Nearly 3,000 salivary stones: Some clinical and epidemiologic aspects

Comparative analysis of approaches to the Wharton's duct during surgery of the submandibular gland: A retrospective case-control study

INTRODUCTION

We investigated complications and recurrence rates after surgical techniques for sialolith removal with intact and resected Wharton's duct of the submandibular gland.

METHODS

The retrospective case-control analysis of a series analysed 271 surgical operations (2003-2022) for sialolithiasis performed at a hospital department of Otolaryngology-Head and Neck Surgery. The study compared two approaches: (1) pure endoscopic technique or pinpoint stone removal with Wharton's duct left intact and (2) transoral duct dissection or pinpoint stone removal technique, after which the duct was shortened. While choosing the surgical option, the size of the stone, the location of the stone, and the presence of multiple stones were taken into account. The rates of complications (lingual nerve paraesthesia, duct stenosis, drooling, and sialoadenitis), the incidence of foreign bodies, and the rate of recurrence during follow-up of ≥18 months were compared.

RESULTS

323 sialoliths were removed from 271 patients. Of these 323 calculi, 150 were removed by the first approach and 173 by the second approach. The calculi varied in diameter from 2 to 38 mm with an average diameter of 8.2 mm. For all 271 patients, the rate of recurrence was 4.8%, but 11 recurrent cases (8.7%) appeared after the first approach surgeries and 2 cases (1.4%) after the second approach surgeries (p = .03). Other variables did not show statistically significant differences.

CONCLUSIONS

Surgical removal of the submandibular calculi, ending with shortening of Wharton's duct, reduces the recurrence rate for sialolithiasis but does not affect the rate of postsurgical complications.

Success rate of sialendoscopy. A systematic review and meta-analysis

OBJECTIVE

To perform a systematic review and meta-analysis on the efficacy and safety of sialendoscopy in the treatment of obstructive diseases of the major salivary glands.

MATERIALS AND METHODS

We searched four databases for literature. The primary outcome assessed was the success rate. Secondary outcomes included the use of supportive devices, number of sialadenectomies and complications. Risk of bias was assessed. Meta-analyses with subgroup analysis were performed.

RESULTS

In total, 91 studies were included, comprising 8218 patients undergoing 9043 sialendoscopic procedures. The majority of studies had a medium or high risk of bias. The incidence of sialadenectomy varied from 0% to 14%. No major complications were reported. Meta-analysis revealed a weighted pooled success rate of 80.9%. Subgroup analyses showed the weighted pooled success rate in patients with sialoliths (89.6%), stenoses (56.3%), submandibular glands (88.3%), parotid glands (81.2%), patients treated by an endoscopic-assisted transoral removal of a sialolith (86.3%), patients treated by a combined approach of the parotid gland (78.2%), patients with JRP (67.0%) and with RAIS (45.8%).

CONCLUSION

The success rate of sialendoscopy did not considerably change in the last 9 years. Sialendoscopy is an efficient and safe procedure for the treatment of major salivary gland obstructive disease.

Non-neoplastic salivary gland diseases in children: a 10-year review at a tertiary center

OBJECTIVES

Non-neoplastic salivary gland diseases are rare in children. This paper aims to present the spectrum of encountered non-neoplastic salivary gland diseases at a tertiary center by describing the demographics, clinical characteristics, and outcomes in this patient population.

METHODS

A review of electronic medical records was performed from 2010 until 2020. Relevant data were retrieved and charted according to the type of salivary gland disease. A comparison between diseases was made for demographics, presenting symptoms, treatment, and outcomes.

RESULTS

Fifty patients with 11 different non-neoplastic salivary gland diseases were identified. Sialolithiasis was the most prevalent condition (12/50), with 83% localized in the submandibular gland. In contrast to gender, age, and symptoms, the location of pathology was significantly associated with the diagnosis (p < 0.001). In patients with sialolithiasis, a hybrid procedure (combined endoscopy and lithotomy) resulted in 100% resolution of symptoms. For (plunging) ranula, marsupialisation had a relative risk of recurrence of 9.6 compared to (partial) extirpation of the sublingual gland.

CONCLUSIONS

Children with salivary gland diseases present with overlapping symptoms, making clinical diagnosis challenging. The present study may aid physicians and specialists in diagnosing the most prevalent conditions in children. Although no gold standards exist for their treatment, hybrid procedures (sialolithiasis) and subglingual gland extirpation (ranula) showed superior results over alternatives.

Transoral removal of submandibular hilar lithiasis: results on the salivary duct system, glandular parenchyma, and quality-of-life recovery

OBJECTIVE(S)

To confirm that hilar transoral submandibular sialolitectomy (TOSL) is the first treatment option for submandibular hilar lithiasis (SHL) in terms of glandular parenchyma recovery, salivary system restoration, and patient quality of life (QoL) improvement.

METHODS

Depending on whether the stone was easily palpable, TOSL was carried out with or without sialendoscopy. For the first time in the literature, Magnetic Resonance Sialography (MR-Si) was performed before and after TOSL, to evaluate stone characteristics, glandular parenchyma status, hilum dilation and main duct recanalization. Radiological data was examined independently by two radiologists. COSQ, a recently validated and specific questionnaire, was used to assess associated QoL.

RESULTS

Between 2017 and 2022, 29 TOSL patients were examined. With a high interobserver correlation, MR-Si was confirmed as a very useful radiological test in the pre- and post-surgical evaluation of SHL. The salivary main duct was completely recanalized in all cases. The presence of lithiasis was found in 4 patients (13.8%). After surgery, the majority of patients (79.31%) had hilum dilation. There was a statistically significant improvement in parenchyma status, but no significant progression to glandular atrophy. After surgery, COSQ mean values always improved (22.5 to 4.5).

CONCLUSIONS

TOSL is the ideal surgical technique for the management of SHL, resulting in improved parenchymal inflammatory changes, recanalization of Wharton's duct, and enhancement patients' QoL. As a result, before removing the submandibular gland, TOSL should be considered as the first treatment option for SHL.

