LAUSR

BACKGROUND Debate exists surrounding the morphological evolution of the submandibular gland (SMG) with aging, and due to the inconclusive influence of patient demographics, there remains hesitancy to incorporate targeted interventions of the SMG into clinical practice. OBJECTIVES To determine whether SMG ptosis, hypertrophy, or both is the primary etiology behind increased submandibular volume as one ages. METHODS MRI segmentation was used to calculate the total and inframandibular (IM) volume and height of the SMG. Adult subjects with prior MRIs of the head and neck were used for analysis. Those with pathology or artifact compromising the SMG were excluded. Subjects were divided into four age-defined cohorts, for clinical applicability. RESULTS The study included 129 patients (Females n=65; Male n=64) with a mean age of 52.3 (range 20-85). No significant change in total SMG volume was observed between the reference group and all cohorts. IM-SMG volume of the reference cohort was 5.77 cm 3. All 3 cohorts had a greater IM-SMG volume compared to the reference group. The 45-54 cohort had a mean volume of 6.7 cm 3 (p=.4), the 55-64 cohort, 7.5 cm 3 (p=.01), and the 55-64 cohort, 7.2 cm 3 (p=.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. Given no significant difference in total volume or height with aging emphasizes glandular descent.