Hyaluronic Acid Crosslinking Clinical Study

Hyaluronic acid (HA) dermal fillers are widely used in facial aesthetic medicine because of their biocompatibility, hydration capacity, and volumizing properties. Crosslinking is an essential manufacturing process that enhances the mechanical stability, rheological properties, and clinical longevity of HA hydrogels. Different degrees of divinyl sulfone (DVS) crosslinking may influence tissue integration, lifting capacity, volumetric performance, and safety profile, potentially affecting clinical outcomes in different facial indications.

This prospective observational case series aims to evaluate the clinical performance of HA dermal fillers with different degrees of DVS crosslinking in routine clinical practice. Twenty adult participants with indications for facial aesthetic treatment will be allocated according to clinical indication and the crosslinking characteristics of the filler used. Treatments will include applications for skin quality improvement, lip and perioral enhancement, jawline and chin contouring, and midface, zygomatic, piriform fossa, and nasolabial fold correction.

Participants will be followed for 90 days, with evaluations performed at baseline (Day 0), Day 30, Day 60, and Day 90. Clinical efficacy will be assessed using three-dimensional stereophotogrammetry (Vectra® 3D), soft tissue ultrasonography, and standardized clinical evaluation. Patient-reported outcomes will include the Global Aesthetic Improvement Scale (GAIS), Net Promoter Score (NPS), and Likert-based satisfaction questionnaires. Safety will be evaluated through systematic recording of immediate and delayed adverse events throughout the study period.

The study is designed to characterize the clinical behavior of HA fillers with different crosslinking degrees, exploring their efficacy, safety, and patient satisfaction across distinct facial treatment indications. The findings are expected to contribute to evidence-based clinical decision-making and to improve treatment planning for facial aesthetic procedures.

Inclusion criteria

• Adults aged 18 years or older. Male or female participants. Seeking facial aesthetic treatment with hyaluronic acid dermal fillers. Clinical indication for treatment according to the investigator's assessment. Willing and able to provide written informed consent. Willing to comply with all scheduled visits, assessments, and follow-up procedures.

Able to undergo standardized photographic documentation, three-dimensional facial imaging (Vectra® 3D), ultrasonography, and patient-reported outcome assessments.

Exclusion criteria

• Pregnancy or breastfeeding. Known hypersensitivity to hyaluronic acid or any component of the dermal filler.

Active infection, inflammation, or skin disease at the intended treatment site. Previous facial aesthetic procedure that could interfere with study assessments, according to the investigator's judgment.

Participation in another clinical study that could affect study outcomes. Any medical condition considered by the investigator to make participation unsafe or interfere with study evaluations.

Inability or unwillingness to complete the follow-up schedule or study assessments.