Skip to main content
NCBI home page
Wiley Open Access Collection logoLink to Wiley Open Access Collection
. 2026 Mar 1;54(7):1577–1584. doi: 10.1002/jcu.70217

Quantitative Assessment of Vascularization and Stiffness in Salivary Glands During Pregnancy Using Superb Microvascular Imaging and Shear Wave Elastography Techniques

Halil İbrahim Şara 1,✉, Fatih Ateş 2, Ömer Faruk Topaloğlu 3, Mustafa Koplay 4, Özlem Şeçilmiş 4, Mehmet Sedat Durmaz 4
PMCID: PMC13540546  PMID: 41766051

ABSTRACT

Purpose

The purpose of this research was to quantitatively evaluate the vascular supply and tissue stiffness of the salivary glands—namely, the submandibular and parotid glands—in pregnant individuals throughout the three trimesters, employing superb microvascular imaging (SMI) and shear wave elastography (SWE).

Methods

A longitudinal prospective study was executed involving 35 healthy pregnant women. Salivary gland ultrasonography was conducted during each trimester. The vascularization index (VI) was quantified using the two‐dimensional SMI VI (2DcSMIVI) mode by manually delineating the glandular parenchyma. Glandular elasticity was measured through SWE in kilopascals (kPa) and meters per second (m/s). Statistical evaluations incorporated repeated measures ANOVA and the Friedman test (p < 0.05).

Results

Submandibular gland stiffness showed significant trimester‐based variations, with kPa values peaking in the second trimester and declining in the third (F(2,68) = 5.31, p < 0.05, η 2 = 0.13). Likewise, m/s values were elevated in the second trimester relative to the third (X 2 = 7.79, p < 0.05). In contrast, the stiffness and VI values of the parotid gland exhibited consistency across trimesters (p > 0.05).

Conclusion

The dynamic shifts in submandibular gland stiffness, highlighted by a rise in the second trimester followed by a decrease in the third, most likely signify the hormonal and hemodynamic adaptations that come with pregnancy. These findings underscore the importance of monitoring salivary gland function in pregnant women and pave the way for future investigations into the diagnostic and prognostic implications of these changes. To the best of our knowledge, this represents the inaugural study demonstrating normative stiffness and vascularity parameters of salivary glands across each trimester of pregnancy.

Keywords: pregnancy, salivary glands, shear wave elastography (SWE), superb microvascular imaging (SMI), ultrasonography

This study evaluates the vascular supply and tissue stiffness of the submandibular and parotid salivary glands during pregnancy using superb microvascular imaging (SMI) and shear wave elastography (SWE). Significant trimester‐based variations were observed, particularly in the submandibular gland's stiffness, highlighting pregnancy‐induced hemodynamic changes.

graphic file with name JCU-54-1577-g003.webp

1. Introduction

The salivary glands play noteworthy roles in ensuring the lubrication of the mouth and the digestion of food with their secretions (Karnik et al. 2015). The vascularity of these glands may change in some physiological processes such as pregnancy or in some diseases such as diabetes and inflammation (Karnik et al. 2015; Chikui et al. 2000; Yilmaz et al. 2024). Prior investigations have underscored that the vascular supply and elastic attributes of these glands can demonstrate considerable variability, primarily stemming from hormonal changes and physiological adjustments that manifest under differing conditions (Rahatli et al. 2019; Xu et al. 2023). Superb microvascular imaging (SMI) is an innovative imaging method that can measure tissue vascularity with high precision by reducing artifacts and can document this quantitatively with the color SMI (cSMI) vascular index (VI) method. Shear wave elastography (SWE) is an impressive imaging technique developed to measure tissue stiffness noninvasively and eliminate user‐dependent effects. In addition, as in SMI, SWE provides quantitative data in kilopascals (kPa) or meters per second (m/s) and enables objective evaluation. Various publications have shown that both techniques can be used effectively in evaluating physiological and pathological conditions in different tissues (Xu et al. 2023; Ustabaşıoğlu et al. 2020; Kara et al. 2020; Seher et al. 2025; Ates, Durmaz, Yorulmaz, and Sara 2022; Ates, Durmaz, Sara, and Kara 2022; Bakdik et al. 2018; Erdoğan et al. 2020; Arslan et al. 2020).

Although the evaluation of the deep lobe of the parotid gland is challenging, ultrasonography is considered the first‐line imaging method in the examination of the salivary glands. It has been shown that changes in the salivary glands in conditions such as diabetes and Sjögren's syndrome can be effectively detected with SMI and SWE techniques (Ustabaşıoğlu et al. 2020; Arslan et al. 2020; Erdem and Tosun 2024; Badarinza et al. 2019). Pregnancy, by its nature, changes physiology with the hormonal effects it creates. It creates serious effects on the cardiovascular system and the immune system. The risk of some infections increases due to the effects of pregnancy on the immune system (Abu‐Raya et al. 2020). To prevent this possible increase in infection risks, the functions and secretions of the salivary glands, which play critical roles in providing oral hygiene, may be important and may be important to examine during pregnancy. There are studies that define normal values for SWE in healthy individuals (Arda et al. 2011; Bedewi et al. 2020). However, to our knowledge, there is no study in the literature that provides normal SMI and SWE values of salivary glands in pregnant women and examines whether there is a change in these values during pregnancy. This study aims to investigate these issues that are missing in the current literature.

