Australian Dental Journal

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Australian Dental Journal The official journal of the Australian Dental Association CASE REPORT Australian Dental Journal 2013; 58: 112 116 doi: 10.1111/adj.

Queensland. Registrar, Townsville Hospital, Queensland. ABSTRACT There are many causes for benign salivary gland disease but the most common relate to inflammation and infection.

1 Australian Dental Journal The official journal of the Australian Dental Association CASE REPORT Australian Dental Journal 2013; 58: doi: /adj The management of benign salivary disease: a case series RHB Jones,* GJ Findlay *Professor, James Cook University and Consultant Oral and Maxillofacial Surgeon to the Townsville Hospital, Queensland. Registrar, Townsville Hospital, Queensland. ABSTRACT There are many causes for benign salivary gland disease but the most common relate to inflammation and infection. This usually revolves around duct obstruction and a reduction in the normal salivary flow from the gland into the mouth. This leads to retention of saliva, proximal to the obstruction and ascending infection from the mouth, usually because of the decrease in salivary flow. The increase in tension behind the obstruction causes significant pain and swelling, along with the inevitable infection if the obstruction is not relieved. This paper discusses the various treatments available for benign salivary gland disease, the traditional methods of treatment through to the use of endoscopic techniques which are currently available, including a discussion about the use of sialoendoscopy. Keywords: Salivary glands, benign disease, sialendoscopy. (Accepted for publication 13 July 2012.) INTRODUCTION There are many causes for benign salivary gland disease but the most common relate to inflammation and infection. This usually revolves around duct obstruction and a reduction in the normal salivary flow from the gland into the mouth. This leads to retention of saliva, proximal to the obstruction and ascending infection from the mouth, usually because of the decrease in salivary flow. The increase in tension behind the obstruction, within the gland, will cause significant pain and swelling, along with infection if the obstruction is not relieved. The obstruction can be caused by a number of things but is usually as a result of inflammatory diseases such as Sj ogren s syndrome, or other connective tissue diseases, stones or calculi within the ducts and gland, or tumours. There are three main salivary glands in the head and neck and a multitude of minor salivary glands. The minor salivary glands are usually not a problem but duct obstruction can occur and commonly patients present with mucous retention cysts in the lips or cheeks. Of more concern is the fact that tumours of the minor salivary glands are more often malignant than those of the major glands. The major salivary glands include three pairs of glands, the parotid, submandibular and sublingual glands, one on each side of the face and mouth. Anatomy The anatomy of the salivary glands is important and will give some indication of the problems associated with the obstruction and where this is most likely to occur. The parotid glands are located on either side of the face in front of the ear and superficial to the masseter muscle and the mandible, and extend from just below the zygoma and zygomatic arch to the angle of the mandible and forward to the middle of the cheek. The glands extend deeply around the posterior part of the vertical ramus of the mandible to produce the deep lobe of the gland. The gland is a tree-like structure with a multitude of ducts and at the periphery of the ducts are the acini which produce the saliva. The main duct enters the mouth from the middle of the cheek opposite the maxillary first molar tooth and is the main gland responsible for the production of serous saliva for the lubrication of the mouth, the early stages of mastication and swallowing of the food bolus. In addition, the saliva contains various enzymes which start to break down food along with protective factors for the teeth. Of importance, in relation to the parotid gland, is the fact that the facial nerve runs through the middle of the gland and effectively divides the gland into deep and superficial parts. The superficial part (Fig. 1a) is above the facial nerve (Fig. 1b) and the deep part below the facial nerve Australian Dental Association

Benign salivary disease (a) (b) Fig. 1 (a) Patient with parotid swelling. Reproduced with permission from the Australian Dental Journal.

The submandibular glands are deep to the platysma muscle and below the deep cervical fascia, immediately deep to the posterior facial vein and marginal mandibular branch of the facial nerve (Fig.

