However, it should be noted that patient-rated improvement on the GAIS at 6 months was consistent with blinded investigator ratings at this time point (with 82.2% of investigators and 92.8% of patients rating midface volume as improved or much improved at 6 months), as previously reported. 20 Another limitation was the lack of blunt cannula use, as the researchers employed a variety of injection techniques using needles to inject into the subcutaneous and supraperiosteal planes.
Source: wiktionary