The Effect of Microneedle Thickness on Pain During Minimally Invasive Facial Procedures: A Clinical Study

Background: Minimally invasive procedures are becoming increasingly popular because they require minimal downtime and are effective for achieving a more youthful appearance. The choice of needle for minimally invasive procedures can be a major factor in the patient's comfort level, which in turn affects the physician's comfort level. Objectives: In this comparative study, the authors assessed levels of pain and bruising after participants were injected with 30-gauge or 33-gauge (G) microneedles, which are commonly used for minimally invasive injection procedures. Methods: Twenty healthy volunteers were recruited for this prospective study. Eight injection points (4 on each side of the face) were determined for each patient. All participants received injections of saline with both microneedles in a randomized, blinded fashion. Levels of pain and bruising were assessed and analyzed for significance. Results: The highest level of pain was in the malar region, and the lowest level was in the glabella. Although all pain scores were lower for the 33-G microneedle, the difference was significant only for the forehead. Because most minimally invasive procedures require multiple injections during the same sitting, the overall procedure was evaluated as well. Assessment of the multiple-injection process demonstrated a significant difference in pain level, favoring the 33-G needle. Although the difference in bruising was not statistically significant between the 2 needles, the degree of bruising was lower with the 33-G needle. Conclusions: For procedures that involve multiple injections to the face (such as mesotherapy and injection of botulinum toxin A), thinner needles result in less pain, making the overall experience more comfortable for the patient and the physician.