The duct of the submandibular gland is long with a sharp bend from the gland, as it passes through the mylohyoid muscle and around the lingual nerve to pass superficially along the floor of the mouth

2 Benign salivary disease (a) (b) Fig. 1 (a) Patient with parotid swelling. Reproduced with permission from the Australian Dental Journal. 17 (b) Diagram of the parotid gland (black) and facial nerve (red). The submandibular glands are much smaller and situated below the mandible on either side and are well encapsulated. The submandibular glands are deep to the platysma muscle and below the deep cervical fascia, immediately deep to the posterior facial vein and marginal mandibular branch of the facial nerve (Fig. 2) Below the gland are the digastric muscles and deeper again, the hypoglossal nerve. The facial artery usually courses deep to the gland or on occasions through the main substance of the gland. The duct of the submandibular gland is long with a sharp bend from the gland, as it passes through the mylohyoid muscle and around the lingual nerve to pass superficially along the floor of the mouth and exits in the midline, below the tongue, in the anterior floor of the mouth. 2 As a result, duct obstruction is a common problem, often as a result of stone formation but strictures are also common in the submandibular duct. The most common site for stone formation is at the junction of the gland and the duct, because of the sharp turn in the direction of the duct through the mylohyoid muscle and along the floor of the mouth. Swelling of this gland will be in the submandibular area and pain is a common feature because of the well defined capsule and the pressure within the gland as a result of the continuing production of saliva and the subsequent ascending infection. The sublingual glands are in the floor of the mouth immediately below the mucosa of the floor. They lie between the mucosa and the mylohyoid muscle. They do not have a single duct, like the submandibular or parotid glands but more a series of ducts which enter the mouth through the mucosa. They tend not to be subject to stone formation but obstruction can occur and because of their architecture and anatomy, mucous extravasations can occur with the production of a ranula in the floor of the mouth and on occasions this can separate the mylohyoid muscle to produce the so-called plunging ranula. 3 Benign pathology of the glands is usually inflammatory in origin, but tumours can occur in all of the salivary glands and can arise from the different elements within the gland. The various types of tumours within the salivary glands have been categorized by the WHO 4 and are numerous, but the common ones include the pleomorphic adenoma, the muco-epidermoid carcinoma and the adenoid-cystic carcinoma. Tumours of the parotid gland are most often benign and are commonly the pleomorphic adenoma, while those of the submandibular, sublingual and the minor salivary glands are more likely to be malignant. As mentioned, these tumours will present as swellings within the glands and will produce obstruction and possible infection. However, the most common problems relate to inflammatory conditions, such as strictures of the ducts, and stones. Back pressure and recurrent infections will produce atrophy of the acini, cell death, cavitation and abscess formation within the gland. Fig. 2 Swelling of the submandibular gland. Reproduced with permission from the Australian Dental Journal. 17 Diagnosis and imaging Most patients with duct obstruction of the salivary glands will complain of pain and swelling of the gland. Sometimes infection will be present and this is usually as a result of ascending infection from the oral cavity. If severe, patients will be systemically ill and require urgent attention. Clinical examination will usually point to the diagnosis but imaging will be necessary to determine the cause. 5 The imaging modalities may include ultrasound, plain radiography (OPG, Fig. 3), CT scan and MRI scan. This paper will discuss the various treatments available for benign salivary gland disease and include the traditional methods of treatment through to the use of endoscopic techniques which are currently available, including a discussion about the use of sialoendoscopy Australian Dental Association 113

