Ⅰ. INTRODUCTION

Sialolithiasis is one of the most common diseases of the salivary glands^1,2). The clinical presentation is usually characterized by local swelling, pain, infection of the affected area, and dilation of the salivary duct¹⁾. Sialolithiasis usually affects adults between the third and fourth decades of life, with a frequency of 12:1000³⁾. It is estimated that 80-90% of cases occur in the submandibular gland, while 10-20% occur in the parotid gland³⁾. The size of the calculi varies from <1 mm to a few centimeters. Although the frequency of sialolithiasis is relatively high, the occurrence of giant sialoliths, larger than 1.5 cm in any diameter, is rare¹⁾.

Sialolith are calcified structures that develop within the salivary ductal system. They are believed to arise from deposition of calcium salts around a nidus of debris within the ductal lumen. This debris may include inspissated mucous, bacteria, ductal epithelial cell, or foreign bodies. The cause of sialoliths is unclear, but their formation can be promoted by chronic sialadenitis and partial obstruction⁴⁾.

In histopathologic features sialolith appear as hard masses that area round, oval, or cylindrical on gross examination. They are typically yellow, although they may be white or yellowish-brown. Submandibular stones tend to be larger than those of the parotid or minor glands. Microscopically, the calcified mass exhibits concentric laminations that may surround a nidus of amorphous debris⁴⁾.

This report described a case of giant sialolith consisted of tooth-like tissue in the duct of submandibular gland in a 20-year-old female patient.

Ⅱ. CASE REPORT

A 20-year-old woman who had a main symptom of intermittent pain in both mandibular third molar visited our hospital. She has had intermittent #38 and 48 tooth pains since a year ago, so she recently stopped by a private dentist and visited our hospital after being advised to go to a large hospital for removal of the teeth. Clinical tests showed an impaction of #38, 48 teeth and a panoramic radiation was taken. The panoramic radiation showed that the root portions of #38, 48 teeth were completely overlapped with the canal of inferior alveolar nerve, requiring confirmation of the relationship between the canal of inferior alveolar nerve and the root of the teeth in three dimensions through CBCT imaging(Fig. 1). In CBCT findings, the #38, 48 teeth were located on the lingual side of the inferior alveolar nerve. In addition, a large stone about 12mm in length was observed in the right Wharton's duct in CBCT finding(Fig. 2). She had no previous symptoms related to salivary glands. No saliva secretion was observed in the examination of right Wharton's duct opening. Neck CT scan was performed for further observation of the right submandibular gland. On the neck CT, a large stone about 12mm in length was observed, and the accumulation of saliva in the rear of the stone was observed(Fig. 3). The patient underwent sialolithotomy and #38, 48 tooth extraction through intraoral approach under general anesthesia. The removed stone was similar in shape and color to a tooth(Fig. 4). The removed stone was markedly fragmented and composed of dentin and enamel-like tissue which showed lamellate arrangement in microscopic examination(Fig. 5). Pathological diagnosis was made with R/O impacted tooth. Patient was presently symptom free after 10-months postoperatively.

Ⅲ. DISCUSSION

Sialoliths most often develop within the ductal system of the submandibular gland; the formation within the parotid gland system is distinctly less frequent. The long, tortuous, upward path of the submandibular(Wharton’s) duct and thicker, mucoid secretions of this gland may be responsible for its greater tendency to form salivary calculi. Salivary stones can occur at almost any age, but they are most common in young and middle-aged adults.⁴⁾ In this report, the sialolith was developed within the duct of the submandibular gland in the patient who was young age.

The reported symptoms usually are pain and swelling in the gland, which worsen during the meal time.^2,3) The severity of the symptoms varies, depending on the degree of obstruction and the amount of resultant back pressure produced within the gland.⁴⁾ Sometimes, the patient remained asymptomatic despite the exuberant dimensions of the stone.⁵⁾ In the current report, the patient also had no pain or other symptoms in the submandibular gland. The patient visited our hospital for the extraction of the wisdom tooth due to pain in the wisdom tooth, and the presence of the sialolith was confirmed by the radiological examination and Cone beam CT by accident.

On gross examination, sialoliths appear as hard masses that around, oval, or cylindrical. They are typically yellow, although they may be white or yellowish- brown.⁴⁾ Sialoliths are usually 5–10 mm in length, and the stones more than 10 mm are termed sialoliths of unusual length or a giant sialolith.^6,7) In this report, the stone was similar in shape and color to a tooth on gross examination. The size of the stone in this paper was 12mm in length, which was the size of a giant sialolith.

Microscopically, the calcified mass exhibits concentric laminations that may surround a nidus of amorphous debris.⁴⁾ The removed stone in this report was markedly fragmented and composed of dentin and enamel-like tissue which showed lamellate arrangement in microscopic examination. Pathological diagnosis was made with R/O impacted tooth.

Regarding the treatment, a less invasive procedure is of utmost importance in order to preserve the gland’s function.^2,5,8) The pertinent literature indicated some surgical procedures such as trans-oral sialolithotomy, sialoendoscopy, and resection of the gland.^2,3) In the report, the patient underwent sialolithotomy using a trans-oral approach. The alternative methods tried and available are lithotripsy using a piezoelectric lithotripter and laser sialolithectomy, using CO2 lasers.^9,10)

After these surgical operations, complications such as mandibular nerve damage or stenosis of the Wharton’s duct can occur.²⁾ There was no evidence of any of these complications in the present case.

In conclusion, this report described a case of giant sialolith consisted of tooth-like tissue in the duct of submandibular gland in a 20-year-old female patient by using sialolithotomy via trans-oral approach.