2. Materials and Methods

This detailed longitudinal study aimed ahead was conducted with individuals chosen from healthy pregnant women who showed up at the obstetrics and gynecology clinic from December 2022 until December 2023. This research study was conducted on humans according to the Helsinki Declaration of 1975, as revised in 2013. The study received approval from the local research ethics committee, designated with the number 2022/517. Patients with a history of surgery, radiotherapy, or radioactive iodine treatment in the neck region, a known disease or those using regular any medication—especially sympatholytic and parasymphatolytic drugs—and as well as pregnant individuals with autoimmune or rheumatologic diseases were excluded from the study. Informed consent was secured from all participating pregnant women. A structured approach to ultrasonography aimed at assessing the salivary glands, especially the parotid and submandibular glands, was conducted for every expecting mother in her first trimester (11–14 weeks), second trimester (21–24 weeks), and third trimester (31–34 weeks). The sample size for this study was determined to be 56 participants using Daniel Soper's calculator, based on the number of independent variables (n = 7), a significance level of 0.05, a statistical power of 80%, and an effect size of 0.30 (Soper 2025). To exceed this number slightly, the study was originally designed to include 60 pregnant women devoid of comorbid conditions. A total of 14 expectant mothers who missed their evaluations in the second or third trimester following the first trimester assessment, 6 mothers because of early delivery or miscarriage, three individuals due to gestational diabetes, and those suffering from preeclampsia were left out of the research. Consequently, a total of 35 healthy expectant mothers were incorporated into the study.

US evaluation was performed with a Canon Aplio 500 (Canon Medical System Corporation, Tokyo, Japan) device using a high frequency (4–14 MHz) linear transducer. The submandibular and parotid glands of all participants were meticulously evaluated through B‐mode imaging and cSMI. All US and two‐dimensional SMI vascularity index (2DcSMIVI) assessments were conducted by a radiologist possessing 16 years of experience in ultrasonography and 6 years in SMI (MSD). The examinations were performed with the subjects in a supine position with the neck slightly extended, commencing with a conventional gray‐scale US examination. However, since some pregnant women were not comfortable in this position during the third trimester, their examinations were performed by placing their bodies in a slightly left lateral decubitus position, with their heads remaining fixed. The depth setting was set to 3.5 cm for the submandibular gland and 4 cm for optimal evaluation of the deep lobe when evaluating the parotid gland. The examinations were performed with a standard single focus and the focus was placed at the midpoint of the depth setting. The gain setting was set to 55 dB as standard. Other B‐mode imaging parameters, such as time gain compensation, were adjusted by the radiologist based on real‐time image quality. No changes were made to the settings during SMI and SWE examinations. The vascularity of the salivary glands was assessed quantitatively with objective numerical values derived from the VI values obtained by delineating the entirety of the submandibular and parotid glands using the free region of interest (ROI) on cSMI mode (2DcSMIVI) along the longitudinal planes for each gland. These values were obtained by freezing the images after a 5‐s cSMI examination period in a fixed position, then examining these images backwards and noting the highest VI value detected without artifacts (Figure 1).

FIGURE 1.

FIGURE 1

Open in a new tab

2DcSMIVI measurements of parotid and submandibular glands. (2DcSMIVI: Two dimensional color super microvascular imaging vascular index).

SWE measurements were made by drawing a round ROI in the axial plane for both submandibular and parotid glands. Parallelism of elastography lines in SWE measurements and coding of the glands with a homogeneous color map were determined as criteria for optimal measurement quality. At least three measurements were made in elasticity mode (kPa) and velocity mode (m/s) images for both submandibular and parotid glands, and the average of the obtained values was calculated. Subsequently, the average gland SWE value was calculated by averaging the values of the right and left glands ([right mean SWE value + left mean SWE value]/2) (Figure 2).

FIGURE 2.

FIGURE 2

Open in a new tab

SWE measurements of parotid and submandibular glands (SWE: Shear wave elastography).

3. Statistical Analysis

All statistical analyses were performed using the Statistical Package for the Social Sciences (SPSS) version 27.0 (IBM Corp., Armonk, NY, USA). Initially, the distribution of continuous variables was assessed using the Shapiro–Wilk test, and Box Plot graphs were examined to identify potential outliers. For parameters that exhibited a normal distribution and satisfied the assumption of sphericity—as confirmed by Mauchly's test—a one‐way repeated measures analysis of variance (ANOVA) was employed. This approach was utilized for evaluating the mean kPa values of the submandibular and parotid glands, as well as the mean m/s values of the parotid glands across the three trimesters, allowing for robust within‐subject comparisons over time.

