The Submandibular Gland and The Aging Neck: A Longitudinal Volumetric Study

Introduction The true effect of aging and other patient factors on submandibular gland (SMG) volume is unclear. We sought to evaluate the effects of age, body mass index (BMI), sex and race on SMG volume using computed tomography (CT) imaging. Methods We conducted a retrospective longitudinal study of adult subjects with multiple CT images of the neck at least 7 years apart. Subjects with history of salivary gland pathology, neck dissection, head and neck radiation, active infection or dental artifact were excluded. Three-dimensional volumes were measured. Age, BMI, sex and race data were analyzed to track their longitudinal effect on SMG volume. Results The study comprised 64 patients (Females n= 36; Males n= 28) with mean age of 47.1 and 58.5 at each respective time point (mean difference 11.4). Mean SMG volume increased from 10.1 ml to 10.5 ml ( P < 0.05). Males had significantly greater SMG volume compared to females. Majority of growth occurred in the < 40 year age bracket (0.1 ml/year), more significantly in the male cohort. When controlling for aging and sex, a change in BMI was the only patient factor that predicted a change in SMG volume. An increase of 1.0 kg/m 2 predicted a 0.17 ml increase in gland volume. Race had no significant effect. Conclusion Our findings suggest that the majority of SMG volume change occurs in early adulthood ( < 40 years), especially in males. Among the factors we studied, a change in BMI was the only significant predictor of SMG volume change. Level of Evidence IV This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to Table of Contents or the online Instructions to Authors www.springer.com/00266 . Genital Surgery