This paper published in “Aesthetic Dermatology” discusses the risks of hyaluronic acid fillers and advises on the correct proportions of the upper and lower lip. Lip augmentation is a popular procedure worldwide, especially among younger patients. However, it is a difficult procedure to perform and is often attempted by practitioners with limited training, which can lead to adverse effects and aesthetically poor results. To learn more about this procedure, download the full paper.

Risks with HA Fillers

Most lip augmentation procedures are performed with hyaluronic acid (HA) fillers. These are reversible with hyaluronidase and have a good safety record with few allergenic issues. However, the main risk with HA fillers is embolisation of the superior labial artery. This artery typically runs about 5 mm deep along the upper lip. Any deep injection into the upper lip risks embolisation, which can lead to vascular necrosis due to significant variation in the anatomy.

Other risks and side effects include:

• Pain, which can be minimized by using small gauge needles, blunt cannulae, and nerve blocks.
• Oedema and bruising, which are not unusual and generally subside within two weeks.
• Reactivation of herpes simplex, which is fairly common. Patients with a pre-existing condition are best treated with antivirals prophylactically.
• The development of biofilms, a potential longer-term risk. These are collections of bacteria that are around 1000 times more resistant to antibiotics and are thought to occur if a non-sterile procedure is undertaken.
• Foreign body granuloma, another long-term issue. The incidence of foreign body granuloma after the injection of HA fillers ranges from 0.02% to 0.4%.

Upper and Lower Lip Proportions

A lack of understanding of the correct proportions of the upper and lower lip accounts for many aesthetically poor results. The phi ratio of the upper lip to lower lip (1:1.6) is considered a reasonable guide to attractiveness. The trend for larger or equal upper lips is likely to be viewed as aesthetically poor with hindsight and accounts for many aesthetically poor results.

The lower lip is considered safer to inject into than the upper lip due to its vascular anatomy, but no area can be considered completely safe. Aesthetic and anatomical considerations such as the Cupid’s bow and the philtrum need to be observed, as does the appearance of the lips from a lateral view.

This summary highlights key points from the paper. To gain a complete understanding of the risks and aesthetic considerations of lip augmentation, we encourage you to download the full paper.