Nonneoplastic parotid swellings: a review

Pneumoparotid: Practical impact of Surgeon performed Ultrasound in an effective Diagnostic Approach

OBJECTIVES

Pneumoparotid is characterized by air inclusions in the parotid duct system. Use of ultrasound has proved valuable for evaluating air inclusions in various parts of the body; the diagnostics of this condition has not been systematically analyzed, however. The aim of this study was to evaluate the value of ultrasound in the detection of air inclusions along the parotid duct system and its closer characterization.

METHODS

Retrospective analysis was carried out of patients diagnosed with pneumoparotid between 2005 and 2020 in a salivary gland center. Ultrasound was performed in all cases, and features of air inclusions were described. Reference standard was the clinical demonstration of foamy saliva after gland massage and/or sialendoscopic evidence of intraductal air inclusions.

RESULTS

Twenty-one patients were identified (48.8 ± 3.8 years). Two were associated with wind instruments; seven were iatrogenic, following treatment for duct stenosis; one after radiotherapy; four with known bruxism and seven were idiopathic and without associated conditions. On ultrasound examination, pneumoparotid was characterized by three phenomena: flattened, mobile hyperechoic reflexes, dirty shadows with reverberation or "sunbeam effect," and shifting shadows during gland massage.

CONCLUSIONS

Ultrasound was useful for characterizing pneumoparotid in a fast and practical way and could serve as imaging tool of first choice.

Etiology of Pneumoparotid: A Systematic Review

Pneumoparotid describes retrogradely insufflated air within the Stensen's duct and/or parotid gland. It is a rare condition with variable causative factors. This study aimed to elucidate the clinical characteristics of pneumoparotid. Reports in all languages were evaluated following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement 2020. A literature search was conducted using electronic medical databases (PubMed, Scopus, Web of Science, EBSCO, Ovid, Google Scholar, SciElo, LILIACS, and others) from 1890 to 30 June 2022. One hundred and seventy patients (mean age; 28.4 years) from 126 studies were reviewed. Common symptoms included swelling (84.7%) and pain (35.9%). Characteristic findings were crepitus in the parotid region (40%) and frothy saliva from the orifice (39.4%). The common etiologies included abnormal habits such as blowing out the cheeks (23.5%), idiopathic (20%), self-induced (15.9%), playing wind instruments such as trumpets or flutes (8.8%), and diseases inducing coughing or sneezing (8.2%). The treatments included antibiotic therapy (30%), behavioral therapy to avoid continuing causative habits (25.9%), psychiatric therapy (8.2%), and surgical procedures (8.2%). Treatment should be individualized and etiology-based. However, the etiology was not identified in 20% of patients. Further detailed data from larger samples are required to clarify and improve the recognition of this entity.

Iatrogenic Causes of Salivary Gland Dysfunction

Saliva is important for maintaining oral health and function. There are instances when medical therapy is intended to decrease salivary flow, such as during general anesthesia, but most instances of iatrogenic salivary gland dysfunction represent untoward or unavoidable side-effects. The clinical expression of the salivary dysfunction can range from very minor transient alteration in saliva flow to a total loss of salivary function.

The most common forms of therapy that interfere with salivation are drug therapies, cancer therapies (radiation or chemotherapy), and surgical therapy. These therapies can affect salivation by a number of different mechanisms that include: Disruption of autonomic nerve function related to salivation, interference with acinar or ductal cell functions related to salivation, cytotoxicity, indirect effects (vasoconstrictiondilation, fluid and electrolyte balance, etc.), and physical trauma to salivary glands and nerves.

A wide variety of drugs is capable of increasing or decreasing salivary flow by mimicking autonomic nervous system actions or by directly acting on cellular processes necessary for salivation; drugs can also indirectly affect salivation by altering fluid and electrolyte balance or by affecting blood flow to the glands. Ionizing radiation can cause permanent damage to salivary glands, damage that is manifest as acinar cell destruction with subsequent atrophy and fibrosis of the glands. Cancer chemotherapy can cause changes in salivation, but the changes are usually much less severe and only transient. Finally, surgical and traumatic injuries interfere with salivation because of either disruption of gland innervation or gross physical damage (or removal) of glandular tissue (including ducts).

