**6. Available donor sites**

#### **6.1. Submental island flap**

#### *6.1.1. Anatomy*

In the male child or adolescent, a facial skin defect reconstruction is completely different from females because transferring a hair bearing flap in a child is unsightly and the definite reconstruction of the facial hair bearing areas must be postponed until the patient has grown

Zone 9 is the neck area contiguous with the chin and if the facial hair is present there is no need to reconstruct this area with hair bearing flaps, in these instances the patient can cover the neck

hair (Figures 16 and 17).

596 A Textbook of Advanced Oral and Maxillofacial Surgery Volume 2

**Figure 16.** A 14-year-old male patient with a unit 4 scar

**Figure 17.** Lateral view of the same patient

**5. Neck reconstruction**

scar with a beard.

The submental island flap is a fasciocutaneous flap that includes a rhomboid area of skin, subcutaneous tissue, and platysma located below the inferior border of the mandible (Figure 18). This flap was first reported by Martin et al. [26]

**Figure 18.** The submental flap raised on its vascular pedicle

Injection studies into the submental artery have found that it can supply a large skin paddle, as large as 10 \_16 cm, reaching from one angle of the mandible to the contralateral angle. [27] Although this horizontal dimension includes an area supplied by bilateral submental arteries, the entire flap can be perfused by one side. Practically speaking, the anteroposterior dimension of the skin flap that can be harvested is limited by the ability to achieve primary closure, which depends on the patient's skin laxity and age, which can be estimated by marking out the desired anteroposterior dimension of the flap and attempting to pinch the marks together with forceps.

The locations of the perforator vessels connecting the submental artery to the subdermal plexus (which perfuses the areas listed above) are variable. This flap has a shorter pedicle compared to scalp flaps, is rather thick and arch of rotation or pivot point is short; in the young the donor site scar becomes hypertrophic and in view.

#### **6.2. Expanded scalp**

The expanded scalp has two benefits namely thinning the density of the hair follicles and also a thinner skin brought in to the defect. These flaps can be transferred as pedicle flaps or free flaps. [28, 29] The expanded flap can be covered by the scalp hair is not very noticeable until late in expansion (Figure 19).

**Figure 19.** The expander is in place; the patients usually grow hair on the opposite side of the expansion area to com‐ pensate.

#### **6.3. Visor flap**

The frontal visor flap first described by Leon Dufourmental in 1919 has stood the test of time; and with tissue expansion to overcome the donor site morbidity it is the only solution in bilateral facial defects in the male patient. [30] The scalp visor flap has an excellent blood supply, guaranteed by its double pedicle with the two superficial temporal arteries.

#### **6.4. Adjacent skin reconstruction, expanded and non-expanded**

In small defects it is possible to expand the adjacent skin and reconstruct the defect by the "same skin".

#### **6.5. Hair transplantation**

Another option for reconstruction of facial hair is Hair Transplantation; there are differ‐ ent techniques of hair transplantation, each with their inherent advantages and disadvantag‐ es. The most common and known hair transplantation method is the so-called 'strip' method. [31]

A strip of skin containing hair follicles is removed, cut into grafts and implanted in the recipient area. In the past years, new methods have developed of which the most promising is the follicle unit extraction (FUE). [32] With this method, whole follicle units are extracted one by one and implanted one by one into the recipient area. Although the FUE method is more patient friendly and leaves only tiny scars compared with the strip method, which leaves visible linear scars at the donor area, the major disadvantage of both methods is that the extracted hair follicles are removed and the source of potential grafts will be consumed in time. The only way to preserve a significant part of the donor hair follicles could be partial FUE. This idea is not unrealistic and is supported by different experiments [33] Reynolds found that, although the dermal papillae of humans cannot induce new hair growth, the sheath of the lower part of the hair follicle can.

The main drawback of hair transplantation is the esthetic result; in a full thickness facial scar with depressed and discolored skin with poor vascularity the result might not be very satisfactory.

Hair transplantation can be very useful in small and patchy hair bearing area defects or as an adjunct operation in the remaining hairless scar.
