4. Next, place the treatment needle to a depth of 1 inch. Needle size is determined by the injectionist at the time of the procedure, based on what is determined to be best suited for the patient and the procedure from the following quinke point needles: 26-gauge 3.5", 25-gauge 3.5", or 22-gauge 3.5" needle. The same size needle will be used on each side.