Pneumoparotitis: a case report

BACKGROUND

Pneumoparotid is a rare cause of parotid enlargement. Pneumatic enlargement of the gland is caused by retrograde insufflation via Stensen's duct. Most reported cases have been managed conservatively, thus running a short course.

METHODS AND RESULTS

We report on a case of a 48-year-old man with a chronic painful right facial swelling and symptoms of repeated infection. Clinical examination found a parotid swelling with surgical emphysema and a dilated Stensen's duct. Pneumoparotitis with cystic changes and dilated intraparotid ducts was confirmed by CT. The patient proceeded to undergo excision of the gland, with subsequent resolution of symptoms.

CONCLUSION

Repeated retrograde movement of air and contaminated saliva leads to chronic infection and sialectasis. Management is aimed at preventing these sequelae by identifying and addressing the insult early; however, repeated pneumoparotid leads to chronic pneumoparotitis, the management of which is excision of the gland.

Salivary calculus diagnosis with 3-dimensional cone-beam computed tomography

OBJECTIVE

The objective of this study was to evaluate cone-beam CT (CBCT) diagnoses of sialoliths in the major salivary glands.

STUDY DESIGN

Twenty-nine CBCT images containing salivary calculi were retrospectively evaluated for image quality and artifact influence. Additionally, the reproducibility of calculus measurement and the differences between CBCT measurements and ultrasonography (US) and histomorphometry (HM) measurements were determined. Diagnostic sensitivity and specificity calculations were based on the observations of 3 masked clinicians, who reviewed a total of 58 CBCT volumes.

RESULTS

Salivary calculi were sufficiently visualized in all patients. Metal artifacts were detected in images of 7 patients, and movement artifacts in 2. CBCT calculi measurements were highly reproducible, with mean differences of less than 350 microm. Mean CBCT measurements of calculi diameters differed from mean US measurements by approximately 500 microm and differed from mean HM measurements by approximately 1 mm. For calculus diagnoses, the mean sensitivity and specificity were both 98.85%.

CONCLUSION

Although poor image qualities and artifacts can reduce diagnostic information, salivary calculi can be evaluated adequately with CBCT. CBCT measurements of calculi are highly reproducible and differ little from measurements made with US and HM. Diagnostic sensitivity and specificity levels with CBCT are as high as or higher than those obtained with other diagnostic methods. Because of its high diagnostic-information-to-radiation-dose ratio, CBCT is the preferable imaging modality for salivary calculus diagnosis.

Tuberculosis of the parotid gland: sonographic manifestations and sonographically guided aspiration

OBJECTIVE

Involvement of the parotid gland by tuberculosis (TB) is rare. If treated properly, the prognosis of TB of the parotid gland is good. In this retrospective study, we report our experience with sonography and sonographically guided aspiration in the diagnosis of parotid TB.

METHODS

Over 12 years, 9 adults (mean age, 48 years) with parotid gland TB had been examined with high-resolution sonography and color Doppler sonography for their clinical problems of swelling on the mandibular angle. Sonographically guided fine-needle aspiration was done for cytologic study, stains for acid-fast bacilli, and cultures for mycobacterium.

RESULTS

The sonographic patterns were classified as chiefly the parenchymal type (4 patients) and chiefly the periparotid type (5 patients). The parenchymal type appeared as a diffusely enlarged, comparatively hypoechoic gland (compared with the contralateral asymptomatic gland), with or without focal intraparotid nearly anechoic zones, which might have a cavity or cavities within it. The periparotid type appeared as hypoechoic nodules located in the peripheral zone of the hyperechoic parotid gland, consistent with enlarged periglandular lymph nodes. The diagnosis of parotid TB was made in 8 of 9 patients on the basis of sonographically guided aspiration for acid-fast bacilli stains, cytologic study, and cultures for mycobacterium.