Sialendoscopy in Pediatric Sialolithiasis: Two Cases of Salivary Stones in the Parotid Gland and Review of the Literature

Sialolithiasis is one of the most common diseases of the salivary glands and the most common cause of chronic obstructive sialadenitis. Whereas salivary stones are responsible for most of the cases of obstructive sialadenitis in the adult population, sialolithiasis in children is considered relatively rare. We describe two cases of a 9 and a 4-year-old male respectively, with parotid sialolithiasis treated with sialendoscopy. A systematic review of the current literature was also completed in order to evaluate all described cases of parotid sialolithiasis in the pediatric population. We found 25 articles eligible for a total of 42 cases of pediatric parotid sialolithiasis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-023-03508-8.

Recovery of gland function after endoscopy-assisted removal of impacted hilo-parenchymal stones in the Wharton's duct

The aim of this study was to evaluate the gland function of patients following endoscopy-assisted removal of impacted hilo-parenchymal stones in the Wharton's duct. The study cohort comprised 115 patients who had undergone successful endoscopy-assisted lithotomy for hilo-parenchymal stones (mean diameter 7.7 mm). Gland function was evaluated at a mean 12 months after surgery using ultrasonography, sialography, and/or sialometry. Postoperative ultrasonography of 51 affected glands revealed a regular gland size in 58.8%, normal parenchyma density in 51.0%, and ductal ectasia in 80.4%. Postoperative sialograms of 109 affected glands were scored as type I (approximately normal) in 13 cases, type II (saccular ectasia of the hilo-parenchymal duct with/without stenosis, and no contrast retention) in 64, type III (saccular ectasia of the hilo-parenchymal duct with/without stenosis, and mild contrast retention) in 23, and type IV (poor shape of the main duct with evident contrast retention) in nine cases. The existence of ductal ectasia corresponded well to larger stone cases (P = 0.002). In the postoperative sialometry of 35 patients with unilateral stones, differences between the two sides were insignificant (P > 0.05). For patients with hilo-parenchymal submandibular gland stones, endoscopy-assisted surgery and extended postoperative follow-up help preserve the gland with good function.

Proteomic analysis of sialoliths from calcified, lipid and mixed groups as a source of potential biomarkers of deposit formation in the salivary glands

Salivary stones, also known as sialoliths, are formed in a pathological situation in the salivary glands. So far, neither the mechanism of their formation nor the factors predisposing to their formation are known despite several hypotheses. While they do not directly threaten human life, they significantly deteriorate the patient's quality of life. Although this is not a typical research material, attempts are made to apply various analytical tools to characterise sialoliths and search for the biomarkers in their proteomes. In this work, we used mass spectrometry and SWATH-MS qualitative and quantitative analysis to investigate the composition and select proteins that may contribute to solid deposits in the salivary glands. Twenty sialoliths, previously characterized spectroscopically and divided into the following groups: calcified (CAL), lipid (LIP) and mixed (MIX), were used for the study. Proteins unique for each of the groups were found, including: for the CAL group among them, e.g. proteins from the S100 group (S100 A8/A12 and P), mucin 7 (MUC7), keratins (KRT1/2/4/5/13), elastase (ELANE) or stomatin (STOM); proteins for the LIP group-transthyretin (TTR), lactotransferrin (LTF), matrix Gla protein (MPG), submandibular gland androgen-regulated protein 3 (SMR3A); mixed stones had the fewest unique proteins. Bacterial proteins present in sialoliths have also been identified. The analysis of the results indicates the possible role of bacterial infections, disturbances in calcium metabolism and neutrophil extracellular traps (NETs) in the formation of sialoliths.

Ultrasound shear wave elastography for patients with sialolithiasis undergoing interventional sialendoscopy

Objective

Ultrasound shear wave elastography is an objective tool to evaluate the stiffness of human tissues. Patients with sialolithiasis could be treated by interventional sialendoscopy with a high success rate. Sialolithiasis could be extracted, and the diseased gland could be preserved and evaluated after treatment. Whether ultrasound shear wave elastography could be used for objective outcome measurement and short-term follow-up of the parenchyma of gland in patients with sialolithiasis remains unclear.

Methods

This retrospective self-controlled study was conducted. Patients with sialolithiasis treated by interventional sialendoscopy and followed by high-resolution ultrasound shear wave elastography were selected between January and September 2017.

Results

Seventeen patients with sialolithiasis (mean age: 39.63 ± 12.49 years), including 10 women and 7 men, were enrolled. Fifteen patients had sialolithiasis in the submandibular gland and two in the parotid gland. The preoperative value of shear wave velocity was significantly higher in the diseased gland than in the contralateral normal gland (p < .001; 95% confidence interval [CI], 0.3915-0.6046). After successful treatment by interventional sialendoscopy surgery, the shear wave velocity of the diseased gland decreased significantly (p = 0.001; 95% CI, -0.38792 to -0.20474). However, there was a significant difference between the diseased and contralateral normal glands (p = 0.001; 95% CI, 0.0423-0.2895) after 1.55 months of surgery.

Conclusion

Ultrasound shear wave elastography could be an adjuvant tool to distinguish sialolithiasis-affected diseased glands from contralateral normal glands and assess the short-term treatment outcome objectively. The changing trend of shear wave velocity could help monitor the healing process of the parenchyma in the diseased gland after treatment.

Level of Evidence

4.

The roles of heteromorphic crystals and organic compounds in the formation of the submandibular stones

Objective

The study aimed to analyze the formation process of submandibular stones based on the theory of biological mineralization and inorganic crystal structure variation.

Study design

From January 2021 to December 2021, patients with submandibular stones treated in the Affiliated Hospital of Stomatology, Sun Yat-sen University (Guangzhou, China) were selected. According to the criterion of maximum transverse diameter ≥3 mm, a total of five submandibular stones meeting the requirement were included. After the surface of sample stones were washed, they were cut along the maximum transverse diameter. Next, the study employed Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectroscopy (EDS), and polycrystalline X-ray Diffraction (XRD) to analyze the composition and structure of submandibular stones.

