We have read with interest the article by Tseng et al on a retrospective personal survey of positive aspiration.1 However, we are unable to understand what message this article is trying to convey. It is a truly impressive testament to accurate record-keeping and analysis and is instructive in a number of areas. The incidence of positive aspirations from the seemingly safe supraperiosteal plane is sobering. It would tend to suggest that relying purely on depth of injection as a safety measure is inadequate. Interestingly, the article states no adverse vascular events were noted in patients with a positive aspiration. The article, however, makes no mention as to whether any adverse vascular events occurred in patients with negative aspiration treated by the author over the study period. This is important, for others have reported vascular accidents despite negative aspiration.2