SUPPLEMENTARY FILES: Mapping the Anatomic Distribution Patterns of Medium-to-Large Congenital Melanocytic Nevi on the Face

Supplement A: A) A CMN with a medial Frontonasal (MFN) distribution pattern, involving the medial forehead, glabella, and nasal root. B) A CMN with a medial Centrofacial (MCF) distribution predominantly involving the medial cheek and lateral nose from the nasal bridge to the nostril. C) A lateral CMN with a forehead/temple (LFT) distribution involving the lateral forehead and extending to the temple and eyebrow. Supplement B: Principles for categorizing medium-to-large facial congenital melanocytic nevi to anatomic distribution categories. Supplement C: An extensive congenital melanocytic nevus (CMN) on the cheek, which crosses the nasolabial fold (left), may have formed earlier during the embryologic development, prior to formation of the nasolabial fold, compared to a CMN that does not cross the nasolabial fold (right). Supplement D: Similarly-sized horizontally-oriented (LC, left image) vs. vertically-oriented cheek (LEyC, right image) CMN on the cheek. Potential complications of treatment of CMN on the cheek include ectropion, nasal asymmetry, and contracture affecting the upper lip and commissure. Direct advancement of expanded or non-expanded flaps, in a vertical upward direction, to treat horizontally-oriented LC-category nevi on the cheek (left image) runs a higher risk of these complications. This problem is less likely to be encountered with horizontal flap movement for vertically-oriented LEyC-category nevi (right image). Tissue expansion with either transposition or rotation flaps can minimize these risks.