Results

Five submandibular stones were included. The organic and inorganic compounds showed a rhythmic or irregular distribution. Submandibular stones were highly occupied with carbon (C), oxygen (O), calcium (Ca), and phosphorus (P). Hydroxyapatite (HAP) was the primary inorganic component. In addition, the precursor of HAP, namely Amorphous Calcium Phosphate (ACP), was also found. Tetrahedral Substitution Index (TSI) and Ca/P ratio reflected the degree of structural variation in HAP crystal, which fluctuated from 5.62-90.71 and 1.10-1.35, respectively.

Conclusions

The development of submandibular stones was influenced by inorganic crystals' chemical and structural variation as well as the organics' regulation towards the inorganic. The isomorphic substitution was accompanied by the occurrence of inorganic crystals, resulting in the crystal structure change. Organics might influence the appearance, aggregation, and mineralization of HAP during its formation.

Epidemiologic, radiologic, and sialendoscopic aspects in chronic obstructive sialadenitis

PURPOSE

Chronic obstructive sialadenitis (COS) is a recurring inflammation of the salivary gland. To date, there are no known predisposing factors for COS. Given the advances seen in radiology and sialendoscopy, we must update our knowledge of COS, analyzing factors that can favor its development.

METHODS

We prospectively analyzed 333 patients who underwent sialendoscopy between 2012 and 2021. Epidemiologic, radiologic, and sialendoscopy-related factors were correlated. Suspected diagnosis was established based on the clinical and radiologic data. The final diagnosis was determined on the basis of sialendoscopic findings.

RESULTS

The most common etiology of COS was stricture (40.8%). Lack of papilla distensibility (LPD) was also described as an etiology. COS was related to patient gender and age. Submandibular gland involvement was significantly more associated with lithiasis and LPD, while COS of the parotid gland was most frequently caused by stricture. Radioiodine sialadenitis and Sjögren's syndrome were significantly associated with stricture. MR sialography (MR-Si) showed the best overall sensitivity and specificity.

CONCLUSION

In our series, stricture was the most common cause of COS. We describe LPD as a frequent cause of COS in this series; ours is the first study to report this finding. There was a significant association between the salivary gland involved, patient sex and age, and the cause of COS. MR-Si showed the greatest diagnostic yield.

Sialolithiasis: mineralogical composition, crystalline structure, calculus site, and epidemiological features

The purpose of this paper was to describe the characteristics of salivary calculi and their relationship to epidemiological factors, through a cross-sectional study. We analysed 100 calculi obtained in 2017-2021. Patient data including age, time since onset of symptoms, gland involved, and site of location in the salivary system were studied. The calculi were studied to determine their morphological features using scanning electron microscopy and energy dispersive plain radiographic analysis. Most of the calculi had formed in the submandibular gland (SG) (82%). The mean age of patients at onset was 45.83 years; patients presenting parotid gland (PG) stones were somewhat older (p = 0.031). The mean time since the onset of symptoms was longer in PG calculi (p = 0.038). The most common lithiasis site was the main duct (74%), followed by the hilum (22%). Hilar stones were the largest (p < 0.05) and heaviest (p = 0.028). Octacalcium phosphate (OCP) was the most common crystalline phase (Cp) founded, followed by hydroxyapatite (HA) and whitlockite (WH). Specifically, OCP had a higher presence in PG calculi (p = 0.029) and WH was the most common phase in SG calculi (p = 0.017). The most prevalent site of lithiasis was the main duct, and the largest and heaviest calculi were found in the SG. PG stones were associated with a longer history of symptoms and older age. OCP was the most frequent Cp of the calculi studied, and the main Cp in PG stones. WH was the predominant Cp in SG stones. The Cp of the calculi was not influenced by location, patient age, or time of symptoms.

Calcification in Salivary Gland Cancer Mimicking Sialolithiasis-A Diagnostic Pitfall on Imaging: Report of Two Cases and Brief Review of the Literature

Objectives: Sialolithiasis is the most common cause of calcifications detected with ultrasound in patients with chronic inflammatory symptoms and swellings of the salivary glands. Other differential diagnoses of calcifications are extremely rare and mostly benign. Methods: Case report and literature review. Results: Two rare cases of malignant parotid gland tumors with calcifications in a localization typical for sialolithiasis, which were mistaken for salivary calculi based on image findings, are presented. Conclusions: This report intends to highlight the pitfalls in the imaging of parotid gland diseases. Even if malignant tumors of the parotid gland with calcifications are extremely rare, in ambiguous cases, differential diagnoses should be considered carefully. A high suspicion index of the need for further diagnostics in cases with calcifications is practical and could include missing periprandial symptoms, no obstruction signs in the proximal duct, and missing evidence of sialolithiasis in sialendoscopy.

Nomogram to predict the risk of endoscopic removal failure with forceps/baskets for treating submandibular stones

BACKGROUND

Endoscopic removal with forceps/baskets is favored in treating submandibular stones due to its minimal invasiveness. However, recent studies have found that endoscopic removal failure (ERF) is not unusual, and stones in such cases still need to be removed with other surgical methods. If the risk of ERF can be predicted preoperatively, it could be helpful for surgeons when choosing the appropriate therapy.

AIM

To develop a predictive nomogram for the risk of ERF when treating submandibular stones based on their preoperative clinical features.

METHODS

A total of 180 patients with 211 submandibular stones treated from January 2012 to December 2020 were included in the current study. Based on the preoperative clinical features of the stones, independent risk factors for ERF were identified by logistic regression analysis. The stones were then randomly divided into training and testing sets. A nomogram was constructed to predict the risk of ERF using the training set and then validated using both sets. The predictive performance of the nomogram was assessed by calibration curves and the concordance index (C-index).

RESULTS

Three independent predictors, location (P = 0.040), transverse diameter (P < 0.001) and longitudinal diameter (P < 0.001) measured on the cone beam computed tomography (CBCT) images of the submandibular stones, were identified and included in the predictive nomogram. Calibration curves of the nomogram showed good agreement between the predicted and observed probabilities in both sets. The C-index in the training set was 0.917 (95%CI, 0.875-0.959) and that in the testing set was 0.925 (95%CI, 0.862-0.989).

