Torus mandibularis and its implication as a risk factor for the formation of sialolithiasis

  1. Timothy Brandon Shaver 1 and
  2. Arjun S Joshi 2
  1. 1 Otolaryngology, The George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, USA
  2. 2 Otolaryngology-Head and Neck Surgery, The George Washington University, Washington, District of Columbia, USA
  1. Correspondence to Dr Timothy Brandon Shaver; timshaver@mfa.gwu.edu

Publication history

Accepted:13 Jan 2023
First published:20 Feb 2023
Online issue publication:20 Feb 2023

Case reports

Case reports are not necessarily evidence-based in the same way that the other content on BMJ Best Practice is. They should not be relied on to guide clinical practice. Please check the date of publication.

Abstract

Sialolithiasis is the formation of a stone within the salivary gland, and approximately 80% of them occur within the submandibular gland. Sialolithiasis can lead to swelling and pain of the gland in the immediate phase and if left untreated, can lead to sialadenitis and even atrophy of the gland. Certain factors have already been established in the formation of sialolithiasis such as dehydration, tobacco smoke, autoimmune disorders and certain medications. One factor we theorise contributes to the formation of sialolithiasis is bony outgrowths on the tongue surface of the jaw, called mandibular tori. These outgrowths can lead to external compression of the submandibular duct, which leads to impeded salivary flow and the potential for sialolith formation. We present two cases in which individuals had submandibular sialolithiasis in the setting of extensive mandibular tori.

Background

Sialoliths may involve any of the major salivary glands; however, approximately 80% of all sialoliths form within the submandibular gland.1–3 Stone formation leads to complete or near-complete obstruction of the normal salivary flow, leading the affected individual to experience postprandial swelling and pain. The aetiological factors contributing to the formation of these sialoliths are not completely understood; however, two overarching themes that are generally considered to be ideal conditions for stone formation are inflammation of the glandular tissue and salivary stasis.2 Factors that have been studied in the past include tobacco smoke and dehydration, both of which have demonstrated an increase in prevalence, but are not statistically significant.2 4 Other factors including medications known to decrease the production of saliva, systemic and autoimmune disorders, as well as varying levels of proteins or minerals, have been studied with varying degrees of association.1 5–8

One such area that has remained to be studied is physical factors that lead to external compression of the salivary duct, contributing to sialolith formation. One such external factor we theorise could lead to the development of sialolithiasis is the presence of mandibular tori, bony outgrowths of cortical bone on the lingual surface of the mandible. One case report has demonstrated the presence of sialadenitis due to extensive mandibular tori.9 To our knowledge, however, no such papers have been reported on the presence of submandibular stones in association with mandibular tori.

Case presentation

Case 1

A patient in his early 50s presented to an otolaryngology clinic for the development of left submandibular gland swelling for 1 month which had been intermittent since onset, with associated discomfort in the same area. He denied any mucopurulent discharge in his mouth or foul/salty taste. He denied any systemic symptoms of infection including fever or chills. The patient had a history of drinking alcohol occasionally and smoking less than one pack/day for the past 21 years. He had no history of significant radiation exposure, history of gout, nor any serological testing for autoimmune conditions. Physical examination was notable for mild swelling within the left submandibular region with associated tenderness on palpation. Extensive bilateral mandibular tori on the lingual surface of the mandible were also noted (figure 1A). Ultrasound of the left submandibular gland was performed in office which showed a 9 mm hyperechoic focus within the mid to anterior floor of mouth, consistent with a salivary calculus (figure 1B). During this visit, it was agreed upon by the surgeon and patient to perform a left complicated submandibular sialolithotomy with left complicated sialodochoplasty transorally under general anaesthesia. It was also recommended performing bilateral mandibular tori reduction at the time of his sialolithotomy; however, the patient did not wish to pursue this option. The patient underwent transoral sialolithotomy and sialodochoplasty 27 days following his initial in-office evaluation. The patient tolerated the procedure well and developed no acute complications from the procedure.

Figure 1

(A) Oral cavity of case 1 following sialolithotomy and sialodochoplasty. Bilateral mandibular tori are denoted with white arrows. (B) Two-dimensional ultrasound demonstrating a 0.93 cm hyperechoic focus in the left submandibular ductal system.

