Would hyaluronic acid-induced mental bone resorption be a concern? A prospective controlled cohort study and an updated retrospective cohort study.

ABSTRACT

BACKGROUND: Hyaluronic acid (HA) is a widely used filler for face contouring and is generally believed to be safe and effective. However, there have been reports of HA-related bone erosion in the chin area without clear scientific data regarding its existence, incidence, and severity. This exploratory study was to evaluate HA-related mental bone resorption through a prospective, controlled, observer-blind, nonrandomized clinical trial and a retrospective cohort study. METHODS: On the one hand, a prospective, controlled, nonrandomized, single-shot HA-injection clinical trial was conducted. Computed tomographic scans were collected at baseline and at 6-12 months of follow-up for both HA-injection and control groups. On the other hand, an updated retrospective cohort study compared the HA-injection with a blank control group. The primary outcomes composed of three quantitative parameters [bone resorption index (BRI M and BRI N ), bone resorption thickness ratio] and one subjective evaluation index (severity ranking). Information about demographics, complications, and injection volume were also recorded. RESULTS: From June 2021 to March 2023, 78 patients were prospectively recruited for the study. There was a significant association between HA-injection and bone resorption [BRI M pre (84.24±8.10%) vs post (79.21±8.70%), P <0.001; BRI N pre 92.50% (73, 144%) vs 87.99% (63, 132%), P <0.001; bone thickness ratio HA 24.08% (0, 48%) vs control 0 (0, 17%), P <0.001]. However, there was no difference in large-volume (>1 ml) and small-volume (≦1 ml) injection subgroups [bone resorption thickness ratio (21.50±10.91%) vs (24.51±11.92%), P =0.350]. The imaging manifestation revealed discernible bone resorption in 35.90% of the patients, with an median bone resorption thickness ratio of 24.08%. Between October of 2019 and March 2023, 95 HA-injection patients (190 semimandibular cases), 95 normal controls were enrolled. The BRI M was significantly lower in the HA-injection group compared to the controls ( P <0.001). CONCLUSIONS: HA may induce bone resorption in the mentum. Large-scale randomized controlled clinical trial is warranted for further confirmation. Patients should be informed of this potential complication.