CONCLUSION

A nomogram based on the location, transverse and longitudinal diameters on CBCT images of submandibular stones showed satisfactory efficacy in predicting the risk of ERF preoperatively when treating submandibular stones.

Multiple Faces of Cervical Lesions in Children

Pediatric sialolithiasis is a rare condition causing tumefaction, induration, redness, and pain of the affected gland. When the submandibular gland is involved, the lesion can be mistaken for an adenopathy. As there are few studies to elucidate this condition in children, we present a rare case of a 16-year-old female with suggestive symptoms, in which initial clinical examination and two ultrasound examinations mistook the lesion for an adenopathy. A computed tomography examination was performed and the correct diagnosis was established. The patient was sent for oro-maxilo-facial examination and sialolithotomy was performed. A 10-mm yellow calculus was extracted and postoperative case evolution was favorable under wide spectrum antibiotherapy, oral nonsteroidal anti-inflammatory therapy and silagog alimentation. Although submandibular adenopathies are much more frequent in the pediatric age group, when faced with a firm, immobile submandibular lesion, the pediatrician should consider the sialolithiasis diagnosis.

Rapid development of a salivary calculus in submandibular gland and its potential causes in a young victim following Russell's viper bite

Russell's viper bites are known to cause a range of haemotoxic, neurotoxic, myotoxic, cytotoxic and nephrotoxic complications. However, the impact of Russell's viper bites as well as bites from other venomous snakes on sialolithiasis has not been previously reported. Here, we present an interesting case where a Russell's viper bite induced the rapid development of a calculus in submandibular gland in a 10-year-old boy. Upon admission, the victim did not show any symptoms of swelling and/or pain around his oral cavity. He received antivenom treatment to normalise his coagulation parameters, however, on day three he developed swelling and extreme pain around his right mandibular region. An ultrasound investigation revealed the presence of a calculus in his submandibular gland, which was removed using a minor surgical procedure. The histopathological examination revealed this as a poorly calcified salivary calculus, which is composed of cell debris, mucopolysaccharides and lipids. The mechanisms behind its rapid development following a snakebite are unclear although this could be linked to excessive inflammation or modifications to the composition of saliva induced by venom toxins or other unknown factors. This report reveals an unusual complication induced by a Russell's viper bite and alerts clinicians who treat snakebites to be aware of such envenomation effects. Moreover, this will lead to novel research to explore the relationship between venom toxins and functions of salivary glands.

Utility of Ultrasonography for Diagnosis of Salivary Gland Sialolithiasis: A Meta-Analysis

OBJECTIVES

We hypothesized that ultrasonography for salivary gland stone detection would have a diagnostic accuracy similar to that confirmed by sialendoscopy, sialography, or surgery. Therefore, we evaluated the diagnostic characteristics of ultrasonography in terms of submandibular and parotid stone detection compared to confirmatory methods.

METHODS

We searched PubMed, Embase, the Web of Science, SCOPUS, and the Cochrane database to October 31, 2021. The risk of bias was evaluated using the QADAS-2 tool.

RESULTS

Ten studies involving 1393 patients were included in the analysis. The diagnostic odds ratio of ultrasonography was 162.6013 (95% confidence interval [CI] [53.9883; 489.7208] and I² value 81.0%). The area under the summary receiver operating characteristic curve was 0.963. The sensitivity, specificity, negative predictive value, and positive predictive value were 0.8992 (95% CI [0.8534; 0.9318]; I²  = 79.9%), 0.9664 (95% CI [0.9290; 0.9844], I²  = 65.6%), 0.8076 (95% CI [0.7256; 0.8694]; I²  = 80.4%), and 0.9853 (95% CI [0.9629; 0.9943]; I²  = 77.4%), respectively. However, high-level among-study heterogeneity (I²  ≥ 50%) was evident, attributable to the inclusion of different glands. On subgroup analysis, significant differences in the negative predictive values (parotid gland only [0.9392], submandibular gland only [0.6718], and parotid and submandibular glands [0.8105]) were apparent. We found no significant among-study difference in the sensitivity, specificity, positive predictive value, or diagnostic odds ratio (P > .05).

CONCLUSION

Ultrasonography usefully detects submandibular and parotid gland stones. Ultrasonography of the parotid gland was associated with the highest diagnostic accuracy, but further clinical studies are needed.

LEVEL OF EVIDENCE

NA Laryngoscope, 2022.

Minimally invasive transoral robotic surgery for hiloparenchymal submandibular stone: Technical note on Flex Robotic System

Flex Robotic System allows a minimally invasive approach for transoral removal of submandibular salivary stones.

Treatment of Sialolithiasis: What Has Changed? An Update of the Treatment Algorithms and a Review of the Literature

Treatment for sialolithiasis has undergone significant changes since the 1990s. Following the development of new minimally invasive and gland-preserving treatment modalities, a 40–50% rate of gland resection was reduced to less than 5%. Extracorporeal shock-wave lithotripsy (ESWL), refinement and extension of methods of transoral duct surgery (TDS), and in particular diagnostic and interventional sialendoscopy (intSE) are substantial parts of the new treatment regimen. It has also become evident that combining the different treatment modalities further increases the effectiveness of therapy, as has been especially evident with the combined endoscopic–transcutaneous approach. In the wake of these remarkable developments, a treatment algorithm was published in 2009 including all the known relevant therapeutic tools. However, new developments have also taken place during the last 10 years. Intraductal shock-wave lithotripsy (ISWL) has led to remarkable improvements thanks to the introduction of new devices, instruments, materials, and techniques, after earlier applications had not been sufficiently effective. Techniques involving combined approaches have been refined and modified. TDS methods have been modified through the introduction of sialendoscopy-assisted TDS in submandibular stones and a retropapillary approach for distal parotid sialolithiasis. Recent trends have revealed a potential for significant changes in therapeutic strategies for both major salivary glands. For the submandibular gland, ISWL has replaced ESWL and TDS to some extent. For parotid stones, ISWL and modifications of TDS have led to reduced use of ESWL and the combined transcutaneous–sialendoscopic approach. To illustrate these changes, we are here providing an updated treatment algorithm, including tried and tested techniques as well as promising new treatment modalities. Prognostic factors (e.g., the size or location of the stones), which are well recognized as having a strong impact on the prognosis, are taken into account and supplemented by additional factors associated with the new applications (e.g., the visibility or accessibility of the stones relative to the anatomy of the duct system).

