The study included 28 adult patients undergoing facial rejuvenation with PLLA, with volumetric outcomes assessed using standardised three-dimensional imaging at baseline and at multiple follow-up time points. Imaging analysis focused on delayed volume change rather than immediate post-injection effects, reflecting the known mechanism of action of PLLA.  

Results demonstrated statistically significant increases in facial soft-tissue volume over time, with progressive volumetric gains observed across follow-up visits extending several months after treatment. Volume changes were not immediate but developed gradually, consistent with neocollagenesis. Quantitative imaging showed measurable increases compared with baseline, reaching statistical significance at later follow-up points (p < 0.05).  

Volumetric improvements were observed in facial regions commonly affected by age-related volume loss, including the midface and lower face. The timing of peak volume increase aligned with established collagen synthesis timelines, supporting a biological rather than mechanical explanation for the observed changes.  

Safety outcomes were favourable. PLLA was well tolerated when administered using established reconstitution protocols and injection techniques, with reported adverse events limited to transient injection-site reactions. No unexpected safety signals were identified during the observation period.  

The authors also discuss several limitations. The study involved a relatively small sample size and did not include an untreated control group or comparator injectable, limiting the ability to directly compare outcomes or exclude confounding factors. While volumetric changes were followed over several months, the duration was insufficient to fully characterise long-term durability.  

The authors further note that three-dimensional imaging, although objective, can be influenced by factors such as facial positioning and expression despite standardisation, and that volumetric change alone does not necessarily reflect broader improvements in skin quality or patient-reported outcomes.