Multiple, large sialoliths of the submandibular gland duct: a case report.
ABSTRACT This paper reviews the major clinical and radiographic features of sialoliths and illustrates these with an unusual case of multiple sialoliths within the submandibular gland duct. The differential diagnosis of other calcific structures both within and outside the salivary gland that may mimic a sialolith is also presented.
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ABSTRACT: Conflicting reports exist regarding the prevalence of Modic changes among low back pain (LBP) patients and factors associated with their existence. To assess the prevalence of Modic changes and other findings on lumbar magnetic resonance imaging (MRI) among Spanish adult chronic LBP patients and the patient characteristics and radiological findings associated with Modic changes. A cross-sectional imaging study among chronic LBP patients. Four hundred eighty-seven patients (263 women and 224 men) undergoing lumbar spine MRI examination for chronic LBP. Gender, age, body mass index (BMI), lifetime smoking exposure, degree of physical activity, and image features (disc degeneration, type and extension of Modic changes, disc contour, annular tears, spinal stenosis, and spondylolisthesis). Ten radiologists from six hospitals across six cities in Spain consecutively recruited adult patients in whom lumbar MRI had been prescribed for LBP lasting ≥3 months. Patients' characteristics and imaging findings were assessed through previously validated instruments. A multivariate logistic regression model was developed to assess the features associated with Modic changes. Modic changes were found in 81% of the patients. The most common was Type II (51.3%), affecting only the end plate. Variables associated with Type I changes were disc contour abnormalities, spondylolisthesis, and disc degeneration. The same variables were associated with a higher risk of Type II or any type of Modic changes, as well as being male, and having a higher BMI. Modic changes are found in 81% (95% confidence interval, 77-85) of adult Spanish patients in whom an MRI is prescribed for chronic LBP. Modic changes are more likely to be found in males with a high BMI, who also show disc contour abnormalities, spondylolisthesis, or disc degeneration.The spine journal: official journal of the North American Spine Society 05/2011; 11(5):402-11. · 2.90 Impact Factor
- Journal of oral and maxillofacial surgery: official journal of the American Association of Oral and Maxillofacial Surgeons 04/2011; 69(6):e123-7. · 1.58 Impact Factor
Australian Dental Journal 2009; 54: 61–65
Multiple, large sialoliths of the submandibular gland duct:
a case report
TC Huang,* JB Dalton,* FN Monsour,? NW Savage?
*Dento-Maxillofacial Radiology, School of Dentistry, The University of Queensland.
?Maxillofacial Unit, Royal Brisbane and Women’s Hospital, Queensland.
?Oral Medicine, School of Dentistry, The University of Queensland.
This paper reviews the major clinical and radiographic features of sialoliths and illustrates these with an unusual case of
multiple sialoliths within the submandibular gland duct. The differential diagnosis of other calcific structures both within
and outside the salivary gland that may mimic a sialolith is also presented.
Key words: Calcification, case reports, radiopaque lesion, sialolith, salivary gland.
(Accepted for publication 4 June 2008.)