Trial Proteomic Qualitative and Quantitative Analysis of the Protein Matrix of Submandibular Sialoliths

Our studies aimed to explore the protein components of the matrix of human submandibular gland sialoliths. A qualitative analysis was carried out based on the filter aided sample preparation (FASP) methodology. In the protein extraction process, we evaluated the applicability of the standard demineralization step and the use of a lysis buffer containing sodium dodecyl sulfate (SDS) and dithiothreitol (DTT). The analysis of fragmentation spectra based on the human database allowed for the identification of 254 human proteins present in the deposits. In addition, the use of multi-round search in the PEAKS Studio program against the bacterial base allowed for the identification of 393 proteins of bacterial origin present in the extract obtained from sialolith, which so far has not been carried out for this biological material. Furthermore, we successfully applied the SWATH methodology, allowing for a relative quantitative analysis of human proteins present in deposits. The obtained results correlate with the classification of sialoliths proposed by Tretiakow. The performed functional analysis allowed for the first time the selection of proteins, the levels of which differ between the tested samples, which may suggest the role of these proteins in the calcification process in different types of sialoliths. These are preliminary studies, and drawing specific conclusions requires research on a larger group, but it provides us the basis for the continuation of the work that has already begun.

Intraductal Fragmentation in Sialolithiasis Using Pneumatic Lithotripsy: Initial Experience and Results

OBJECTIVE

To report initial experience in using a pneumatic lithotripter to treat salivary stones.

STUDY DESIGN

Level IV retrospective study.

SETTING

University hospital and tertiary referral center.

METHODS

A pneumatic lithotripter was used to treat salivary stones after these were diagnosed. Probes with diameters of 0.7 mm were used. Total fragmentation was intended in all stones. Stone fragments were removed using several instruments in serial sialendoscopies to achieve complete stone clearance.

RESULTS

A total of 62 patients with 77 stones were treated. Forty-three submandibular stones were treated in 34 patients, and 34 parotid stones were treated in 28 patients. An operating pressure of 2.5 bar and a single frequency mode were used. Complete fragmentation was achieved in all but one of the treated stones in both glands (98.7%). Among the patients, 90.32% became stone free and 100% symptom free. Multiple stones were treated in 24.19% of the patients, and multimodal therapy was also carried out in 24.19%. All of the glands were preserved.

CONCLUSIONS

The pneumatic lithotripter proved to be effective in the treatment of sialolithiasis. Stone size, location, and the gland involved were important clinical factors. The device was sufficient to achieve success without any increased risk for complications in the patients or damage to the sialendoscopes.

Surgical navigation in parotid sialolith extraction

Posterior parotid lithiasis may in some cases require a combined surgical approach associating sialendoscopy to an external intraoral or transfacial approach. This single-center retrospective study describes the surgical technique for parotid lithiasis extraction by a combined external and sialendoscopic approach with the help of CT-navigation. Five patients were included between November 2014 and July 2020. The sialolith was extracted in 100% of cases. Navigation and transillumination localizations matched consistently. No patients showed postoperative facial paresis. At 2 to 21 months' follow-up, there was no recurrence of sialolithiasis. Navigation can be a complement to transillumination, improving surgical comfort and safety, but does not replace first-line sialendoscopy. Visual control is required whenever possible after extraction. In combined procedures, it enables accurate identification of parotid sialoliths. In case of impassable stenosis, it could be a therapeutic alternative to parotidectomy.

Sialendoscopy-assisted combined approach for parotid sialolithotomy: Our long-term experience

OBJECTIVES

To assess the long-term outcome of sialendoscopy-assisted combined approach for parotid sialolithotomy with gland preservation.

PATIENTS AND METHODS

A retrospective study of patients treated with a combined sialendoscopic and open approach was conducted between 2011 and 2020. Demographic data of patients such as operative technique, stone size, stone location, complications, and symptom relief were collected. Patients were followed up via clinical examination and questionnaires.

RESULTS

Seventy-four patients were included and underwent endoscopy-assisted combined operations for the removal of 98 parotid stones. Of the 98 stones, 92(94%) stones were completely removed and 6(6%) were partially removed. At a mean follow-up of 47.1 ± 35 months, 65 of 74 patients (88%) achieved long-term success. Patients with stone incomplete removal were significantly more often to develop the recurrence of obstructive symptoms (p = 0.000) There were no cases of facial nerve injury or fistula formation. Gland function was preserved in 73 of 74 patients (99%).

CONCLUSIONS

The combined approach for parotid stones is a safe and gland-preserving alternative to parotidectomy. The techniques described here show high success rates and good long-term results, and they avoided the need for gland resection in >95% of cases.

Relationship between volume of submandibular salivary stones in vivo determined with Cone-Beam Computer Tomography and in vitro with micro-Computer Tomography

Background

Successful removal of salivary stones depends on exact pretreatment information of the location, the size and shape of the stones. This study aimed to compare the volume of submandibular sialoliths determined by preoperative Cone-Beam Computer Tomography (CBCT) scans with the volume of the removed stones on micro-Computer Tomography (micro-CT) scans.

Material and Methods

In this study, using twenty-one submandibular sialoliths, the pretreatment volumes in-vivo measured on CBCT were compared to the volumes of removed stones determined by micro-CT scans. The volume measured on micro-CT scans served as the gold standard. Pre-operative CBCT’s and in-vitro micro-CT’s were converted into standard tessellation language models (STL-models) using an image segmentation software package. The CBCT and micro-CT images of the stones were subsequently metrologically assessed and compared to each other using reverse engineering software.

