Check the Neck - Even in Adolescents and Young Adults!
The evaluation and treatment of thyroid nodules is similar in both adolescents and adults, however the management may be more difficult in a younger population. Interprofessional management involving the endocrine oncology and dental home will help mitigate surgical and radiodine (I-131) side effects. This review emphases the role of the dental professional in detection and management of thyroid carcinoma.
Thyroid carcinoma can be diagnosed in any age, sex or race although it is more commonly seen in females (3:1)2. American Cancer Society estimates about 52,890 new cases in 20202. In fifteen to thirty-nine-year-old American females, thyroid carcinoma is the diagnosis responsible for the most new cases of cancer per year, from 2013-20177. This diagnosis also has the fifth highest incidence in both sexes in the 0-19 age group bracket in the United States (following Lymphoid Leukemia, Astrocytoma, Hodgkin and Non-Hodgkin lymphoma 6. Factors that may play a role in the development of thyroid carcinoma include exposure to radiation (higher dose and younger age increases risk), having a first degree relative with thyroid cancer and the amount of iodine in the diet 2. Based on studies from Atomic bomb survivors, it was determined that children are “ten times more sensitive than adults to the induction of cancer” 5. Although the incidence may seem concerning, the five year survival rate in is 99.3% in children, and 98.3% in adults 3, 6.
During dental extraoral exam, healthcare providers can locate the thyroid, below the laryngeal prominence of the thyroid cartilage (“Adam’s Apple”) and above the collarbones. It is important to check for symmetry, and the presence of any protrusions upon swallowing. Carcinoma is more likely when there is a nodule which is large, hard, irregular, fixed, or accompanied by cervical lymphadenopathy, and they will carry a greater risk of malignancy compared to those in adults 10, 8. Children with thyroid carcinoma often present with higher rate of distant metastasis to the lung, bone or liver compared to adults 11. Early comprehensive examination, referral and therapy are paramount.
Although there is safeguards like rectangular collimation, aprons, thyroid collars, shields, lined gloves and dosimetry monitoring devices, they must be properly maintained for optimum efficacy. For example, hanging the apron properly will prevent cracks from forming. One study demonstrated that a loose thyroid collar during CBCT scans will not effectively reduce radiation dose, however when used tightly around the neck it can offer 46.5% dose reduction 9. Education (ALARA Principle) and a commitment to safety is necessary for every dental professional to minimize exposure to iodizing radiation.
Thyroid ultrasound and fine needle aspiration are useful diagnostic tools. Thyroidectomy (complete thyroid removal) or Lobectomy (Partial removal) surgery is a treatment option for “growing nodules or those exceeding four centimeters and causing compressive symptoms” 11. Total thyroidectomy is also performed in patients’ with Graves Disease (hyperthyroidism).
Surgery is often followed by single, or multiple adjuvant treatments with I-131 to achieve complete ablation of thyroid remnants11. The I-131 should be administered in combination with an antiemetic medication due to gastrointestinal upset which develops four to twelve hours after, and typically resolves in two days 11, 12. Baking soda rinse has been shown to increase the intraoral pH level to counteract the gastric acid bathing tooth enamel.
The I-131 therapy can lead to sialaodenitis, temporary loss of salivary flow and change of taste (e.g. unpleasant, bitter) 11, 12. Side effects seen in in the salivary glands occur in approximately 67% of patients, and typically resolve within a few hours to three days 12. There are select cases in which these symptoms may persist for longer than three months 12. Patients with xerostomia will be at high caries risk and three-month recall visits, supplemental fluoride and diet modification should be considered 1. Patients that are on low-iodine diets are often able to have kosher salt, but are on restricted amounts of other types of salt. It is common to see an increase of cariogenic snacks during this time (jams, honey, gummies, raisins, maple syrup). Oral health recommendations should include hydrating with water, sugar free lozenges, sialagogues and xylitol gum to help stimulate salivary flow.
Another promising adjunctive therapy includes supplemental Vitamin E for one week before, to four weeks after, a single dose of I-131 4. This has been shown to have a protective effect against radiation-induced dysfunction in salivary glands in patients with thyroid carcinoma 4. Encourage families to maintain optimism and a routine follow up schedule with their medical and dental team to aid in timely detection of disease reoccurrence or post-treatment sequalae. There is a need for more studies on the dental complications seen in the adolescent and young adult population. As of today, no long-term studies have been done to ascertain the risk of stunted tooth root growth or dental anomalies following I-131 therapy during adolescence.