Conversely, for variables that did not conform to a normal distribution—specifically, the mean m/s values of the submandibular glands and the VI values of the parotid glands—the non‐parametric Friedman test was applied. The Friedman test was selected as it provides a suitable alternative to repeated measures ANOVA when normality assumptions are violated, thereby ensuring the validity of the statistical inferences drawn. A significance level of p < 0.05 was set for all analyses. In groups showing significant differences, the Bonferroni test was used to determine which group created the difference, since the variance was homogeneous. In measurements where there was a difference between groups, the differences are shown with letters A–C in Table 1. A–C, same superscript letters show values with statistically insignificant differences per property (p > 0.05). This comprehensive statistical approach was adopted to appropriately address the repeated measures design of the study and to ensure that the findings are both statistically robust and clinically meaningful.

TABLE 1.

Comparison of submandibular gland mean stiffness and mean vascular index parameters across trimesters.

Mean kPa Mean m/s Mean VI
X¯ ± SD Med (IQR) Test statistics* X¯ ± SD Med (IQR) Test statistics** X¯ ±SD Med (IQR) Test statistics*
F, p X 2, p F, p
1. Trimester 8.59 ± 0.64A 5.31, p < 0.05 1.69 ± 0.07A 7.79, p < 0.05 3.79 ± 1.20 0.17, p > 0.05
3.90 (2.05)
1.70 (0.10)
8.60 (0.85)
2. Trimester 8.84 ± 0.64B 1.72 ± 0.07AB
3.78 ± 1.64
8.75 (0.90) 1.72 (0.09)
3.45 (2.50)
3. Trimester 8.40 ± 0.57C 1.66 ± 0.12AC 3.63 ± 1.68
3.35 (1.80)
1.68 (0.10)
8.30 (1.00)
Open in a new tab

Note: *one way ANOVA, **Friedman, A–C, same superscript letters show values with statistically insignificant differences per property (p > 0.05).

Abbreviations: X¯: mean, Med (IQR): Median (interquartile range), SD: standard deviation.

4. Results

The mean age of the participants is 28.28 ± 5.96 (Min/Max; 17/40).

The mean kPa values of the submandibular glands of the pregnant women in the first, second, and third trimesters were evaluated using a one‐way repeated measures ANOVA. When the Box Plot graphics were examined, no extreme values were detected. According to the Shapiro–Wilk test, the mean kPa value of the submandibular glands in measurements at different times showed a normal distribution (p > 0.05). According to the result of the Mauchly sphericity test, it was determined that the assumption of sphericity was met (X 2 = 2.53, p > 0.05). According to the results of ANOVA, there was a statistically significant difference between the mean kPa values of the submandibular glands in the first, second, and third trimester measurements (F(2,68) = 5.31, p < 0.05, η 2 = 0.13). Post hoc analysis was performed with Bonferroni correction to determine which group caused the difference. The mean kPa value of the submandibular glands was the highest in the second trimester and the lowest in the third trimester (Table 1).

The mean m/s values of the submandibular glands in the first, second, and third trimesters were analyzed using the Friedman test. Upon examining the Box Plot graphs, no outliers were identified. According to the Shapiro–Wilk test, the mean m/s value of the submandibular glands in measurements at different times did not show a normal distribution (p < 0.05). According to the analysis results, the mean m/s value of the submandibular glands in the first, second, and third trimester measurements of the participants showed a statistically significant difference (X 2 = 7.79, p < 0.05). Post hoc analysis was performed with Bonferroni correction to determine which group caused the difference. This difference occurred between the second and third trimesters. The mean m/s value of the submandibular glands in the second trimester was significantly higher than the mean m/s value of the submandibular glands in the third trimester (Table 1).

The mean VI values of the submandibular glands in the first, second, and third trimesters were evaluated using ANOVA. Box Plot graphs revealed no outliers. According to the Shapiro–Wilk test, the mean VI values of the submandibular glands across different trimesters showed a normal distribution (p > 0.05). According to the Mauchly sphericity test result, it was determined that the assumption of sphericity was met (X 2 = 0.56, p > 0.05). The results of variance analysis indicated no statistically significant differences in the mean VI values of the submandibular glands across the first, second, and third trimesters (F(2,2) = 0.17; p > 0.05).

The mean kPa values of the parotid glands of the pregnant women in the first, second and third trimesters were evaluated using ANOVA. Upon examining the Box Plot graphs, no outliers were identified. According to the Shapiro–Wilk test, the mean kPa value of the parotid glands in measurements at different times showed a normal distribution (p > 0.05). According to the result of the Mauchly sphericity test, it was determined that the assumption of sphericity was met (X 2 = 0.21, p > 0.05). According to the results of the ANOVA, there was no significant difference between the mean kPa values of the parotid glands in the first, second, and third trimester measurements (F(2,68) = 1.68, p > 0.05) (Table 2).

