeal Lithotripsy Shock waves – focused, multiple high intensity acoustic pulses Kinetic energy – compressive & tensile forces

36. paediatric patients Relatively small and distal Bimanual careful palpation is mandatory to diagnostic approach for children suspicious of sialolithiasis . These findings also suggest that intra-oral approach is effective treatment procedure for most of sialolithiasis in children. Int J Pediatr Otorhinolaryngol 2007 May;71(5)

37. MIGRATING SALIVARY STONES

38. Conclusion Sialolithiasis is the main cause of unilateral diffuse parotid or submandibular gland swelling. Mechanical obstruction of the salivary duct, causing repetitive swelling during meals, & often complicated by bacterial infections. Common in submandibular gland , 10 – 20% are radiolucent Newer minimally invasive diagnostic & therapeutic modalities

39. References Contemporary OMFS – Perterson Oral Radiology – principles & interpretation – White & Pharoah Sialoendoscopy & salivary gland sparing surgery - Oral Maxillofaccial Surg Clin N Am 21 (2009) Pathogenesis & diverse histologic findings of sialolithiasis – J Oral Maxillofac Surg 68: 2010 Imaging the major salivary glands – British Journal of Oral & Maxillofacial Surgery 49 (2011) Oral & maxillofacial pathology – Neville Text book of OMFS – Neelima Mallik