A Sialolith and a Megalith: a Report of Two Cases

Case 1

A 26-year-old male nurse attended the oral and maxillofacial surgery clinic with a history of a stone-like sensation under the left side of his tongue for 7 years. This unpleasant feeling was aggravated by tongue movement. However, there was no complaint of pain, even during meals. He was healthy with no medical illnesses but consumed multivitamins and ginkgo as supplements. Although he was a moderate smoker, he had quit smoking six months prior to his presentation and, more recently, had developed a habit of frequently sipping water while having dry foods due to thick and frothy saliva.

Extra-orally there was no swelling, or any form of abnormality detected. On intra-oral examination, a crenated tongue on the left and right lateral border was noticed. On bi-digital palpation, a calcified mass was felt immediately adjacent to the left side of the lingual frenum (Figure 1). No other abnormality was detected and oral hygiene, as well as dental condition, was fair. A lower occlusal radiograph showed a nodular radio-opacity measuring roughly 1.5 mm × 4 mm at the left lingual aspect of the anterior mandible (Figure 2).

The diagnosis of a left submandibular sialolith was established and the patient was scheduled for removal of the sialolith. On the day of the appointment, written consent was taken after explaining the possible complications, which included bleeding, ductal injury, infection and recurrence. Local anaesthesia (2% mepivacaine with adrenaline) was infiltrated and a Bowman Lacrimal Probe (size 3) was used to access and protect the Wharton's duct. A stay suture was placed around the proximal end of the probe using 3/0 silk. The sialolith was palpated and a superficial incision was made over the sialolith using a BP blade no. 15, followed by blunt dissection, and the sialolith was removed (Figures 3 and 4). The silk suture was removed, and patency of the duct was examined, which appeared to be normal. The extracted sialolith measured 4 mm in length and 1.5 mm in width. Post-operative instructions were given to the patient. The patient was advised to consume citrus drinks to stimulate salivary flow. Chlorhexidine (0.2%) 15 ml bid 2/52 and Tab Paracetamol 1000 mg PRN 3/7 were prescribed.

Case 2

A 59-year-old male attended the emergency department with a chief complaint of severe pain over the right side of his neck. He was diagnosed with hypertension which was well controlled with medication. He was a chronic smoker (20 cigarettes/day). History revealed that the presenting complaint started as a pea-sized lump on the right side of his neck which persistently increased in size over 8–9 years. Furthermore, the patient noticed a mass in his oral cavity during the last 6 years but did not consult a physician. However, he was alerted when the lump started growing rapidly in a span of two weeks, which aggravated the pain and caused dysphagia. Extra-oral clinical examination revealed a multilobulated mass measuring 5 cm × 6 cm on the right side of the patient's neck, extending from the infra-auricular region to 2 cm above the clavicle, which was hard in consistency. The patient was initially misdiagnosed as having a submandibular infection and was prescribed antibiotics in the emergency department. When the swelling persisted, the patient was referred to the otolaryngology department, where a diagnosis of a submandibular tumour was established before the patient was referred to the oral and maxillofacial surgery department.

Upon examination by the oral surgeon, intra-orally, a dark cauliflower-like growth measuring 4 × 4 cm was noticed in the retromolar trigone (Figure 5). The mass initially appeared as a necrotic bone. The patient's overall oral hygiene was poor, and discoloration of the soft palate was seen. Further investigation with OPG and CT showed a giant nodular radio-opacity measuring 4.61 cm × 2.53 cm in the aforementioned region (Figures 6 and 7).

A diagnosis of right submandibular sialolithiasis was established and the patient was scheduled for the removal of the giant sialolith or megalith under general anaesthesia. An intra-oral incision posterior to the LR8 was made and a flap was raised using a periosteal elevator. The megalith was gently removed using Allis forceps (Figure 8). Peri-operatively, the right submandibular gland appeared fibrosed and atrophied. The gland was removed via right submandibular incision. All the incisions were sutured appropriately, with a negative pressure drain placed in situ (extra-orally), which was removed after 24 hours as there was minimal collection. Post-operative recovery was uneventful. The patient was recalled two weeks post-operatively to assess the surgical site. On check-up, no sign of infection was detected.

Discussion

The cases that are reported in this article are unusual in nature, because they do not coincide with the conventional data present in the literature. Firstly, the novelty of this case report is evident from the fact that sialolithiasis is mostly characterized by painful swelling of the associated gland but, in the aforementioned cases, the patients remained pain-free for over an average period of 6 years. Secondly, pain during mealtimes is one of the touchstones for the establishment of diagnosis of sialolith, however, in Case 1, the patient was pain-free even during mealtimes. Thirdly, the mammoth-sized submandibular sialolith reported in Case 2 is not common in the literature. Only a few studies have reported a sialolith bigger than the sialolith mentioned in Case 2. Fourthly, this case report highlights the importance of proper diagnosis. A dentist/physician can easily confuse a submandibular sialolith with a mandibular torus or osteoma, calcified lymph nodes, tuberculosis of salivary gland, myositis ossificans, or metastasis from distinct calcifying neoplasms. In Case 2, the patient was initially misdiagnosed as a submandibular tumour by the otolaryngology department. But, after thorough investigation by an oral and maxillofacial surgeon, final and correct diagnosis was established, ie a submandibular sialolith. This reflects that the role of dentist is as crucial as that of a physician in such cases. Healthcare providers associated with medicine and dentistry should liaise with each other when such cases are reported in hospitals or clinics.