3 RHB Jones and GJ Findlay Fig. 3 OPG showing stone in the submandibular gland. Reproduced with permission from the Australian Dental Journal. 17 MATERIALS AND METHODS Traditional treatment for salivary gland disease has revolved around abscess drainage and removal of the obstruction, usually a stone, or dilation of the duct. If the stone is within the substance of the gland then removal of the offending gland will need to be carried out. The parotid gland can be removed, but in general, this will involve a superficial parotidectomy or removal of the superficial part of the gland above the facial nerve. 6 The main branch of the facial nerve exits the stylomastoid foramen and passes more superficially between the stylohyoid muscle and the posterior belly of the digastric muscle and then into the body of the parotid gland where it divides into its classical five branch distribution to the muscles of facial expression. In performing a superficial parotidectomy, the main branch of the facial nerve is found as it enters the gland and the branches dissected free, the superficial part of the gland is then removed, along with the pathology. If the problem is in the deep part of the gland it can be more problematic and the vertical part of the mandibular ramus may require osteotomy in order to gain access to the deep lobe. The submandibular gland is approached from below the mandible by a submandibular incision with protection of the marginal branch of the facial nerve, which is found in the deep cervical fascia below the platysma muscle. The nerve can be found in close association with the facial artery as it curves around the lower border of the mandible anterior to the attachment of the masseter muscle. The artery and vein are dissected free and tied off, which will then allow access to the submandibular gland, which lies immediately below these structures. The capsule is divided and then by blunt dissection, staying within the capsule, the gland can be dissected free. It is important to remember that the facial artery is deep to the gland, often grooves it on the deep surface and on occasions, and passes through the gland to enter the face on its tortuous course. In addition, the hypoglossal nerve can be found deep to the gland and below the digastric muscles. 6 As mentioned above, the duct of the submandibular gland is long, passes through the mylohyoid muscle and exits in the midline of the floor of the mouth, just behind the lower incisor teeth. As a result, stone formation is common in the submandibular gland and duct, and these stones are commonly found in the most proximal end of the duct, at the junction of the duct and the gland. At this point the submandibular duct is very close to the lingual nerve, which can easily be damaged during removal of the stone. Generally, the removal of a stone from the ducts of a salivary gland is relatively straightforward, particularly if they are found in the superficial part of the duct. 7 However, if the stone is found within the body of the gland it is much more difficult to remove and as a result, the gland is usually removed. However, more sophisticated techniques have been developed to break up and remove stones from various glands within the body. Ultrasound has been used to break up stones and lithotripsy 8,9 has been available for some time. Endoscopic techniques have been developed for many different surgical procedures and many abdominal operations are now carried out endoscopically. The gall bladder can be removed endoscopically, as too the appendix. Arthroscopes have been developed for joint surgery and along with these endoscopic procedures, technology has advanced to include smaller video cameras and equipment, which can be used with these different endoscopes. Flexible scopes have been developed to remove kidney stones, and drills and lasers have been developed to break up the stones, along with special baskets, to remove the pieces of stone, once broken up. As a result of these achievements, the sialoendoscope has been developed The sialoendoscope is a small endoscope which can be passed down the ducts of the submandibular and parotid glands and stones can be removed (Fig. 4). The ducts are magnified as a result of the endoscopic cameras, and the stones can be removed using fine instruments which are passed down the ports of the scopes. Small flexible hand drills and lasers can be used to break up the stone and facilitate their removal. If the stone is relatively small, a fine basket can be passed beyond the stone; the stone captured and brought out with the endoscope. If larger stones are found they can be broken up and either flushed out or captured with the basket and removed. If strictures are present, they can be dilated using balloon catheters and if necessary fine stents can be passed to maintain the patency of the ducts. 13 These techniques have revolutionized the management of benign salivary gland disease; however, they are technique sensitive and require patience Australian Dental Association

(a) (b) (e) Benign salivary disease duct, the balloon inflated with saline, and withdrawn past the stricture.

At the same time the duct and the gland were flushed out with saline solution in order to clear the duct of any debris or pus.

A laser is much more efficient but at the current time we do not have a suitable laser for this purpose.

(g) Patient Treatment (d) CW NC RW VD TB TO AJ Parotid sialoendoscopy and stone removal Submandibular sialoendoscopy and stone removal Bilateral parotid sialoendoscopy and dilation of ducts

4 Endoscopic removal of a stone from the submandibular duct.

stone in the submandibular duct being grasped by a basket; (g) stone delivered from the duct snared by the basket. So far we have treated seven patients in this way.

Dilation of the duct is also required in order to pass the endoscope down the duct.

