Submandibular Volume Research Articles

Age-Related Changes in the Submandibular Gland: An Imaging Study of Gland Ptosis Versus Volume.

Debate surrounding the morphological evolution of the submandibular gland (SMG) with aging, and the uncertain influence of patient demographics, has led to hesitancy about incorporating targeted interventions of the SMG into clinical practice. The aim of this study was to determine whether SMG ptosis, hypertrophy, or both is the primary etiology behind the increase in submandibular volume with age. MRI segmentation was used to calculate the total and inframandibular (IM) volume and height of the SMG. Adult subjects with previous MRIs of the head and neck were used for analysis. Those with pathology or artifact compromising the SMG were excluded. Subjects were divided into 4 age-defined cohorts, for clinical applicability. The study included 129 patients (65 females; 64 males) with a mean age of 52.3 years (range, 20-85 years). No significant change in total SMG volume was observed between the reference group and all cohorts. The IM-SMG volume of the reference cohort was 5.77 cm3. All 3 cohorts had a greater IM-SMG volume than the reference group. The 45- to 54-year cohort had a mean volume of 6.7 cm3 (P = 0.4), the 55- to 64-year cohort, 7.5 cm3 (P = 0.01), and the ≥65-year cohort, 7.2 cm3 (P = 0.01). Male sex and overweight or obese BMI were associated with significantly larger total and IM-SMG volumes. The novel finding of a significantly larger IM-SMG volume with no change in total volume provides evidence for SMG ptosis rather than hypertrophy as a significant contributor to age-related submandibular fullness. The lack of any significant difference in total volume or height with aging emphasizes the role of glandular descent.

ARFI quantitative elastography of the submandibular glands. Normal measurements and the diagnosis value of the method in radiation submaxillitis

Evaluation of Acoustic Radiation Force Impulse Imaging (ARFI) elastography performance in predicting the elasticity of the submandibular glands in normal situations and after radiation therapy. A number of 54 normal submandibular glands from 27 voluntary subjects and 33 pathological submandibular glands (radiation submaxillities) from 18 patients who had undergone radiation therapy for various cervical and facial oncological conditions were included in study. All the patients had undergone a B mode ultrasonography (Tissue Harmonic Imaging, 8-14 MHz) while the submandibular volume was determined and subsequently an ARFI examination while the shear wave velocity (SWV) was measured (in the central, peripheral and subcapsular areas, with the results expressed in m/s). In the volunteers' group the mean value of the SWV of the left submandibular gland was 1.68 ± 0.46 m/s, determined in the centre of the gland, 1.88 ± 0.4 m/s in the periphery (corresponding to the subcapsular parenchyma) and the SWV of the right submandibular gland was 1.74 ± 0.35 m/s (centrally) and 1.84 ± 0.43 m/s in the periphery. The mean value of all measurements was 1.82 ± 0.41 m/s. The mean volume of the glands was 7.97 ± 2.63 cm3. In the group of patients who had underwent radiation therapy (at least 35Gy), the mean value of the SWV was 2.24 ± 0.49 m/s centrally and 2.1 ± 0.58 m/s in the periphery on the left and 1.99 ± 0.5 m/s centrally and 2.21 ± 0.52 m/s in the periphery on the right. The mean value of all the measurements was 2.13 ± 0.52 m/s and the mean volume of the gland was 5.95 ± 4.16 cm3. Elastography using ARFI technique is a valid examination in the evaluation of the normal and pathological submandibular gland stiffness. The values of the shear wave velocities that correspond to a normal stiffness, determined through the ARFI technique, are similar in the two glands. After cervical and facial radiation therapy the values of the SWV are increased, indicating a change in the consistency of the gland thus implying a structural transformation. The ARFI technique can be used in the evaluation of the salivary glands pathology.

Salivary glands ultrasound examination after radioiodine-131 treatment for differentiated thyroid cancer.

The most important side effect of radioiodine ((131)I) therapy is sialoadenitis and xerostomy. To evaluate by ultrasound (US) parotid and submandibular glands after (131)I therapy for differentiated thyroid cancer (DTC). Seventy-six subjects thyroidectomized for DTC submitted to salivary glands US examination. Forty-three of them had been previously treated with (131)I: 22 with 1.11 GBq (30 mCi) for remnant ablation, and 21 with higher doses [up to 44.4 GBq (1200 mCi)] for metastases. Thirty-three subjects studied before (131)I therapy served as controls. Parotid and submandibular volume, homogeneity, and echogenicity were determined. (131)I-treated patients filled a questionnaire about sialoadenitis symptoms. Parotid gland volume was significantly higher in treated patients (28.3±16.2 ml) than in untreated patients (20.7±10.4 ml, p=0.0154) and related to the time from last (131)I therapy. Three had parotid volume <1.5 ml and complained severe xerostomy. Submandibular gland volume was similar in treated (11.2±7.6 ml) and untreated patients (8.6±4.2 ml, p=0.0602). Homogeneity and echogenicity were similar in treated and untreated patients. Sialoadenitis symptoms were reported in 26% and were related to the (131)I cumulative dose. Symptoms were not related to gland volume. Hypoechogenicity and inhomogeneity of the parotids were more frequent in patients with salivary stickiness. Parotid, but not submandibular, volume is increased after (131)I treatment depending on the received activity and the time from irradiation but not on sialoadenitis symptoms. Xerostomy is associated to gland atrophy at US.

Histopathological Changes in Parotid and Submandibular Glands of Patients Treated with Preoperative Chemoradiation Therapy for Oral Cancer

We retrospectively evaluated the relationship between computed tomography (CT)- and histopathological findings of parotid and submandibular glands in six patients treated for advanced oral cancer. Eligibility criteria were a pathologic diagnosis of oral squamous cell carcinoma, preoperative chemoradiation therapy (CRT) with a total dose of 30 Gy and oral S-1 (80 mg/m²/day), the availability of morphological assessments by CT and of functional assessments with the Saxon test before- and 2 weeks after CRT, and the availability of histopathological slides of irradiated parotid and submandibular glands. In the histopathological interpretation, gland structures were divided into acinar-, duct-, and adipose cells and other tissues. The Mann-Whitney test and the Spearman rank correlation test were used to determine histopathological changes. After 30-Gy irradiation, saliva production and parotid and submandibular volumes were significantly decreased (P < 0.05 each). Histopathological analysis demonstrated that 30-Gy irradiation resulted in a loss of acinar cells although acinar cells in the submandibular gland were relatively retained; the median acinar rate in the parotid and submandibular glands was 1.1% and 19.0%, respectively. The CT values after CRT were inversely correlated with adipose ratios (r = -0.98, P < 0.01) and there was a strong correlation between CT values before and after CRT (r = 0.97, P < 0.01). Our results suggested that acinar cell loss is a main contributor to changes in the volume and function of irradiated human parotid and submandibular glands. The CT value may reflect the adipose ratio rather than salivary function.