The face can be split into 3 zones – the upper 1/3rd, the middle 1/3rd and the lower 1/3rd. Knowing the important vessels and nerves in each zone as well as their corresponding depth in the skin is crucial in order to minimize injury and utilize a safe technique when injecting neurotoxins and fillers.
Figure 1: D corresponds to areas where deeper injections are safer to avoid vasculature and nerves. S corresponds to areas where superficial (intradermal injections) are safer to avoid vasculature and nerves. Vessels shown are cartoon depictions of some of the more common arteries including the supraorbital, supratrochlear, superficial temporal, facial and superior and inferior labial arteries. Also depicted are the supraorbital, infraorbital and mental foramen that are located along the medial limbus.