Skip to content 
The lip filler market has experienced rapid growth in recent years and is projected to grow at a CAGR of 8% through 2030. North America and Europe, with their advanced socio-economic development, currently dominate the market, while the Asia-Pacific region is experiencing the fastest growth. The increasing demand for aesthetic enhancements driven by economic development, coupled with advances in filler safety and technology, paint a promising future for the lip filler market. In this article, we will address an issue that is often overlooked by both physicians and patients: What needle insertion angle provides the best results for lip filler procedures?
Before we delve into the discussion of needle insertion angles, it’s important to understand why this is important. Filler migration, where the injected filler moves from its intended location to adjacent areas, is one of the most common clinical challenges in facial filler treatments. The primary causes of lip filler migration include the type of filler used, improper injection techniques, individual anatomical variations, increased muscle activity, excessive post-injection massage, and more.
A study conducted in Turkey examined the effect of needle insertion direction on treatment outcomes when injecting hyaluronic acid into the upper lip: the study included 216 female patients between the ages of 19 and 39 who were seeking lip augmentation. They were randomized into four groups: Group 1 received injections with a meso needle inserted from top to bottom; Group 2 received injections with a meso needle inserted from bottom to top; Group 3 received injections with a meso needle inserted from the outer edge inward; and Group 4 received injections with a micro blunt cannula inserted from the outer edge inward (Figure 1). All patients were treated with hyaluronic acid at a concentration of 20 mg/mL in combination with 0.3% (3 mg/mL) lidocaine. Follow-up examinations were performed three weeks after treatment to assess filler migration, and patients were asked to complete a satisfaction questionnaire (scored from 0 to 5).
Operation Process
After local anesthesia, a hyaluronic acid filler containing 0.3% (3 mg/mL) lidocaine at a concentration of 20 mg/mL was used in all patients. The injection volume for the upper lip was 0.6 mL, with a consistent injection depth of 2 mm submucosally. Groups 1, 2, and 3 used 30G meso needle, while group 4 used a 23G micro cannula. Each group used a different injection direction: group 1 injected from top to bottom, group 2 injected from bottom to top, and groups 3 and 4 injected from outside to inside. All patients received linear injections with the needle bevel facing the lip mucosa at an insertion angle of 30°.
What is the patient satisfaction with different needle insertion angles?
Patients who used meso needle to inject from top to bottom had the highest satisfaction scores, followed by meso needle from outside to inside, micro cannula from outside to inside, and microneedles from bottom to top. Regarding patient satisfaction scores after injection: Group 1 was 4.78; Group 2 was 3.70; Group 3 was 4.15; and Group 4 was 3.85. There were no major complications in any of the patients.
The above results show that the injection direction is one of the most important factors influencing the treatment effect and patient satisfaction. The direction of the needle during the injection process determines the distribution direction of the filler on the lips. In this study, Group 1 used a top-to-bottom injection direction, which did not cause the filler to move upward, resulting in a good lip augmentation effect and high patient satisfaction.
Other than this study, no literature has been found on the possibility that injection direction may affect filler migration. Further studies are needed to confirm the clinical relevance of this needle insertion direction.