Results

Volumes of submandibular sialoliths determined by CBCT’s correlated significantly with volumes measured on micro-CT’s (Spearman’s coefficient r = 0.916). The interquartile range (IQR) for the volume measured with micro-CT was 117.23. The median is 26.41. For the volume measured with CBCT the IQR was 141.3 and the median 36.61. The average volume on micro-CT is smaller than on CBCT.

Conclusions

When using CBCT-scans for the detection of submandibular sialoliths one should realize that in-vivo those stones are actually a fraction smaller than assessed on the preoperative scan. This is important when cut-off values of sizes of stones are used in the pretreatment planning of stone removal.

Key words:Salivary stone, sialolith, CBCT, micro-CT, volume.

Transoral Sialolithotomy Without Endoscopes: An Alternative Approach to Salivary Stones

Sialoendoscopy is a valuable technique for a variety of obstructive and nonobstructive disorders of the major salivary glands. However, the utility of sialoscopes is limited for salivary stones, which frequently required open removal. Transoral sialolithotomy without scopes is an efficient, low-cost alternative with excellent outcomes available for most of the submandibular stones.

Transoral robotic removal of submandibular sialolith combined with sialendoscopic assistance

Treatment of symptomatic impacted and palpable submandibular lithiasis generally involves a combined transoral and sialendoscopic approach with an excellent success rate, and a low morbidity. Nevertheless, the approach of proximal or hilar lithiasis may in some cases represent a real challenge and cause major surgical discomfort, which could increase the risk of damage to the lingual nerve. This article details the surgical technique and advantages of submandibular lithiasis removal by transoral robotic surgery combined with sialendoscopy, together with a case video.

Concurrent giant sialoliths within the submandibular gland parenchyma and distal segment of Wharton's duct: Novel case report

OBJECTIVE

This article discusses the clinical significance of an unusual case of the simultaneous occurrence of 2 giant sialoliths within the ipsilateral submandibular gland and distal aspect of Wharton's duct in a 63-year-old patient.

BACKGROUND

The majority of submandibular gland sialoliths are found in Wharton's duct, with fewer within the gland parenchyma. Giant sialoliths (exceeding 15 mm in size) are rare.

MATERIALS AND METHODS

An asymptomatic, otherwise healthy older patient sought dental care and underwent a comprehensive oral and radiographic examination.

RESULTS

A panoramic radiograph revealed 2 incidental radiopaque structures, representing giant sialoliths within the submandibular gland and along the distal segment of Wharton's duct. This synchronous finding apparently represents the first case reported in the geriatric literature.

CONCLUSIONS

The detection of 1 salivary stone should heighten the scrutiny for additional stones. Practitioners should carefully weigh the risk of sialolith removal versus deferment of treatment in older medically compromised patients.

[Sialendoscopy : Indications and treatment]

There is plethora of treatment options for surgeons dealing with salivary stones. During recent decades, emphasis has been laid on gland-preserving minimally invasive techniques for stone removal. In this context, visualization of salivary ducts with semirigid endoscopes for diagnostic and therapeutic purposes, the so-called sialendoscopy, has become increasingly important. This article gives an overview of indications for sialendoscopy and how the procedure is performed. Furthermore, sialendoscopy is discussed in the context of other modalities for salivary stone treatment.

Neutrophil Extracellular Traps Promote the Development and Growth of Human Salivary Stones

Salivary gland stones, or sialoliths, are the most common cause of the obstruction of salivary glands. The mechanism behind the formation of sialoliths has been elusive. Symptomatic sialolithiasis has a prevalence of 0.45% in the general population, is characterized by recurrent painful periprandial swelling of the affected gland, and often results in sialadenitis with the need for surgical intervention. Here, we show by the use of immunohistochemistry, immunofluorescence, computed tomography (CT) scans and reconstructions, special dye techniques, bacterial genotyping, and enzyme activity analyses that neutrophil extracellular traps (NETs) initiate the formation and growth of sialoliths in humans. The deposition of neutrophil granulocyte extracellular DNA around small crystals results in the dense aggregation of the latter, and the subsequent mineralization creates alternating layers of dense mineral, which are predominantly calcium salt deposits and DNA. The further agglomeration and appositional growth of these structures promotes the development of macroscopic sialoliths that finally occlude the efferent ducts of the salivary glands, causing clinical symptoms and salivary gland dysfunction. These findings provide an entirely novel insight into the mechanism of sialolithogenesis, in which an immune system-mediated response essentially participates in the physicochemical process of concrement formation and growth.

Salivary Gland Lithiasis Recurrence After Minimally-Invasive Surgery: Incidence, Risk Factors and Prevention

OBJECTIVE

The aim of this study was to evaluate the recurrence rate of lithiasis following minimally invasive surgery to identify risk factors and mechanisms for recurrence of salivary gland lithiasis.

STUDY DESIGN

Retrospective case series.

METHODS

A retrospective study was conducted including all patients treated for salivary gland lithiasis by minimally invasive surgery, such as sialendoscopy, intracorporeal lithotripsy, extracorporeal lithotripsy, transoral approach, and combined approach in our Department. We analyzed the recurrence rate of salivary lithiasis, their topography and timeline.

RESULT

Three hundred four patients were included in this study, the mean age was 49 years (range 12-90 years), and the mean duration of follow-up was 19.8 months (range 0-66 months). Fifteen patients (5%) presented secondary lithiasis. In all but one case, recurrences involved the same gland as primary lithiasis, and most frequently the submandibular gland. Recurrences occurred from 3 to 46 months postoperatively. Fourteen patients, who presented recurrence, had been initially treated by transoral approach. Recurrent lithiasis were treated by transoral approach or submandibulectomy.

CONCLUSION

Salivary gland lithiasis recurrence was rare after minimally invasive salivary gland surgery. This study reinforced the concept that salivary gland lithiasis should be considered as a duct pathology.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:794-799, 2021.