Salivary gland⁄duct stones or sialoliths are calcifica-
tions that accumulate within the salivary gland paren-
chyma and associated ductal systems.1They develop
from a mineralization nucleus of debris including
bacterial colonies, shed ductal epithelial cells and cell
remnants, mucus plugs and foreign bodies.1Eighty to
90 per cent of sialoliths develop in the submandibular
gland system, and 10–20 per cent in the parotid gland.2
Only 1 per cent of calcifications occur in the sublingual
gland which may be due to a dominant mucoid
secretion and very short ductal tree.2–4Most patients
present with a single stone but multiple stones occur in
32 per cent of cases in the parotid gland and 22 per cent
in the submandibular gland.3Bilateral stones occur in
around 2.2 per cent of cases.3
Sialoliths are typically more common in middle-aged
males but some studies suggest a male to female ratio of
1:1 and with ages ranging from 12 to 93 years.2,3The
most frequent clinical presentation is swelling and pain
in the area of the affected gland with a prodromal
awareness varying from less than six months to
30 years.1,3Sialoliths can often be detected on palpa-
tion, especially when they are located above the
mylohyoid muscle or in the buccal mucosa and lip.1,5
Sialoliths in the submandibular gland duct are usually
diagnosed after longer asymptomatic periods than
those in the parotid gland duct.6This is due to greater
ductal volume between the hilus and submandibular
papilla and the ability to accommodate the obstruction
while still allowing saliva to flow past the obstruction.6
The severity of pain and swelling is pressure-associated
and dependent upon the degree of obstruction and
residual duct patency.1Recurrent partial obstructions
are the usual clinical diagnoses and correlate with mild
symptoms that self-correct within a short period
following stimulation, usually meal related.4Complete
obstruction however, presents as an emergency situa-
tion with severe symptoms including a tense swollen
gland with marked sensitivity, ductal swelling and on
occasion suppuration which may collect as a discrete
abscess or drain from the duct orifice.1,4This may be
accompanied by localized cellulitis, malaise and fever.4
The signs and symptoms are listed in Table 1.
Salivary calculi larger than 1 cm are rare. A review of
literature by Lustmann found that of 302 sialoliths
studied, 79.8 per cent were 1 cm or less and only 7.6
per cent greater than 1.5 cm.2This present article
reviews the significant clinical features of sialoliths and
reports a case of multiple calculi in the submandibular
duct. Patients will often present to the general dental
practitioner for diagnosis and it is important that the
matter can be dealt with competently and referral to
surgical management arranged.
A 57-year-old female presented with pain and swelling
focal to the left submandibular triangle with a duration
ª 2009 Australian Dental Association61
of around three months. Intra-orally she was aware of a
firm mass in the floor of the mouth. Her medical history
was unremarkable and she had not had any previous
similar episodes involving either site.
Clinically, there was a visible swelling of the left
submandibular triangle which, on careful examination,
was localized to a tense and sensitive submandibular
salivary gland. The overlying skin did not show
erythema or a temperature differential compared with
the contralateral side and although the adjacent lymph
nodes were difficult to palpate due to generalized
sensitivity, none were obviously enlarged. The cervical
nodes remained uninvolved. Intra-orally the left floor
of the mouth was oedematous with a multi-nodular
enlargement of the submandibular duct with two
presumed calcifications palpable. It was not possible
to examine the lingual fossa due to swelling and
sensitivity. The calcifications were fixed and did not
move antero-posteriorly with gentle manipulation.
Stimulated flow from the submandibular gland was
difficult to judge due to sensitivity but there was no
discharge of either saliva or suppuration from the
The panoramic radiograph showed an elongated
radiopaque structure superimposed over the roots of
the 31 to 37 and with obscuration of the root anatomy
(Fig 1). An occlusal radiograph revealed at least three
sialoliths occupying most of the length of the left
submandibular duct extending from the distal extent
proximally to the molar area and lingual fossa (Fig 2).
Lamination can be seen within the sialolith.
The calculi were surgically exposed and removed
(Fig 3). The stones were individually dissected free due
to extensive fibrosis and adhesion to the wall of the left
submandibular salivary duct. Following removal of all
stones, the duct was cannulated and expanded and
became patent with transmission of normal secretory
elements. Proximal repositioning of the duct orifice to
the mid-left floor was undertaken with a circular suture
back technique to prevent subsequent fibrosis and duct
Four calculi were identified at operation and removed
with a combined length of 4 cm in their largest
dimension (Fig 4). They were irregular to oval in shape
with rough, multi-nodular and irregular surfaces. There
was also evidence of fibrotic tissue covering the calculi.
