Keywords salivary calculi - sialadenitis - salivary stones - salivary stasis and salivary gland
pathology
Introduction
Sialolithiasis occurs in approximately 1% of the general population. About 80 to 90%
of salivary stones occur in submandibular gland.[1 ] The composition of sialolith can vary depending upon the concentrations of organic
or inorganic components and the gland in which it has occurred. Submandibular gland
sialoliths (SMGS) are usually composed of inorganic materials such as hydroxyapatite,
brushite, and octacalcium phosphate.[2 ] The formation of SMGS is not a single process, it is influenced by various factors
such as stasis of saliva, changes occurring in the salivary biochemistry, and accumulation
of calcium phosphate.[2 ] The inflammation of the salivary gland is termed sialadenitis and it is an insidious
disease usually affecting the major salivary glands and characterized by intermittent
swelling, accompanied by pain and tenderness.[3 ] The microbiology of sialadenitis is not much reported in submandibular and sublingual
glands. Bacterial colonies such as staphylococcus, streptococcus, and Gram-negative
bacteria are the most common etiologic factors to cause this inflammatory condition.[4 ]
Since the exact etiology is still unclear there are few theories considered for the
formation of sialoliths: (1) sialomicroliths agglomerating together, (2) mucus plug
getting calcified, and (3) alteration of the saliva's biochemical composition. The
composition of the sialoliths can be assessed through various methods such as wet
chemical techniques, X-ray powder diffraction, and/or Fourier-transform infrared spectroscopy
(FTIR). The FTIR is the most commonly accepted method since it is rapid and easily
reproducible. The concept of FTIR is that the IR spectrum initially begins from the
vibration of molecules. These motions of molecules due to vibration produces frequencies
which are unique to individual compounds similar to that of fingerprints. This can
be utilized for the classification of organic and inorganic compounds present. Similarly,
in wet chemical analysis the quantification of ions and organic components can be
calculated.[5 ] The most commonly accepted method for assessing the composition of lithiasis is
wet chemical analysis method proposed by Larsson et al,[6 ] he had initially performed in urinary caliculi. The wet chemical method includes
various steps such as:
(1) Drying and dissolution: Initially, the calculus must be weighed and needs to be
pulverized in a mortar and to be dried over silica gel to completely desiccate at
room temperature for 2 days.
(2) Later, 1 mL of concentrated nitric acid to be added to the powder, effervescence
shows the presence of carbon.
(3) Next, the calculus needs to be completely dissolved and kept in magnetic stirring
for 3 hours at room temperature for creating the sample solution to find the presence
of particular component such as calcium, magnesium, ammonium, phosphate, oxalate,
and urate. The sample solution shouldn't be diluted for the analysis of cysteine and
protein but for rest it needs to be diluted.
(4) Result calculation: The molar concentrations and volume of sample solution can
be used to evaluate the amount of analyte in µmol. The composition of calculus can
be computed.[6 ]
The diagnosis of this disease is usually made clinically with conventional radiography
such as orthopantomogram (OPG) or occlusal radiographs followed by surgical removal
of the salivary stone and the gland involved.[5 ]
Case Report
Clinical Examination
A 60-year-old male patient presented with pain and swelling in the lower right side
of the floor of the mouth for the past week. The history of pain was sudden in onset
with moderate intensity and was continuous in nature. The patient did not state any
aggravating or relieving factors. The patient also gave no relevant history about
the change in the size of the mass. On extraoral examination, mild facial asymmetry
was noted on the right side. On palpation of the right submandibular region, there
was a diffused enlargement noted of approximately 2 cm × 2 cm in size roughly along
with tender and palpable lymph nodes. There was no difficulty in mouth opening and
closing along with normal jaw moments.
Radiographic Examination
An OPG was taken ([Fig. 1 ]). The OPG revealed a well-defined radiopaque mass seen superimposed in the right
lower body of the mandible near the angle of the mandible of size approximately 3.5 mm × 1.7 mm
in size and a provisional diagnosis of sialolith was considered. The patient was referred
to the department of oral surgery for further management.
Fig. 1 X-ray showing sialolith on right submandibular region (white arrow).
Surgical Intervention
The surgeons evaluated the patient and prepared for the removal of the sialolith along
with the involved salivary gland. An excisional biopsy was performed and given for
histological evaluation ([Fig. 2 ]).
Fig. 2 (A ) Preop picture of the patient with marking prior to removal of the sialolith and
the involved submandibular gland. (B ) Postop picture of the patient after the removal of sialolith along with submandibular
gland.