In the wise words of Madame Curie, “Nothing in life is to be feared, it is only to be understood. Now is the time to understand more, so that we may fear less.”
- American Academy of Pediatric Dentistry. "Guideline on caries-risk assessment and management for infants, children, and adolescents." Pediatric dentistry (2019) https://www.aapd.org/media/Policies_Guidelines/BP_CariesRiskAssessment.pdf
- American Cancer Society. Thyroid Cancer Causes, Risks, Prevention. Atlanta, Ga: American Cancer Society; 2020. https://www.cancer.org/cancer/thyroid-cancer/causes-risks-prevention/risk-factors.html
- Demidchik, Y. E., Demidchik, E. P. and Reiners, C. “Comprehensive clinical assessment of 741 operated pediatric thyroid cancer cases in Belarus,” Annals of Surgery, vol. 243, pp. 525– 532, 2006.
- Fallahi B, Beiki D, Abedi SM, Saghari M, Fard-Esfahani A, Akhzari F, et al. Does vitamin E protect salivary glands from I-131 radiation damage in patients with thyroid cancer? Nucl Med Commun 2013; 34:777–786.
- Hall, Eric J. "Lessons we have learned from our children: cancer risks from diagnostic radiology." Pediatric radiology 32.10 (2002): 700-706.
- Howlader N, Noone AM, Krapcho M, Garshell J, Miller D, Altekruse SF, et al. Childhood cancer by the ICCC, Table 29.1: incidence rates by age at diagnosis. In: SEER cancer statistics review, 1975–2012. National Cancer Institute, Bethesda, MD. 2015. http://seer.cancer.gov/csr/1975_2012/. Based on November 2014 SEER data submission, posted to the SEER web site April 2020.
- Howlader N, Noone AM, Krapcho M, Miller D, Brest A, Yu M, Ruhl J, Tatalovich Z, Mariotto A, Lewis DR, Chen HS, Feuer EJ, Cronin KA (eds). Age-Adjusted Specific SEER Cancer Incidence Rates by Age Group and Sex for Tumors of Adolescents and Young Adults, 2013-2017, Table 32.1, National Cancer Institute. Bethesda, MD, https://seer.cancer.gov/csr/1975_2017/, based on November 2019 SEER data submission, posted to the SEER web site, April 2020.
- Karapanou, Olga, et al. "Differentiated thyroid cancer in childhood: a literature update." Hormones 16.4 (2017): 381-387.
- Qu, X. M., et al. "Dose reduction of cone beam CT scanning for the entire oral and maxillofacial regions with thyroid collars." Dentomaxillofacial Radiology 41.5 (2012): 373-378.
- Suliburk J, Delbridge L. Thyroid nodule. In: Morita SY, Dackiw AB, Zeigler MA, eds. Endocrine Surgery. New York: McGraw-Hill, 2010; 7.
- Vaisman, Fernanda, et al. "Prognostic factors of a good response to initial therapy in children and adolescents with differentiated thyroid cancer." Clinics 66.2 (2011): 281-86.
- Van Nostrand D, Neutze J, Atkins F. Side effects of ‘rational dose’ iodine- 131 therapy for metastatic well-differentiated thyroid carcinoma. J Nucl Med 1986; 27:1519–1527.
About the Authors
- Robertzon Guloy, DMD, CAGS is an orthodontist local to Pinellas County, Florida. Before obtaining his Orthodontic Certificate, he practiced as a general dentist for over ten years. He has detected a number of thyroid carcinomas and has referred for suspicious palpable nodules found during routine Head and Neck exams.
- Dorothy Cataldo, DMD, CAGS is a pediatric dentist local to Pinellas County, Florida. She is passionate about raising awareness about Thyroid Carcinoma to bridge the gap between medical and dental care, especially during the month of September which is “Thyroid Cancer Awareness Month.” She is active in thyroid cancer support groups and wants other oral health professionals to appreciate the role they can play in the early detection of cancer.
The views, information, and opinions expressed in this content are solely of the individual author, and do not necessarily represent those of AAOSH or its employees. The primary purpose of this content is to educate and bring you the latest information. The information does not constitute medical advise.