TABLE 2.

Comparison of parotid gland mean stiffness and mean VI parameters across trimesters.

Mean kPa Mean m/s Mean VI
X¯ ± SD Test statistics* X¯ ± SD Test statistics** X¯ ± SD Test statistics*
Med (IQR)
Med (IQR) Med (IQR)
F, p X 2, p F, p
1. Trimester 8.46 ± 0.84 1.68, p > 0.05 1.68 ± 0.09 1.67, p > 0.05 0.67 ± 0.75 0.41; p > 0.05
0.50 (0.40)
1.68 (0.10)
8.50 (1.05)
2. Trimester 8.15 ± 0.81 1.64 ± 0.08 0.55 ± 0.27
1.66 (0.12) 0.50 (0.45)
8.30 (1.10)
3. Trimester 8.42 ± 0.97 1.66 ± 0.10 0.62 ± 0.67
0.45 (0.40)
1.66 (0.10)
8.20 (0.80)
Open in a new tab

Note: *one way ANOVA, **Friedman.

Abbreviations: X¯: mean, Med (IQR): median (interquartile range), SD: standard deviation.

The mean m/s values of the parotid glands of the pregnant women in the first, second, and third trimesters were evaluated using ANOVA. Box Plot graphs revealed no outliers. According to the Shapiro–Wilk test, the mean m/s of the parotid glands in the first, second, and third trimester measurements showed a normal distribution (p > 0.05). According to the result of the Mauchly sphericity test, it was determined that the assumption of sphericity was met (X 2 = 1.35, p > 0.05). According to the results of the variance analysis, there was no significant difference between the mean m/s of the parotid glands in the first, second, and third trimester measurements (F(2,68) = 1.67, p > 0.05). (Table 2).

The mean VI values of the parotid glands in the first, second, and third trimesters were evaluated using the Friedman test. Box Plot graphs revealed no outliers. According to the Shapiro–Wilk test, the mean VI values of the parotid glands across different trimesters did not follow a normal distribution. The Friedman test results indicated no statistically significant differences in the mean VI values of the parotid glands across the first, second, and third trimesters (X 2 = 0.41, p > 0.05) (Table 2).

5. Discussion

Pregnancy is a multifaceted process that affects multiple organs and involves various physiological, metabolic and endocrine changes in the maternal body. Therefore, endocrine and exocrine glands are also affected by this process. Monitoring maternal changes is also very important for the health of the pregnant woman and the fetus (Chandra and Paray 2024). The salivary glands are also naturally affected by this situation. There are various literature studies on salivary glands. However, studies on the salivary glands in the maternal period are quite limited. In particular, studies comparing the three trimesters are very few. In our study, we compared VI values and SWE values in all three trimesters. There is a study in the literature comparing the saliva flow rate in three trimesters of pregnancy and non‐pregnant women, and it was found that the saliva flow rate in pregnant women, especially in the first trimester, increased compared to non‐pregnant women and compared to the saliva flow rates in the second and third trimesters (Migliario et al. 2021). In another study evaluating the thyroid gland vascularity and volume and thyroid hormones from endocrine gland functions during three trimesters of pregnancy, it was determined that the VI increased as pregnancy progressed (Ates et al. 2024). There are also various literature studies evaluating the salivary glands in autoimmune diseases such as Sjögren's disease, sarcoidosis, sialolithiasis and salivary gland tumors (Erdem and Tosun 2024; Sluijpers, Pringle, et al. 2024; Hofauer et al. 2022; Kim et al. 2022; Xu and Chang 2021; Bruneton and Mourou 1993; Peng et al. 2022). In addition, there is another study in which the parotid gland was examined with ultrasound elastography and microvascular imaging in diabetic patients and studies in which the salivary and lacrimal glands in healthy people and patients with diabetes and/or obesity, with or without sialosis, were evaluated with multimodal ultrasound examination (gray scale, Doppler, and 2D‐SWE) (Erdem and Tosun 2024; Badarinza et al. 2019). However, to the best of our knowledge, there is no study comparing maternal salivary gland SWE and SMI VI values across three trimesters. This study is the first of its kind. It is also the first study to show normal SMI and SWE values of the salivary glands in pregnant women throughout the trimesters.

