Cheek Reconstruction 

The incidence of skin cancer continues to rise, with more than 1 million cancers diagnosed annually in the United States alone.^[1] Many of these cancers occur on the face, including the cheeks, which comprise a significant portion of the overall facial surface area. While in most cases the extensive mobility of cheek skin provides for excellent and relatively simple closures following tumor extirpation, larger defects, those located near free margins, or those within areas of decreased skin laxity may require a more complicated closure.^{[2, 3]} This article reviews the principles of cheek reconstruction, from aesthetic and anatomic considerations (see the images below) to specific reconstructive options. Lipodystrophy related to HIV therapy can be addressed with a variety of fillers and is beyond the scope of this article.^{[4, 5]}

In this article, cheek reconstruction is indicated for the surgical excision of a variety of cutaneous tumors. These include, but are not limited to, the following entities:

• Basal cell carcinoma
• Squamous cell carcinoma
• Melanoma^[6]
• Keratoacanthoma
• Bowen disease
• Microcystic adnexal carcinoma
• Merkel cell carcinoma
• Atypical fibroxanthoma
• Malignant fibrous histiocytoma
• Dermatofibrosarcoma protuberans
• Sweat gland carcinoma
• Sebaceous carcinoma

Each cheek is a large cosmetic unit demarcated by several junction lines as follows: medially at the nasofacial groove and melolabial crease, laterally at the preauricular crease, superiorly at the orbital rim and superior zygomatic arch, and inferiorly at the border of the mandible.^[7] Moreover, the cheek can be further divided into 5 subunits whose skin surface attributes are consistent within.^[8] Even so, the subunit principle of reconstruction is not as critical here as it is on the nose, because cheek subunits themselves are less distinct.^{[9, 10]} Although junctional lines can offer convenient sanctuaries in which to camouflage scars, most cheek defects lie in more aesthetically exposed regions, where placement of scars along relaxed skin tension lines is a primary principle.^[11]

Cheek reconstruction requires attention to the free margins of the lower eyelid, nasal rim, upper lip, and oral commissure. Special care must be exercised during surgery near the lower eyelid in particular, owing to the relatively low tension capable of producing an immediate or delayed ectropion. Repositioning the patient to an upright position after principle suture placement is often helpful to assess the effects of gravity. Subtle distortions can be found by asking the patient to gaze upward while opening the mouth widely. A Frost suspension suture is sometimes useful in this area to counteract temporary forces such postoperative edema or bleeding.^[12]

The cheek is relatively devoid of zones in which neurovascular, glandular, or mucosal tissue is at great risk of tumor infiltration or iatrogenic compromise. However, some anatomic considerations merit mention. After exiting the stylomastoid foramen and splitting the posterior auricular branch, the inferior division of the facial nerve divides into 2 main trunks within the substance of the parotid gland. These further divide into the 5 main branches of the facial nerve that supply motor innervation to the superficial muscles of facial expression: temporal, zygomatic, buccal, marginal mandibular, and cervical. These are at greatest risk as they exit the anterior border of the parotid gland, on the deep fascia of the masseter muscle, where they are only covered by superficial soft tissue. Deep excisions near the parotid gland may warrant intraoperative nerve stimulation studies by a head and neck surgeon, beyond the purview of a dermatologic surgeon.

For most individuals (approximately 85%), the zygomatic, buccal, and cervical branches of the facial nerve comprise multiple rami with considerable cross-arborization such that paresis resulting from transection of one of these branches is often temporary.^{[13, 14]} Injury to the temporal branch, however, results in an ipsilateral inability to raise the eyebrow or open the eye widely and can eventually lead to brow ptosis. During cheek surgery, this nerve is most frequently encountered over the zygoma. The marginal mandibular branch of the facial nerve is at greatest risk where it crosses the mandible anterior to the masseter muscle. Loss of this nerve may impair the ability to depress and evert the ipsilateral lower lip, resulting in a permanent grimace.

Cheek sensation is provided mainly by the trigeminal nerve, whose branches often travel above the superficial musculoaponeurotic system (SMAS), just below subcutaneous fat. Although easily exposed to iatrogenic compromise, most resulting dysfunction is neither debilitating nor permanent.^[15] Similarly, the well-arborized blood supply of the cheek minimizes any vascular compromise from transecting branches of the facial artery along the cheek’s medial border or superficial temporal artery along its lateral extent.^[14] Lastly, the Stenson duct can be palpated along the anterior border of the masseter muscle during teeth clenching. The main drainage channel of the parotid, injury to the Stenson duct is rare during dermatologic surgery but may result in chronic drainage through a fistula, which often requires a reparative procedure.^{[10, 13]}

Contraindications to performing dermatologic cheek reconstruction with the patient under local anesthesia include any underlying medical illness that would preclude safe treatment in an outpatient setting. For instance, patients with advanced cardiac or pulmonary disease, severe hypertension, or a bleeding diathesis often benefit from a monitored operating room. Those patients with psychiatric disorders that would interfere with a surgical procedure, such as tumor removal and closure, may not tolerate cheek reconstruction without sedation.

Following the excision of malignancies with increased recurrence potential, it is often wise to facilitate secondary intention healing, or cover the defect with a split-thickness skin graft, rather than proceed with a complicated reconstruction. This enables close surveillance of the area during follow-up examinations. Likewise, a simpler reconstructive option is preferred for patients whose physicians require them to remain on anticoagulants during the procedure, to minimize the risk of excessive or postoperative bleeding. Furthermore, cheek reconstruction should always be managed such that functional concerns override aesthetics.