Histopathological Examination
The gross specimen was received for histopathological evaluation ([Fig. 3 ]). A radiograph of the gross specimen was also taken to check for any other calcifications
present within the gland ([Fig. 4 ]). On gross examination of the sialolith it roughly measured around 1.3 cm × 0.9 cm
in size ([Fig. 5 ]).
Fig. 3 (A ) the gross specimen. (B ) Sialolith along with submandibular gland approximately measuring 5.5 cm × 4.5 cm.
Fig. 4 X-ray of the excisional biopsy of sialolith along with submandibular gland.
Fig. 5 Macroscopic view of sialolith roughly measuring 1.3 cm × 0.9 cm in size.
The hematoxylin and eosin-stained section showed encapsulated lobules of the salivary
gland which were seen separated by thin fibrous septa. Numerous seromucous acini were
seen. One part of the section showed loss of architecture of the acini and a focal
area of diffused infiltration of inflammatory cells into the gland along with numerous
ducts. Periductal inflammation was also noted along with blood vessels and extravasated
red blood cells ([Fig. 6 ]).
Fig. 6 Photomicrograph of submandibular sialadenitis showing: (A ) Lobules of gland with mixed seromucinous acini in lower power magnification. (B ) Periductal inflammation with dense inflammatory infiltrate. (C ) Infiltration of inflammatory cells into the gland. (D and F ) Higher power image showing infiltration of inflammatory cells in between acini and
ducts. (E ) Destruction of the ducts by the inflammatory cells.
Discussion
Sialolithiasis
Sialolithiasis is formation of salivary stones in the ducts of the major salivary
glands: the parotid, submandibular, and sublingual glands with a reported prevalence
of 1 in 10,000 to 1 in 30,000, and it is the most common cause of salivary gland enlargement.[7 ] Sialoliths can occasionally restrict the salivary ducts, causing inflammation and
root a secondary bacterial infection, or in extremely rare circumstances form an abscess.
There are many presenting signs, but the two most prevalent signs are reduced salivary
flow and cyclical postprandial enlargement of the afflicted gland.[8 ] The etiology and pathophysiology are presented as a flowchart ([Fig. 7 ]).[9 ]
[10 ]
Fig. 7 Flowcharts showing the pathophysiology and etiology of sialolithiasis.
Sialadenitis
Sialadenitis is the inflammatory condition of salivary glands. It most commonly occurs
in major salivary glands. Submandibular sialadenitis is usually caused due to stasis
of saliva which in turn leads to retrograde seeding of bacteria from the oral cavity.
Submandibular glands are present bilaterally in the submandibular triangle covered
by the investing layer of deep cervical fascia and it drains into the oral cavity
through the Wharton's duct in the floor of the mouth. The submandibular gland saliva
is rich in potassium and low in sodium. There are two forms of submandibular gland
sialadenitis: acute and chronic form. The acute form is characterized by insidiously
occurring and the chronic form is characterized by long-standing infection due to
obstruction. The usual clinical presentation will be swelling of the gland without
erythema accompanied by pain. The common causes and pathophysiology are listed in
[Fig. 8 ].[11 ]
[12 ]
[13 ]
[14 ]
Fig. 8 Common causes and pathophysiology of sialadenitis.
Since there are numerous causative factors, all differential diagnosis must be excluded
by the clinician based on the clinical criteria to arrive at a diagnosis. The clinical,
radiographical, laboratory, and histological tests need to be done for confirmatory
diagnosis. To assist the diagnostician in reaching a diagnosis and course of treatment,
we suggest a straightforward but practical diagnostic algorithm. This algorithm takes
into consideration the palpable salivary stones as well[15 ]
[16 ]
[17 ]
[18 ] ([Fig. 9 ]).
Fig. 9 Diagnostic algorithm for sialadenitis and sialolithiasis.
The most common cause of sialadenitis is sialolithiasis, which occurs in the submandibular
region and accounts for approximately 80% of cases.[19 ] There are various theories put forth on the formation of salivary stones, but they
are most likely to occur in the submandibular gland because of salivary stagnation,
increased alkalinity of saliva, physical trauma, being more susceptible to infection
and inflammation, and the production of saliva against gravity.[20 ] Also, the contents of submandibular saliva contribute due to their increased levels
of mucin, protein, calcium, and phosphate compared to that of other major salivary
glands.[19 ] In fact, tobacco can also contribute to the formation of sialoliths because it greatly
influences the rate of salivary flow and can also cause inflammation of the gland.[20 ] About 85% of the sialoliths occur in Wharton's duct because of its complex morphology,
while the rest, 15%, occur in the gland parenchyma.[20 ]
[21 ] The obstruction of the gland can cause swelling with a subsequent risk of superinfection.