CONCLUSIONS

Sonographic examination contributes substantially in the diagnosis of parotid TB infection. In the presence of diffuse parotid echo pattern changes with periparotid lymphadenopathy, and with or without focal hypoechoic zones, TB infection should be differentiated. Sonographically guided fine-needle aspiration may provide further diagnostic information by means of stains, cultures, and cytologic study.

Quantitative analysis of normal major salivary glands using computed tomography

OBJECTIVES

We sought to calculate the size and the computed tomography (CT) number of normal parotid and submandibular glands and to evaluate their relationship with respect to sex, age, and obesity in the Korean population.

STUDY DESIGN

The authors investigated the axial CT images of 42 healthy volunteers. The maximum cross-sectional area (MCSA) was used as an indicator of the size of the gland. Three regions of interest on axial scans were selected to calculate the mean CT number.

RESULTS

There was a significant decrease in the mean MCSA of the submandibular gland and the CT number of both glands with age. The MCSA of the submandibular gland in males was larger than that in females. There was a close correlation between the parotid and the submandibular glands with respect to the CT number, as well as between the left and right glands with respect to the MCSA and the CT number. The body mass index was positively correlated with the MCSA of the parotid gland, whereas the body mass indexes and the CT numbers of both glands were negatively correlated.

CONCLUSIONS

Both age and obesity are closely correlated with the size and the CT number of the major salivary glands. Moreover, the correlation between the CT numbers of the parotid and the submandibular glands may be used for diagnostic purposes.

The role of computerized tomography in the diagnosis and therapy of parotid stones: a case report

BACKGROUND

Small, semi-calcified parotid stones are difficult to diagnose as imaging can be extremely difficult. Understanding how to diagnose parotid stones is important to dentists, however, because people with this condition develop parotid swellings and may seek routine dental care.

CASE DESCRIPTION

The authors describe a classic case of parotid sialadenitis secondary to a small lucent stone in Stensen's duct. They discovered the stone only because of the keen sensitivity of computerized tomography, or CT, to minimal amounts of calcific salts. The CT scan's ability to accurately locate the stone and its position within 1 centimeter of the orifice facilitated a successful intraoral surgical approach.

CLINICAL IMPLICATIONS

CT can be a significant aid in early diagnosis and therapy of patients with parotid stones, who eventually develop sialadenitis. With early intervention, further gland degeneration and parotidectomy will be prevented.

Mycobacterial cervical lymphadenitis. A clinicopathological study of 3 cases

Three adult patients with tuberculous cervical (submandibular) lymphadenitis were treated in the past year in the Department of Oral and Maxillofacial Surgery, Evangelismos Hospital, University of Athens. None had a history of exposure to tuberculosis. In all, the chest X-rays were clear but the PPD tests were positive. All patients underwent excisional biopsy of grossly involved lymph nodes and histological examination and special stains confirmed the diagnosis. The patients were subsequently treated with triple drug administration. Antituberculosis chemotherapy consisted of isoniazid, rifampin and ethambutol and all are well after a follow-up of 9, 10 and 11 months respectively. Medical approaches often failed to diagnose tuberculous cervical lymphadenitis conclusively, and this disease remains a diagnostic and therapeutic challenge, because it mimics other pathological processes. The treatment of choice seems to be surgical excision and long term antituberculosis chemotherapy. Surgery provides a rapid tissue diagnosis, because the histological examination of the excisional biopsy is the most reliable diagnostic test.

Pneumoparotitis with orthodontic treatment

Self-induced pneumoparotitis has not been commonly associated with orthodontic treatment nor dental treatment in general. However, the patient described previously and the other reported cases demonstrate the distinct possibility that accommodation to appliance irritation by "puffing out" the cheeks could result in parotid swelling. Pneumoparotitis should definitely be considered in the evaluation of patients with parotid swelling, particularly in cases of unexplained swelling with rapid onset.

