Topographic Analysis of the Supratrochlear Artery and the Supraorbital Artery: Implication for Improving the Safety of Forehead Augmentation

Background: The supratrochlear and supraorbital artery branches from the ophthalmic artery are the primary suppliers of blood to the forehead. Filler injection into the forehead without precise knowledge of its vascular topography poses a risk of severe complications. Methods: Twenty hemifaces from 11 cadavers were dissected. Results: Based on the presence of the deep branch of the supratrochlear artery, two main arterial distribution patterns of the forehead were observed. Type I (deep branch of the supratrochlear artery–present pattern) was classified into two subtypes: type Ia, in which the layer superficial to the frontalis was supplied medially by the superficial branch of the supratrochlear artery and laterally by the superficial branch of the supraorbital artery, and the deep branch of the supratrochlear artery and the deep branch of the supraorbital artery were distributed deep to the frontalis; and type Ib, in which the layer superficial to the frontalis was supplied by the superficial branch of the supratrochlear artery and the superficial branch of the supraorbital artery in addition to the central artery or the paracentral artery, and the layer deep to the frontalis was supplied the same with type Ia. For type II (deep branch of the supratrochlear artery–absent pattern), the layer superficial to the frontalis was supplied the same with type Ia; only the deep branch of the supraorbital artery supplied the layer deep to the frontalis. Conclusion: This study yielded novel arterial systems of the forehead and provided guidance for the safe forehead augmentation.