Author: Pallavi Beura, B.A.,LL.B from Sinhgad technical education society
Sinhgad Law college, Pune
The human salivary gland system can be divided into two separate groups: major and minor glands. The major salivary glands are parotid, submandibular, and sublingual glands. The minor glands are distributed in groups of hundreds in the upper aerodigestive tract mucosa. These glands produce the saliva required for mastication, swallowing, digestion, tasting and dental hygiene.
Scientists have identified and discovered a previously unknown set of salivary glands found in the human body in 300 years which is about average 1.5 inches located in the nasopharyngeal region below the nose and above the throat which would help improve people’s quality of life. The medical researchers first came across the body part, which they called tubarial glands, during a scan designed to look for tumorous growths. The scientists then looked at scans of the head and neck of a further 100 individuals who were treated for prostate cancer and dissected two cadavers -- one male and one female.
The new glands are labelled as tubercular salivary glands because they are located on cartilage called the torus tuberous.
Researchers at the Netherlands Cancer Institute in Amsterdam stated that circulating these glands in radiotherapy can help those dealing or suffering from neck and head cancer in talking, chewing and swallowing food easily no matter how the glands are described, the authors said their discovery had clinical implications, especially for patients with head and neck cancer, including tumours in the throat or tongue. Radiotherapy can damage salivary glands, which can lead to dry mouth and trouble swallowing, speaking and eating.
According to a Science report, more research is needed to confirm that these are a new primary set of salivary glands, and if approved, it will occur in about 300 years of new salivary glands.
Head and neck cancers are a leading contributor to India's cancer burden, with a large majority comprising cancer of the oral cavity, followed by that of the pharynx (part of the throat behind the mouth and nasal cavity), according to the Indian Council of Medical Research's cancer registry.
The glands cannot be seen with conventional methods of medical imaging like ultrasound, CT scans (computerized tomography) or MRI (magnetic resonance imaging), the study authors said.
The "unknown entity" was only identified when the doctors were using an advanced and new type of scan called PSMA PET/CT that has been used to detect the spread of prostate cancer. PSMA PET is shorthand for prostate-specific membrane antigen imaging using positron emission tomography. The researchers confirmed the presence of tubarial glands in PSMA PET/CT scans of 100 patients (99 male, one female; median age 69.5; range 53-84) and the tissue of two human bodies. Salivary glands show up clearly on this highly sensitive kind of imaging. the data of 723 patients who had undergone radiation treatment and found that the radiotherapy dose to this area was associated with complications (xerostomia and dysphagia).
The glands could be newly discovered, "but it is difficult to exclude that these might represent groups of minor salivary glands," said Dr. Valerie Fitzhugh, the interim chair of pathology at Rutgers New Jersey Medical School and Rutgers Robert Wood Johnson Medical School. Fitzhugh wasn't involved in the study.
Because the study concentrated on a small number of patients who were mostly male and used specific rather than standard tests, she added, the examination of more women and healthier patients would allow for better data.
"The next step is to find out how to spare these new glands and in which patients. If it is successful the patients may experience fewer side effects which will benefit their overall quality of life after treatment."
The researchers believe that these glands would qualify as the fourth pair of major salivary glands. The proposed name is based on their anatomical location, the other three glands are called parotid, submandibular and sublingual.
Why are these glands being discovered now?
Researchers note that the location of these glands is at a poorly accessible anatomical location under the base of the skull, which is an area that can only be visualised using nasal endoscopy.
What is the purpose of these glands?
So far, researchers suspect that the physiological function of the glands is to moisten and lubricate the nasopharynx and the oropharynx, but this interpretation needs to be confirmed with additional research, they have said.
What is the significance of this research?
Researchers believe that their discovery is potentially good news for some cancer patients with head and neck cancers. Patients with head and neck cancers and tumours in the tongue or the throat are treated with radiation therapy that can damage the new salivary glands, whose location was not previously known.
Now, with their discovery, radiation oncologists will be able to circumvent these areas. Some patients may even face an increased risk of caries and oral infections that can significantly impact their life.
The major salivary glands whose location is already known are regarded as organs-at-risk while conducting radiation therapy and need to be spared, researchers note.
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