Pneumoparotitis associated with the use of an air-powder prophylaxis unit

A case reporting barotrauma to the parotid gland secondarily to the use of an air-powder prophylaxis unit is presented. Air pressure associated with these units usually exceeds that for air/driven turbines or air/water dental syringes, yet the reported incidence of iatrogenic trauma is very low. Improper angulation in the use of these instruments may result in serious sequellae. Differential diagnosis and physical examination following trauma to the parotid is discussed.

CT of pneumoparotitis

A case of clinically unsuspected pneumoparotitis diagnosed by CT is presented. The CT demonstration of air collections in the parotid gland and in the parotid ducts until their buccal orifices, as well as in the adjacent high-pressure buccal air pockets, determines the diagnosis.

Pneumoparotis, an unusual occurrence of parotid gland swelling during dental treatment. Report of a case with a review of the literature

A 24-year-old male with pneumoparotis caused by the use of an air syringe during a routine restorative dental procedure during clinical training is presented. Reflux of air into the parotid gland due to increasing pressure is a rare cause of acute parotid swelling.--A discussion of this unusual case and review of the literature including its differential diagnosis and management form the basis of this report. Judicious use of intra-oral dental instruments using compressed air or gas is advised.

An unusual case of intraparotid foreign body

Foreign bodies in salivary glands are an unusual event; foreign bodies simulating parotid tumors are an exceptional finding. A posttraumatic case of intraparotid foreign body and a brief literature review are presented.

Self-induced pneumoparotitis in an adolescent. Report of a case and review of the literature

Pneumoparotitis is a rare cause of parotid inflammatory disease in both adults and children. A 12-year-old girl is reported who presented with recurrent bilateral parotid swelling. Radiologic evaluation revealed pneumoparotitis associated with masseter muscle hypertrophy. Further investigation revealed the self-induced nature of the condition in this teenager. Self-induced pneumoparotitis has been reported almost exclusively in adolescents who often have psychosocial problems. The clinical presentation, proposed pathophysiology, diagnosis and management of this rare condition are discussed and a review of the literature is presented.

Iatrogenic causes of salivary gland dysfunction

Saliva is important for maintaining oral health and function. There are instances when medical therapy is intended to decrease salivary flow, such as during general anesthesia, but most instances of iatrogenic salivary gland dysfunction represent untoward or unavoidable side-effects. The clinical expression of the salivary dysfunction can range from very minor transient alteration in saliva flow to a total loss of salivary function. The most common forms of therapy that interfere with salivation are drug therapies, cancer therapies (radiation or chemotherapy), and surgical therapy. These therapies can affect salivation by a number of different mechanisms that include: disruption of autonomic nerve function related to salivation, interference with acinar or ductal cell functions related to salivation, cytotoxicity, indirect effects (vasoconstriction/dilation, fluid and electrolyte balance, etc.), and physical trauma to salivary glands and nerves. A wide variety of drugs is capable of increasing or decreasing salivary flow by mimicking autonomic nervous system actions or by directly acting on cellular processes necessary for salivation: drugs can also indirectly affect salivation by altering fluid and electrolyte balance or by affecting blood flow to the glands. Ionizing radiation can cause permanent damage to salivary glands, damage that is manifest as acinar cell destruction with subsequent atrophy and fibrosis of the glands. Cancer chemotherapy can cause changes in salivation, but the changes are usually much less severe and only transient. Finally, surgical and traumatic injuries interfere with salivation because of either disruption of gland innervation or gross physical damage (or removal) of glandular tissue (including ducts).

Pneumoparotitis: an unusual manifestation of hay fever

This case concerns bilateral parotitis apparently caused by increased intraoral pressure generated by sneezing and forceful clearing of the nares during an attack of hay fever. This was accompanied by painful anterior cervical lymphadenopathy. The condition responded well to an oral cephalosporin and increased fluid intake along with an analgesic agent. The patient recovered without sequelae.