There are studies in the literature evaluating salivary glands vascularity. In a study evaluating the vascularity of salivary glands in Sjogren's disease, it was stated that the Color Doppler technique is a reliable imaging method in the evaluation of intraparenchymal vascularity (Sluijpers, Sluijpers, et al. 2024). In another study in which the submandibular and parotid glands in diabetic patients were evaluated with color Doppler and SWE and compared with healthy volunteers, it was observed that the size, volume, and SWE values of both submandibular and parotid glands were higher in the diabetes mellitus (DM) patient group than in the control group. It was also determined that there was hypovascularization in the parotid glands compared to the control group (Ozturk and Yalcin 2024). We evaluated the VI values of the salivary glands with objective numerical values for each trimester with the 2DcSMIVI method. In our study, 2DcSMIVI values in maternal salivary glands were compared throughout three trimesters. We chose the 2DcSMIVI method for the evaluation of vascularization because there are publications in the literature indicating that the 2DcSMIVI method shows small microvascular structures better and is superior to conventional Doppler techniques in showing microvessels (Ates et al. 2023; Arslan et al. 2018; Durmaz and Sivri 2018). We did not find any significant differences between trimesters in the evaluation of vascularity in the parotid and submandibular glands. However, we know from the literature that saliva flow rate increases, especially in the first trimester (Migliario et al. 2021). This may be due to the changing hormonal internal hemostasis during pregnancy and increased subcutaneous tissue and extravascular edema. However, in the context of the current study, we did not observe any statistically significant differences in the VI values associated with the SMI. This finding can likely be attributed to the relatively limited size of the sample population utilized in our research, which may have limited the generalizability of the results obtained. We did not evaluate the size of salivary glands. Because the patient group in our study was a special group due to pregnancy and since they were followed for three trimesters, we could not evaluate salivary glands sizes for all trimesters because we could not keep patients on a stretcher for a long time as the pregnancy progressed.

We evaluated elastography values of salivary glands too. There was no significant difference between the mean m/s and kPa values of the parotid glands in the first, second and third trimester measurements. But the mean m/s and kPa values of the submandibular glands in the second trimester were significantly higher when comparing with first and third trimester values. We know that in the resting (unstimulated) state, approximately two‐thirds of the total volume of all saliva is produced by the submandibular glands (Iorgulescu 2009). In the stimulated state, the parotid glands provide approximately 50% of the volume of saliva secretion (Chen, Su, and Yu 2022). Our patient group was a group of pregnant patients who were at rest and whose salivary secretion was not stimulated. This significant decrease in submandibular gland stiffness in the third trimester may be due to changes in tissue composition or edema developing in the glandular tissue as pregnancy progresses. Various studies have reported that the physiological changes during pregnancy and the formation of edema on the cardiovascular system increase significantly, especially in the later stages of pregnancy, that is, in the third trimester (Kepley et al. 2023; Kazma et al. 2020). There are also studies reporting that sex hormone receptors are found in different amounts in the salivary glands and that this affects saliva secretion and composition (Leimola‐Virtanen et al. 2000; Valimaa et al. 2004). As is known, there are serious changes in the amounts of sex hormones during pregnancy. As is well known, significant changes occur in the levels of sex hormones during pregnancy. We believe that the stiffness change observed only in the submandibular gland may be closely related to the differential expression of hormone receptors in these glands, and that this may lead to distinct physiological responses to the hormonal fluctuations that occur throughout pregnancy. There is also a study reporting that liver elastography values in normal pregnancies increase in the second and third trimesters and return to normal in the postpartum period (Stenberg Ribeiro et al. 2019). This process may be related to the fact that pregnancy is a multifaceted, hormonal and complex process. There are also studies in the literature in which the cervix, placenta and pelvic floor muscles were evaluated with elastography during pregnancy (Chen, Zhu, et al. 2022; Feng et al. 2022; Gachon et al. 2024).

The results of this study are extremely important to improve our understanding of the physiological adaptations that occur in the salivary glands during pregnancy. This study stands out as one of the first to quantify dynamic changes in the salivary glands during pregnancy. In particular, the documentation of a significant increase in submandibular glandular stiffness during the second trimester, followed by a decrease in the third trimester, provides new insights into dynamic physiological adaptations during pregnancy.

This study has several limitations. Among these, the most significant are its single‐center design and the relatively small sample size. Although the study aimed to reach a broader population, factors such as patient noncompliance and various health conditions necessitated working with a limited sample. Furthermore, we did not examine the changes in vascularization and stiffness of the salivary glands during the pre‐pregnancy and postpartum periods, as our focus was exclusively on the alterations occurring during the gestational period. We also did not evaluate the sizes of salivary glands during sonographic examinations. In order to ensure the comfort of pregnant women, sonographic examination was attempted to be performed as soon as possible and under the most optimal conditions. For this reason, due to the examination method being conducted in a single plane as planned in order not to prolong the study period, it was not possible to evaluate all parts of the salivary glands. Consequently, the effects of pregnancy on the salivary glands may not have been fully elucidated. This topic could be addressed in future, more comprehensive and extensive studies. However, despite these limitations, the fact that this study establishes the normal ranges of salivary gland stiffness and vascularity values for each trimester of pregnancy and that no previous study in the literature has demonstrated this makes our study highly valuable.

