Introduction: Although adding a local anesthetic is an effective way to reduce pain during intradermal Hyaluronic Acid (HA) injections, it is not clear if the pain control is as effective when performing injections close to the bone. The primary aim of these preliminary observations was to explore this issue. As a secondary aim, we wanted to assess if the addition of lidocaine alters the behavior of HA gel in the tissues over time. Subjects: Two women provided informed written consent to participate in the study. Participants were blind to the type of HA gel used for either temporal fossa. Methods: A cross-linked HA gel was used for the study. One side was injected with the gel with and the other without lidocaine, in no particular order. Photographs from the front, profile and three-quarter left and right and frontal MRI scans were taken before and just after the injections, then every 6 months for 2 years. Results: The side injected with the gel with lidocaine was significantly less painful than that injected without lidocaine. Both types of gel changed shape on MRI in the first 6 months but stayed stable thereafter till the end of our follow-up at 24 months. Based on MRI, patient reported outcomes and expert assessed aesthetic outcomes, using MAS® and the global aesthetic improvement scale, both types of gel were comparable. Conclusion: The addition of lidocaine to HA volumiser gels reduces pain to a remarkable degree.

Introduction: Hyaluronic Acid (HA) gels are a commonly used option for correcting facial volume loss. Over the past 2 years, we have been testing the clinical results of two HA gels, without lidocaine, made by the same manufacturer using the patented “Inter- Penetrating NetworkLike” (IPN-Like) cross-linking technology. The aim of this work was to evaluate if there is a difference in the tissue stability and associated clinical outcomes between these two gels. Material and methods: A 67 and 75 years old Caucasian women, from our private aesthetic center, agreed to be injected with the different HA volumiser gel, one in each of their temporal fossae. The Stylage® XL and XXL HA gels (LABORATOIRES VIVACY, Archamps, France) were used for this study. The gels have different concentrations and levels of cross-linking, but have the same indications for correcting facial volume loss resulting from the ageing process. Clinical outcomes included assessing the degree of pain experienced by participants during and after injection using a Visual Analog Scale (VAS). Aesthetic improvement was evaluated using the Merz Analogic Scale® (MAS)® and Global Aesthetic Improvement Scale (GAIS) scales completed by patients and independent experts at different pre-set time-points using photographs taken from the front, profile and three-quarter left and right angles. Moreover, Serial magnetic Resonance Imaging (MRI) scans were used to assess the tissue behavior of the gels immediately after injection and then 6 monthly for 2 years. Results: Both gels led to an improvement in the patients’ clinical outcomes. This improvement persisted over time. The MRI scans showed that, at Day 0, the injected gel was spherical in shape and became elongated by 6 months. This appearance did not change throughout the follow-up period. The scans showed little resorption at 24 months. Conclusion: Despite the relatively advanced age of the two patients and the small quantities of gel injected, the IPN-Like cross-linked hyaluronic acid volumiser gels had a satisfactory sustainable clinical effect as assessed by patients and experts. There was a slight advantage in favor of the gel with the lower HA concentration but higher level of cross-linking (Stylage® XXL). Given the observed persistent effect of the gels in our preliminary observation, it is now important to conduct a larger study with longer follow- up.