OBJECTIVE: The aim of this study was to determine the optimal injection site for botulinum neurotoxin injections in the submandibular gland.
MATERIALS AND METHODS: Anatomical considerations when injecting botulinum neurotoxin into the submandibular gland were determined using ultrasonography. The thickness of the submandibular gland, its depth from the skin surface, and the location of the vascular bundle were observed bilaterally in 42 participants. Two cadavers were dissected to measure the location of the submandibular gland corresponding to the ultrasonographic observation.
RESULTS: The thickest part of the submandibular gland measured 11.12 ± 2.46 in width with a depth of 4.63 ± 0.76. At the point where it crosses the line of the lateral canthus, it measured 5.53 ± 1.83 in width and 8.73 ± 1.64 in depth.
CONCLUSION: The authors suggest optimal injection sites based on external anatomical landmarks. These guidelines aim to maximize the effects of botulinum neurotoxin therapy by minimizing its deleterious effects, which can be useful in clinical settings.
METHODS: The study involved conducting intradermal injections on four cadavers and participants using a 2 mm length, 34-gauge needle (N-Finders, Inc., South Korea). During the cadaveric study, the polynucleotide prefilled syringe was dyed green, and an anatomist performed dissections, removing only the skin layer. Ultrasonographic observations were carried out to ensure accurate intradermal injection placement.
RESULTS: In all four cadavers, the facial injections at the anterior cheek region were precisely administered intradermally at a 30-degree injection angle. However, the 90-degree injection was found just below the dermal layer upon skin layer removal.
DISCUSSION: The findings suggest that using a 2 mm needle length allows for easy and convenient intradermal injections.