For a patient experiencing pain and swelling of a salivary gland, neoplastic, infectious, granulomatous and inflammatory aetiologies should be considered.⁵ In a 13-year research study, Kenefick concluded that 35% of patients experiencing salivary gland disorders were having sialolithiasis.⁶ Stones may form without any related glandular pathology, but also form in the majority of patients suffering from chronic sialadenitis. The only systemic condition associated with sialolithiasis is gout, in which the calculi are composed of uric acid.⁷ It is imperative for a clinician to rule out other diagnoses that may be present with submandibular calcifications, especially when there is no pain. Among these are phleboliths associated with facial/oral hemangiomas, mandibular osteoma occurring in Gardner's syndrome, and calcified lymph nodes associated with mycobacterial adenitis.⁸

Several imaging techniques play a vital role in successful diagnosis of sialolithiasis. Ultrasonography (US) is regarded as the first-line imaging modality because it is noninvasive, inexpensive and readily available.⁹ Moreover, it does not have any radiation exposure.¹⁰ According to Jäger et al,¹¹ the sensitivity of US in the detection of sialolithiasis is 59.1%–93.7%, while having specificity equal to 86.7%–100%. Conventional intra-oral radiography is considered to be more effective than extra-oral X-rays, especially trans-occlusal end-oral radiography. Sialography is also considered an adequate imaging modality that permits the whole duct system to be visualized after injecting either water soluble (like renografin) or fat soluble contrast media (like ethiodol). However, it is contra-indicated if the patient is sensitive to contrast medium or has an acute infection. Scintigraphy can also be utilized when sialography is contra-indicated, or when glandular ducts are non-permeable. Sialoendoscopy is another technique of directly visualizing intra-ductal calculi, which has largely replaced the old gold standard sialography. However, it is contra-indicated in instances where the ductal system is extremely tortuous.¹² Other modalities, like digital subtraction sialography and high-resolution ultrasonography, have also been recommended for the evaluation of salivary gland disorders. Computerized tomography (CT) is performed only if the stone is large, or if radiological slices need to be visualized in every millimetre. Its limitations include, inability to localize the salivary stone precisely and lack of visualization of the ducts and their anomalies.¹³ In the cases discussed, a lower occlusal radiograph, OPG and CT were used for diagnostic purposes.

Various treatment modalities can be used for the removal of sialoliths, depending on their size and location. They can be removed either by invasive procedures or by minimally invasive techniques. An intra-oral approach is recommended when the calculi can be palpated intra-orally. If the stone is small and located sufficiently forward in the duct, it can be ‘milked out’ through the duct orifice by bimanual palpation. However, in the case of medium- or large-sized stones, surgical removal becomes mandatory. Newer, minimally invasive treatment methods include intra-corporeal lithotripsy, StoneBreaker or extra-corporeal shockwave lithotripsy, and basket retrieval. These are impressive alternatives to surgical excision for sialoliths smaller than 7 mm. Lithotripsy is the fragmentation of salivary stones into smaller pieces so that they can be easily flushed out from the salivary duct system immediately or after salivation, induced by citric acid or other sialagogues. Extra-corporeal Shock Wave Lithotripsy (ESWL) is regularly used for fragmentation of kidney stones. This method is now implemented in the fragmentation of salivary gland sialoliths. It uses electromagnetic waves with a pulse frequency of 0.5–2 Hz, which create acoustic radiation and cause fragmentation of the sialolith.¹⁴ However, it is relatively contra-indicated in ductal stenosis and pregnancy. It is absolutely contra-indicated in patients with cardiac pacemakers.¹⁴ The basket retrieval technique is another method which is usually utilized when the stone is less than 5 mm. This technique can be used in conjunction with ultrasound¹⁵ or sailoendoscopy.¹⁶ Sialoendoscopy is helpful in the detection and treatment of ductal pathologies using 0.9–1.6 mm diameter semi-rigid endoscopes. These endoscopes have the provision for various attachments, such as grasping forceps, micro-drills and a flexible wire basket. Micro-drills are used for the fragmentation of larger sialoliths. Alternatively, a wire basket is carefully pushed past the stone under endoscopic monitoring and then opened (as an umbrella) which engulfs the stone and assists in the safe retrieval of the stone. Endoscopically-controlled, intra-corporeal lithotripsy includes:

Most of these techniques use a kinetic or ballistic approach, which imposes a high risk of tissue trauma or perforation. However, for megaliths, trans-oral sialolithotomy with sialadenectomy or sialodochoplasty remains the backbone of management.¹

Intra-glandular sialoliths and longstanding obstructions can cause severe damage to the gland, resulting in a decrease or complete absence of salivary flow. This leads to recurrent infections which mandates complete removal of the gland along with the sialolith,^{17, 18} as was undertaken in Case 2.

Conclusion

Clinicians should evaluate painless as well as painful swellings in the submandibular area, including sialolithiasis as a possible diagnosis. Once diagnosis is established, the best possible approach for removal should be used to avoid post-operative complications. Early identification and removal of sialoliths is essential to prevent permanent damage and to re-instate function of the salivary glands.