Sialolith usually occurs predominantly in adult male population. In the current case
report a 60-year-old male was affected which is in accordance to the literature.[21 ] The signs and symptoms include cyclical episodes of pain accompanied by inflammation
and swelling, the inflammation and swelling occur due to the obstruction of the flow
of saliva, resulting in increased intraglandular pressure. In partial or incomplete
ductal obstruction, the saliva can escape around the sialolith. In these types of
cases, the patients will be asymptomatic and can only be diagnosed as an incidental
finding in routine dental radiography.[22 ] The imaging of the salivary gland is crucial because it aids in determining the
location, kind, and extent of the lesion, assessing the ductal morphology, choosing
the site of the biopsy, and formulating a treatment strategy.[23 ] Conventional radiography, digital subtraction sialography, sonography, computed
tomography, and magnetic resonance (MR) imaging sialography are imaging methods that
can be used to investigate salivary calculi. Just 20% of calculi are radiopaque, and
conventional radiography depends on the nature of the stone. Digital subtraction sialography
has a sensitivity range of 96 to 100% and a specificity range of 88 to 91%. Because
of the possibility for an infection's symptoms to worsen, it is contraindicated in
the acute context. According to reports, sonography has a sensitivity range of 59.1
to 93.7% and a specificity range of 86.7 to 100%.[22 ]
[23 ] According to reports, MR imaging sialography has a 91% sensitivity rate and a 94
to 97% specificity rate.[24 ]
The choice of imaging modality should be made based on the disease and the characteristics
of the patient. There are numerous therapy options that principally rely on the sialolith's
size and location. Frequently performed is bimanual palpation for tiny stones which
pass through the duct and are “milked out.” Surgical shock wave lithotripsy is advised
for salivary stones up to 10 mm which have been found in the proximal part of the
duct and it is an extremely minimal invasive procedure for removing substantial salivary
stones. Sialoliths greater than 10 mm and which are not palpable are removed surgically
along with the gland involved.[15 ]
[16 ]
[17 ]
[18 ]
The differentials that can be considered in case of swelling in the submandibular
region and radiopacities seen in radiographs are listed out in [Table 1 ].
Table 1
Differential diagnosis that can be considered for swelling in submandibular region
and radiopacities seen in radiographs[25 ]
[26 ]
Differential diagnosis considered for submandibular gland swelling
Acute symptoms
Chronic symptoms
- Viral infections
- Bacterial infections
- Obstruction of the duct due to caliculi
- Low-grade non0pyogenic bacterial infection
- Lymphoepithelial disease such as sicca syndrome
- Granulomatous conditions such as tuberculosis, fungal infections
- Sarcoidosis
- Salivary gland neoplasm
Lesions with similar clinical presentations in the submandibular region are:
- Space infections
- Dental abscess
- Thyroglossal cyst
- Non-neoplastic, noninflammatory swelling of the salivary gland can occur due to
various reasons such as metabolic and nutritional imbalances which also includes liver
cirrhosis due to alcoholism, pellagra, and uremia
Differential diagnosis to be considered for radiopacities in submandibular region
- Sialoliths (salivary stone or caliculi)
- Calcified lymph nodes
- Phleboliths
- Tuberculosis
- Atherosclerotic plaques
- Metastasis from calcified carcinoma
The uniqueness of this case study is that it provides a detailed insight on sialolith
in the submandibular gland; its etiology, pathogenesis, analysis and composition of
salivary caliculi, and a diagnostic algorithm is proposed which can help the surgeons
to manage sialoliths with sialadenitis more efficiently and contribute to the literature
on the subject. The terms “sialolithiasis” and “submandibular gland sialolithiasis”
were used in searches on PubMed and Google Scholar. Pertinent published articles in
dentistry journals were reviewed and included in the current case report. Only English-language
studies published after the year 2010 reporting cases of sialoliths with sialadenitis
occurring in the submandibular gland among Indian population were chosen for the review
and tabulated ([Table 2 ]).