Submandibular sialoliths measuring less than 1 cm in
greatest dimension are quite common but larger
sialoliths are considerably less so.2,7,8Their presence
can cause salivary gland dysfunction and obstruction of
salivary flow resulting in chronic or acute bacterial
infections. Varying degrees of atrophy of the glandular
Table 1. Signs and symptoms
Size fluctuation, usually rapid onset and partial resolution over one
to several hours
Residual glandular swelling
Decreased stimulated salivary flow compared to the contralateral
Pain (intensifies during mealtimes or when salivary flow is stimulated)
Stones commonly visible in submandibular duct
Swelling and erythema of submandibular papilla for distal stones
Localized cellulitis (uncommon)
Fig 1. Panoramic radiograph showing the submandibular salivary
stone superimposed over the roots of the left anterior and posterior
Fig 2. Lower occlusal radiograph showing two definite submandibular
gland duct stones and possibly a third.
ª 2009 Australian Dental Association
TC Huang et al.
parenchyma with ductal ectasia⁄expansion and fibrosis
of the interstitium may also occur. This depends upon
the position of the stone within the ductal system,
hilum or gland parenchyma and the duration and
degree of obstruction and resultant retrograde pressure.
Intraductal stones may lie free within the duct and able
to move antero-posteriorly depending upon pressure
build-up from saliva trapped within the proximal sector
or intra-oral manipulation. Stones present for an
extended period and particularly those with an irreg-
ular external surface may provoke a focal inflammatory
reaction within the duct wall with resultant scarring
and enhanced obstruction.
There are several factors that may contribute to the
increased incidence of sialoliths in the submandibular
gland. These include the more viscous mucus content
of the saliva and the high concentration of calcium
phosphate. This creates a more alkaline pH which not
only favours the solid-liquid phase exchange of calcium
phosphate species in the mouth and maintenance of the
dentition but causes precipitation of the more reactive
species dibasic calcium phosphate dihydrate⁄brushite.
This process is helped by the ascending course and
narrow orifice of Wharton’s duct compared to the
calibre of the duct itself, both of which encourage
stagnation of saliva.6,9
The initial radiographic examination of sialoliths is
usually undertaken with plain films (Table 2). Lust-
mann found that sialoliths were detected in 94.7 per
cent of cases using intra-oral radiographs alone.2Large
and well mineralized calculi are visible on plain
radiographs but small or partially mineralized calculi
may remain undetected.6Significantly, Blatt found that
around 20 per cent of sialoliths remain unseen on plain
film examination due to a low mineral content.4
Sialoliths developing in the hilus of the submandibular
gland tend to be oval and may grow larger before
becoming symptomatic reflecting the dynamics of fluid
flow around the developing stone and the ductal
structure in this part of the arborization system.5,10
Given the postero-inferior position of the gland, a
mandibular oblique lateral radiograph may be useful
for visualization.10Sialoliths located within the duct
distal to the hilum tend to be elongated, again due to
fluid flow characteristics and a more defined luminal
architecture, and are better visualized with an occlusal
radiograph displaying the floor of the mouth without
overlap from other anatomy (Fig 2).10Sialoliths are
well visualized on panoramic and periapical radio-
graphs but can be obscured with superimposition over
the roots of the premolar and molar teeth and muscle
attachment ridges on the cortices of the mandible.
Intraductal, large stones will usually show as an
anteriorly inclined stone due to the ascending course
of the duct from the flexure in the lingual fossa to the
anterior floor of the mouth. Both small and sometimes
large sialoliths can be asymptomatic and can appear as
coincidental findings on radiographs.11
Other imaging techniques that may be used to
diagnose sialoliths include sialography, ultrasound,
computed tomography and magnetic resonance sialo-
graphy. Sialography is rarely indicated and should be
restricted to those cases with a suspected ductal
stricture or other obstruction but without a calcification
visible on routine imaging. Ultrasound will locate a
sialolith but, with the subsequent requirement for
Fig 3. Removal of the distal and largest sialolith from the
submandibular gland duct.
Fig 4. Four discrete calculi were removed from the duct and are
shown to scale.