Case 2

A man in his mid-60s presented to our otolaryngology clinic for persistent right submandibular gland swelling for the past year and a half. The patient noted swelling mainly occurred around meals but denied any associated symptoms such as fever, chills, pain, dysphagia, salty/foul-tasting saliva or mucopurulent discharge. The patient was a former cigarette smoker of 7–8 years, one pack/day, but quit 35 years ago, and was a current social drinker at the time of presentation. The patient’s medications included atorvastatin 40 mg and telmisartan 40 mg for which he had taken for ‘at least several years’. Physical examination demonstrated significant bilateral mandibular tori (figure 2A) and a palpable stone within the mid to anterior floor of mouth on the right. In-office ultrasound of the right submandibular gland was obtained and demonstrated a 1.15 cm sialolith in the mid to anterior floor of mouth of the right submandibular duct with associated intraglandular and main ductal dilation (figure 2B). A transoral sialolithotomy and sialodochoplasty with concurrent mandibular tori reduction were recommended to the patient; however, he wished to avoid general anaesthesia. The patient underwent an in-office sialolithotomy and sialodochoplasty approximately 1 month after his initial visit. The patient tolerated the procedure well. He followed up 1 week later and denies any recurrence of his symptoms nor any complications from the procedure. He was advised to follow up on an as-needed basis.

Figure 2

(A) Oral cavity of case 2 following right-sided sialolithotomy and sialodochoplasty. Bilateral mandibular tori are denoted with white arrows. (B) Two-dimensional ultrasound demonstrating a 1.15 cm hyperechoic focus in the right submandibular ductal system.

Outcome and follow-up

Following in-office treatment, both patients returned to normal activity immediately and were advised to eat normally, if it was tolerable. Both patients were treated 12 months ago and neither have returned due to recurrence of symptoms.

Discussion

We presented two cases in which two men were found to have submandibular sialolithiasis with findings of bilateral mandibular tori on examination. Although a true causal relationship has not been identified, the logical concept of extensive mandibular tori causing external compression and/or distorted anatomy of the submandibular ducts should not be understated. As stated, one case report has identified a patient with complete obstruction leading to submandibular sialadenitis. Sialoliths have the potential, if left untreated, to cause many chronic issues such as sialadenitis, atrophy and fibrosis of the gland, as well as scarring within the duct leading to strictures and further stone formation.1 Thus, individuals with mandibular tori that have grown extensively over their life span should be aware that they may be prone to submandibular sialolith formation. In addition, reduction of mandibular tori may decrease the chance of sialolith recurrence. Our patients were given the recommendation of tori reduction; however, both declined. There is a paucity of information regarding this topic and further research is needed to determine the true risk of developing submandibular gland sialolithiasis when mandibular tori are present.

In addition, the potential complexity of transoral sialolithotomy when large mandibular tori are present should be considered as well. Techniques like in-office transoral sialolithotomy and sialoendoscopy have been described, greatly reducing the need for general anaesthesia and the financial burden it entails.10 The presence of mandibular tori in a patient with submandibular sialolithiasis should be taken into consideration when contemplating the treatment plan. Conversely, our case of performing an in-office transoral sialolithotomy in a patient with mandibular tori shows that it can successfully be done and more radical procedures like sialoadenectomy should not be rushed to.

Learning points

  • Sialolith formation is largely due to two broad concepts, salivary stasis and inflammation of the glandular tissue.

  • Although many intrinsic and systemic factors that contribute to stone formation have been studied, it is imperative to also think of other factors like external compression of the ducts.

  • Mandibular tori, bony outgrowths on the lingual surface of the jaw, can impinge the submandibular duct leading to salivary stasis and ultimately stone formation.

  • Although mandibular tori can make the treatment of sialolithiasis complex, it is not a contraindication for transoral sialolithotomy and sialodochoplasty.

Ethics statements

Patient consent for publication

Footnotes

  • Contributors TBS is responsible for the conception and design, data collection, primary manuscript drafting, critical revision, final approval and accountability for all aspects of the work. ASJ is responsible for the conception and design, revising manuscript critically for intellectual content, final approval and accountability for all aspects of the work.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Case reports provide a valuable learning resource for the scientific community and can indicate areas of interest for future research. They should not be used in isolation to guide treatment choices or public health policy.

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.

References

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