Computed tomography and sialography of chronic pyogenic parotitis

We performed Computed Tomography (CT) immediately following, or simultaneous with, conventional sialography on a group of 45 patients with parotid gland swellings over a two-year period. Tumours occurred in eight, sarcoidosis in 22, actinomycosis in two and chronic pyogenic parotitis in 13 patients. In the latter group, there were two cases of bilateral disease, for a total of 15 glands. The sialographic and the combined CT-sialographic features were retrospectively analysed. In all cases, ductal pathology was more severe in the main and proximal branches, was better demonstrated on conventional sialography and was diagnostic in 10/14 glands (71%). CT-sialography was the superior modality in the evaluation of the gland parenchyma and the adjacent structures, demonstrating diagnostic features of infection in 8/14 glands (57%). However, a combination of both modalities presented a consistent pattern of infection in all cases, distinctive from tumours and sarcoidosis. CT-directed aspiration was performed on the four glands which were equivocal on conventional sialography, and two of these underwent a simultaneous aspiration-irrigation with antibiotics. Although this report is based on a limited experience, CT-sialography with aspiration appears to be an interventional radiological alternative to the traditional diagnostic superficial parotidectomy. Ultrasonography (two cases) and nuclear scintigraphy (one case) added little useful information in chronic pyogenic parotitis.

Cervicofacial mycobacterial infections presenting as major salivary gland disease

Mycobacterium tuberculosis and atypical mycobacterium are well-known causes of cervical lymphadenopathy, most often presenting without symptoms of systemic infection. These organisms may also directly involve the parenchyma of the major salivary glands and their periglandular or intraglandular nodes. The diagnosis of mycobacterial infections of the major salivary glands, compared to cervical lymph nodes, is equally--if not more--difficult to make. The differential must include the same spectrum of inflammatory and neoplastic diseases as well as lesions unique to the salivary glands. Selected cases are presented and discussed to show that principles established for the treatment of cervical mycobacterial infections must also be applied to major salivary gland infections. In particular, cutaneous fistulas may result from incisional biopsy or incision and drainage of the involved gland. Partial parotidectomy or submaxillary gland excision may be required, followed by multidrug, antituberculous chemotherapy for one to two years. Culturing of the organisms is extremely difficult, and the diagnosis of either mycobacterium tuberculosis or atypical mycobacterial infection must be based on a combination of history and clinical examination, skin testing, histopathology, acid-fast stains, culture, and response to surgery and antituberculous chemotherapy.

Obstruction of salivary flow caused by denture overextension

An unusual case of submandibular gland salivary flow obstruction created by an overextended denture has been described. The many potential causes of submandibular gland swelling are listed. Clinically, the opening of both Wharton's ducts appeared more anterior than usual. This anatomic fact, combined with the overextended lingual flange of the denture, combined to produce the phenomenon of bilateral submandibular gland swelling.

Recurrent parotitis during childhood

A case of a child suffering from recurrent parotitis secondary to inadvertant chewing on Stensen's duct orifice suggests that this cause may be common to other children plagued by this puzzling disorder.

A study on the pathogenesis of recurrent parotitis in childhood

Roentgenologic, histopathologic, electron microscopic, virologic and immunologic studies were performed to investigate the etiologic features of recurrent parotitis in children. When examined sialographically and histopathologically, it was considered that pathologic changes in the parotid gland had developed as latent chronic inflammation with mild glandular destruction long before the disease became manifest clinically with acute exacerbation. Proliferation of the duct epithelium in the regenerative process and increase of intraductal pressure due to obstruction of the salivary outflow were assumed to be the causative factors of dilative changes of the peripheral ductal system. Investigation of complement fixation antibody, hemoagglutination inhibition antibody and neutralization antibody responses to mumps virus showed that onset of the disease was unrelated to mumps infection in the majority of cases. Increase of complement fixation antibody titer to various viruses was observed in many cases during acute exacerbation, and were considered to have brought about secondary ascending bacterial infection of the parotid gland by lowering of the systemic resistance. Comparison of serums IgA, IgG, IgM and salivary IgA in these patients with those of control children did not reveal participation of immunodeficiency in the development of this disease. But judging from the results of the long-term clinical follow-up study it was difficult to disregard the possibility that physiological immaturity of the immune response in young children may play some role in onset and recurrent exacerbation of the disease.