Table 2
Cases of sialoliths occurring in submandibular gland reviewed in literature from the
year 2010 to 2023 among the Indian population
Author name
Year of publication
Age and gender of the patient
Feature and site of occurrence
Chandra Mouli et al[27 ]
2011
44/M
Pain on lower left side below the tongue
Shetty and Sharma[28 ]
2010
50/M
Left submandibular region, swelling
Lokesh Babu and Jain[29 ]
2011
50/M
Left side on the floor of the mouth, pain with swelling
Parkar et al[30 ]
2012
84/F
Left floor of the mouth, swelling
Iqbal et al[31 ]
2012
55/M
Left submandibular duct region
Arunkumar et al[32 ]
2015
55/M
Left border of the mandible, swelling
Marwaha and Nanda[33 ]
2012
10/F
Left submandibular gland region, intermittent pain
Saluja et al[34 ]
2012
65/M
Right side floor of the mouth, pain and swelling
Kuruvila et al[35 ]
(6 cases)
2013
1- 55/F
2- 25/F
3,4,5- F (age not mentioned)
6- 8/F
Right mandibular region
Lower left back tooth region
Swelling in the floor of the mouth
Swelling below the tongue
Dalal et al[36 ]
2013
40/F
Left floor of the mouth, intermittent pain
Singh and Singh[37 ]
2013
55/M
Floor of the mouth, asymptomatic
Dewan et al[38 ]
(multiple sialoliths)
2013
26/M
Pus discharge from the opening of the duct
Kiran et al[39 ]
(2 cases)
2013
26/M
44/M
Right submandibular region, swelling and pain
Left submandibular region, swelling
Divya and Sathasivasubramanian[40 ]
(2 cases)
2013
22/M
69/F
An insidious swelling appears during meals and disappears
Pain below the tongue
Trivedi[41 ]
2014
9/F
Right submandibular region
Sinha et al[42 ]
2014
55/M
Right lower side of the face, swelling with intermittent pain
Mathew Cherian et al[43 ]
2014
36/M
Floor of the mouth, pain and swelling
Shruthi Hegde et al[44 ]
2014
55/M
Left submandibular region, swelling
Baliah et al[45 ]
(2 cases)
2014
10/M
55/M
Right submandibular region, swelling
Lower border of mandible, swelling
Krishnan et al[46 ]
2014
43/M
Left side on the floor of the mouth, swelling
Mohapatra et al.[47 ]
2015
18/F
Right submandibular region, swelling
Kiran et al[48 ]
2015
65/M
Floor of the mouth, swelling
Gopinath[49 ]
2015
35/M
Intraoral swelling with chronic pain
Thopte et al[50 ]
2016
23/M
Lower right back tooth region, pain
Singh et al[51 ]
2016
35/M
Floor of the mouth, pain and swelling
Sabu et al[52 ]
2017
55/M
Bilateral swelling noted on the lower jaw
Rana and Arya[53 ]
(3 cases)
2017
22/M
35/M
48/F
Right side of the face, pain and swelling
Left side of the face, pain and mild swelling
Right submandibular region
Sakthivel et al[54 ]
2017
42/M
Right submandibular region, swelling
Monika et al[55 ]
2017
52/F
Floor of the mouth, swelling
Ujjwal et al[56 ]
(2 cases)
2018
58/F
Young female (age not mentioned)
Left submandibular region, swelling
Right submandibular region, intermittent pain and swelling
Sengupta and Bose[57 ]
2018
35/M
Pain on mastication
Neeraj et al[58 ]
2018
37/M
Left submandibular region, pain
Wadhawan et al[59 ]
2019
19/M
Right back jaw region, swelling
Kumar et al[60 ]
2021
29/M
Left angle of mandible
Nirola et al[61 ]
(2 cases)
2020
37/M
35/F
Right side floor of the mouth
Left side floor of the mouth, swelling
Khorate and Vaidya[62 ]
2020
39/M
Left submandibular region, swelling
Chandak and Chandu[63 ]
2020
23/M
Left submandibular region, pain and swelling
Anand et al[64 ]
2020
69/M
Floor of the mouth, pain
Mathew et al[65 ]
2022
50/M
Right submandibular region, swelling
Present case
2023
60/M
Right lower side in floor of the mouth, pain and swelling
Abbreviations: F, female; M, male.
Conclusion
Sialoliths need to be assessed and managed properly prior to the involvement of the
gland because sialadenitis can cause detrimental effects. A meticulous history collection
and appropriate imaging techniques would preserve time. This case report adds to the
literature, it illustrates a case of sialolithiasis occurring along with sialadenitis
that was diagnosed clinically and interpreted using a simple radiograph and treated
with no complications. A diagnostic algorithm has been proposed to arrive at a quick
diagnosis and initiate a prompt treatment.
