A Novel Approach to Assessing Oral Health Status in Hashimoto's Thyroiditis: Perspective of Ultrasonography

Hashimoto's thyroiditis (HT) is a T-cell-mediated autoimmune disease that affects the thyroid glands (Farhangi et al. 2016). HT shares similar features with Sjögren's Syndrome (SS) in terms of genetics, immunopathology, and patient characteristics, and since xerostomia is the most important clinical finding of SS, HT patients should also be evaluated in terms of salivary composition and salivary gland function (Zeher et al. 2009). The simplest and most basic method preferred for evaluating salivary physiology in HT patients is measuring salivary flow rate, and studies in this area generally indicate the presence of xerostomia in HT (Morawska et al. 2020; Borsöken and Surmelıoğlu 2024). In saliva composition analysis, inflammatory cytokine levels are usually compared with control groups, and increased interleukin and C-reactive protein levels are highly probable findings (Morawska et al. 2021; Tuzcu et al. 2005). Among imaging methods for assessing the function of the salivary gland parenchyma, salivary gland scintigraphy (SGS) is a widely used method with proven effectiveness. The findings obtained with SGS are consistent with the general salivary physiology and immune composition of saliva characteristics of HT patients (Chang et al. 2003; Changlai et al. 2002). Although SGS is considered a non-invasive imaging method, the high risk of allergic reactions during the procedure and the patient's exposure to radiation are its most significant disadvantages (Kim et al. 2022). Ultrasonography (USG), which is increasingly used in imaging soft tissues in the maxillofacial region, especially among dentists, makes it possible to examine salivary glands. The homogeneity of the salivary gland parenchyma and the status of associated lymph nodes can be imaged using USG B-mode. Vascular structures within the parotid gland, such as the retromandibular vein, and the hemodynamics of the salivary gland can be analyzed using Doppler mode, while degenerative changes can be diagnosed using shear wave or strain elastography (Martins et al. 2024). Although its diagnostic accuracy in evaluating salivary gland activity is not yet as sufficient as SGS, ultrasonography, as a radiation-free imaging technique with a low risk of allergic reactions (except for ultrasound gel) and a stronger non-invasive aspect compared to SGS, may find widespread use in Hashimoto's thyroiditis cases. Further studies are needed to develop hybrid diagnostic protocols integrating ultrasound and molecular biomarkers for the early detection of HT. New approaches could encourage dentists to collaborate with rheumatologists in referring patients with Hashimoto's thyroiditis who have suspicious clinical findings, thus facilitating early diagnosis. Furthermore, developing new perspectives could contribute to preventing systemic complications as well as oral health problems in HT. Emre Can Kaya: methodology, writing – original draft, investigation. Sumeyye Celik Ozsoy: methodology, writing – original draft, conceptualization. Samed Satir: conceptualization, methodology, writing – original draft, writing – review and editing. The authors have nothing to report. The authors have nothing to report. The authors have nothing to report. The authors declare no conflicts of interest. The data that support the findings of this study are available from the corresponding author upon reasonable request.