Saturday, March 13, 2021

Salivary Stone Case File

Posted By: Medical Group - 3/13/2021 Post Author : Medical Group Post Date : Saturday, March 13, 2021 Post Time : 3/13/2021
Salivary Stone Case File
Author: Eugene C. Toy, MD, Lawrence M. Ross, MD, PhD, Han Zhang, MD, Cristo Papasakelariou, MD, FACOG

CASE 45
A 36-year-old woman complains of pain and swelling beneath the left mandible, particularly after eating a meal. On examination, she is noted to have edema and tenderness of the left submandibular region. Palpation of her mouth reveals a 4-mm, irregular, nonmobile, hard mass in the mucosa of her mouth. She denies trauma to the region and does not have an eating disorder.

 What is the most likely diagnosis?
 What is the anatomical course of the affected structure?


ANSWER TO CASE 45:

Salivary Stone
Summary: A 36-year-old woman complains of pain and swelling of the left submandibular
area. On examination, she has tenderness of the left submandibular salivary
gland and a palpable, irregular, 4-mm mass along the floor of her mouth. She denies
trauma to the region and does not have an eating disorder.

Most likely diagnosis: Stone in the submandibular duct (sialolithiasis).

Anatomical course of the affected structure: The submandibular salivary duct drains from the deep lobe of the submandibular gland and courses anterolaterally along the base of the tongue. Occlusion of the duct by a stone will cause secreted saliva to accumulate proximally to the stone, thus causing distention and pain.


CLINICAL CORRELATION
This 36-year-old woman has sudden onset of pain to the left submandibular area. The pain is most intense after a meal. She also complains of a “sandlike” or “gritty” sensation in her mouth. The left submandibular gland appears swollen. This is most consistent with a stone in the submandibular duct. Pain after a meal is due to the accumulation of saliva proximal to the occluded duct, which stretches the duct or the capsule of the gland. Generalized swelling may be due to a secondary infection. The pathogenesis of sialolithiasis is unknown but appears to be due to lodging of a small particle in the duct, which serves as a nucleus for deposition of organic and inorganic material. The particle could be food, bacteria, or an inorganic constituent of tobacco smoke. The next diagnostic step would be examination with sialoendoscopy. Treatment would be excision of the stone under endoscopy and administration of antibiotics. If necessary, the gland would be removed surgically.


APPROACH TO:
Salivary Glands

OBJECTIVES
1. Be able to describe the salivary glands and the course of their ducts to the oral
cavity
2. Be able to identify structures in the floor of the mouth related to the submandibular
gland

DEFINITIONS
CARUNCLE: Small protuberance, or papilla

FRENULUM: Mucosal fold that extends along the midline from the floor of the mouth to the inferior surface of the tongue


DISCUSSION
Three salivary glands form an irregular, space-filling ring around the oral cavity (Figure 45-1). The parotid gland lies superficial and posterior to the ramus of the mandible and inferior to the ear. The submandibular gland lies below the angle and the body of the mandible superficial to the mylohyoid muscle. The sublingual gland lies in the floor of the mouth between the mandible and the genioglossus muscle. All of the glands secrete saliva into the oral cavity through characteristic ducts. The parotid duct emerges from the anterior border of the parotid gland. The parotid duct crosses over the masseter muscle and pierces through the buccinator muscle to open into the oral cavity, typically at the level of the second upper molar. The submandibular duct forms from the deep lobe of the submandibular gland, deep to the mylohyoid muscle. The duct runs anteriorly on the surface of the hyoglossus muscle and opens into the oral cavity through the submandibular caruncles, just lateral to the lingual frenulum. The sublingual glands give rise to numerous small ducts that empty at the base of the tongue.

The submandibular duct has a close relation to several important structures in the floor of the mouth. The submandibular gland folds around the free posterior border of the mylohyoid muscle, and the duct arises from the deep lobe of the gland. It courses anteriorly between the mylohyoid and hyoglossus muscles and then on

large salivary glands anatomy

Figure 45-1. The large salivary glands. (Reproduced, with permission, from Lindner HH. Clinical Anatomy. East Norwalk, CT: Appleton & Lange, 1989:60.)

the deep surface of the sublingual gland. The hypoglossal nerve (CN XII) courses inferior to the submandibular duct to enter the inferior surface of the genioglossus muscle. The lingual nerve descends on the surface of the medial pterygoid muscle and loops underneath the duct before innervating the anterior portion of the tongue.


COMPREHENSION QUESTIONS

45.1 A 22-year-old male is involved in a knife fight after a soccer game. He is brought to the emergency department. An 8-cm laceration that involves the right cheek, from his right ear to near the corner of his mouth, is noted. Which of the following structures is most likely injured?
    A. Parotid duct
    B. Submandibular duct
    C. Superficial temporal artery
    D. Lingual artery
    E. Mandibular branch of the facial nerve

45.2 A 45-year-old woman is undergoing surgical resection of the salivary gland for probable cancer. After surgery, she notes that she cannot move her tongue well. Which of the following salivary glands is most likely involved in the surgery?
    A. Parotid
    B. Sublingual
    C. Submandibular
    D. Maxillary

45.3 A 16-year-old girl is brought into the physician’s office because her mother suspects an eating disorder. The patient has bilateral swelling of the cheeks that are nontender. There are multiple dental caries. She appears to be of normal weight. Which of the following is the most likely diagnosis?
    A. Anorexia nervosa
    B. Bulimia
    C. Irritable bowel syndrome
    D. Facetious hyperphagia


ANSWERS
45.1 A. The buccal branch of the facial nerve and the parotid duct travel in the area of the cheek and can be located by a line drawn from the tragus of the ear (or the external auditory meatus) to the corner of the mouth.

45.2 C. The hypoglossal nerve courses deep to the submandibular gland, and injury to this nerve weakens or paralyzes muscles of the tongue.

45.3 B. Enlargement of the parotid glands and multiple dental caries are common in individuals who have bulimia. Affected patients may be of normal weight or even slightly overweight, and their behavior is characterized by binges of eating and inducing vomiting or use of laxatives.


ANATOMY PEARL
 The cranial nerve that passes through the substance of the parotid gland is the facial nerve (CN VII) which innervates the facial muscles. The parotid gland itself receives its parasympathetic secretomotor innervation from the glossopharyngeal nerve (CN IX).
 The duct of the parotid gland pierces the buccinator muscle at about the level of the 2nd upper molar tooth, and its termination is usually visible during a physical exam inspection of the cheek mucosa.
 During its anteromedial course in the floor of the oral cavity, the submandibular gland’s duct is closely related to the hypoglossal and lingual nerves.
 The parasympothetic secretomotor innervation of both the submandibular and sublingual glands, is by fibers of the facial nerve (CN VII).

References

Gilroy AM, MacPherson BR, Ross LM. Atlas of Anatomy, 2nd ed. New York, NY: Thieme Medical Publishers; 2012:580−581. 

Moore KL, Dalley AF, Agur AMR. Clinically Oriented Anatomy, 7th ed. Baltimore, MD: Lippincott Williams & Wilkins; 2014:914−915, 943−945, 950. 

Netter FH. Atlas of Human Anatomy, 6th ed. Philadelphia, PA: Saunders; 2014: plates 46, 58−59.

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