4 (a) (b) (e) Benign salivary disease duct, the balloon inflated with saline, and withdrawn past the stricture. This was repeated on a number of occasions until the duct was found to be free of obstruction and the catheter could be freely moved along the duct. At the same time the duct and the gland were flushed out with saline solution in order to clear the duct of any debris or pus. (c) (f) RESULTS Generally, these procedures were successful, but on occasions it was difficult to completely break up the stone, particularly with the fine drill used to carry out this manoeuvre. A laser is much more efficient but at the current time we do not have a suitable laser for this purpose. Where these stones could not be removed endoscopically, they had to be removed by open operation, or the gland removed. (g) Patient Treatment (d) CW NC RW VD TB TO AJ Parotid sialoendoscopy and stone removal Submandibular sialoendoscopy and stone removal Bilateral parotid sialoendoscopy and dilation of ducts Submandibular sialoendoscopy and dilation of ducts Submandibular sialoendoscopy and removal stone Parotid sialoendoscopy and removal of stone Submandibular sialoendoscopy and removal of stone Fig. 4 Endoscopic removal of a stone from the submandibular duct. (a) sagittal scan showing the stone; (b) coronal scan showing the stone; (c) axial scan showing the stone; (d) bifurcation of the duct and inflammation; (e) stone being broken up by the drill; (f) stone in the submandibular duct being grasped by a basket; (g) stone delivered from the duct snared by the basket. So far we have treated seven patients in this way. In many instances there were strictures and scarring of the duct and duct orifice, which then required a surgical cut down, in order to gain access to the duct. Dilation of the duct is also required in order to pass the endoscope down the duct. In these instances, and once the stone had been removed, the duct orifice can be sutured to the mucosa of the cheek or the floor of the mouth, in order to maintain the patency of the duct. In some instances the duct orifice was relocated to a new position and on occasions stented open to maintain its patency. In cases where the duct obstruction was as a result of a stricture or multiple strictures, the endoscope was passed down the duct and the strictures identified and then a fine balloon catheter was passed down the DISCUSSION Benign pathology of the glands is usually inflammatory in origin, but tumours can occur in all of the salivary glands and arise from the different elements within the gland. The various types of tumours within the salivary glands have been categorized by the WHO 4 and are numerous, but the common ones include the pleomorphic adenoma, the muco-epidermoid carcinoma and the adenoid-cystic carcinoma. Tumours of the parotid gland are most often benign and are commonly the pleomorphic adenoma, while those of the submandibular, sublingual and the minor salivary glands are more likely to be malignant. As mentioned these tumours will present as swellings within the glands and will produce obstruction and possible infection. However, the most common problems relate to inflammatory conditions, such as strictures of the ducts and stones. Back pressure and recurrent infections will produce atrophy of the acini, cell death, cavitation and abscess formation within the gland. Benign salivary gland pathology is relatively common in the community and can cause considerable pain and discomfort for those people suffering from the disease. In general, duct obstruction is the cause of this 2013 Australian Dental Association 115

