Abstract
BACKGROUND: The understanding of nasolabial fold (NLF) change with aging is essential for facial rejuvenation. OBJECTIVES: The aim of the authors of the study is to develop an objective method measuring the severity of NLFs and to evaluate the age-related characteristics of the NLF through quantitative parameters. METHODS: A total of 150 healthy participants (ages 21-70) were divided into 5 age groups. Ten NLF features were measured: length, NLF-fold area, maximum width, maximum color depth, area(upper NLF), width(upper-NLF), color depth(upper-NLF), area(lower-NLF), width(lower-NLF), and color depth(lower-NLF). These features were compared across age groups and genders, and their predictive values for age were evaluated. RESULTS: Significant increases in NLF length, width, fold area, and color depth were observed between the twenties and the thirties. Upper NLF features showed changes starting in the thirties, with gradual increases until the fifties, plateauing by 70. Lower NLF changes began in the thirties, peaked in the fifties to sixties, and leveled off thereafter. Males exhibited a more rapid increase in volume-related NLF features between 35 and 40 years, surpassing females in this regard. Males also had greater color depth between 35 and 40 years, whereas females predominated after age 56. Several NLF features demonstrated superior predictive value for age compared with the Wrinkle Severity Rating Scale. CONCLUSIONS: Upper NLF changes begin in the thirties and continue through the fifties, whereas lower NLF changes peak from the forties to sixties. Gender differences were observed, with males showing earlier changes. These findings provide a reliable, objective method for assessing mid-facial aging in clinical practice.