Table 2. Radiographic features
Radiopaque (homogeneous or with a laminated structure)
Some may be radiolucent
Cylindric or irregularly-shaped
Anatomical position important
Imaging must include full duct length and gland
Stone orientated antero-posteriorly within duct
Fixed stones tend to be more rounded
ª 2009 Australian Dental Association63
conventional imaging, it is of limited clinical usefulness
and in most cases introduces an unnecessary step in
the diagnostic sequence. Until proven otherwise it is
prudent to consider and exclude the presence of
multiple sialoliths in any patient presenting with a
sialolith. These may be located in either or both the
duct and the gland. Computed tomography is useful in
any situation where there are multiple stones or when
the stone is situated in a site not readily examined intra-
orally, for example, the lingual fossa and proximally
including intraglandular stones and similarly for the
In most cases of sialolithiasis, treatment is advised
either for management of symptoms or, in quiescent
lesions, to prevent periductal inflammation and fibrosis
and the development of an obstructive situation. When
the stone is small, conservative management such as
moist heat, increased intake of fluids, sialagogues and
gentle massage of the gland towards the gland duct
opening may be all that is required to allow spontane-
ous release of the stone.1,5A small sialolith near the
orifice of the duct may also be removed following
widening of the orifice with a lacrimal probe.2If this is
not successful or a large stone is present, surgical
removal is necessary. Sialoliths in the gland duct can
often be removed without damage to the gland but
intraglandular sialoliths generally require removal of
the gland.1,8,12Stone removal in the posterior part
of the duct or removal of the gland may lead to
complications such as damage to the lingual and
hypoglossal nerves or bleeding into the floor of the
mouth. Haemorrhage in the floor of the mouth can lead
to major complications and can even be life threaten-
ing. Therefore, postoperative observation is vital. This
procedure is usually performed under general anaes-
thesia to better control any bleeding and to dissect
and protect the lingual and hypoglossal nerves. Other
treatments used successfully in the management of
sialoliths include interventional sialendoscopy with
wire-basket extraction for small sialoliths (< 4 mm)
and fiberoptic laser lithotripsy with basket retrieval for
larger sialoliths (> 4 mm).13In any retrieval procedure
within the ductal system, care must be exercised firstly
to ensure the stone does not track proximally and be
lost to the extraction process or that both the duct and
adjacent anatomical structures are not damaged to the
extent of causing significant scarring or other anatom-
ical deficit on healing.
It is important to distinguish sialoliths from other
calcific structures outside the salivary gland and con-
siderations in the differential diagnosis are listed in
Table 3.14,15A mandibular torus or osteoma can occur
in a similar position but both remain in a constant
relationship with the mandible on films with different
angulations. Their surface contour both clinically and
radiographically also reflect the nature of these two
lesions and are almost always diagnostic. Due to the
large size of this patient’s sialolith on the panoramic
radiograph, the presentation does mimic an osteoma
but pain is usually not a symptom.
Calcified lymph nodes are usually both radiopaque
and radiolucent with mottled and irregular borders.9,10
A calcified submandibular lymph node may be difficult
to differentiate from a submandibular sialolith due to
its position near the submandibular gland and a similar
projection on a radiograph. Differential diagnosis of a
calcified mass in the submandibular area would favour
a sialolith due to its relative higher incidence. In this
instance, an ultrasound may be of assistance in dif-
ferentiating the typical echopattern of a lymph node.
Phleboliths are calcified thrombi occurring in ven-
ules, veins or vascular malformations⁄haemangiomas.
Phleboliths can occur in the floor of the mouth and tend
to have a dense ring with a radiolucent centre giving a
bull’s eye or target appearance on an occlusal radio-
graph.9,14A radiopacity in the floor of the mouth in
the absence of sialadenitis and the presence of a clini-
cally discernible varicosity would favour a diagnosis
of phlebolith. However, there is a reported case of
cavernous hemangioma with numerous phleboliths in
the submandiblar gland which clinically and radio-
graphically (on plain film and computed tomography
imaging) resembled sialolithiasis.16
Calcification in a short section of the facial artery
near the submandibular area could simulate a sialolith.
If a longer area of artery is involved, the serpentine,
calcified image is usually diagnostic.17A calcification in
the common carotid usually lies next to the C3–C4 and
more laterally on a panoramic view than a sialolith.18
A rare differential diagnosis may include myositis
ossificans. Although most common in the masseter,
other muscles of mastication such as the temporalis,
medial pterygoid and lateral pterygoid can also be
involved.19Myositis ossificans in the medial pterygoid
can mimic a submandibular sialolith.20However,
trismus should alert the clinician to the possibility of
Sialoliths are always a consideration in submandibular
and facial pain particularly when related to mealtimes.
