|Year : 2014 | Volume
| Issue : 4 | Page : 357-361
Congenital parotid fistula
Departments of Pedodontics and Preventive Dentistry, Rajiv Gandhi Dental College & Hospital, Bangalore, Karnataka, India
|Date of Web Publication||17-Sep-2014|
Department of Pedodontics & Preventive Dentistry, Rajiv Gandhi Dental College & Hospital, Cholanagar, Hebbal, Bangalore - 560 032, Karnataka
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Parotid fistula is a cause of great distress and embarrassment to the patient. Parotid fistula is most commonly a post-traumatic situation. Congenital parotid salivary fistulas are unusual entities that can arise from accessory parotid glands or even more infrequently, from normal parotid glands through an aberrant Stensen's duct. The treatment of fistulous tract is usually surgical and can be successfully excised after making a skin incision along the skin tension line around the fistula opening. This report describes a case of right accessory parotid gland fistula of a 4-year-old boy with discharge of pus from right cheek. Computed tomography (CT) fistulography and CT sialography demonstrated fistulous tract arising from accessory parotid gland. Both CT fistulography and CT sialography are very helpful in the diagnosis and surgical planning. In this case, superficial parotidectomy is the treatment of choice. A detailed history, clinical and functional examination, proper salivary gland investigations facilitates in correct diagnosis followed by immediate surgical intervention helps us to restore physical, psychological health of the child patient.
Keywords: fistula, fistulography, parotidectomy, salivary gland, sialography
|How to cite this article:|
Natasha S. Congenital parotid fistula
. J Indian Soc Pedod Prev Dent 2014;32:357-61
| Introduction|| |
Salivary gland fistula is defined as "an abnormal passage between a salivary duct or gland and the cutaneous surface, or into the oral cavity through other than a normal pathway." Salivary gland fistulas may be classified according to congenital and acquired varieties depending upon the pathogenesis.  Most parotid fistulas are acquired and arise secondary to trauma, surgery, malignant tumors, and inflammation.  In extreme rare instances, they occur congenitally as malformation during fetal development. ,
The accessory parotid gland or the accessory parotid, is a nodule of normal salivary tissue that is separate from the main parotid gland and it is located on the masseter muscle, and it is connected to Stensen's duct at that level.  Accessory parotid glands occur as a common variation  and are generally seen to be continuous with Stenson's duct, on the other hand, parotid fistula arising from an ectopic accessory gland is extremely rare. ,
Congenital salivary fistulas are uncommon; those that arise from an accessory parotid gland are even more rare. , To the best of the authors knowledge, only seven cases of congenital fistula from an accessory parotid gland have been previously reported in the English-language literature. ,,,,, Accessory parotid gland having a duct of its own is exceedingly rare. , The two most recent cases were described by Sun et al. in 2011.  Those two cases were associated with Goldenhar syndrome, a hereditary disorder characterized by several abnormalities that affect the first and the second branchial arches.
Accessory parotid glands have been described in about 21% of general population.  Moon et al. reported a case in a 5-year-old girl with an ectopic accessory parotid gland with a fistulous duct from Korea. They accurately demonstrated the ectopic gland by computed tomography (CT) sialography and CT fistulography. Gadodia et al. reported the imaging findings in an 8-year-old boy with congenital salivary fistula from an accessory parotid gland in 2008, from India. 
It was reported that congenital fistula from an accessory parotid gland could be diagnosed with performing CT sialography or CT fistulography.  Superficial parotidectomy is the preferred method of treating lesions of the parotid gland.
This paper describes a case of parotid gland fistula arising from right accessory parotid in a 4-year-old child with the discomfort of both pus and later serous fluid discharge both intra orally and extra orally.
| Case Report|| |
A 4-year-old boy presented with the chief complaint of pus discharge from the right side of his face, near the tragus extra orally and also from inside his mouth [Figure 1], [Figure 2], [Figure 3]. History revealed that the pus discharge was present since 2-2½ years. Pus discharge was present only on palpation and increased on or before meal both from inside (through the Stenson's duct) and outside his mouth. There was no history of trauma, any previous infection or dental abscess or any treatment performed previously for the same given by the patient.
