# Prospective assessment on the cephalometric profile changes induced by labial hyaluronic acid infiltrations: A before-and-after study

## TL;DR

This study shows that hyaluronic acid lip injections can change facial profile angles and distances, with effects lasting up to six months.

## Contribution

The study provides empirical evidence on the aesthetic effects and durability of hyaluronic acid lip injections on facial profile changes.

## Key findings

- Angle(Ls-Sn/Sn-Col) decreased by 5.76±9.81°, p < 0.01.
- Distance(Ls-SL) decreased by 1.27 ± 2.11 mm, p < 0.01.
- Greater changes were observed with injection volumes >0.7 mL and in patients over 30 years old.

## Abstract

Facial disharmonies are caused mainly by aging and malocclusions. Hyaluronic acid has been positioned as the dermal filler of choice for volume restoration. This study aimed to assess the effects of hyaluronic acid lip injections on facial profile and their durability.

A before-and-after study was carried out on 32 patients receiving hyaluronic acid lip infiltrations. A follow-up was scheduled at one-month intervals for three months, and at six months, in which four angular and two linear measurements were evaluated to determine changes in facial profile. These measurements consisted of the angle formed by lines Ls-N and L-N-Po; the angle between lines Li-N and L-N-Po; the angle subtended by lines Ls-Sn and Sn-Col; and the angle constructed from lines Li-Sn and Sn-Col. Likewise, the distance between point Ls and line SL, and the distance between point Li and line SL. Additionally, they were evaluated stratigraphically according to age ( 30 or &gt;30 years) and volume ( 0.7 or &gt; 0.7 mL).

Statistically significant results were obtained. A decrease of 5.76±9.81°, p &lt;0.01, was found for Angle(Ls-Sn/Sn-Col). Additionally, the Distance (Ls-SL) showed a decline of 1.27 ± 2.11 mm, p &lt; 0.01. Concerning the results stratified by infiltrated volume, greater angular changes were observed for volume &gt;0.7ml, as well as for age, an increase of 3.06±6.81°,p&lt;0.05 was gained for Angle(Li-N/N-Po), as a decrease of 2.91±1.80 mm, p&lt;0.05 was observed for Distance(Ls-SL) in patients &gt;30.

The data revealed variability in angular and linear measurements among visits, indicating that final, sustained changes translated into aesthetic improvements. However, these results may vary depending on the volume injected and the patient's age.