Their work-up requires a careful history and the
Table 3. Differential diagnosis
Calcified lymph nodes
Phleboliths and other vascular calcifications
Tuberculosis of lymph nodes or of the salivary gland itself
Calcified atherosclerotic plaques in major blood vessels
Metastasis from distinct calcifying neoplasms
ª 2009 Australian Dental Association
TC Huang et al.
selection of the correct imaging techniques to both
confirm the clinical diagnosis and to define the precise
position of the calcification. This paper has reviewed
the major features of sialoliths and illustrated these
with an unusual case of multiple sialoliths within the
submandibular duct. At surgery an additional stone
was found reinforcing the need for caution at removal.
The procedural work is not discussed in detail as this is
usually best undertaken by clinicians skilled in salivary
gland and ductal surgery to avoid post-procedural
morbidity and functional deficit.
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patients and a review of the literature. Int J Oral Maxillofac Surg
3. Levy DM, William MD, ReMine H, Devine KD. Salivary gland
calculi. Pain, swelling associated with eating. JAMA 1962;
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treatment. South Med J 1964;57:723–729.
5. Williams MF. Sialolithiasis. Otolaryngol Clin North Am 1999;
6. Som PM, Curtin HD. Head and neck imaging. 4th edn. St. Louis:
7. Zakaria MAK. Giant calculi of the submandibular salivary gland.
Br J Oral Surg 1981;19:230–232.
8. Siddiqui SJ. Sialolithiasis: an unusually large submandibular sal-
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9. Rabinov K, Weber AL. Radiology of the salivary glands. Boston:
GK Hall, 1985.
10. White SC, Pharoah MJ. Oral radiology: principles and interpre-
tation. 5th edn. St. Louis: Mosby, 2004.
11. Graziani F, Vano M, Cei S, Tartaro GP, Mario G. Unusual
asymptomatic giant sialolith of the submandibular gland: a clin-
ical report. J Craniofac Surg 2006;17:549–552.
12. Yildirim A. A case of giant sialolith of the submandibular salivary
gland. Ear Nose Throat J 2004;83:360–361.
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14. Bar T, Zagury A, London D, Shacham R, Nahlieli O. Calcifica-
tions simulating sialolithiasis of the major salivary glands.
Dentomaxillofac Radiol 2007;36:59–62.
15. Mandel L. Tuberculous cervical node calcifications mimicking
sialolithiasis: a case report. J Oral Maxillofac Surg 2006;
16. McMenamin M, Quinn A, Barry H, Sleeman D, Wilson G, Toner
M. Cavernous hemangioma in the submandibular gland mas-
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Pathol Oral Radiol Endod 1997;84:146–148.
17. Suarez-Cunqueiro MM, Duker Jg, Liebehenschel N, Scho ¨n R,
Schmelzeisen R. Calcification of the branches of the external
carotid artery detected by panoramic radiography: a case report.
18. Pornprasertsuk-Damrongsri S, Thanakun S. Carotid artery cal-
cification detected on panoramic radiographs in a group of Thai
population. Oral Surg Oral Med Oral Pathol Oral Radiol Endod
19. Steiner M, Gould AR, Kushner GM, Lutchka B, Flint R. Myositis
ossificans traumatica of the masseter muscle: review of the liter-
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Oral Pathol Oral Radiol Endod 1997;84:703–707.
20. Parkash H, Goyal M. Myositis ossificans of medial pterygoid
muscle: a cause for temporomandibular joint ankylosis. Oral Surg
Oral Med Oral Pathol 1992;73:27–28.
Address for correspondence:
Dr Neil W Savage
Oral Medicine and Pathology
School of Dentistry
The University of Queensland
200 Turbot Street
Brisbane QLD 4000
ª 2009 Australian Dental Association65