The child was being regularly taken to a local doctor for the dressing and was later referred to Department of Pedodontics and Preventive Dentistry, V.S Dental College and Hospital, Bangalore for further evaluation and treatment planning.
Extra oral examination revealed a small opening of diameter 5 mm about 20 mm in front of the tragus [Figure 2]. There was change in the surrounding skin color and also the pus discharge seen, which was thick, creamy in consistency initially, later on with further palpation there was flow of serous fluid seen.
Regular radiographic examination of orthopantomogram was carried out, which detected no hard tissue abnormalities. Fistulography was tried, but as the child was not co-operative it was decided to be performed under general anesthesia. Parent's consent was obtained prior to performing the investigations and surgical procedure.
Under general anesthesia, CT fistulogram was obtained by injecting 1.5 ml contrast medium extra orally through the fistulous tract. Furthermore, CT sialogram (obtained by injecting through the Stenson's duct) [Figure 4] revealed parotid gland located in normal position, but showed a nodule anterior to the masseter suggestive of an ectopic accessory parotid gland with an ectopic drainage pattern on the skin. On further injection of contrast medium into the fistulous tract revealed the involvement of the fistulous tract into the duct [Figure 5].
A diagnosis of parotid fistula originating from the accessory parotid gland was established. Under general anesthesia, superficial parotidectomy was performed. Pathological examination of the excised specimen revealed keratin deposits with typical tissue of the parotid gland.
The procedure begins with an S-shaped pre-auricular incision through the skin and subcutaneous tissue [Figure 6]. The parotid gland is exposed anterior and inferior to the ear by sharp dissection of the subcutaneous tissue and the skin flap is elevated to the anterior border of the parotid gland. An elliptical incision with a diameter of approximately 5 mm was made around the fistula and a tunnel was formed from the fistula region [Figure 7]. This tunnel was made to open into the oral cavity after passing beneath the fistula. Suction drain was placed, and the flap was sutured using 3-0 vicryl [Figure 8].
Post-operative course was uneventful, with normal salivary secretions in the oral cavity. Scarring of facial skin was seen [Figure 9]. Patient was instructed to maintain good oral hygiene.
The patient's recovery was uneventful. On follow-up after a period of 1 month, 6 month and 1 year no sign of salivary duct stricture or fistula recurrence was observed.
Most of the authors who have treated this condition before used the following surgical technique: The aberrant duct was dissected, attached with a small skin island, and transposed into the oral cavity to redirect the fistula outflow. ,,,, The same technique may eventually be used to treat acquired parotid duct fistulas as reported by Kabakkaya et al. 
Numerous other methods of treatment both conservative and operative have been described in the literature with varying success and morbidity. Management options include pressure dressings and use of antisialagogues,  total parotidectomy, tympanic neurectomy,  intraoral transposition of parotid duct,  radiation therapy,  use of botulinum toxin A, ,, fibrin glue,  and use of hypertonic saline. 
Conservative methods are directed toward reducing the parotid secretions. The surgical techniques can be classified as those that divert parotid secretions into the mouth and those that depress parotid secretion either by ductal ligation or nerve sectioning. Conservative approaches include attempts to depress secretion by antisialagogues or radiotherapy.
| Discussion|| |
Most of the cases of congenital salivary fistulas are seen to originate from the parotid gland, submandibular gland and ectopic salivary gland and rarely accessory parotid gland. , The sites of opening of the fistulas have been the retroauricular region, facial skin of the cheek, the oral mucosa or skin of the cervical region. The accessory gland was found in close relation to Stenson's duct because the duct passed along the lateral aspect of the masseter muscle and was usually positioned on or above the duct. In our case, the abnormal tissue was found along the duct and placed anterior along the anterior border of masseter.
