xRead - Facial Reconstruction Following Mohs Micrographic Surgery

Larrabee & Moyer

440

branches of the mental nerve (third division of the trigeminal nerve).

noticeable and are distracting. Z-plasty followed by dermabrasion can be very helpful in improving the final appearance of these scars (see Fig. 6 E).

H-Plasty

CHIN DEFECTS Anatomy

The classic chin repair for central chin defects is an H-plasty. If possible, one of the horizontal incisions is placed in the mentolabial crease for scar cam ouflage. One of the disadvantages of H-plasty for chin defects is the lack of naturally occurring skin creases in which to place incisions. H-plasty of the chin is designed in the same fashion as that described earlier for the lip with Burrow triangles excised from the lateral aspect of each flap ( Fig. 22 ). Central chin defects may be repaired using an O-T flap with a central vertical limb as described earlier for lip defects. Lateral chin defects can also be closed by designing an O-T flap with flaps that are asymmetrical such that more advancement occurs from the lateral chin than the medial chin ( Fig. 23 ). O-T

The chin is the aesthetic unit that confers strength to the face. 12 The lower lip and chin compose two thirds of the lower portion of the face. The mento labial sulcus separates the cutaneous lower lip from the chin. The chin is a single subunit of the face and is bordered superiorly by the mentolabial sulcus, inferiorly by the inferior border of the osseous chin, and laterally by the mentolabial crease. The chin is structured by skin, subcutane ous tissue, and the chin muscles. The skin of the chin is the thickest skin of the face with an average thickness of 2.6 mm. This thickness results in poorer scars than other parts of the face with more depressed scarring. The arterial supply to the chin consists mainly of the mental artery, the labiomental artery, and the terminal branch of the submental artery. Motor innervation to the chin is by the facial nerve. Sensation to the chin is from

Fig. 22. Chin H-plasty. ( A ) Patient undergoing an excision of anterior chin melanoma measuring 2.5 cm 2.5 cm. Design of H-plasty with Burrow triangles marked. ( B ) Bilateral advancement flaps elevated and adjacent tissue widely undermined and advanced into the defect. ( C ) The 11-month postoperative appearance.