Clinical, ultrasonographic and ultrasonographic elastographic evaluation of salivary glands in patients with hypothyroidism

Objective: Hypothyroidism (HT), defined by decreased thyroid hormone production and thyroid gland function, is a common oral manifestation of macroglossia, salivary gland enlargement, xerostomia, delayed eruption, poor periodontal health, increased incidence of caries, and delayed wound healing. The aim of this study was to compare salivary flow rates in HT patients and healthy controls and to evaluate B-mode ultrasonography (USG) parameters such as size, volume, presence of lymph nodes, and echogenicity, shear-wave elastography (SWE) values, and color Doppler features of the submandibular and parotid salivary glands. Method: In total, 160 right and left submandibular glands and 160 right and left parotid glands consisting of 80 patients (40 HT) and 40 healthy controls were examined by USG. Echogenicity, parenchymal internal structure, margin features, lymph node presence and dimensional measurements (antero-posterior length, supero-inferior length, medio-lateral length and volume) and color Doppler and SWE measurements were made with a linear probe. In addition, stimulated and unstimulated salivary flow rates of each participant were calculated as milliliters per minute (ml/min). Results: A statistically significant difference was observed between the HT and control groups in terms of echogenicity, margin features, parenchymal homogeneity, color Doppler variables, medio-lateral dimension, SWE (kPa) and SWE (m/Sn) mean values in the right submandibular gland; margin features, parenchymal homogeneity, color Doppler variables, SWE (kPa) and SWE (m/Sn) mean values in the left submandibular gland; and echogenicity, margin features, parenchymal homogeneity, SWE (kPa) and SWE (m/Sn) mean values in the right and left parotid glands (p < 0.05). Stimulated and unstimulated salivary flow rates were found to be significantly lower in the patient group. (p < 0.05) Conclusion: HT has an effect on the salivary glands and salivary flow, and USG is a reliable imaging technique for evaluating the salivary glands. Key words: hypothyroidism, salivary gland, ultrasonography, shear wave elastography