SIALOLITHIASIS Dr ARJUN SHENOYPG STUDENT DEPT OF OMFS

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

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

SUBMANDIBULAR GLAND OCCURENCE

Abundant calcium concentration Alkaline Ph

Anatomic factors

Wharton’s duct - longest - two sharp curves - small punctum

Composition

Organic substances

organic Inorganic

MUCOPOLYSACCHARIDES

GLYCOPROTEINS

CELLULAR DEBRIS

INORGANIC

CALCIUM PHOSPHATE

Fe

Cu

Mn

CALCIUM CARBONAT

E

CHEMICAL COMPOSITION

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

BRUSHITE

WEDDELLITE

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

PATHOGENESIS

Multifactorial event

Secretory disturbances & precipitation – inflammatory process

Specific changes in structure of organic molecules – supportive frame formation

Metabolic disturbances – alkalinity & precipitation

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.

Dyschylia - Disturbed salivary secretion & change in the

composition

Accumulation of organic substances & mineralisation of organic matrix

Accumulation of calcium Increase in pH

Decreases the solubility of calcium phosphates

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

OTHER FACTORS

Infection Salivary dysfunction Ductal anamolies Foreign bodies Ductal epithelium metaplasia

SYMPTOMS

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

lymphadenopathy

CHARACTERISTICS

The annual growth rate - 1 mm per year

Shape - round or irregular

Size - 2 mm to 2 cm

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.

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.

HISTOLOGIC FEATURES

Stratified & mineralized with metaplastic excretory duct cells

Concentric laminated structures Acini infiltrated by lymphocytes Dialatation of duct Epithelium exfoliation

DIAGNOSIS

History

Clinical examination Bi-manual palpation

Imaging

BIMANUAL

IMAGING

Conventional radiography

Sialography

Ultrasonography

Computed tomography (CT)

Magnetic resonance imaging (MRI)

Sialoendoscopy

Imaging

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

Sialography

"Gold Standard”

Retrograde infusion of oil or water based contrast & the architecture of the salivary duct system is visualized radio graphically .

LIMITATIONS

Advantagedetects

radiolucent stones

Therapeutic

Disadvantage

• invasive• bleeding &

perforations

contraindicated• acute infections

• allergic to contrast

Ultrasonography

Non invasive, alternative method

Stones > 2mm detected as echo-dense spots with a characteristic acoustic shadow.

MR Sialography

Non invasive Acute infections Canulation not possible

COMPUTED TOMOGRAPHY

Posterior of the duct Hilum of the gland Substance of the gland

Radiation exposure Non invasive & do not require contrast media

SIALOENDOSCOPY

Minimally invasive

Diagnostic & therapeutic

Small endoscope – light at end of flexible cannula

Differential diagnosis

Phleboliths – radiolucent center

Dystrophic calcification of lymph nodes – Cauliflower shaped

Palatine tonsiliths- multiple & punctate

Haemangiomas with calcifications

TREATMENT

Symptomatic Surgical

• Opening of wharton’s ductTrans oral

Ductotomy ( sialolithotomy)

• Deep intra glandular• Multiple stones• Prevent recurrence

Sialoadenectomy

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

Sialoendoscopy – assisted Sialolithectomy

Large sialolith

Lithotripsy Fragmentation

Types – intracorporeal - extracorporeal

Intracorporeal techniques

Mechanical fragmentation

Intracorpreal laser lithotripsy - Er: YAG - Ho: YAG

Pneumatic lithotripsy

ARCH OTOLARYNGOL HEAD NECK SURG/VOL

129, SEP 2003

Extracorporeal Lithotripsy

Shock waves – focused, multiple high intensity acoustic pulses

Kinetic energy – compressive & tensile forces

Complications

-Inability to remove fragment

-Postoperative infections

-Neural damage -Intraductal

adhesion

-Subglossal scar band formation

-Sialocele & Ranula formation

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)

MIGRATING SALIVARY STONES

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

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