5 RHB Jones and GJ Findlay problem and can either be as a result of stone formation within the gland of duct system, strictures of the ducts, tumours or in some instances as a result of connective tissue disorders such as Sj ogren s syndrome. As a result of these obstructions, swelling and infection is a common problem, and because of their well defined capsules, these swellings are particularly painful and require urgent treatment to initially drain the abscess and decompress the swelling, but also to relieve the pain. Following this initial surgery the obstruction is removed. In the case of a stone this can be removed by conventional open operation or by the use of endoscopes, as outlined above. If a stricture is the cause of the obstruction then a diagnosis is required, along with the location and position of the stricture and then it can be dilated by using a fine balloon catheter. In order to determine the position of the stricture, an exploratory endoscopic procedure is carried out first and then the duct dilated and the stricture removed. If the stone is large then removal is required and this is usually carried out by open operation as the endoscope is very fine. In some instances the larger stones can be broken up and the pieces removed using a basket and flushing the smaller fragments out. 14 On occasions the gland will need to be removed by formal operation and in the case of the submandibular gland this is relatively straightforward, but in the case of the parotid gland, this is more difficult because of the anatomy of the facial nerve. On occasions the endoscope can be used as a marker for the obstruction of the stone as the endoscope can be passed down the duct to the obstruction and the light of the endoscope will point to the obstruction, which can then be more easily removed. 15 If, however, the obstruction is caused by a tumour then it needs to be removed and the type of surgery defined by the nature of the pathology. In general, parotid tumours are benign but the smaller the gland the more malignant they become. The most common tumour in the parotid gland is the pleomorphic adenoma and that of the minor salivary gland is the muco-epidermoid carcinoma or the adenoid cystic carcinoma. Formal biopsy or fine needle aspirate cytology is required in order to determine the nature of the pathology before definitive surgery is carried out. 16 REFERENCES 1. Sicher H. Oral anatomy. St Louis: CV Mosby, 1949: McGregor IA, McGregor FM. Cancer of the face and mouth. New York: Churchill Livingstone, 1986: Regezi JA, Sciubba J. Oral pathology. Clinical pathological correlations. Philadelphia: WB Saunders, 1993: Batsakis JG. Tumours of the head and neck. 2nd edn. London: Williams and Wilkins, 1979: Hasson O. Modern sialography for screening of salivary gland obstruction. J Oral Maxillofac Surg 2010;68: Stell PM, Maran AGD. Head and neck surgery. 2nd edn. London: William Heinemann, Chapter Baurmarsh HD. Submandibular salivary stones: current management modalities. J Oral Maxillofac Surg 2004;62: Ottaviani F, Capaccio P, Cosmacini P, Castagnone D. Salivary gland stones: US evaluation in shockwave lithotripsy. Radiology 1997;204: Wehrmann T, Kater W, Marlingaus EH, Peters J, Caspary WF. Shockwave treatment of salivary duct stones: substantial progress with a mini lithotripter. Clin Investig 1994;72: Papadaki ME, McCain JP, King K, Katz RL, Kaban LB, Troulis MJ. Interventional sialoendoscopy: early clinical results. J Oral Maxillofac Surg 2008;66: Zenk J, Koch M, Bozzato HI. Sialoscopy initial experiences with a new endoscope. Br J Oral Maxillofac Surg 2004;42: Chuangji Y, Chi Y, Lingyan Z, Daming W. Endoscopic observation and strategic management of obstructive submandibular sialadenitis. J Oral Maxillofac Surg 2010;68: Ardekian L, Dror S, Trabelsi M, Peled M. Chronic obstructive parotitis due to strictures of Stenson s duct our treatment experience with sialoendoscopy. J Oral Maxillofac Surg 2010;68: Yu CQ, Yang L, Zheng Y, Wu DM, Zhang J, Yun B. Selective management of obstructive submandibular sialadenitis. Br J Oral Maxillofac Surg 2008;46: Overton A, Combes J, McGurk M. Outcome after endoscopically assisted surgical retrieval of symptomatic parotid stones. J Oral Maxillofac Surg 2012;41: Karavidas K, Nahlieli O, Fritsch M, McGurk M. Minimal surgery for parotid stones: a 7-year endoscopic experience. J Oral Maxillofac Surg 2010;30: Lawlor B, Pierce A, Sambrook PJ, Jones RHB, Goss AN. The diagnosis and surgical management of major salivary gland pathology. Aust Dent J 2004;49:9 15. Address for correspondence: Professor Robert Jones PO Box 2049 Townsville QLD Robert_ Jones@health.qld.gov.au Australian Dental Association

Salivary ultrasound. Dr T J Beale Royal National Throat Nose & Ear and UCLH Hospitals London UK

Salivary ultrasound. Dr T J Beale Royal National Throat Nose & Ear and UCLH Hospitals London UK Salivary ultrasound Dr T J Beale Royal National Throat Nose & Ear and UCLH Hospitals London UK Two main groups of patients with presenting symptoms of: Obstructive or chronic inflammatory symptoms (salivary