Embryologically, the parotid gland develops from as an outgrowth from the buccal cavity, spreading back toward the ear and the arrest during this development process could result in the unusual position of the parotid gland.  CT fistulography is obtained by CT scanning of the parotid gland during injection of water soluble contrast medium after cannulation of the fistulous tract or CT sialography obtained by cannulating Stensen's duct.
CT sialography helps in distinguishing intrinsic from extrinsic lesions, differentiating benign from malignant tumors and determining the relationship of these tumors to the facial nerve.  CT sialography allows for mapping of the gland's parenchyma and revealed abnormal location of right parotid gland in our case, also CT fistulography with cannulation of fistulous opening revealed opacification of accessory parotid gland. It was a useful technique to demonstrate the connection between the fistulous tract and accessory salivary gland tissue. Exact location of the gland tissue and identification of the ductal communication with glands have therapeutic implications. CT sialography and CT fistulography were very helpful in the diagnosis of parotid gland fistula originating from an ectopic accessory parotid gland or better known only as accessory parotid gland and allowed proper surgery.
As mentioned before superficial parotidectomy is one of the most commonly used method for treating parotid salivary gland lesions. , Parotidectomy can be classified according to the extent of tissue removed as superficial, total or deep. With reference to the facial nerve, it may be either radical conservative or semi conservative. Conservative superficial parotidectomy is the most accepted surgical procedure by surgeons all over the world for the management of infections restricted to superficial part of the gland, benign tumors, and some low grade malignant tumors. Conservative superficial parotidectomy is known as functional superficial parotidectomy as with this method, we preserve both facial nerve and main duct to maintain excretory function of the residual part of the gland.
Our literature search revealed only four previously published case reports of congenital accessory parotid fistula. ,,, There was not enough research data stating the recurrence rate in treated cases of congenital parotid fistula.
Some authors ,,, choose to employ anticholinergic agents to suppress glandular function during healing or in an attempt to close a fistula or resolve a sialocele spontaneously. The anticholinergic drugs have many undesired side-effects such as xerostomia, constipation, photophobia, tachycardia, and urinary retention.  Radiation therapy induces fibrosis and atrophy of the gland. Approximately 1,800 rads for more than 6 weeks is required. Surgical excision of the fistulous tract followed by tight pressure dressing of the wound is an effective management option. Pressure dressings lead to atrophy of the gland as the lobules of the gland are contained in relatively inelastic capsule. The sustained rise in ductal pressure leads to compression of capillaries and veins, resulting in a decrease in secretion and atrophy of gland.  Three operative techniques have been described include repair of the duct over a stent, ligation of the duct, and fistulization of the duct into the oral cavity.  Duct ligation may lead to early edema of the gland with accompanying pain from stretching of the capsule. Late complications of ligating the duct include chronic infections of the remaining glandular substance. Transtympanic sectioning of the Jacobson's nerve by drilling into temporal bone at hypotympanium has been reported. Glandular atrophy occurs in 6 months. High failure rate due to varied anatomy of nerve reinnervation. , Fibrin glue has also been used recently;  however, it is said that fibrin glue is rendered inactive by saliva leading to recurrence of fistula.
| Conclusion|| |
There are various treatment options mentioned in the literature depending upon the origin of parotid fistula; however, in our paper, we have a child presenting with congenital parotid fistula originating from accessory salivary gland tissue; thus, the treatment preferred was superficial parotidectomy. Congenital parotid fistula being embryologic in origin it occurs at birth and symptoms start appearing at a very young age. We being pediatric dentist becomes utmost important for us to collaborate with Pediatric Surgery Department and perform early diagnosis and suitable treatment.
CT sialography and CT fistulography were very helpful in the diagnosis of congenital parotid gland fistula originating from an ectopic accessory parotid gland and allowed proper surgery.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9]