Journal of Oral and Maxillofacial Radiology

CASE REPORT
Year
: 2021  |  Volume : 9  |  Issue : 2  |  Page : 52--55

An angulated parotid duct sialolith: Radioimaging in diagnosis


Jigna S Shah, Mayur Rathod, Jaya Dubey 
 Department of Oral Medicine and Radiology, Government Dental College and Hospital, Ahmedabad, Gujarat, India

Correspondence Address:
Jaya Dubey
Department of Oral Medicine and Radiology, Government Dental College and Hospital, Ahmedabad - 380 016, Gujarat
India

Abstract

Sialolithiasis is one of the most common diseases of salivary glands and major cause for their dysfunction. It is more common in submandibular glands than in the parotid glands. In this report, the diagnosis and treatment of an unusual angulated parotid duct sialolith in a 25-year-old female in left Stensen's duct are presented with recurrent pericoronitis. Role of soft tissue intraoral periapical radiograph and cone beam computerized tomography in diagnosis and determining location and dimensions of sialolith is discussed.



How to cite this article:
Shah JS, Rathod M, Dubey J. An angulated parotid duct sialolith: Radioimaging in diagnosis.J Oral Maxillofac Radiol 2021;9:52-55


How to cite this URL:
Shah JS, Rathod M, Dubey J. An angulated parotid duct sialolith: Radioimaging in diagnosis. J Oral Maxillofac Radiol [serial online] 2021 [cited 2021 Dec 1 ];9:52-55
Available from: https://www.joomr.org/text.asp?2021/9/2/52/325041


Full Text



 Introduction



Sialolithiasis is caused by the obstruction of a salivary gland or its excretory duct which in turn caused by the formation of calcareous concretions or sialoliths. It is the most common disease of the salivary glands and accounts for 30% of salivary diseases. Sialolithiasis commonly involves the submandibular glands (83%–94%), less frequently the parotids (4%–10%), and the sublingual glands (1%–7%).[1]

The exact etiology of sialolith formation remains unknown, but it is thought that the more alkaline, viscous, mucus-rich saliva, which contains a higher percentage of calcium phosphates, in addition to the long and sinuous position of Wharton's duct and secretion against gravity contributes to stasis and making the submandibular salivary system more prone to the development of sialoliths than the parotid gland.[2] Submandibular sialoliths are thought to be formed around a nidus of mucus, whereas parotid sialoliths are thought to be formed around a nidus of inflammatory cells or a foreign body. A retrograde theory for sialolithiasis has also been proposed, i.e., aliments, substances, or bacteria within the oral cavity migrate into the salivary ducts and become a nidus for further calcification.[1]

Sialoliths may be asymptomatic or symptomatic. The symptoms are pain and swelling. The symptoms of salivary-secretion blockage vary depending on the size of the stone, its location, and the severity of the obstruction to the salivary flow.[1] The usual symptom is that of an intermittent recurrent swelling in the region of the involved gland, usually associated with eating. In case of long-standing sialolithiasis, the symptoms are not severe and the patient complains only of a tender swelling at the site of involvement that may have been presented for a few years. Few patients report severe pain or a diffuse cellulitis following an acute exacerbation of the inflammatory process in the gland, which is mostly in complete occlusion cases. Parotid stones are difficult to diagnose. However, large stones near the ductal orifice produce a noticeable swelling which can be felt by bimanual palpation and can be demonstrated by the use of proper radiographic views.[3] Radiological investigations for localization of a stone in the parotid gland include plain periapical films, sialograms, ultrasound, computerized tomography (CT), and cone beam computerized tomography (CBCT). A soft tissue periapical view of the cheek using a periapical film followed by a standard posteroanterior film will confirm the presence of a radiopaque stone in the duct or in the superficial lobe of the parotid gland. A parotid sialogram may reveal the site of the obstruction as a filling defect with proximal dilation of the ducts. CT and CBCT scans have a greater accuracy than plain X-rays.[4]

Initial management of sialolithiasis is conservative with penicillinase-resistant staphylococcal antibiotic coverage, moist heat, sialagogues, and gentle massage. Most stones will respond to such a regimen combined with simple sialolithotomy when needed.[5] Open surgical treatments such as transoral ductal incision, external approaches, or a combined venture for removal of large stone are indicated.[6],[7]

 Case Report



A 25-year-old female patient came to the Oral Medicine and Radiology Department, GDCH, Ahmedabad, with complaint of pain in lower right third molar region and pain and swelling with pus discharge in left parotid duct orifice region for 2 days.

