Needle versus Cannula to Treat Tear Trough: A Prospective Study Comparing both Methods.

Background: We aimed to clinically compare needle and cannula techniques in vivo with ultrasound and magnetic resonance imaging, to better understand the best technique and adverse events. Methods: Ten adults without previous fillers in the area were injected with hyaluronic acid (CPM 22.5 HA mg/mL) with a 25G cannula on one side and a Becton Dickinson syringe needle (31G 0.3 mL) on the other. The product was fractionated among two visits. Assessment was made at time 0d, 14d, 30d, 60d, 90d, 180d, and 365d with standard camera, Vectra H2, ultrasound, and magnetic resonance imaging. Level of satisfaction was also evaluated. Results: All the patients showed natural results with both techniques and a high satisfaction index. Cannulas were minimally less traumatic in terms of bruises. However, the product was applied in a more superficial layer and in a less precise manner, despite the fact that a deep technique was used with cannulas, depositing the product on the orbital bone. Patients reported a more noticeable change immediately after the procedure on the side treated with cannulas but less edema and a more comfortable procedure on the Becton Dickinson syringe treated side. None of the patients required hyaluronidase to dissolve overcorrection of the area, and no severe complications were observed. The product remained in most of them at day 365. Conclusions: Cannulas seem to be less traumatic regarding bruises, but less precise in vivo. Thin needles seem to be more precise with minimal trauma. However, this difference disappears during patient's evolution.

The Anatomy of the Frontalis Muscle Revisited: A Detailed Anatomic, Clinical, and Physiologic Study.

BACKGROUND: There are differing opinions with regard to the specific mechanical forces related to contraction of the frontalis muscle and how it exerts its effects on eyebrow motion. OBJECTIVES: To perform a detailed anatomic and clinical study of the frontalis muscle in cadavers and patients to better define the movement of the frontalis muscle. METHODS: This study consisted of four arms that included: 1) dynamic ecography to evaluate movement of the frontalis muscle, 2) anatomical study of the relationship between the frontalis muscle and the deep fascia, 3) histological study to define the frontalis muscle attachments and 4) clinical study to evaluate the action of the frontalis muscle in patients undergoing a temporal face lift. RESULTS: The frontalis muscle was attached, inserted, and adhered to the deep layer of the fascia in the superior cephalic and middle third of the forehead. In the superior cephalic third of the forehead, loose areolar tissue was observed deep to the frontalis muscle and the deep layer of the fascia. Within the middle third of the forehead, the deep layer of the galea was fused with the periosteum and firmly adhered. In the inferior caudal third of the forehead, the frontalis muscle was separated from the deep galeal aponeurosis and interdigitated with the orbicularis muscle. When the frontal muscle end was dissected free from the deep fascia by approximately 1 cm and pulled upward, no movement of the eyebrows was observed. Eyebrow elevation was only achieved by pulling on the inferior part of the muscle. CONCLUSIONS: Frontalis muscle movement occurs from the inferior caudal end towards the mid part of the muscle as it contracts centripetally on its superficial layer sliding over the deep part strongly attached to the deep fascia.