The Aging Parotid Gland: A Longitudinal Volumetric Study and Implications for Treatment.

Abstract

The parotid gland accounts for significant soft tissue volume in the face and is therefore of central relevance to facial and neck rejuvenation. The aim of this study was to determine how parotid gland volume is predicted by age and other factors. We conducted a retrospective longitudinal study of patients with multiple computed tomography (CT) scans of the neck performed at least 7 years apart. Parotid gland volumes were measured and multiple linear regression analysis was performed to model the relations between age, body mass index (BMI), and parotid volume. The study cohort comprised 70 patients. The mean [standard deviation] ages at initial and final imaging time points were 47.5 [12.6] and 58.8 [12.2] years, respectively, with an average of 11.3 years elapsed between CT scans. The mean parotid gland volume increased from 28.7 [10.0] to 32.2 [10.7] mL over the average 11.3-year period (P = 0.03). However, the results of the multiple linear regression analysis show that when controlling for BMI and sex, age alone does not predict parotid volume (P = 0.29). BMI was directly correlated with gland volume (P < 0.01). An increase of 1.0 kg/m2 in BMI predicted an increase in parotid volume by 1.1 mL. Male sex was also associated with significantly greater parotid volume. Mean parotid volume increased over time but these gains were driven by increases in BMI and not age alone. These findings are highly relevant to the treatment of the aging face and neck.