The patient had a history of painful extra and intraoral swelling in the same region before 8 months. After taking medication, extraoral complaints were relieved, but intraoral small painless swelling in parotid duct orifice region with pus discharge was still present. Recurrent history of pericoronitis was also present. Before 2 days, she developed swelling and pain intraorally on the same site and came to our hospital. On examination, intraorally inflamed single small swelling was noted at the opening of Stensen's duct without any extraoral swelling [Figure 1]a. Bidigital palpation revealed a small, tender, and hard swelling with pus discharge from duct orifice with reduced salivary flow. Pericoronitis in relation to lower right third molar region was present [Figure 1]b. Bilateral submandibular lymph nodes were enlarged, palpable, firm in consistency, and tender. Clinical diagnosis of salivary duct calculus was given. Radiographic examination by intraoral periapical radiograph (IOPA) of the left cheek region (reducing exposure parameters) showed an angulated calcified mass in the left parotid duct [Figure 2]a. Panoramic radiograph and anteroposterior (AP) puff view revealed big radio-opacity at the area of maxillary left first molar, supporting our clinical diagnosis of sialolith in Stensen's duct [Figure 2]b and [Figure 2]c. Accurate measurement and shape of sialolith were revealed in CBCT having size of 12.5 mm × 7.5 mm in coronal section, 14.6 mm × 7.1 mm in axial sectional section, and 10.6 mm × 6.3 mm in sagittal section [Figure 3]a, [Figure 3]b, [Figure 3]c. As the calculus was located near the duct orifice, surgical removal by transoral duct incision under local anesthesia was done [Figure 4]a, [Figure 4]b, [Figure 4]c and the patient was kept under follow-up.{Figure 1}{Figure 2}{Figure 3}{Figure 4}

 Discussion



Sialolithiasis represents approximately one-third of salivary gland disease and most common cause of acute inflammatory symptoms in the salivary glands. Incidence of parotid gland stone in male-to-female ratio is 2:1, and in general, it occurs at 3rd to 6th decades of life. Incidence increases as the patients grow older. This may be because of less maintenance of oral hygiene and more prone to smoking-related xerostomia which promotes retrograde infection.[1],[6],[8] The present case was reported in 25-year-old female patient with complaint of chronic recurrent pericoronitis. This may be considered as a cause of retrograde infection in parotid duct and causing sialadenitis leading to formation of salivary stone. In reported case, the patient also had past history of swelling of the gland with pus discharge from duct orifices. Hence, sialolith formation in parotid duct associated with sialadenitis and recurrent pericoronitis can be considered. Till today, many cases have been reported of parotid sialolith but pericoronitis causing retrograde infection is not mentioned earlier.

Parotid gland stones are thought to form most often around nidus of inflammatory cells or a foreign body. Most often, they are unilateral, single, having round or ovoid shape, porous texture, white to pale yellow color and varied in size from <1 mm to up to 3 cm and generally located within the ductal system.[1],[3],[4],[6],[8] Intraparenchymal sialoliths are very rare and mostly multiple in number.[2],[9] In the present case, 17-mm-sized unilateral, single, porous, yellow-colored, angulated sialoliths was present. Most common shape of stone is round and oval due to round shape of duct and concentric calcification around nidus.[1],[2],[3],[6] However, the present case showed angulated large stone; this may be due to tortuous path of duct or fusion of two or more calcified stone.

Salivary stones are generally represented with characteristic symptoms. These are swelling and pain of the salivary gland, during food intake. Some salivary stones may be asymptomatic and determined accidentally during maxillofacial imaging.[1] Glandular or parenchymal stones are associated with painful swelling, fever, and sometimes abnormal facial nerve functions. Bimanual intraoral palpation is a useful method for detecting ductal stones around Stensen's duct orifice or along its route. In the present case, the patient had painful swelling on the cheek and the stone was palpated intraorally at the Stensen's duct orifice.[10]

Parotid sialoliths are smaller and 80% of them are radiolucent. Conventional X-rays may not be sufficient for imaging stone until they are 60%–70% calcified.[6] For calcified parotid gland stones, periapical view in the buccal vestibule (reducing the exposure parameters) is most generally used as they are inexpensive, readily available and results in minimal radiation exposure.[8] In the present case, IOPA showed angulated calcified mass. In calcified parotid stone, soft tissue radiograph is very important as it excludes the other possibilities such as lymphadenitis, benign lymphoid hyperplasia, or extra parotid tumor. Other imaging techniques such as panoramic and AP puff view should be considered for localization of the calcified stone, i.e., either present in Stensen's duct or superficial lobe of parotid. In the present case, both panoramic view and AP puff view were taken which showed stone near Stensen's duct orifice similar to other studies. Recently, noninvasive technique, i.e. CBCT is being used for the diagnosis of sialoliths as it provides high resolution, high sensitivity, reduced superimposition, and distortions of anatomical structures over two-dimensional radiography and low dose radiation than medical CT.[4],[11] In the present case, CBCT was helpful in visualization of the structure and determining the exact size and location of the calcified mass. Other advanced imaging techniques are also there which are helpful in the diagnosis of salivary stones but not required when stones are visible over periapical radiographs and exact position and dimensions can be located by CBCT.

Open surgical procedure by transoral ductal incision was carried out in the present case as it was of large size and angulated in shape located at parotid duct.

 Conclusion



Parotid sialolithiasis is very less frequent and generally unilateral and predominantly affects salivary duct more than the gland. Intraoral periapical soft tissue radiograph is very useful in detecting salivary ductal stones due to its easy availability with less patient exposure. CBCT further helps for diagnosis as it projects without any superimposition of bony structures or teeth and gives exact dimensions, shape, and position of stone.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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