6. Conclusion

In summation, our investigative study brings to light the dynamic and significant changes that occur in the stiffness of the submandibular gland throughout the course of pregnancy, with particular attention drawn to the notable reduction in stiffness that is observed from the second trimester to the third trimester. These findings serve to underscore the critical importance of closely monitoring the functional status and health of salivary glands in pregnant women, as any alterations in stiffness and blood supply may have far‐reaching implications for both oral health and the overall well‐being of the individual. It is imperative that future research endeavors strive to further elucidate the mechanisms that underlie these observed changes and to explore their potential impact on disorders related to salivary gland dysfunction.

Author Contributions

Conception and design of the study: H.İ.Ş., F.A., Ö.F.T., M.K., Ö.Ş., and M.S.D. Acquisition of data: F.A., Ö.F.T., M.K., Ö.Ş., and M.S.D. Analysis of data: H.İ.Ş., F.A., and M.S.D. Interpretation of data: F.A., Ö.F.T., and M.S.D. Drafting the article: H.İ.Ş., M.S.D., and F.A. Revising it critically for important intellectual content: H.İ.Ş., M.S.D., and F.A. Final approval of the version to be published: H.İ.Ş., M.S.D., and F.A.

Funding

The authors have nothing to report.

Ethics Statement

This study was approved by Selçuk University Non‐Interventional Clinical Research Ethics Committee (2022/517).

Conflicts of Interest

The authors declare no conflicts of interest.

Acknowledgments

The authors thank Yasemin Şara for her assistance with statistical analysis.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