The association between sialolithiasis and smoking, alcohol drinking and obesity in Korea: a nested case-control study

BACKGROUND

Smoking and alcohol consumption are the most common social habits in patients with sialolithiasis. Moreover, obesity has been reported to have a significant association with poor oral hygiene, one of the causes of sialolithiasis. The purpose of this study was to evaluate the relationships among tobacco smoking, drinking alcohol, obesity and sialolithiasis in a Korean population.

METHODS

The Korean National Health Insurance Service-Health Screening Cohort, which includes patients ≥40 years old, was assessed from 2002 to 2013. A total of 947 sialolithiasis participants were matched with 3788 control subjects at a ratio of 1:4 with respect to age group, sex, income group, region of residence, hypertension, diabetes, and dyslipidemia. We analyzed the participants' previous histories of smoking (current or past smokers compared to nonsmokers) and alcohol consumption (≥ 1 time per week compared to < 1 time per week) in the sialolithiasis and control groups. Obesity was measured using body mass index (BMI, kg/m²), which was categorized as < 18.5 (underweight), ≥ 18.5 and < 23 (normal), ≥ 23 and < 25 (overweight), ≥ 25 and < 30 (obese I), and ≥ 30 (obese II). Crude and adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using conditional logistic regression analyses.

RESULTS

The rate of smoking was higher in the sialolithiasis group (32.4% [307/947]) than in the control group (29.1% [1103/3788], P = 0.047). The adjusted OR of smoking for the sialolithiasis group was 1.31 (95% CI = 1.08-1.59, P = 0.006). Alcohol consumption and obesity were not statistically significantly related to sialolithiasis.

CONCLUSION

The odds of smoking were increased in sialolithiasis patients compared with control subjects in the population ≥ 40 years of age.

Incidental findings in a consecutive series of digital panoramic radiographs

Purpose

The aim of this study was to determine the prevalence of incidental findings (IFs) on digital dental panoramic radiographs (DPRs) of asymptomatic patients attending a general dental practice.

Materials and Methods

This was a retrospective study of 6,252 consecutive digital (photostimulatable phosphor) DPRs of patients who visited a Canadian general dental practice for a complete new patient examination. The IFs were grouped into dental-related anomalies, radiopacities and radiopacities in the jaws, changes in the shape of the condyles, and other findings in the jaws, such as tonsilloliths and mucosal antral pseudocysts. Their prevalence was determined.

Results

Thirty-two percent of the DPRs showed at least 1 IF. The highest prevalence was found for dental-related anomalies (29% of all DPRs), of which impacted teeth were the most prevalent finding (24% of all DPRs), followed by idiopathic osteosclerosis (6% of all DPRs). A lower prevalence was noted for tonsilloliths (3%), and the prevalence of root tips, mucosal antral pseudocysts, and anomalies in condylar shape was approximately 1% each.

Conclusion

The observed prevalence of 32.1% for IFs of any type underscores the need for a dental practitioner to review the entire DPR when a patient presents for an initial dental examination (or check-up) or for dental hygiene. Only a single IF (a central giant cell granuloma) provoked alarm, as it was initially considered malignant. Similarly, impacted teeth and suspected cysts need careful evaluation upon discovery to determine how they may be optimally managed.

Ultrastructural analysis of the submandibular sialoliths: Raman spectroscopy and electron back-scatter studies

The aim of work was the epidemiological analysis of the occurrence of sialolithiasis of the submandibular gland in adults and the evaluation of the ultrastructure of salivary stones. The study sample consisted of 44 sialoliths. Analysis of the structure and chemical composition of sialoliths was performed using a Scanning Electron Microscope and Raman Spectroscopy. Comparing our results with the literature we can say that the epidemiology of sialolithiasis has not changed significantly over the past 50 years. A wide variety of sialoliths structure was observed. In 75% (33) cases a layered structure of salivary stones was observed, while in 25% (11) - homogeneous structure. The various distribution of organic and inorganic components was observed among all the analyzed sialoliths. Raman spectroscopy allows for preliminary analysis of the sialoliths structure with only a qualitative assessment of their composition, which significantly reduces the research value of this method. The presence of organic and inorganic compounds in the core and inner layers of the salivary glands stones confirms 2 basic theories of the formation of sialoliths: inflammation and deposition of the inorganic component as a result of disruption of saliva flow in the salivary glands.

Time trends in the prevalence of diagnosed sialolithiasis from Taiwanese nationwide health insurance dental dataset

Background/Purpose

Sialolithiasis, the so-called salivary gland stone, is a condition forming salivary calculi within a salivary gland or ducts. Little is known about the epidemiological survey of sialolithiasis in Taiwanese population. In this study, we conducted an age-period-cohort (APC) analysis evaluating the prevalence of sialolithiasis.

Materials and methods

A retrospective study was conducted to analyze the registered database compiled by the Taiwanese National Health Insurance Research Database from 1996 to 2013. The APC analysis was performed to investigate the effects of age, diagnosis period, and birth cohort with sialolithiasis.

Results

We found that the prevalence of sialolithiasis varied from 1.4 (10⁵) to 2.3 (10⁵). The mean age ±standard deviation with sialolithiasis from 1996 to 2013 was 37.7 ± 18.5 and 46.2 ± 18.6 years old, respectively. The prevalence was higher among male than female (RR: 1.10; 95% CI: 1.05–1.15, p < 0.001). The age >65 group had higher risk compared to age <40 group (RR: 2.27; 95% CI: 2.13–2.43, p < 0.001). The relative risk for sialolithiasis demonstrated significant age effect (p < 0.001). The relative risk for sialolithiasis did not show the significant period effect (p = 0.742). The relative risk for sialolithiasis demonstrated significant cohort effect (p = 0.01). The relative risk for sialolithiasis demonstrated significant APC effect (p = 0.002).

Conclusion

Form this nationwide population-based database, the prevalence of sialolithiasis occurs more frequently in male than in female. In addition, the relative risk for sialolithiasis demonstrated the significant APC effects.

