Injecting the Human Lip: Unique Features of the Human Lip, Foetal Development, Anatomical Jargon, Anterograde Needle Injection Technique and Laws of Physics. Three Interesting Cases, Their Considerations and Approach

Introduction: Injection of the human lips with soft tissue filler is a common instance in daily aesthetic medicine practice. This article aims to clarify particular structural characteristics that define the human lip. Salient clarifications at the anatomical, histological and embryological details are covered, followed by further clarification on anatomical jargon. Injection technique: The anterograde needle injection technique and its merits are briefly described through three very different interesting cases that were treated strategically with this technique: case 1: a patient with an ‘inverted cupid bow’ in the lower lip vermilion border; case 2: a patient with maxillofacial asymmetries at the coronal and sagittal planes and sideward ‘tilting’ of the head; case 3: a senile patient with advanced senile lip changes. Conclusions: Important conclusions are drawn upon the characteristics that define the human lip; an accurate lip injection technique is achieved through detailed knowledge of lip anatomy jargon. In this article, the white lip roll is defined in terms of a particular living anatomy observation. The term ‘Anterograde Needle Injection Technique’ is coined, with citations from previous authors also being covered. Haemodynamic and technical observations are made regarding the merit of using the 27G needle versus the 30G needle. The anterograde needle injection technique can serve a strategic role in making complex or unusual lips easier to treat. The concept of the ‘Rheological Sum’ is coined to highlight the salient decision-making steps that injectors cover in daily practice for any given treatment. This is an especially important and delicate consideration for lip treatment with soft tissue filler.