References

  1. Abu‐Raya, B. , Michalski C., Sadarangani M., and Lavoie P. M.. 2020. “Maternal Immunological Adaptation During Normal Pregnancy.” Frontiers in Immunology 11: 575197. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Arda, K. , Ciledag N., Aktas E., Aribas B. K., and Köse K.. 2011. “Quantitative Assessment of Normal Soft‐Tissue Elasticity Using Shear‐Wave Ultrasound Elastography.” American Journal of Roentgenology 197, no. 3: 532–536. [DOI] [PubMed] [Google Scholar]
  3. Arslan, S. , Durmaz M. S., Erdogan H., Esmen S. E., Turgut B., and Iyisoy M. S.. 2020. “Two‐Dimensional Shear Wave Elastography in the Assessment of Salivary Gland Involvement in Primary Sjögren's Syndrome.” Journal of Ultrasound in Medicine 39, no. 5: 949–956. [DOI] [PubMed] [Google Scholar]
  4. Arslan, S. , Karahan A. Y., Oncu F., Bakdik S., Durmaz M. S., and Tolu I.. 2018. “Diagnostic Performance of Superb Microvascular Imaging and Other Sonographic Modalities in the Assessment of Lateral Epicondylosis.” Journal of Ultrasound in Medicine 37, no. 3: 585–593. [DOI] [PubMed] [Google Scholar]
  5. Ates, F. , Durmaz M. S., Sara H. I., and Kara T.. 2022. “Comparison of Testicular Vascularity via Superb Microvascular Imaging in Varicocele Patients With Contralateral Normal Testis and Healthy Volunteers.” Journal of Ultrasound 25: 1–7. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Ates, F. , Durmaz M. S., Yorulmaz A., and Sara H. I.. 2022. “Quantitative Assessment of Bladder Wall Vascularity Index in Children With Acute Cystitis Using Superb Microvascular Imaging.” Journal of Ultrasound 25: 59–65. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Ates, F. , Sivri M., Durmaz M. S., Sekmenli T., Gunduz M., and Ciftci I.. 2023. “Comparison of Conventional Doppler Imaging Techniques and Superb Microvascular Imaging in Determination of Vascularization in Undescended Testes.” Journal of Ultrasonography 23, no. 93: e66. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Ates, F. , Topaloglu Ö. F., Secilmis O., et al. 2024. “Evaluation of the Thyroid Gland Vascularity During Pregnancy Using 2‐Dimensional Color Superb Microvascular İmaging Vascularization Index Technique.” European Journal of Obstetrics & Gynecology and Reproductive Biology 296: 316–320. [DOI] [PubMed] [Google Scholar]
  9. Badarinza, M. , Serban O., Maghear L., et al. 2019. “Multimodal Ultrasound Investigation (Grey Scale, Doppler and 2D‐SWE) of Salivary and Lacrimal Glands in Healthy People and Patients With Diabetes Mellitus and/or Obesity, With or Without Sialosis.” Medical Ultrasonography 21, no. 3: 257–264. [DOI] [PubMed] [Google Scholar]
  10. Bakdik, S. , Arslan S., Oncu F., et al. 2018. “Effectiveness of Superb Microvascular Imaging for the Differentiation of Intraductal Breast Lesions.” Medical Ultrasonography 20, no. 3: 306–312. [DOI] [PubMed] [Google Scholar]
  11. Bedewi, M. A. , Elsifey A. A., Nassir E. M., et al. 2020. “Shear Wave Elastography of the Submandibular Gland in Healthy Individuals.” Journal of International Medical Research 48, no. 12: 0300060520979445. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Bruneton, J. , and Mourou M.. 1993. “Ultrasound in Salivary Gland Disease.” ORL: Journal for Oto‐Rhino‐Laryngology and Its Related Specialties 55, no. 5: 284–289. [DOI] [PubMed] [Google Scholar]
  13. Chandra, M. , and Paray A. A.. 2024. “Natural Physiological Changes During Pregnancy.” Yale Journal of Biology and Medicine 97, no. 1: 85–92. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Chen, C. L. , Su J. Z., and Yu G. Y.. 2022. “Effects of Acid Stimulation on Saliva Flow Rate and Compositions of Human Parotid and Submandibular Glands.” Beijing Da Xue Xue Bao Yi Xue Ban = Journal of Peking University Health Sciences 54, no. 1: 89–94. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Chen, Q. , Zhu Y. M., Zhang Y. K., et al. 2022. “The Role of Shear Wave Elastography in the Assessment of Placentas in Healthy Pregnancy Women During Third‐Trimester: A Preliminary Study.” Journal of Gynecology Obstetrics and Human Reproduction 51, no. 2: 102292. [DOI] [PubMed] [Google Scholar]
  16. Chikui, T. , Yonetsu K., Izumi M., Eguchi K., and Nakamura T.. 2000. “Abnormal Blood Flow to the Submandibular Glands of Patients With Sjögren's Syndrome: Doppler Waveform Analysis.” Journal of Rheumatology 27, no. 5: 1222–1228. [PubMed] [Google Scholar]
  17. Durmaz, M. S. , and Sivri M.. 2018. “Comparison of Superb Micro‐Vascular Imaging (SMI) and Conventional Doppler Imaging Techniques for Evaluating Testicular Blood Flow.” Journal of Medical Ultrasonics 45: 443–452. [DOI] [PubMed] [Google Scholar]
  18. Erdem, S. , and Tosun A.. 2024. “Examination of Parotid Gland in Diabetics With Ultrasound Elastography and Microvascular Imaging.” Medicina Oral, Patología Oral y Cirugía Bucal 30, no. 1: e117. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Erdoğan, H. , Durmaz M. S., Özbakır B., Cebeci H., Özkan D., and Gökmen İ. E.. 2020. “Experience of Using Shear Wave Elastography in Evaluation of Testicular Stiffness in Cases of Male Infertility.” Journal of Ultrasound 23: 529–534. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Feng, Q. , Chaemsaithong P., Duan H., et al. 2022. “Screening for Spontaneous Preterm Birth by Cervical Length and Shear‐Wave Elastography in the First Trimester of Pregnancy.” American Journal of Obstetrics and Gynecology 227, no. 3: 500.e1–500.e14. [DOI] [PubMed] [Google Scholar]
  21. Gachon, B. , Fritel X., Pierre F., and Nordez A.. 2024. “In Vivo Measurement of the Elastic Properties of Pelvic Floor Muscles in Pregnancy Using Shear Wave Elastography.” Archives of Gynecology and Obstetrics 309, no. 6: 2623–2631. [DOI] [PubMed] [Google Scholar]