Transoral Ultrasound in the Diagnosis of Obstructive Salivary Gland Pathologies

Transcutaneous ultrasound (TCUS) is an accepted diagnostic method in salivary gland diseases. However, sparse data are available on the use of transoral ultrasound (TOUS) in sialadenopathies. One hundred five patients presenting with various obstructive sialadenopathies were examined using TOUS and TCUS. Ultrasound findings were validated by direct visualization in subsequent sialendoscopy examinations. By TOUS, but not by TCUS, all patients with sialolithiasis (70/105) could be identified and virtually all concrements, even very small ones, were detected and distinguished from artifacts. Ductal stenoses (16/105) could be correctly differentiated from sialoliths, and exceptional insights into the delicate anatomy of parotid duct stenoses were gained. TOUS provided detailed information on other space-occupying lesions (14/105) and circumvented the method-related diagnostic weaknesses of TCUS. As a valuable tool in the diagnosis of obstructive sialadenopathies, TOUS seems superior to TCUS in pathologies involving the distal parotid duct, the submandibular duct system and the floor of the mouth.

Removal of stones from the superficial lobe of the submandibular gland (SMG) via an intraoral endoscopy-assisted sialolithotomy

OBJECTIVES

Sialolithiasis is the most common cause of chronic sialadenitis of the submandibular gland (SMG). Symptomatic superficial lobe stones are often treated by submandibulectomy. A gland preserving operation allows for transoral stone removal through endoscopically assisted sialolithotomy. Herein, we provide clinical and sonographical follow-up data in patients who underwent sialolithotomy under general anesthesia.

MATERIALS AND METHODS

Sixty patients treated at the Department of Oral and Maxillofacial Surgery at Düsseldorf University Hospital for superficial lobe sialolithiasis of SMG were included in this study. All received transoral sialolithotomy under general anesthesia. Follow-up was conducted via standardized patient questionnaires, clinical examination, and B-mode and color Doppler sonography.

RESULTS

Mean patient age was 48.9 years. 56.6% of right and 43.4% of left SMG were affected. Mean follow-up was 45 months. Fifty-five of 59 detected stones could be removed. Mean operation time was 71 min. 3.3% of patients reported recurrent episodes of postoperative pain and 10% felt recurrent episodes of gland swelling. Persistent postoperative lingual nerve hypesthesia was described in one patient. No facial nerve damages occurred. Salivary flow rates remained reduced in most of the affected glands upon stone removal. Sonographical follow-up data of the previously affected SMG after intraoral endoscopy-assisted sialolithotomy showed a regular gland size in 70.8% of cases, a parenchyma free of inflammation in 93.8%, and without signs of fibrosis in 72.9% of cases. 68.7% of patients showed a regular structure of Wharton's duct at time of follow-up. In total, 89.6% of patients were diagnosed stone-free within both glands on follow-up. No case required subsequent submandibulectomy.

CONCLUSIONS

Sialolithotomy of Wharton's duct for removal of stones from the SMG's superficial lobe is a promising alternative to submandibulectomy.

CLINICAL RELEVANCE

Reduction of postoperative morbidity through endoscopically assisted sialolithotomy for removal of superficial lobe stones from SMG.

TRIAL REGISTRATION

Ethics Committee of Heinrich-Heine-University Düsseldorf (no. 5586).

A case-control study of the association between sialolithiasis and osteoporosis

OBJECTIVE

The purpose of this study was to evaluate the association between osteoporosis and salivary gland stone using a population-based claims database.

DESIGN

A case-control design.

SETTING

Taiwan.

PARTICIPANTS

We retrieved the sample for this case-control study from the Taiwan "Longitudinal Health Insurance Database 2005." All 557 patients aged 40 years or older with a diagnosis of sialolithiasis were cases, and 1671 matched controls (without sialolithiasis) were selected.

SUBJECTS AND METHODS

We used the chi-square test to explore differences between cases and controls on socio-demographic characteristics. Furthermore, conditional logistic regressions were used to examine the association of sialolithiasis with previously diagnosed osteoporosis.

RESULTS

Of 2228 sampled patients, 171 (7.68%) had ever been previously diagnosed with osteoporosis; 58 (10.41%) among cases and 113 (6.76%) among controls (P = 0.005). Conditional logistic regression analysis found that the odds ratio (OR) of prior osteoporosis for cases was 1.79 (95% confidence interval [CI]: 1.24-2.59, P = 0.002) relative to controls after adjusting for urbanisation and the selected medical co-morbidities. Furthermore, we found that among patients aged ≥65 years, the adjusted OR of prior osteoporosis for cases was 1.89 (95% CI = 1.02-3.51). No significant relationship was observed among patients aged <65 years old.

CONCLUSION

This study demonstrates an association between sialolithiasis and osteoporosis. Although the finding warrants further investigation, the results call for more awareness of the possible concurrence of osteoporosis among physicians and patients with salivary gland stones.

Airway obstruction caused by pharyngolaryngeal swelling after intraoral removal of a submandibular gland stone

Intraoral removal of a submandibular gland stone is less invasive than submandibulectomy, with no life-threatening airway complications reported until now. We report a case involving airway obstruction caused by pharyngolaryngeal swelling after intraoral removal of a submandibular gland stone. A 31-year-old man with a left submandibular gland stone underwent intraoral removal of the stone under general anesthesia and was discharged 1 day after surgery. That night, he was transported back to our hospital by ambulance for dyspnea. Because computed tomography showed pharyngolaryngeal swelling, he was intubated and managed by a ventilator. Four days later, the pharyngolaryngeal swelling had mostly resolved and he was extubated and discharged. Surgeons should be vigilant of the potential risk of airway complications following an intraoral approach for submandibular gland stone removal.

Chew on This: Emergency Imaging of the Oral Cavity and Salivary Glands-What the Clinician Really Needs to Know

Nontraumatic emergencies of the oral cavity, sublingual and submandibular spaces, and salivary glands are common and those requiring imaging will most often be infectious in nature.^1,2 However, noninfectious pathologies such as sialolithiasis, autoimmune sialoadenitis, and soft tissue swelling due to angioedema or hemorrhage are also important conditions that radiologists must be familiar with in order to inform the clinician of critical imaging findings that can have a profound impact on patient outcomes. To understand these pathologies, familiarity with the anatomy of these spaces is essential.