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

Background 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. Objectives 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. Methods 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. Results 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 cm(3). 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 cm(3) (P = 0.4), the 55- to 64-year cohort, 7.5 cm(3) (P = 0.01), and the >= 65-year cohort, 7.2 cm(3) (P = 0.01). Male sex and overweight or obese BMI were associated with significantly larger total and IM-SMG volumes. Conclusions 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.