  22. Hofauer, B. , Wiesner M., Stock K., et al. 2022. “Multimodal Evaluation of Long‐Term Salivary Gland Alterations in Sarcoidosis.” Journal of Clinical Medicine 11, no. 9: 2292. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Iorgulescu, G. 2009. “Saliva Between Normal and Pathological. Important Factors in Determining Systemic and Oral Health.” Journal of Medicine and Life 2, no. 3: 303–307. [PMC free article] [PubMed] [Google Scholar]
  24. Kara, T. , Ateş F., Durmaz M. S., et al. 2020. “Assessment of Thyroid Gland Elasticity With Shear‐Wave Elastography in Hashimoto's Thyroiditis Patients.” Journal of Ultrasound 23, no. 4: 543–551. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Karnik, A. A. , Pagare S. S., Krishnamurthy V., Vahanwala S. P., and Waghmare M.. 2015. “Determination of Salivary Flow Rate, pH, and Dental Caries During Pregnancy: A Study.” Journal of Indian Academy of Oral Medicine and Radiology 27, no. 3: 372–376. [Google Scholar]
  26. Kazma, J. M. , van den Anker J., Allegaert K., Dallmann A., and Ahmadzia H. K.. 2020. “Anatomical and Physiological Alterations of Pregnancy.” Journal of Pharmacokinetics and Pharmacodynamics 47, no. 4: 271–285. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Kepley, J. M. , Bates K., and Mohiuddin S. S.. 2023. Physiology, Maternal Changes. StatPearls Publishing. [PubMed] [Google Scholar]
  28. Kim, D. H. , Kang J. M., Kim S. W., Kim S.‐. H., Jung J. H., and Hwang S. H.. 2022. “Utility of Ultrasonography for Diagnosis of Salivary Gland Sialolithiasis: A Meta‐Analysis.” Laryngoscope 132, no. 9: 1785–1791. [DOI] [PubMed] [Google Scholar]
  29. Leimola‐Virtanen, R. , Salo T., Toikkanen S., Pulkkinen J., and Syrjänen S.. 2000. “Expression of Estrogen Receptor (ER) in Oral Mucosa and Salivary Glands.” Maturitas 36, no. 2: 131–137. [DOI] [PubMed] [Google Scholar]
  30. Migliario, M. , Bindi M., Surico D., et al. 2021. “Changes in Salivary Flow Rate and pH in Pregnancy.” European Review for Medical and Pharmacological Sciences 25, no. 4: 1804–1810. [DOI] [PubMed] [Google Scholar]
  31. Ozturk, E. M. A. , and Yalcin E. D.. 2024. “Evaluation of Submandibular and Parotid Salivary Glands by Ultrasonography in Patients With Diabetes.” Journal of Oral Rehabilitation 51, no. 7: 1144–1157. [DOI] [PubMed] [Google Scholar]
  32. Peng, L. , Li N., Luo Y., Fei X., Li Q., and Zhao X.. 2022. “Ultrasonographic Prediction Model for Benign and Malignant Salivary Gland Tumors: A Preliminary Study.” Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology 134, no. 6: 758–767. [DOI] [PubMed] [Google Scholar]
  33. Rahatli, F. K. , Turnaoglu H., Iyidir O. T., et al. 2019. “Assessment of Parotid and Submandibular Glands With Shear Wave Elastography Following Radioactive Iodine Therapy for Papillary Thyroid Carcinoma.” Journal of Ultrasound in Medicine 38, no. 2: 357–362. [DOI] [PubMed] [Google Scholar]
  34. Seher, N. , Nayman A., Dilek İ., et al. 2025. “Evaluation of Lymph Nodes Using a Combination of Advanced Sonographic Techniques: Superb Microvascular Imaging and Shear Wave Elastography.” Journal of Clinical Ultrasound 53: 1213–1220. [DOI] [PubMed] [Google Scholar]
  35. Sluijpers, N. R. , Sluijpers N. R. F., Fadhil M., et al. 2024. “Reliability of Colour Doppler Ultrasonography of the Major Salivary Glands in Sjögren's Disease.” Clinical and Experimental Rheumatology 42, no. 12: 2476–2482. [DOI] [PubMed] [Google Scholar]
  36. Sluijpers, N. R. F. , Pringle S., Bootsma H., Spijkervet F. K. L., Vissink A., and Delli K.. 2024. “Connecting Salivary Gland Inflammation to Specific Symptoms in Sjögren's Disease.” Expert Review of Clinical Immunology 20, no. 10: 1169–1178. [DOI] [PubMed] [Google Scholar]
  37. Soper, D. 2025. “A‐Priori Sample Size Calculator for Multiple Regression [Software].” https://www.danielsoper.com/statcalc.
  38. Stenberg Ribeiro, M. , Hagström H., Stål P., and Ajne G.. 2019. “Transient Liver Elastography in Normal Pregnancy—A Longitudinal Cohort Study.” Scandinavian Journal of Gastroenterology 54, no. 6: 761–765. [DOI] [PubMed] [Google Scholar]
  39. Ustabaşıoğlu, F. E. , Korkmaz S., İlgen U., et al. 2020. “Quantitative Assessment of Salivary Gland Parenchymal Vascularization Using Power Doppler Ultrasound and Superb Microvascular Imaging: A Potential Tool in the Diagnosis of Sjögren's Syndrome.” Balkan Medical Journal 37, no. 4: 203–207. [DOI] [PMC free article] [PubMed] [Google Scholar]
  40. Valimaa, H. , Savolainen S., Soukka T., et al. 2004. “Estrogen Receptor‐Beta Is the Predominant Estrogen Receptor Subtype in Human Oral Epithelium and Salivary Glands.” Journal of Endocrinology 180, no. 1: 55–62. [DOI] [PubMed] [Google Scholar]
  41. Xu, M. J. , and Chang J. L.. 2021. “Practical Salivary Ultrasound Imaging Tips and Pearls.” Otolaryngologic Clinics of North America 54, no. 3: 471–487. [DOI] [PubMed] [Google Scholar]
  42. Xu, Z. , Li R., Xia B., et al. 2023. “Combination of Ultra‐Micro Angiography and Sound Touch Elastography for Diagnosis of Primary Sjögren's Syndrome: A Diagnostic Test.” Quantitative Imaging in Medicine and Surgery 13, no. 10: 7170–7179. [DOI] [PMC free article] [PubMed] [Google Scholar]
  43. Yilmaz, F. , Carti Dorterler O., Eren Halici S., Kasap B., and Demirbas A.. 2024. “The Effects of Pregnancy on Oral Health, Salivary ph and Flow Rate.” BMC Oral Health 24, no. 1: 1286. [DOI] [PMC free article] [PubMed] [Google Scholar]

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Articles from Journal of Clinical Ultrasound are provided here courtesy of Wiley

RESOURCES